fishwayA device made up of a series of stepped pools, similar to a staircase, that enables adult fish to migrate up the river past dams.
state revolving fundsa program, capitalized in part by federal funds, that provides low-interest loans for construction of publicly owned wastewater treatment and water recycling facilities, for implementation of nonpoint source and storm drainage pollution control management programs, and for the development and implementation of estuary conservation and management programs.
ecological nicheIs all of the physical, chemical and biological conditions required by a species for survival, growth and reproduction
specific heatthe amount of heat required to raise the temperature of a kilogram of a substance (water) by 1 degree Celsius.
dischargerany person who discharges waste that could affect the quality of state waters
enrichmentWhen the addition of nutrients, such as nitrogen and phosphorus, from sewage effluent or agricultural runoff to surface water, greatly increases algal growth.
backwashA backward flow or water, also referred to as Backrush
tropic of cancerLatitude of 23.5° North
hummock  A hillock of broken ice which has been forced upward by pressure.
sewageThe waste and wastewater produced by residential and commercial establishments and discharged into sewers.
seawardPositioned or located away from land but towards an ocean or sea.
flood peakThe highest magnitude of the stage of discharge attained by a flood
wildlife treeA live tree retained to become future snag habitat.
transient snowlineThe line separating transient accumulation and ablation areas, also a transient equilibrium line.
cirqueA bowl-shaped depression carved out of a mountain by an alpine glacier.
reference wetlandA wetland within a relatively homogeneous biogeographic region that is representative of a specific hydrogeomorphic wetland type.
hydrologic modela computer model of a watershed used to evaluate how precipitation contributes to flow in streams
ground water disposalRefers to wastewater that is disposed of through the ground either by injection or seepage
mesaA flat topped hill that rises sharply above the surrounding landscape
exchangeA process by which water, under certain conditions, may be diverted out of priority at one point by replacing a like amount of water at a downstream location.
snow pelletsPrecipitation of white, opaque grains of ice
storm sewera sewer that carries only surface runoff, street wash, and snow melt from the land
base flowThe fair-weather or sustained flow of streams; that part of stream discharge not attributable to direct runoff from precipitation, snowmelt, or a spring
pingoLarge mounds of earth-covered ice which form in a permafrost environment which are found in Alaska, Greenland and Antarctica
palaeoclimateevidence of past climate that can be seen in the present e.g
perennial yieldThe amount of usable water of a ground water reservoir that can be withdrawn and consumed economically each year for an indefinite period of time
pressure changeThe net difference between the barometric pressure at the beginning and ending of a specified interval of time, usually the three hour period preceding an observation.
rockSee cobble.
wastewaterdisposed water that enters the sewer system from  homes, schools or businesses/industry that cannot be reused unless it is treated.
rainA form of precipitation
glacier dammed lake  The lake formed when a glacier flows across the mouth of an adjoining valley and forms an ice dam.
urban flash flood guidanceA specific type of flash flood guidance which estimates the average amount of rain needed over an urban area during a specified period of time to initiate flooding on small, ungaged streams in the urban area.
finger lakeAn elongated lake that fills much of an even longer, fairly narrow glacial trough.
estuaryAn estuary is where a river meets the sea or ocean.
mycorrhizaeMutualistic association of a fungus with the root of higher plant
suspended loadspecific sediment particles maintained in the water column by turbulence and carried with the flow of water.
punchcardA card (alternatively called a tag or stamp) used by steelhead and salmon anglers to record catch information; it is returned to management agency after the fishing season.
ground water moundRaised area in a water table or other Potentiometric Surface, created by Ground Water Recharge.
glacial(1) Period of time during an ice age when glaciers advance because of colder temperatures
usgsUnited States Geological Survey
limnologyscientific study of physical, chemical, and biological conditions in lakes, ponds, and streams.
crustaceasmall aquatic invertebrates that are food for fish, free living forms are       common in benthic and planktonic samples, some species are parasitic.
nephelometric turbidity unitunit of measure for the turbidity of water
lakean inland body of water, usually fresh water, formed by glaciers, river drainage etc
ground blizzard warning  When blizzard conditions are solely caused by blowing and drifting snow.
artesian zonea zone where water is confined in an aquifer under pressure so that the water will rise in the well casing or drilled hole above the bottom of the confining layer overlying the aquifer.
glacial portalCavernous openings in subglacial ice and debris above meltwater streams.
leeSide of a slope that is opposite to the direction of flow of ice, wind, or water
hygroscopic nucleipiece of dust or other particle around which water condenses in the atmophere
normal lapse rateAverage rate of air temperature change with altitude in the troposphere
evaporationsublimation, vapourization,       transpiration, evapotranspiration).
srh  An acronym for Storm-relative Helicity.
bergy bitA large chunk of glacial ice (or a very small iceberg) which floats in the sea.
humboldt currentAlso known as the Peru Current, this ocean current flows northward along the western side of South America, offshore Chile and Peru
average megawattThe average amount of energy (in megawatts) supplied or demanded over a specified period of time; equivalent to the energy produced by the continuous operation of one megawatt of capacity over the specified period.
flood plainrelatively flat and normally dry land alongside  water that is covered  during a flood.
snowpackThe amount of annual accumulation of snow at higher elevations.
hydrogeologic unitAny soil or rock unit or zone that because of its hydraulic properties has a distinct influence on the storage or movement of ground water.
baroclinityThe state of stratification in a fluid in which surfaces of constant pressure intersect surfaces of constant density
continental shelfShallow submerged margin of the continents that lies between the edge of the shoreline and the continental slope
channel lead  An elongated opening in the ice cover caused by a water current.
englacialAll the glacial environments which occur within the ice itself are called englacial environments.
undercurrentA current below the upper currents or surface of a fluid body.
marshA marsh is a type of freshwater, brackish water or saltwater wetland that is found along rivers, pond, lakes and coasts
maritime air massAn air mass influenced by the sea
salt-water barrierA physical facility or method of operation designed to prevent the intrusion of salt water into a body of fresh water.
warm frontthe front edge of a body of warm air where it meets and rises above a body of colder air.
service hydrologistThe designated expert of the hydrology program at a WFO.
isohyetA line that connects points of equal rainfall.
sea-waveat sea, waves represent a horizontal movement of energy but a vertical elliptical movement of water.
hydrophilicHaving an affinity for water.
snow devilA small, rotating wind that picks up loose snow instead of dirt (like a dust devil) or water (like a waterspout)
baroclinic zone  A region in which a temperature gradient exists on a constant pressure surface.  Baroclinic zones are favored areas for strengthening and weakening systems; barotropic systems, on the other hand, do not exhibit significant changes in intensity.  Also, wind shear is characteristic of a baroclinic zone.
dischargeis the volume of water (or more broadly, volume of fluid plus suspended sediment) that passes a given point within a given period of time.
critical flow(1) The flow conditions at which the discharge is a maximum for a given specific energy, or at which the specific energy is a minimum for a given discharge
offshore waters1) The waters extending from 5 miles to the midpoint of the Great Lakes.
radio-telemetryAutomatic measurement and transmission of data from remote sources via radio to a receiving station for recording and analysis.
sinkingcontrolling oil spills by using an agent to trap the oil and sink it to the bottom of the body of water where the agent and the oil are biodegraded.
environmental indicatora measurement, statistic or value that provides evidence of the effects of environmental management programs or of the state or condition of the environment.
fresh waterwater containing less than 1,000 parts per million (ppm) of dissolved solids of any type
striations/striaGouges in bedrock or on glacial sediments which record abrasion by the moving glacier
mudslideA condition where there is a river, flow or inundation of liquid mud down a hillside usually as a result of a dual condition of loss of brush cover, and the subsequent accumulation of water on the ground preceded by a period of unusually heavy or sustained rain
cambrianin geologic time, a period lasting from 570m to 505m years ago.
rejuvenationthe increased erosional activity of a river brought about by a relative fall in sea-level which means the river must flow further and at increased gradient thus giving it more energy.
bank-full capacitythe rate of water flow that completely fills a channel; the flow rate at which the water surface is level with the flood plain.
bedSedimentary structure that usually represents a layer of deposited sediment.
firewhirlA tornado-like rotating column of fire and smoke created by intense heat from a forest fire or volcanic eruption.
outlet discharge structure  Protects the downstream end of the outlet pipe from erosion and is often designed to slow down the velocity of released water to prevent erosion of the stream channel.
trade windseasterly winds which blow from the tropics towards the equator
rating curvea graph showing the relationship between water surface elevation and discharge of a stream or river at a given location
clean water actThe federal law that establishes how the United States will restore and maintain the chemical, physical, and biological integrity of the country's waters (oceans, lakes, streams and rivers, ground water and wetlands)
samplebacterial       colonies on laboratory media resulting from filtering and culturing bacteria from a water       sample, each colony in the laboratory culture is presumed to have arisen from the multiplication       of a single bacterium in the original sample.
frost(1) Thin ice crystals in the shape of scales, needles, feathers or fans which are deposited by Sublimation at temperatures of 32°F (0°C) or lower
floodwallA long, narrow concrete, or masonry embankment usually built to protect land from flooding
spawner trapA barrier erected in a stream or in a fish ladder intended to divert adult salmon or steelhead for holding prior to taking their eggs or sperm for culturing.
pulse lengthThe linear distance in range occupied by an individual pulse from a radar
eolianGeomorphic process involving wind
flood crestThe maximum height of a flood wave as it passes a location.
riverA river is a large, flowing body of water that usually empties into a sea or ocean.
injection wellrefers to a well constructed for the purpose of injecting treated wastewater directly into the ground
slateA fine grained metamorphic rock with well developed bedding planes derived from the slight recrystrallization of shale.
lentic system  A nonflowing or standing body of fresh water, such as a lake or pond
monsoona seasonal prevailing wind
front(1) Land bordering a lake or river
river basin developmentA program to develop the use of the water and land resources of a river basin, so coordinated as to obtain a greater efficiency of use than would be possible if the resources were developed by uncoordinated, multiple-purpose projects.
oligotrophichaving a low supply of plant nutrients
ribbon lakelong, narrow, shallow lake formed in the bottom of a glacial trough due to a segment of over-deepening and/or blocking by deposits such as terminal moraine.
trade windsTwo belts of prevailing winds that blow easterly from the subtropical high pressure centers towards the equatorial trough
withdrawalWater removed from the ground or diverted from a surface water source for use.
hydraulic radiusThe cross-sectional area of a stream of water divided by the length of that part of its periphery in contact with its containing conduit; the ratio of area to wetted perimeter.
confluenceA rate at which wind flow comes together along an axis oriented normal to the flow in question
ionosphereA complex atmospheric zone of ionized gases that extends between 50 and 400 miles (80 to 640 kilometers) above the earth's surface
cycle of povertythe process which maintains conditions of chronic poverty in rural areas of ELDCs
saddleA depression or sag on the ice sheet between domes.
ground-water rechargeinflow of water to a ground-water reservoir from the surface
glacial polishThe smooth and shiny surfaces that are produced on rocks underneath a glacier by material carried in the base of that glacier.
pluvialOf rain, formed by the action of rain, for example a body of water.
isohyetline that connects points of equal rainfall.
cross-contaminationa condition created when a drill hole, boring, or improperly constructed well forms a pathway for fluid movement between a saturated zone which contains pollutants and a formerly separated saturated zone containing uncontaminated groundwater
coriolis forceAn apparent force due to the Earth's rotation
cirquesee corrie
refractionChanges in the direction of energy propagation as a result of density changes within the propagating medium
law of stream lengthsMorphometric relationship observed in the cumulative size of stream segment lengths in stream channel branching
orographic precipitationPrecipitation which is caused by hills or mountain ranges deflecting the moisture-laden air masses upward, causing them to cool and precipitate their moisture.
dama structure of earth, rock, or concrete designed to form a basin and hold water back to make a pond, lake, or reservoir.
ice sheeta large area of ice, usually over 50000km2
stream segmentrefers to the surface waters of an approved planning area exhibiting common biological, chemical, hydrological, natural, and physical characteristics and processes
confluence(1) The act of flowing together; the meeting or junction of two or more streams or rivers; also, the place where these streams meet
sidelobeA secondary energy maximum located outside the main radar beam
algal bloomsPeriods of enlarged algal growths that affect water quality
gueltapools found in overly-deepened portions of river beds in mountainous areas of North Africa
greenbeltStrip of natural vegetation growing parallel to a stream that provides wildlife habitat and an erosion and flood buffer zone
acequiaacequias are gravity-driven waterways, similar in concept to a flume
moistureRefers to the water vapor content in the atmosphere, or the total water, liquid, solid or vapor, in a given volume of air.
streamflowWater flowing in the stream channel
ice jamThe accumulation of ice at a specific location along a stream channel
dew pointtemperature at which air becomes saturated i.e
moisture holding capacitythe amount of liquid that can be held against gravity, by waste materials or soil, without generating free liquid.
confined aquiferA water-bearing subsurface stratum that is bounded above and below by formations of impermeable soil or rock.
water qualitythe chemical, physical, biological, radiological, and thermal condition of water.
sanitary sealThe neat cement seal at the top of a water well intended to prevent well contamination from surface water or shallow ground water flows containing potential contaminants.
supra-glacialon the surface of a glacier.
glacial budgetThe annual relationship between accumulation and wastage
doppler dilemmaThe interdependence of maximum unambiguous range and maximum unambiguous velocity on the pulse repetition frequency, PRF
field sprinkler systemA system of closed conduits carrying irrigation water under pressure to orifices designed to distribute the water over a given area.
lapse ratesthe rates at which air temperature decreases with altitude
boiling pointthe temperature at which a liquid boils
weighing-type precipitation gage  A rain gage that weighs the rain or snow which falls into a bucket set on a platform of a spring or lever balance.  The increasing weight of its contents plus the bucket are recorded on a chart
anvil crawlerSlang for a lightning discharge occurring within the anvil of a thunderstorm, characterized by one or more channels that appear to crawl along the underside of the anvil
crest widthThe thickness or width of a dam at the level of the crest (top) of the dam
artesian waterGround water under sufficient pressure to rise above the level at which the water-bearing bed is reached in a well
fracturing  Deformation process whereby ice is permanently deformed, and fracture occurs.
hydraulic mean depth  The right cross-sectional area of a stream of water divided by the length of that part of its periphery in contact with its containing conduit; the ratio of area to wetted perimeter
ice bridge  A continuous ice cover of limited size extending from shore to shore like a bridge.
troughAn elongated area of low pressure in the atmosphere.
withdrawalwater removed from a ground- or surface-water source for use.
deltaan alluvial deposit made of rock particles (sediment, and debris) dropped by a stream as it enters a body of water.
altimeter settingThe pressure value to which an aircraft altimeter scale is set so that it will indicate the altitude above mean sea level of an aircraft on the ground at the location for which the value was determined.
operational modeA combination of scanning strategies and product mixes tailored to one or more meteorological situations.
turbineA mechanism in a dam that rotates with the force of water and produces electricity.
cape(1) A point or head of land projecting into a body of water
cumulus cloudThese clouds form in convective currents and are characterized by relatively flat bases and dome-shaped tops
infiltration/inflow studyInspection and analysis to identify and understand vulnerabilities in a wastewater system that allow the undesirable ingress of infiltration and inflow into the wastewater system.
macrophyteA member of the macroscopic plant life, especially of a body of water.
hydrological cyclethe circulation of water around the world between stores by various transfers
lotic systemA flowing body of fresh water, such as a river or stream
mapThe average rainfall over a given area, generally expressed as an average depth over the area.
salt panthe dried out bed of a salt lake
foreset bedDeltaic deposit of alluvial sediment that is angled 5 to 25° from horizontal
mitigating measuresModifications of actions that (1) avoid impacts by not taking a certain action of parts of an action; (2) minimize impacts by limiting the degree or magnitude of the action and its implementation; (3) rectify impacts by repairing, rehabilitating, or restoring the affected environment; (4) reduce or eliminate impacts over time by preservation and maintenance operations during the life of the action; or (5) compensate for impacts by replacing or providing substitute resources or environments.
sublimationtransformation between solid and gas, and vice versa, without being in a liquid stage.
frontolysisThe destruction or dying of a front where the transition zone is losing its contrasting properties
canalA waterway dug across land through which ships can pass.
boiling pointThe temperature at which a liquid changes to a vaporous state
hydraulic mean depthThe right cross-sectional area of a stream of water divided by the length of that part of its periphery in contact with its containing conduit; the ratio of area to wetted perimeter
glacial budgetthe net result of accumulation and ablation.
fungusoften       associated with pulpmill effluent and wood preservatives.
hydroThe prefix denoting water or hydrogen.
mixing zonea limited volume of receiving water that is allocated for diluting a wastewater discharge without causing adverse effects to the overall water body.
reliefThe vertical difference between the surface in valleys and hilltops or the vertical between the base of a glacier and its top.
eskerA narrow, sinuous ridge of sorted sands and gravels deposited by a supraglacial, englacial or subglacial stream.
freshwater marshOpen wetlands that occur along rivers and lakes.
eluviation(1) The removal of soil material in suspension (or in solution) from a layer or layers of a soil
mesocycloneA cylinder of cyclonically flowing air that form vertically in a severe thunderstorm
mountain breezeLocal thermal circulation pattern found in areas of topographic relief
flood stageThe elevation at which overflow of the natural banks of a stream or body of water begins in the reach or area in which the elevation is measured.
toeThe break in slope at the foot of a stream bank where the bank meets the bed.
surface impoundment  An indented area in the land's surface, such as a pit, pond, or lagoon.
drought index  Computed value which is related to some of the cumulative effects of a prolonged and abnormal moisture deficiency
forbes bandsAlternating bands of light and dark ice on a glacier usually found down glacier from steep narrow icefalls and considered to be the result of different flow and ablation rates in summer and winter
international date lineThe line of longitude located at 180° East or West (with a few local deviations) where the date changes by a day
erraticA large boulder that a glacier deposits on a surface made of different rock.
cross seas  Steep waves with short, sharp wave crests.  They form when two or more wave trains moving in different directions run together.
hatcheryRefers to facilities that incubate eggs and rear the young for release into streams and rivers.
stratified driftSediments laid down by glacial meltwater show unconfined sorting.
blowout depressiona small, shallow bowl-shaped feature created by wind erosion in coastal and arid areas.
geohydrologya term which denotes the branch of hydrology relating to subsurface or subterranean waters; that is, to all waters below the surface.
colorado lowA low pressure disturbance that forms in the lee of the Rocky Mountains, usually in southeastern Colorado.
gaging stationA particular site on a stream, canal, lake or reservoir where systematic observations of gage height or discharge are made.
pancake iceCoherent plates of ice that can reach a few meters across and grow from thickened grease ice and resembles pancakes or lily pads.
depletion curvein hydraulics, a graphical representation of water depletion from storage stream channels, surface soil, and groundwater
galeBreaks twigs off trees; impedes progress; moderately high waves of greater length; edges of crests begin to break into spindrift; foam on water surface is blown in well-marked streaks along wind.
snow flurry/flurriesLight showers of snow, generally very brief without any measurable accumulation
piedmont glacierA valley glacier that flows out of a mountainous area onto a gentle slope or plain and spreads out over the surrounding terrain.
combined sewersA sewer that carries both sewage and storm water runoff.
developing gale/storm  In the National Weather Service High Seas Forecast, a headline used in the warnings section to indicate that gale/storm force winds are not now occurring, but they are expected before the end of the forecast period.
mass wastingGeneral term that describes the downslope movement of sediment, soil, and rock material.
pressure jumpA sudden increase in the observed atmospheric pressure or station pressure.
water vaporWater in gaseous form
wave-poundingthe breakdown of rock through the sheer impact force of waves
swellsee sea-wave.
plumethe area taken up by contaminant(s) in an aquifer.
raindropA drop of rain.
heat strokeIntroduced to the body by overexposure to high temperatures, particularly when accompanied by high humidity
interbasin transferthe physical transfer of water from one watershed to another; regulated by the Texas Water Code.
damA concrete or earthen barrier constructed across a river and designed to control water flow or create a reservoir.
zone of influence(1) (Hydrologic) The area surrounding a pumping well within which the water table or Potentiometric Surfaces has been changed due to ground-water withdrawal
hydrologic basinThe complete drainage area upstream from a given point on a stream.
drumlinA hill shaped deposit of till
lateritesee hardpan.
consolidated ice cover  Ice cover formed by the packing and freezing together of floes, brash ice and other forms of floating ice.
hardpana shallow layer of earth material which has become relatively hard and impermeable, usually through the deposition of minerals
snow depthThe actual depth of snow on the ground at any instant during a storm, or after any single snowstorm or series of storms.
permitted wellA well from which water is used for other than a domestic use and which has received a permit for a Beneficial Use from the water regulatory body or other appropriate official.
lakeA body of water completely surrounded by land.
magnetic fieldThe space influence by magnetic force
dynamical modelIn hydrology, a hydrological computer model that is mathematically and physically correct because it accounts for every molecule of moisture entering, stored in and leaving a basin or an area.
blowdownTrees felled at the base by high winds.
straight-line windsAny surface wind that is not associated with rotation
surface impoundmentan indented area in the land's surface, such a pit, pond, or lagoon.
public water systema system for the provision to the public of water for human consumption through pipes or other constructed conveyances.  In Texas, a public water system is one that serves at least 15 service connections or serve at least 25 individuals at least 60 days out of the year.
lentic systemA nonflowing or standing body of fresh water, such as a lake or pond
pump stationA station housing relatively large pumps and their appurtenances
snow squallA heavy snow shower accompanied by sudden strong winds, or a squall.
pumped hydroelectric storagestoring water for future use in generating electricity
dischargeIn glaciers, the total volume of ice passing through a specified cross section of the glacier during a particular unit of time.
blowing snowSnow that is raised by the wind to heights of six feet or greater
occluded frontA transition zone in the atmosphere where an advancing cold air mass sandwiches a warm air mass between another cold air mass pushing the warm air into the upper atmosphere.
water analysisThe determination of the physical, chemical, and biological characteristics of water
overdetermined multiple doppler analysis  A multiple Doppler analysis technique in which there are more radars than the desired number of wind components to be retrieved
centrifugal forceThe apparent force in a rotating system that deflects masses radially outward from the axis of rotation
extending flowin a glacier, when gradient becomes steeper and ice accelerates and becomes thinner.
fenA type of wetland that accumulates peat deposits
food chaingenerally, but not always, occurs due to a       contaminant being soluble in fatty tissues and not in water
manning's equationan empirical equation used to estimate the average hydraulic conditions of flow within a channel cross section.
skew t-log p diagramA thermodynamic diagram, using the temperature and the logarithm of pressure as coordinates
interim spillThe spilling of water over John Day, The Dalles, Bonneville, Lower Monumental and Ice Harbor dams to aid fish passage
hatchery rackA weir or trap where returning adult fish are intercepted for hatchery or other use.
ice push  Compression of an ice cover particularly at the front of a moving section of ice cover.
virgin flowthe streamflow which exists or would exist if man had not modified the conditions on or along the stream or in the drainage basin.
ground water hydraulicsThe study of the movement of water, especially water under pressure and water's movement through various soil medium.
xeriscapelandscaping that doesn't require a lot of water
breezy  15 to 25 mph winds
hydrolysisthe decomposition of organic compounds by interaction with water.
ridge iceIce piled haphazardly one piece over another in the form of ridges or walls.
langelier indexAn expression of the ability of water to dissolve or deposit calcium carbonate scale in pipes
frazil ice  Fine spicules, plates, or discoids of ice suspended in water
streaming flowWhere glaciers are constricted, such as in a valley, the flow may or may not be controlled by underlying topography
englacialwithin a glacier.
hook or hook echoA pendant or hook on the right rear of a radar echo that often identifies mesocyclones on the radar display
dischargeVolume of water released from a dam or powerhouse at a given time, usually expressed in cubic feet per second.
rocketsondeA type of radiosonde that is shot into the atmosphere by a rocket, allowing it to collect data during its parachute descent from a higher position in the atmosphere than a balloon could reach.
brooka small stream.
threshold runoff  The runoff in inches from a rain of specified duration that causes a small stream to slightly exceed bankfull.  When available, flood stage is used instead of slightly over bankfull.
hydraulic radiusThe cross-sectional area of a stream divided by the wetted perimeter.
till plainExtensive flat plain of till that forms when a sheet of ice becomes detached from the main body of the glacier and melts in place depositing the sediments it carried.
alkalinitythe capacity of water for neutralizing an acid solution.
arctic airan air mass originating over the Arctic Circle.
glacier dammed lakeThe lake formed when a glacier flows across the mouth of an adjoining valley and forms an ice dam.
intertropical convergence zoneAn area where the Northern and Southern Hemispheric trade winds converge, usually located between 10 degrees North and South of the equator
rearTo feed and grow in a natural or artificial environment.
s-wavea seismic wave which moves material in a motion perpendicular to the direction in which the energy of the wave itself is travelling.
evaporationEvaporation can be defined as the process by which liquid water is converted into a gaseous state
conservationthe maintenance of a landscape (natural or man-made) in its current state.
chemical weatheringDissolving of rock by exposure to rainwater, surface water, oxygen, and other gases in the atmosphere, and compounds secreted by organisms.
environmentThe sum of all external influences and conditions affecting the life and development of an organism or ecological community; the total social and cultural conditions.
snowfieldThe zone of accumulation sometimes a cirque, cwm or corrie; or a large open collecting point between mountains.
shear lineA line of maximum horizontal wind shear
hicThe Hydrometeorological Information Center of the Office of Hydrology (OH).
breakup jamIce jam that occurs as a result of the accumulation of broken ice pieces.
snow lineThe lowest elevation area of a perennial snow field on high terrain, such as a mountain range.
ice boomA floating structure designed to retain ice.
convectionThe process of heat transfer through gas or liquid due to its own movement.
strataThe layers or beds found in sedimentary rock.
pressure regulating valveA device that takes pressure from a high zone through a valve and regulates it to a zone of lower pressure.
meridionalMovement of wind or ocean waters in a direction that is roughly perpendicular to the lines of latitude.
synclineA fold in rock layers that forms a trough-like bend.
moveable bed streams  These are most common in the arid West, where steep slopes and lack of vegetation result in a lot of erosion
tsunamiLarge ocean wave created from an earthquake or volcanic eruption
hurricane  A warm-core tropical cyclone in which the maximum sustained surface wind (using the U.S
average year water demandDemand for water under average hydrologic conditions for a defined level of development.
radius of influencethe radial distance from the center of a wellbore to the point where there is no lowering of the water table or potentiometric surface; the edge of the cone of depression.
cnif  Calibration Network Information Files
genetic conservationThe preservation of genetic resources in breeding populations.
confluence  A pattern of wind flow in which air flows inward toward an axis oriented parallel to the general direction of flow
drainage areaof a stream at a specified location is that area, measured in a horizontal plane, enclosed by a topographic divide from which direct surface runoff from precipitation normally drains by gravity into the stream above the specified location.
subsistencefarming system where the farmer produces just enough to sustain himself and his family.
stability indexThe overall stability or instability of a sounding is sometimes conveniently expressed in the form of a single numerical value
dechlorinationRemoval of chlorine from treated wastewater before discharge into a receiving stream.
outcropexposed at the surface
microclimatethe local climate conditions that show variations to the general climate conditions of the wider environment.
dropstonesRock pieces trapped in icebergs and released (dropped) when the iceberg melts.
frontogenesisThe birth or creation of a front
snow bannerA plume of snow blown off a mountain crest, resembling smoke blowing from a volcano.
impoundmenta body of water such as a pond, confined by a dam, dike, floodgate or other barrier
critical depth  The depth of water flowing in an open channel or conduit, partially filled, corresponding to one of the recognized critical velocities.
dynamics  Generally, any forces that produce motion or affect change
domeThe high, central stable portion of an ice sheet with low rates of accumulation and slow ice movement.
csoDesigned discharge from a combined sewer system into a stream
secondary treatmentsecond step in most waste treatment systems, in which bacteria break down the organic parts of sewage wastes; usually accomplished by bringing the sewage and bacteria together in trickling filters or in the activated sludge process
perennial stream  A stream that flows all year round
clinometerAn instrument used to measure angles of inclination
stormwaterStormwater is rainwater, snowmelt runoff or precipitation that accumulates in stormwater storage systems during and immediately following a storm event, that enters the storm drain system and empties into lakes, rivers and streams.
floraplant population of a region.
earth dayEarth Day is an annual event to raise awareness of taking care of the environment
biological treatmentA treatment technology that uses bacteria to consume organic wastes.
ground water tableThe upper surface of the Zone of Saturation for underground water
glacial valley(also glacial trough) a broad, flat bottomed (U-shaped) valley created by glacial erosion and deposition
end moraineUnlike terminal moraines which mark the furthest advance of the ice sheet or lobe, end moraines record the continuing retreat of the ice.
net increaseNew body substance elaborated in a stock, less the loss from all forms of mortality.
lakesponds and reservoirs, (see lotic).
heterogenic aquiferan aquifer that has a variety of forms or characteristics, such as differering permeabilities
clear ice  It is a glossy, clear or translucent ice formed by the relatively slow freezing of large supercooled droplets.  The large droplets spread out over the airfoil of an airplane before complete freezing, forming a sheet of clear ice.
sustainabilitythe long-term capacity of an ecosystem to maintain ecological processes and functions, biological diversity, and productivity.
bodBiochemical Oxygen Demand
valley trainA linear accumulation of glaciofluvial outwash sediments found in a once glaciated valley.
rock cycleGeneral model describing the geomorphic and geologic processes involved in the creation, modification and recycling of rocks.
earthquakeA sudden, transient motion or trembling of the earth's crust, resulting from the waves in the earth caused by faulting of the rocks or by volcanic activity.
percolationThe movement of water, under hydrostatic pressure, through the interstices of a rock or soil, except the movement through large openings such as caves.
dew pointThe temperature to which air must be cooled at a constant pressure to become saturated.
glaciologyThe study of the physical and chemical propeties of snow and ice.
cumuliform anvil  A thunderstorm anvil with visual characteristics resembling cumulus-type clouds (rather than the more typical fibrous appearance
overrunning  A weather pattern in which a relatively warm air mass is in motion above another air mass of greater density at the surface
infiltration and inflow(Water Quality) The entrance of groundwater (infiltration) or of surface water (inflow) into sewer pipes
physical and chemical treatmentProcesses generally used in wastewater treatment facilities
subsurface waterAll water which occurs below the ground surface.
interfacethe common boundary between two substances such as water and a solid, water and a gas, or two liquids such as water and oil.
unravelThe lose material from the edges of a revetment.
industrial wastewater facilityRefers to those facilities that produce, treat or dispose of wastewater not otherwise defined as a domestic wastewater
adjudicationa court proceeding to determine all rights to the use of water on a particular stream system or ground water basin.
organotinschemical compounds used in antifoulant paints to protect the hulls of boats and ships, buoys, and pilings from marine organisms such as barnacles.
frazil iceFine spicules, plates, or discoids of ice suspended in water
groundwater rechargeThe addition of water to the zone of saturation
salinityThe presence of soluble minerals in water.
windy  20 to 30 mph winds
squall lineA band of thunderstorm development found ahead of a cold front.
wedge  Slang for a large tornado with a condensation funnel that is at least as wide (horizontally) at the ground as it is tall (vertically) from the ground to cloud base
drawdownThe release of water from a reservoir for power generation, flood control, irrigation or other water management activity.
ice capLarge dome-shaped glacier found covering a large expanse of land
glacial depositSedimentary material carried by the glacier and left behind when the ice melts.
equilibrium timeThe time when flow conditions become substantially equal to those corresponding to equilibrium discharge or equilibrium drawdown.
isostatic reboundthe rising of a landmass after the removal of ice.
cycloneAn area of low atmospheric pressure that has a closed circulation
sedimentsoil particles, sand, and minerals washed from the land into aquatic systems as a result of natural and human activities.
wadisteep-sided valley or ravine in desert and semi-arid areas
beginning of freezup  Date on which ice forming a stable winter ice cover is first observed on the water surface.
subglacialThe area below the glacier
isothermline that connects points of equal temperature.
ponda body of water usually smaller than a lake and larger than a pool either naturally or artificially confined.
sub basin(1) A portion of a subregion or basin drained by a single stream or group of minor streams
hmt  Individuals who, at the technical level, have knowledge in meteorology and hydrology
rivera natural stream of water of considerable volume.
backwater poolA pool that formed as a result of an obstruction like a large tree, weir, dam, or boulder.
pool/riffle ratioThe ratio of surface area or length of pools to the surface area or length of riffles in a given stream reach; frequently expressed as the relative percentage of each category
environmental assessmentAn environmental analysis prepared pursuant to the National Environmental Policy Act (NEPA) that presents the first thorough examination of alternative plans to positively demonstrate that the environmental and social consequences of an applicable project or action were considered
oxygen demanding wasteorganic water pollutants that are usually degraded by bacteria if there is sufficient dissolved oxygen (DO) in the water.
opencast miningextraction of a mineral deposit after first removing the layers of rock laid over it
obsequent streamin a trellised drainage pattern, those streams flowing parallel but in the opposite direction to the consequent stream
climatological data   This National Climatic Data Center (NCDC) publication, also produced monthly and annually, contains daily temperature and precipitation data for over 8,000 locations.
ramsar conventionThe Convention on Wetlands of International Importance especially as Waterfowl Habitat held at Ramsar in Iran in 1971
snowpackThe total snow and ice on the ground, including the new snow, the previous snow and ice which has not melted.
canal automationThe implementation of a control system that upgrades the conventional method of canal system operation.
blowing dustDust that is raised by the wind to heights of six feet or greater
isostacyThe buoyant condition of the Earth's crust floating in the asthenosphere
low latitudesThe latitude belt between 30 and 0 degrees North and South of the equator
pressure gradient forceForce due to spatial differences in atmospheric pressure
chlorine demandthe difference between the amount of chlorine added to water, sewage, or industrial wastes and the amount of residual chlorine remaining at the end of a specific contact period
monoculturean agricultural system in which the cultivation of a single crop is the norm.
diurnal  Daily; related to actions which are completed in the course of a calendar day, and which typically recur every calendar day (e.g., diurnal temperature rises during the day, and diurnal falls at night).
scarificationExtensive movements of soil, sediment, and rock material caused by humans.
phytoplanktonfree-floating, mostly microscopic aquatic plants.
tropical waveA trough or cyclonic curvature maximum in the trade wind easterlies and it is not classified as a tropical cyclone.
rejuvenationA change in condition of erosion that causes a stream to begin more active erosion and a new cycle.
shield volcanoVolcano created from alternate layers of lava flows
noncontact recreationrecreational pursuits not involving a significant risk of water ingestion, including fishing, commercial and recreational boating, and limited body contact incidental to shoreline activity
dischargethe volume of water that passes a given point within a given period of time
terracean area of flat ground set into or onto a steep slope.
gullya deeply eroded channel caused by the concentrated flow of water.
thermohalineIn oceanography, it pertains to when both temperature and salinity act together
headward erosionErosion which occurs in the upstream end of the valley of a stream, causing it to lengthen its course in such a direction.
storm drainAny underground pipe or conduit designed to carry only stormwater to a known outfall
biological weatheringThe disintegration of rock and mineral due to the chemical and/or physical agents of an organism.
tail waterthe runoff of irrigation water from the lower end of an irrigated field.
ground water miningPumping ground water from a basin where the safe yield is very small, thereby extracting ground water which had accumulated over a long period of time.
rain gaugean instrument used to quantify the amount of rain falling in a particular location over a period of hours
terminal moraineA moraine found near the terminus of a glacier; also known as an end moraine.
dredgingThe removal of material from the bottom of water bodies using a scooping machine
evaporationThe process by which a liquid changes to a vapour.
loadingSynonym for the pollution Load of a stream.
appropriative rights"first in time, first in right” principle of allocating water rights based
erosion controlAnything that will keep soil on site and out of streets and storm drains
septic tankAn underground storage tank for wastes from homes not connected to a sewer line
fillingUsed in describing the history of a low pressure system or an area of cyclonic circulation, it means an increase in the central pressure of the system
floe iceIce usually several feet thick, which has formed on the surface of a body of water and then has broken into pieces and is floating on the water's surface.
caveA natural cavity or recess that is roughly positioned horizontally to the surface of the Earth.
soil moisture regimeThe changes in the moisture content of soil during a year.
inspectionAn entry into and examination of premises for the purpose of ascertaining the existence or nonexistence of water violations.
kettle moraineAn area of glaciofluvial influenced moraine deposits pitted with kames and kettle holes.
oasisA fertile or green spot in a desert or wasteland, made so by the presence of water.
wave cycloneSee mid-latitude cyclone.
taigathe Russian term for boreal.
aquifera geologic formation(s) that is water bearing
firm yieldThe maximum annual supply of a given water development that is expected to be available on demand, with the understanding that lower yields will occur in accordance with a predetermined schedule or probability.
sublimationAn endothermic physical process whereby ice passes directly into the vapor state
isobathAn imaginary line on the earth's surface or a line on a map connecting all points which are the same vertical distance above the upper or lower surface of a water-bearing formation or aquifer.
anemophobia  The fear of air drafts or wind.  See Ancraophobia.
ecospheretotal of all the ecosystems on the planet, along with their interactions; the sphere of air, water, and land in which all life is found.
flumea natural or artificially made channel that diverts water.
wet floodproofing  An approach to floodproofing which usually is a last resort
plate tectonicsrefers to the folding and faulting of rock and flow of molten lava involving lithospheric plates in the earth's crust and upper mantle.
spring-linea line of springs emerging from a valley side at approximately the same height which reflect the underlying rock conditions.
tropic of capricornLatitude of 23.5° South
polycyclic landformLandform that shows the repeated influence of one or more major geomorphic processes over geological time
piedmont glacierA large glacier formed from the merger of several alpine glaciers.
debris cloudConsidered a rotating cloud of debris or dust that is on the ground or near the ground
jar testa laboratory procedure that simulates a water treatment plant's coagulation/flocculation units with differing chemical doses, mix speeds, and settling times to estimate the minimum or ideal coagulant dose required to achieve certain water quality goals.
channelizationThe modification of a natural river channel; may include deepening, widening, or straightening.
poles/polarThe poles are the geographic point at 90 degrees latitude North and South on the earth's surface
exfoliationthe 'peeling' away of outer layers of rock in a process of physical weathering found where diurnal temperature range is very wide
pressure pipePipe used to distribute potable water throughout the city for fire fighting and domestic purposes.
flow meterA device which allows for measurement of stream flow by measuring velocity in a given cross-sectional area.
subsidya government grant used to save or stimulate a particular operation or whole industry sector.
bellot windsRefers to the winds in the Canadian Arctic that blow through the narrow Bellot Strait between Somerset Island and the Boothia Peninsula, connecting the Gulf of Boothia and Franklin Strait.
pipingThe progressive development of erosion of a dam structure by seepage, appearing downstream of the dam as a hole or seam discharging water that contains soil particles.
rated capacityThe volume of water a treatment plant is capable of producing under normal operating conditions.
caverna large cave.
impaired water bodya water body that has been determined under state and federal law as not meeting water quality standards, or having the potential to do so in the future.
mass curve  A graph of the cumulative values of a hydrologic quantity (such as precipitation or runoff), generally as ordinate, plotted against time or date.
irrigation water useArtificial application of water on lands to assist in the growing of crops and pastures or to maintain vegetative growth on recreational lands such as parks and golf courses
watercourse  Any surface flow such as a river, stream, tributary.
morainedebris deposited by a glacier
river recreation statement  A statement released by the NWS to inform river users of current and forecast river and lake conditions
sludgeA semi-liquid mass of accumulated settled solids deposited from the treatment plant process
antarcticOf or relating to the area around the geographic South Pole, from 90° South to the Antarctic Circle at approximately 66 1/2°South latitude, including the continent of Antarctica
map projectionCartographic process used to represent the Earth's three-dimensional surface onto a two-dimension map
clayMineral particle with a size less than 0.004 millimeters in diameter
inchoate water rightan unperfected water right.
climateThe sum total of the meteorological elements that characterize the average and extreme conditions of the atmosphere over a long period of time at any one place or region of the earth's surface
percolationdownward movement of water through soil and bedrock.
index modelIn hydrology, a hydrologic computer model based on empirical, statistical relationship.
anticyclonea stable, generally subsiding air mass producing high pressure, warming conditions
displacementdistance by which portions of the same geological layer are offset from each other by a fault.
dama large wall or earth barrier used to block a river valley
valley trainOutwash confined between two rock walls, moraines or by unmelted ice, ice blocks or calving ablation fields.
meltwaterWater from melted snow or ice.
soil erosionTransport of soil mineral particles and organic matter by wind, flowing water, or both
base floodplainThe floodplain that would be inundated by a one percent chance flood (100-Year Flood).
pump curveThe relationship between the head developed by a pump and the capacity (flow) for a constant rotative speed.
critical low flowlow flow conditions below which some standards do not apply
free ground waterwater in interconnected pore spaces in the zone of saturation down to the first impervious barrier, moving under the control of the water table slope.
subsidenceSinking down of part of the earth's crust due to underground excavation, such as the removal of groundwater.
isopodasmall but generally visible species flattened from       top to bottom, common benthic and epibenthic invertebrates.
overbank flowsthe component of an instream flow regime that represents infrequent, high flow events that exceed the normal channel
epicenterSurface location of an earthquake's focus.
phreatic surfaceThe free surface of ground water at atmospheric pressure.
white-outA weather condition in which the horizon cannot be identified and there are no shadows
north atlantic driftthe name for the warm ocean current in the North-East Atlantic that originates in the Caribbean as the Gulf Stream.
ntunephlometric turbidity units.
freezing rain advisory  This product is issued by the National Weather Service when freezing rain or freezing drizzle causes significant inconveniences, but does not meet warning criteria (normally an ice accumulation of 1/4 inch or greater) and if caution is not exercised, it could lead to life-threatening situations.
control structureDam, dike, pump or any structure built for the purpose of controlling the water level of a lake or pond.
forecast crest  The highest elevation of river level, or stage, expected during a specified storm event.
zero datumA reference "zero" elevation for a stream or river gage
ground water registrationA statement made by a well owner registering the Beneficial Use of ground water.
saline(1) Term used to describe waters containing common salt, or sodium chloride
magnetic polesEither of the two points on the earth's surface where the magnetic meridians converge
sedimentSolid material that has been or is being eroded, transported, and deposited
geysera thermal spring that erupts intermittently and to different heights above the surface of the Earth; eruptions occur when water deep in the spring is heated enough to turn into steam, which forces the liquid water above it out into the air glacial striations - lines carved into rock by overriding ice, showing the direction of glacial movement glacier - a large mass of ice formed on land by the compacting and recrystallization of snow; glaciers survive from year to year, and creep downslope or outward due to the stress of their own weight groundwater - water under ground, such as in wells, springs and aquifiers gullying - small-scale stream erosion
polar cellThree-dimensional atmospheric circulation cell located at roughly 60 to 90° North and South of the equator
routing  The methods of predicting the attenuation of a flood wave as it moves down the course of a river.
sea iceAt temperatures of -2° C (28.5° F), freezes directly from ocean water to a thickness of five meters (15 feet)
icebergA massive piece of ice that breaks off and floats away from a Glacier
streamflowis the discharge that occurs in a natural channel
wind directionThe true direction from which the wind is moving at a given location
newly industrialised countrycountries that have undergone rapid industrialisation since the 1960s
columnar ice  Ice consisting of columnar shaped grain
spawning surveysSpawning surveys utilize counts of redds and fish carcasses to estimate spawner escapement and identify habitat being used by spawning fish
aquifersoil or rock below the land surface that is saturated with water
eutrophicReferring to water that is rich in nutrients such as nitrogen and phosphorous.
solidA state of matter, neither liquid nor gas
recessional morainesEnd moraines created during occasionally stabilization of the ice front during retreat.
headward erosion  Erosion which occurs in the upstream end of the valley of a stream, causing it to lengthen its course in such a direction.
frontolysisThe process in which a front dissipates
convective condensation levelIt is the height to which a parcel of air, if heated sufficiently from below, will rise adiabatically until it is just saturated (condensation starts)
recarbonizationprocess in which carbon dioxide is bubbled into water being treated to lower the pH.
static water pressureThe pipeline or municipal water supply pressure when water is not flowing.
ground waterWater within the earth that supplies wells and springs; water in the zone of saturation where all openings in rocks and soil are filled, the upper surface of which forms the water table
fluvialOf or pertaining to rivers and streams; growing or living in streams ponds; produced the action of a river or stream.
river observing stationAn established location along a river designated for observing and measuring properties of the river.
lateral morainesA moraine which forms on the side of the ice stream, often where the ice meets the rock wall
velocityIn this concept, the speed of water flowing in a watercourse, such as a river.
subsidenceLowering or sinking of the Earth's surface.
surface creepThe sliding and rolling movement of soil particles on the Earth's surface because of wind
polar air massAn air mass that forms over a high latitude region
sunny  When there are no opaque (not transparent) clouds.  Same as Clear.
calcificationA dry environment soil-forming process that results in the accumulation of calcium carbonate in surface soil layers.
floeAn ice flow
base periodA period of time specified for the selection of data for analysis
wave-cut platformat a coast, where wave action erodes into a cliff, causing it to collapse and retreat, a rock platform is left behind between the low and high water marks.
flow augmentationthe addition of water to meet flow needs.
groundwater reservoir storageThe amount of water in storage within the defined limit of the aquifer.
mill wheelA wheel, typically driven by water, that powers a mill.
irrigation water usewater application on lands to assist in the growing of crops and pastures or to maintain vegetative growth in recreational lands, such as parks and golf courses.
land applicationdischarge of wastewater onto the ground for treatment or reuse.
single cell thunderstormThis type of thunderstorm develops in weak vertical wind shear environments
sargasso seaAn area of the North Atlantic Ocean between Bermuda and the Azores
glacierBodies of land ice that consist of recrystallized snow accumulated on the surface of the ground, and that move slowly downslope.
eskerLong twisting ridges of sand and gravel found on the Earth's surface
wavelengthDistance between two successive wave crests or troughs.
soundA sound is a wide inlet of the sea or ocean that is parallel to the coastline; it often separates a coastline from a nearby island.
confining bed or unita body of impermeable or distinctly less permeable material stratigraphically adjacent to one or more aquifers.
floodplainThe area adjacent to a stream that is on average inundated once a century.
normal annual precipitationAverage annual precipitation during a base period.
waterfallWhen a river falls off steeply, there is a waterfall.
spillwaythe channel or passageway around or over a dam through which excess water is diverted.
sea level pressureThe atmospheric pressure at mean sea level, usually determined from the observed station pressure.
natural flowthe rate of water movement past a specified point on a natural stream
stratiformClouds composed of water droplets that exhibit no or have very little vertical development
stratopauseThe boundary zone or transition layer between the stratosphere and the mesosphere
lagoon(1) A shallow pond where sunlight, bacterial action, and oxygen work to purify wastewater
tidal pilingAbnormally high water levels caused by the accumulation of successive incoming tides that do not completely drain due to opposing strong winds and/or waves.
drought  A period of abnormally dry weather sufficiently prolonged from the lack of precipitation to cause a serious hydrologic imbalance.
trihalomethaneschemical compounds in which three of the four hydrogen atoms of methane (CH4) are replaced by halogen atoms
eschericha coliColiform bacterium that is often associated with human and animal waste and is found in the intestinal court
inflow jets  Local jets of air near the ground flowing inward toward the base of a tornado.
hydroelectric powerusing water to generate electricity; turbine generators  driven by falling water.
jetteaua jet of water.
ground water barrierRock, clay, or other natural or artificial materials with a relatively low permeability that occurs (or is placed) below ground surface, where it impedes the movement of ground water and thus causes a pronounced difference in the heads on opposite sides of the barrier.
drifting snowIt is an uneven distribution of snowfall/snow depth caused by strong surface winds
glacier terminusWhere the glacier ends, the leading edge of the glacier, also called the glacier nose.
transverse bands  Bands of clouds oriented perpendicular to the flow in which they are embedded
spawning escapementThe total number of adult fish returning to a hatchery or stream to spawn.
glacierA glacier is a long-lasting, slowly-moving river of ice on land.
ground water storage capacityThe space or voids contained in a given volume of soil and rock deposits
surgeThe increase in sea water height from the level that would normally occur were there no storm
illinoianNorth American glaciation related to European Riss glaciation.
compactA formal agreement between states concerning the use of water in a river or stream that flows across state boundaries.
permeablea rock which can absorb water (porous) or allow water to pass through cracks and joints (pervious).
greenhouse effectThe warming of the earth's atmosphere caused by a build-up of carbon dioxide or other trace gases; it is believed by many scientists that this build-up allows light from the sun's rays to heat the earth but prevents a counterbalancing loss of heat.
polar frontA semi-continuous, semi-permanent boundary between polar air masses and tropical air masses
oligotrophic lakeLake with a low supply of nutrients in its waters
latitudeThe location north or south in reference to the equator, which is designated at zero (0) degrees
ice streamsIn glaciers, ice flows in lineaments which, if they encounter other ice streams, do not mix
solar eclipseAn eclipse of the sun occurs when the moon is in a direct line between the sun and the earth, casting some of the earth's surface in its shadow
streamalso the upper reaches of a reservoir, the water       upstream from a structure or point on a stream, the small streams that come together to form a       river, any and all parts of a river basin except the mainstream river and main tributaries.
supersaturationIn water, the condition which occurs in the atmosphere when the relative humidity is greater than 100 percent.
escarpmentan elongated, steep slope at the edge of an upland area such as a plateau or cuesta.
water supplierone who owns or operates a public water system.
coldA condition marked by low or decidedly subnormal temperature
stream gage  A site along a stream where the stage (water level) is read either by eye or measured with recording equipment.
humiditythe water vapour content of the atmosphere
contributing areaThat portion of a watershed which contributes to measured runoff under normal conditions.
air mass thunderstormA thunderstorm that is produced by convection within an unstable air mass through an instability mechanism
straitA strait is a narrow body of water that connects two larger bodies of water.
isotachA line on a weather map connecting points of equal wind speed.
temperate glacierGlacier in which the ice found below 10 to 20 meters from its surface is at the pressure melting point
bypass systemA channel or conduit in a dam that provides a route for fish to move through or around the dam without going through the turbine units.
lavamolten rock flowing on the surface
piedmont glaciera glacier formed when a valley glacier spills from an alpine range onto a lowland plain.
hydrostatic pressurepressure exerted by or existing within a liquid at rest with respect to adjacent bodies.
stone circlea circle of large stones found in periglacial areas when the formation of an ice lens just beneath the surface creates a dome from which stones on the surface roll away.
methyl orange alkalinityA measure of the total alkalinity in a water sample in which the color of methyl orange reflects the change in level.
perigeeThe point nearest the earth on the moon's orbit
kilogramone thousand grams.
vortex rocksRocks placed in a streambed to help direct flows for the formation of meanders and creation of riffles and pools
mariculturea branch of aquaculture specializing in the cultivation of marine organisms in salt water usually by enclosing a cubic volume of a natural waterway
electrophoresis-2Electrophoresis refers to the movement of charged particles in an electric field
geothermicsThe science pertaining to the earth's interior heat
mesocycloneA area of rotation of storm size that may often be found on the southwest part of a supercell
biological reference pointsFishing mortality rates that may provide acceptable protection against growth overfishing and/or recruitment overfishing for a particular stock
glacial surgeA rapid forward movement of the snout of a glacier
mesohabitatbasic structural elements of a river or stream such as pools, backwaters, runs, glides, and riffles.
frazil slushAn agglomerate of loosely packed frazil which floats or accumulates under the ice cover.
suspended solidsthe small solid particles in water that cause turbidity
saline waterWater that contains more than 1,000 milligrams per liter of dissolved solids
boraTerm used to describe a katabatic wind in Yugoslavia.
habitatThe place where a population (e.g
dredgingremoval of sediment from the bottom of a sea or river
disinfectionthe killing of the larger portion of the harmful and objectionable bacteria in the sewage
blowingA descriptor used to amplify observed weather phenomena (dust, sand, snow, and spray) whenever the phenomena are raised to a height of 6 feet or more above the ground and reduces horizontal visibility to less than 7 statue miles.
      organic wastesa quantitative measure of the degree to which organic compounds consume       oxygen in water, based on a five-day test in which loss of oxygen in a sample results from       bacterial respiration and chemical processes, a traditional water quality measurement applied to       wastewater such as treated sewage.
overcastThe amount of sky cover for a cloud layer that is 8/8ths, based on the summation layer amount for that layer.
valleyA linear depression in the landscape that slopes down to a stream, lake or the ocean
snow core  A sample of either freshly fallen snow, or the combined old and new snow on the ground
glacier karstStagnant ice covered by debris with surficial lakes, lakes in buried caverns or tunnels, typically found at the ice/soil or ice/water interface of a retreating glacier.
cumulus humilisCumulus clouds with little or no vertical development characterized by a generally flat appearance
base flowRate of discharge in a stream where only the throughflow and groundwater flow from subsurface aquifers contribute to the overall flow.
river capacitythe maximum amount of load a river can carry.
apparent temperatureThe apparent temperature is a measure of human discomfort due to combined heat and humidity.  It was developed by Dr
limnologyThe study of lakes, ponds and streams.
boga type of wetland that accumulates appreciable peat deposits
source regionthe type of area from which an air mass originates. 
mainstemThe principle channel of a drainage system into which other smaller streams or rivers flow.
polar highSurface area of atmospheric high pressure located at about 90° North and South latitude
horizontal distributionThe location of fish in the cross section of a river or a lake.
100-year 24-hour designThis design criteria is used for determining storm sewer size, and assumes 5.9" falling in 24 hours in a SCS Type II storm event.
vadoseOf, relating to, or being water that is located in the Zone of Aeration in the earth's crust above the ground water level.
photosynthesisThe process of conversion of water and carbon dioxide to carbohydrates
public water systemA system that provides piped water for human consumption to at least 15 service connections or regularly serves 25 individuals.
cone of depressionThe depression, roughly conical in shape, produced in a water table, or other piezometric surface, by the extraction of water from a well at a given rate
transpirationWater discharged into the atmosphere from plant surfaces.
sleetAlso known as ice pellets, it is winter precipitation in the form of small bits or pellets of ice that rebound after striking the ground or any other hard surface
degradation  The geologic process by means of which various parts of the surface of the earth are worn down and carried away and their general level lowered, by the action of wind and water.
wetlandAn area that is regularly wet or flooded and has a water table that stands at or above the land surface for at least part of the year.
glaciera huge mass of ice, formed on land by the compaction and recrystallization of snow, that moves very slowly downslope or outward due to its own weight.
mesaa flat-topped hill standing up from a plain.
river ice statement  A public product issued by the RFC's containing narrative and numeric information on river ice conditions.
permanent monumentFixed monuments placed away from the dam which allow movements in horizontal and vertical control points on the dam to be monitored by using accurate survey procedures.
potamodromousExhibiting a behavior involving migrations into smaller river tributaries for spawning and rearing
tiltThe inclination to the vertical of a significant feature of the pressure pattern or of the field of moisture or temperature
chemosynthesisProcess in which specific autotrophic organisms extract inorganic compounds from their environment and convert them into organic nutrient compounds without the use of sunlight
flash floodA sudden flood of great volume, usually caused by a heavy rain
parallelA line parallel to the equator and connecting all places of the same latitude.
channela natural or artificial watercourse that continuously or intermittently contains water, with definite bed and banks that confine all but overbanking streamflows.
through talikIs a form of localized unfrozen ground (talik) in an area of permafrost
groundwaterwater within the earth that supplies wells and springs; water in the zone of saturation where all openings in rocks and soil are filled, the upper surface of which forms the water table.
icebergsFloating chunks of ice which calved off the glacier 5/6th underwater 1/6th above
freezing rainRain that falls as liquid and freezes upon impact to form a coating of glaze on the colder ground or other exposed surfaces
deformed iceA general term for ice which has been squeezed together and forced upwards and downwards in places
mixed layerIt is the upper portion of the boundary layer in which air is thoroughly mixed by convection
rossby waveSee long wave.
transition zoneThe intervening area between distinct environments.
radiant energyEnergy in the form of electromagnetic waves and photons
nimbyacronym from 'not in my back yard' applied to people who may agree to the idea of a development that is, on balance, of high social value, but who don't want the development in their own area because of the possible negative consequences that go with it
ice quakesThe beginning of the formation of a crevasse or moulin is often accompanied by shaking ice and a hissing or cracking sound.
storm relative  Measured relative to a moving thunderstorm, usually referring to winds, wind shear, or helicity.
key speciesspecies that are targeted for instream flow assessment or more generally taxa of interest; may include lotic-adapted species, imperiled species, sport fishes, or other species related to study objectives.
fallow(1) Allowing cropland, either tilled or untilled, to lie idle during the whole or greater portion of the growing season
maximum unambiguous velocity  The maximum radial velocity that can be detected without velocity aliasing
firnThe granular ice formed by the recrystallization of snow; also known as névé.
river ice statementA public product issued by the RFC's containing narrative and numeric information on river ice conditions.
tropical waveAnother name for an easterly wave, it is an area of relatively low pressure moving westward through the trade wind easterlies
wastewater-treatment return flowwater returned to the environment by wastewater-treatment facilities.
rip currentA strong relatively narrow current of water that flows seaward against breaking waves.
rain gardenRain gardens are native plant gardens that are designed to reduce the amount of stormwater and pollutants from entering our streams, lakes and rivers, as well as to aesthetically improve properties.
environmental assessmentA systematic analysis of site-specific activities used to determine whether such activities have a significant effect on the quality of the human environment and whether a formal environmental impact statement is required; and to aid an agency's compliance with the National Environmental Policy Act when no environmental impact statement is necessary.
esturine zone  The area near the coastline that consists of estuaries and coastal saltwater wetlands.
channel efficiencythe ability of the channel to conserve energy that may otherwise be lost to friction
polderreclaimed land created by the construction of an embankment or dyke to hold back water that would otherwise flood the new surface.
immiscibilityThe inability of two or more solids or liquids to readily dissolve into one another.
glacial valleyValley that was influenced by the presence of glaciers
altocumulus castellanusThey are middle level convective clouds and possibly they should be classified as clouds with extensive vertical development
frost pointDew point below freezing.
habitatThe native environment or specific surroundings where a plant or animal naturally grows or lives
ice capa large area of ice
combined sewageWastewater and storm drainage carried in the same pipe.
sedgeGrass-like plant that is adapted to grow in moist habitats.
cone of depressionnatural depression in the water table around a well during pumping.
percolation(1) The movement of water through the openings in rock or soil
zone of accumulationThe snowfields or cirques of mountain glaciers and the snowfields of continental glaciers are called the zone of accumulation because it is here than new snow falls to nourish the glacier.
influent streamA stream that contributes water to the Zone of Saturation and to Bank Storage
soil fertilitythe ability of a soil to provide nutrients for plant growth.
raw sewageUntreated wastewater and its contents.
laser land levelingThe use of instruments featuring laser beams to guide earth-moving equipment for leveling land for surface-type irrigation.
biosolidsThe organic by-product of wastewater treatment (also called “sludge”).Biosolids contain essential plant nutrient and organic matter and are recycled as a fertilizer and soil amendment.
headwallThe steep rock at the top edge of the cirque.
per capita usethe average amount of water used per person during a standard time period, generally per day.
fill(1) (Geology) Any sediment deposited by any agent such as water so as to fill or partly fill a channel, valley, sink, or other depression
estuarythin zone along a coastline where freshwater system(s) and river(s) meet and mix with a salty ocean (such as a bay, mouth of a river, salt marsh, lagoon).
barrageAn artificial obstruction, such as a dam or an irrigation channel, built in a watercourse to increase its depth or to divert its flow either for navigation or irrigation
midstreamThe middle part of a stream.
forfeitureThe invalidation of a water right because of five or more consecutive years of nonuse.
straight line winds  Generally, any wind that is not associated with rotation, used mainly to differentiate them from tornadic winds.
productivitystanding crop).
secondary treatmentIn sewage, the biological process of reducing suspended, colloidal, and dissolved organic matter in effluent from primary treatment systems
water cycleevapotranspiration, evaporation,       incorporation into plant tissue, infiltration into ground water and consumption by humans,       wildlife or livestock, are some of the reasons water may not be immediately available for reuse
discharge  The rate at which water passes a given point
consumptive water useWater removed from available supplies without return to a water resources system; water used in manufacturing, agriculture, and food preparation.
palatable waterWater, at a desirable temperature, that is free from objectionable tastes, odors, colors, and turbidity.
population vulnerability analysisA systematic process for estimating species, location and time specific criteria for persistence of a population.
lifting condensation levelIt is the height at which a parcel of air becomes saturated when lifted dry-adiabatically.
pumpA device which moves, compresses, or alters the pressure of a fluid, such as water or air, being conveyed through a natural or artificial channel.
settling chamber(Water Quality) An enclosed container into which wastewater contaminated with solid materials is placed and allowed to stand
stressForce applied to an object per its unit area
secondary pollutantAtmospheric pollutants that are created chemically in the atmosphere when primary pollutants and other components of the air react
eddy viscositya model parameter that reproduces the effects of turbulent mixing in fluid flow.
activated sludgeProduct that results when primary effluent is mixed with bacteria-laden sludge and then agitated and aerated to promote biological treatment, speeding the breakdown of organic matter in raw sewage undergoing secondary waste treatment.
glacier troughSteep U-shaped valley with a flat bottom caused by glacial scour and erosion.
viscosityA measure of the resistance of a fluid to flow
safe yieldThe annual amount of water that can be taken from a source of supply over a period of years without depleting that source beyond its ability to be naturally refilled.
domestic useThe quantity of water used for household purposes such as washing, food preparation, and bathing.
ice stormIt is usually used to describe occasions when damaging accumulations of ice are expected during freezing rain situations
hydrologic cycleThe natural pathway water follows as it changes between liquid, solid, and gaseous states.
evapotranspirationtotal moisture lost through evaporation and transpiration.
sky coverThe amount of the celestial dome that is hidden by clouds and/or obscurations.
ocean-maturingSteelhead that enter fresh water with well-developed gonads and spawn shortly thereafter; commonly referred to as winter steelhead.
lee effect  The effect of topography on winds to the lee (downwind) side of an obstacle such as a steep island, cliff, or mountain range.
crackDefective line visible on the sewer wall, with the pieces of the wall still in place
basinA topographic rock structure whose shape is concave downwards.
itcz  Acronym for Intertropical Convergence Zone.
nivationthe expansion of a hollow through freeze-thaw under a patch of snow and the subsequent washing out of the debris by meltwater.
floodplainAny normally dry land area that is susceptible to being inundated by water from any natural source
fungicidea chemical used in farming to kill funguses which inhibit plant growth.
grooves/groovingAs the glacier moves forward, rocks imbedded in the ice scratch the underlying materials
squall lineA line or narrow band of active thunderstorms
foreshockSmall earth tremors that occur seconds to weeks before a significant earthquake event.
water yearThe time period form October 1 through September 30.
truncated spursteep cliff face at the side of a glacial trough where a valley glacier has removed an interlocking spur
corn snow iceRotten granular ice.
water hammer(1) Very rapid pressure wave in a conduit due to a sudden change in flow; the potentially damaging slam, bang, or shudder that occurs in a pipe when a sudden change in water velocity (usually as a result of too-rapidly starting a pump or operating a valve) creates a great change in water pressure
derechoA line of intense, widespread, and fast-moving thunderstorms that moves across a great distance
perched water tableWater table that is positioned above the normal water table for an area because of the presence of a impermeable rock layer.
ground water storageThe storage of water in ground water reservoirs.
lake effect snowSnow showers that are created when cold dry air passes over a large warmer lake, such as one of the Great Lakes, and picks up moisture and heat.
restricted use pesticidesA pesticide that can be sold to or used by only certified applicators.
thunderstormA local storm produced by cumulonimbus clouds
ball valveA valve regulated by the position of a free-floating ball that moves in response to fluid or mechanical pressure.
occluded mesocyclone  A mesocyclone in which air from the rear-flank downdraft has completely enveloped the circulation at low levels, cutting off the inflow of warm unstable low-level air.
flood plainThe portion of a river valley that has been inundated by the river during historic floods.
stable canal systemA canal system in which flow disturbances are attenuated.
sewage contaminationThe introduction of untreated sewage into a water body.
dry crackCrack visible at the surface but not going right through the ice cover, and therefore it is dry.
gramIn metric units the weight of one cubic centimeter of water at 20° Celsius and 1 atm.
fallsA waterfall or other precipitous descent of water.
solsticeDates when the declination of the Sun is at 23.5° North or South of the equator
headlandat the coast, land utting out-further into the sea and separating bays.  see also discordant coast .
stream-gaging stationA gaging station where a continuous record of the discharge of a stream is obtained.
condensation nucleiMicroscopic particle of dust, smoke or salt that allows for condensation of water vapor to water droplets in the atmosphere
sdm  an acronym for Station Duty Manual
capeA cape is a pointed piece of land that sticks out into a sea, ocean, lake, or river.
recharge areaAn area where rainwater soaks through the ground to reach an aquifer.
base floodThe national standard for flood plain management is the base, or one percent chance flood
troposphereLayer in the atmosphere found from the surface to a height of between 8 to 16 kilometers of altitude (average height 11 kilometers)
wild stockA stock that is sustained by natural spawning and rearing in the natural habitat, regardless of parentage (includes native).
activated carbon adsorptionthe process of pollutants moving out of water and attaching on to activated carbon.
soil erodibilityAn indicator of a soil's susceptibility to raindrop impact, runoff, and other eroding processes.
dense fog advisoryAdvisory issued when fog reduces visibility to 1/8 mile or less, creating possible hazardous conditions.
effluenttreated water flowing from a sewage treatment plant; can be used for landscape watering and artificial recharge.
water tablethe upper boundary of the saturated portion of a soil or rock.
weirA vertical structure in an open channel with a calibrated opening that measures water's rate of flow
influent seepageThe movement of gravity water in the Zone of Aeration from the ground surface toward the water table.
hydrologyThe scientific study of the water of the earth, its occurrence, circulation and distribution, its chemical and physical properties, and its interaction with its environment, including its relationship to living things.
slip-off slope bankThe bank of a meandering stream which is not eroded by stream action, and which may be built up gradually.
maritime effectThe effect that large ocean bodies have on the climate of locations or regions
freeboardthe vertical distance between the lowest point along the top of a surface impoundment dike, berm, levee, treatment works or other similar feature and the surface of the liquid contained therein.
breach  The failed opening in a dam.
base flowThe sustained portion of stream discharge that is drawn from natural storage sources, and not affected by human activity or regulation.
wastewaterwater containing waste including greywater, blackwater or water contaminated by waste contact, including process-generated and contaminated rainfall runoff.
backgroundValue for a parameter that represents the conditions in a system prior to a given influence in space or time.
river observing station  An established location along a river designated for observing and measuring properties of the river.
bid-rent theorythe idea that land is acquired by the highest bidder which is in turn a function of the user who can make the most profit from the site
newhall windsThe local name for winds blowing downward from desert uplands through the Newhall Pass southward into the San Fernando Valley, north of Los Angeles.
altimeterAn instrument used to determine the altitude of an object with respect to a fixed level
terra rossaa soil found on limestone where silicates have leached out leaving oxidized iron-rich deposits which give the soil a distinctive red colour, hence the name.
bournea seasonal river which flows in normally dry valleys during wetter periods of the year.
gallons per minuteA unit used to measure water flow.
interceptionIs the capture of precipitation by the plant canopy and its subsequent return to the atmosphere through evaporation or sublimation
depositsomething dropped or left behind by moving water, as sand or mud.
subsidencesinking to a lower level.
moisture advection  Transport of moisture by horizontal winds.
cfs-dayThe volume of water discharged in twenty four hours, with a flow of one cubic foot per second is widely used; 1 cfs-day is 24 x 60 x 60 = 86,000 cubic feet, 1.983471 acre-feet, or 646,317 gallons
internal flowThe movement of ice inside a glacier through the deformation and realignment of ice crystals; also known as creep.
sediment rating curveNumerical expression or graphical curve that describes the quantitative relationship between stream discharge and the sediment transported by a particular stream.
composite hydrographA stream discharge hydrograph which includes base flow, or one which corresponds to a net rain storm of duration longer than one unit period.
ceremonial or subsistence harvestHarvests of fish by Native Americans for ceremonies and to support traditional lifestyles.
hydroelectric power water usethe use of water in the generation of electricity at plants where the turbine generators are driven by falling water.
perched water tableThe water table of a relatively small ground-water body supported above the general ground water body.
valley glacierAn alpine glacier flowing downward through a preexisting stream valley.
drainage reusereuse of agricultural drainage on salt-tolerant crops.
wastewaterwater that has been used in homes, industries, and businesses that is not for reuse unless it is treated.
prevailing windDominant direction that a wind blows from for a location or region.
calving **Ice sheets calve by breaking off flat pieces when the walls of crevasses give way or chunks fall off the front of an ice sheet
jettyA structure extending into a sea, lake, or river to influence the current or tide, in order to protect harbors, shores, and banks.
brokenThe amount of sky cover for a cloud layer between 5/8ths and 7/8ths, based on the summation layer amount for that layer.
hazardous wasteWaste that poses a risk to human health or the environment and requires special disposal techniques to make it harmless or less dangerous.
100-year stormA precipitation event used for stormwater drainage system design, based on a frequency analysis of historical data
fissureOpening or crack in the Earth's crust.
water pipe(1) A pipe that is a conduit for water
seawaterThe mixture of water and various dissolved salts found in the world's oceans and seas.
streama general term for a body of flowing water.
kameA low, but steep-sided hill or mound composed of poorly sorted sands and gravels deposited in strata by meltwater plunging into crevasses near the melting edge of an ablating glacier.
nondegradationan environmental policy that does not allow any lowering of naturally occurring water quality regardless of pre-established health standards.
surge  A rise in water level caused by strong wind or fluctuations in the atmospheric pressure.  This term is usually applied to a sharp set-up effect at the downwind end of the lake, but thunderstorms can cause brief local storm surges in bays and harbours.  See Set-up.
food webA model describing the organisms found in a food chain
colA mountain pass.
urban run-offWater from city streets domestic properties that carries pollutants into the sewer systems and receiving waters.
monsoonA wind which blow from opposite directions between winter and summer
textureThe relative quantities of the different types and sizes of mineral particles in a deposit of sediment
mitigationThe act of alleviating or making less severe
undercurrentA current, as of air or water, below another current or beneath the surface.
beaufort wind scaleA system of estimating and reporting wind speeds
red tidea bloom of surface algae, red in colour, found in coastal waters when a heavy nutrient load is washed from the land stimulating the algal growth.
reverse osmosisa water treatment method whereby water is forced through a semipermeable membrane which filters out impurities.
insolation  Incoming solar radiation
altitudeIn meteorology, the measure of a height of an airborne object in respect to a constant pressure surface or above mean sea level.
snoutthe front end of a corrie glacier or valley glacier.
subsidencesinking down of part of the earth's crust due to underground excavation, such as removal groundwater.
particulatesVery small solids suspended in water
pressure gageA device for registering the pressure of solids, liquids, or gases
soluteany substance derived from the atmosphere, vegetation, soil, or rock that is dissolved in water.
safe yieldthe annual amount of water that can be taken from a source of supply over a period of years without depleting that source beyond its ability to be replenished naturally in "wet years."
limestonea sedimentary rock formed from at least 80% calcium carbonate
corrieA steep-walled semicircular basin in a mountain caused by glacial erosion
pressure melting pointunder a glacier, the pressure brought to bear by the mass of ice above can lower the freezing/meting point of water.
nutrient cyclethe cyclic conversions of nutrients from one form to another within biological communities
groundwater dischargethe reemergence of groundwater to the surface at springs or resurgences, or by seepage.
transpiration ratioThe number of pounds of water required for transpiration per pound of dry plant tissue produced.
calibration  The process of using historical data to estimate parameters in a hydrologic forecast technique such as Sacramento Soil Moisture Accounting Model (SACSMA), routings, and unit hydrographs.
artesianthe upward movement of groundwater by hydrostatic pressure.
frost wedgingA process of physical weathering in which water freezes in a crack and exerts force on the rock causing further rupture.
stratified driftA type of glacial drift that has been partially sorted by glaciofluvial meltwater.
gully washerA heavy rain shower that occurs suddenly, possibly creating a flash flood.
button-up fryA salmonid fry that has not completely absorbed its yolk sac and has emerged from its spawning gravel.
closed low  A low pressure area with a distinct center of cyclonic circulation which can be completely encircled by one or more isobars or height contour
threshold velocityVelocity required to cause entrainment in the erosional agents of wind, water or ice
proglacial ground angleIf the proglacial ground angle and the ice are similar, meltwater flows away
invertThe internal elevation at the bottom of the sewer.
convergenceWhere two ice streams or glaciers flow together, convergence occurs.
ocean basinthe area of sea floor that is properly made up of oceanic crust i.e
columbia river compactAn interstate compact between the states of Oregon and Washington by which the states jointly regulate fish in the Columbia River.
wind powerthe generation of electricity by turbines which are turned by wind.
soundA narrow body of water separating an island from the mainland.
ground moraineA thick layer of till deposited by a melting glacier.
field-moisture deficiencyThe quantity of water which would be required to restore the soil moisture to Field-Moisture Capacity.
set-up  The process whereby strong winds blowing down the length of a lake cause water to "pile up" at the downwind end, raising water levels there and lowering them at the upwind end of the lake.
destructive plate marginin plate tectonics, a plate boundary where the relative movement of the crustal plates is towards each other and where one is subducted beneath the other thus being destroyed as it returns to the mantle
gradientthe steepness of a slope.
egg takeThe number of eggs taken at hatcheries when adult salmon and steelhead are spawned.
potentiometric surfaceThe surface to which water in an aquifer can rise by hydrostatic pressure.
comma cloudA feature seen on satellite images with a distinctive comma-shape
water useused for a specific purpose, i.e., domestic, agricultural or industrial.
outfallThe place where a wastewater treatment plant discharges treated water into the environment.
contaminantorganism, group of contaminants or constituent which       signals the presence of something else, coliforms indicate the possible presence of other       pathogenic bacteria, tests for a specific contaminant, or constituent which signals the       possible presence of something else.
bankfull dischargethe maximum discharge that a particular river channel is capable of carrying without flooding.
flood problemsProblems and damages that occur during a flood as a result of human development and actions
water-soluble substancea substance that can readily disperse through the environment.
saline waterwater that contains significant amounts of dissolved solids.
retention basinA permanent lake or pond used to slow stormwater runoff.
bar chartbars of equal width placed within perpendicular axes and used to represent varied amounts or frequencies through variations in length.
attenuationThe process where the flood crest is reduced as it progresses downstream.
halophytea plant that is able to tolerate environments with a high level of salt
natural erosionWearing away of the earth's surface by water, ice, or other natural agents under natural environmental conditions of climates and vegetation.
cartographerA map maker
stream channelA long narrow depression shaped by the concentrated flow of a stream and covered continuously or periodically by water.
water systemA river and all its branches.
ice rafted debrisMaterial carried by floating ice that eventually melts and is deposited on the floor of the sea or a lake.
lotic-adapted speciesspecies for which all or part of their life history is dependent on flowing water.
confined waterWater under artesian pressure
net rainfall  The portion of rainfall which reaches a stream channel or the concentration point as direct surface flow.
disinfectantkilling       most of the harmful and objectionable bacteria in sewage or drinking water usually       accomplished by introduction of chlorine or exposure to ultraviolet radiation which sterilizes       the bacteria.
bergschrundA deep crevasse commonly found at the head of an alpine glacier
lifting condensation levelThe height at which a parcel of moist air becomes saturated when it is lifted dry adiabatically.
rainliquid precipitation from the atmosphere in drops of at least 0.5mm in diameter.
latitudethe angular distance north or south of the equator on any meridian
graupel  A lightly rimed ice aggregate often found in vigorous storms
low water(1) The lowest level of water in a body of water, such as a river, lake, or reservoir
hydrometeorology  The interdisciplinary science involving the study and analysis of the interrelationalships between the atmospheric and land phases of water as it moves through the hydrologic cycle.
diffluencethe breakaway from a large glacier of a smaller, secondary flow of ice which then crosses a drainage divide
observation wellA non-pumping well used for observing the elevation of the water table or piezometric surface.
impactA spatial or temporal change in the environment caused by human activity.
water qualitya term used to describe the chemical, physical, and biological characteristics of water, usually in respect to its suitability for a particular purpose.
topset bedslayers of sediment at the landward side of a delta. 
vapor pressureThe pressure exerted by the molecules of a given vapor
lateralBuilding or house service connection to sewer or sewer-to-sewer connection.
landscape impoundmentbody of reclaimed water which is used for aesthetic enjoyment or which otherwise serves a function not intended to include contact recreation.
laminar flowA flow in which rapid fluctuations are absent.
toe(1) The downstream edge at the base of a dam
dog daysThe name given to the very hot summer weather that may persists for four to six weeks between mid-July through early September in the United States
river reachAny defined length of a river.
laminar flowA flow in which fluid moves smoothly in streamlines in parallel layers or sheets
segmenta water body or portion of a water body that is individually defined and classified
tributaryA stream or river that flows into a larger one.
conveyance loss  The loss of water from a conduit due to leakage, seepage, evaporation, or evapo-transpiration.
degradationThe geologic process by means of which various parts of the surface of the earth are worn down and carried away and their general level lowered, by the action of wind and water.
surface erosionThe detachment and transport of soil particles by wind, water, or gravity
terraceAn elevated surface above the existing level of a floodplain or shore that is created by stream or ocean wave erosion.
ice shove  On-shore ice push caused by wind, and currents, changes in temperature, etcetera.
hanging valleysTributary glaciers are often smaller than the main glacier and do not cut as deeply
rolled filled damAn embankment dam of earth or rock in which the material is placed in layers and compacted by using rollers or rolling equipment
tail cloud  A horizontal, tail-shaped cloud (not a funnel cloud) at low levels extending from the precipitation cascade region of a supercell toward the wall cloud (i.e., it usually is observed extending from the wall cloud toward the north or northeast)
aqueducta pipe, conduit, channel or canal used to transport water, generally by gravity.
convectionMotions in a fluid that transport and mix the properties of the fluid
reachA section of stream between two defined points.
seaocean or lake       by a relatively narrow opening or channel.
lateral sewersPipes that run under city streets and receive the sewage from homes and businesses, as opposed to domestic feeders and main trunk lines.
nitrogenA colorless, tasteless, odorless gas that is the most abundant constituent of dry air
bed material loadThat portion of the total sediment load with sediments of a size found in the streambed.
capillary fringe(1) The zone at the bottom of the Zone of Aeration (Vadose Zone) where ground water is drawn upward by capillary force
equilibrium drawdownThe ultimate, constant drawdown for a steady rate of pumped discharge.
granitic magmaFelsic magma that generates mainly granitic rocks.
attritionThe action of one particle rubbing against the other in a filter media or ion exchange bed that can in time cause breakdown of the particles.
metamorphic rockA rock that forms from the recrystallization of igneous, sedimentary or other metamorphic rocks through pressure increase, temperature rise, or chemical alteration.
agglomerate  An ice cover of floe formed by the freezing together of various forms of ice.
pressure jump  A sudden, sharp increase in atmospheric pressure, typically occurring along an active front and preceding a storm.
sleetSee ice pellets.
thermal metamorphismIs the metamorphic alteration of rock because of intense heat released from processes related to plate tectonics.
limnology  The branch of hydrology that pertains to the study of lakes.
aquatic habitatHabitat that occurs in free water.
rhi  An acronym for Range-Height Indicator
snow garlandSnow appearing as a beautiful long thick rope draped on trees, fences and other objects
tillMany writers use till for any glacial deposit
open systemsystem in which energy and matter are exchanged between the system and its environment, for example, a living organism.
sediment trapping efficiencythe ratio of sediment retained within the reservoir to the sediment inflow to the reservoir.
northwest power actThe Pacific Northwest Electric Power Planning and Conservation Act of 1980 (16 U.S.C
outfall sewerA sewer that receives wastewater from a collection system or from a treatment plant and conveys it to the point of final discharge.
jökulhlaupDestructive flood that occurs as the result of the rapid ablation of ice by volcanic activity beneath the ice of a large glacier.
pre-spawning mortalityGenerally refers to non-fishery mortality of adult salmon and steelhead between the time the fish enter the Columbia River and the completion of spawning.
antarctic oceanAlthough not officially recognized as a separate ocean body, it is commonly applied to those portions of the Atlantic, Pacific, and Indian Oceans that reach the Antarctic continent on their southern extremes.
snow lineThe lower limit of permanent snow cover, below which snow doesn't accumulate.
detention timethe time required for a volume of water to pass through a tank at a given rate of flow; in storage reservoirs, the length of time water will be held before being used.
pressure gradient  The amount of pressure change occurring over a given distance.
windthrowA tree or trees uprooted or felled by the wind.
radial flowThe flow of water in an aquifer toward a vertically oriented well.
light airDirection of wind shown by smoke drift not by wind vanes
incubation channelA man-made channel in the streambed used for hatching fish eggs.
puget sound convergence zoneA situation where wind forced around the Olympic Mountains converges over the Puget Sound
corridorA defined tract of land, usually linear, through which a species must travel to reach habitat suitable for reproduction and other life-sustaining needs.
daylight savings timeThe setting of time so it is one hour ahead starting in the spring and one hour back beginning in the fall in the Northern Hemisphere
glacial upliftthe isostatic recovery of land after ice has been removed.
interceptor sewervery large sewer lines that collect the flow from main and trunk lines and carry them to treatment plants.
fast iceSea ice permanently attached to its coastal glacier.
aqueousSomething made up of water.
bottom(1) The deepest or lowest part, as the bottom of a well
nebraskanNorth American glaciation related to European Gunz glaciation.
algicidesubstance or chemical used specifically to kill or control algae.
scourthe erosive action of running water in streams, which excavates and carries away material from the bed and banks
katabatic windA wind that is created by air flowing downhill
evaporationthe change by which any substance is converted from a liquid state and carried of in vapor
breakup jam  Ice jam that occurs as a result of the accumulation of broken ice pieces.
thermoclineA vertical negative temperature gradient in some layer of a body of water which is appreciably greater than the gradients above and below it
fish passage efficiencyThe proportion of juvenile fish passing a project through the spillway, sluiceway, or juvenile bypass system, as opposed to passing through the turbines.
peatPartially decomposed remains of plants that once flourished in a waterlogged environment.
settling basinAn enlargement in the channel of a stream to permit the settling of materials carried in suspension.
cold advectionThe horizontal movement of colder air into a location
seepage lakeA lake that gets its water primarily from the seepage of groundwater.
glacierA huge mass of ice, formed on land by the compaction and re-crystallization of snow, that moves very slowly downslope or outward due to its own weight.
water tableSee groundwater table.
shore ice  An ice sheet in the form of a long border attached to the bank or shore.  See border ice.
cloudsvisible masses of water droplets and/or ice crystals formed by condensation in the atmosphere.
percolating waterWater that passes through rocks or soil under the force of gravity.
purgeable organicsvolatile organic chemicals which can be forced out of the water sample with relative ease through purging.
freezingThe change of a liquid into a solid as temperature decreases
concrete spaceActual geographic space in the real world
inland freshwater wetlandsswamps, marshes, and bogs found inland beyond the coastal saltwater wetlands.
ice run  Flow of ice in a river
snow meltthe spring and summer mass thawing of snow and ice which provides a sudden and massive increase in discharge to downslope rivers.
capillary waterWater that moves horizontally and vertically in soils by the process of capillary action
lentic systema nonflowing or standing body of fresh water, such as a lake or pond
probability of exceedenceThe probability that a random flood will exceed a specified magnitude in a given period of time.
crude densityThe number of individuals in an area.
calcium carbonateCompound consisting of calcium and carbonate
habitat indicatora physical attribute of the environment measured to characterize conditions necessary to support an organism, population, or community in the absence of pollutants
sleetDescribes solid grains of ice formed by the freezing of raindrops or the refreezing of largely melted snowflakes
portal **Cavernous openings in subglacial ice and debris above meltwater streams.
catadromousRefers to fishes that migrate from fresh water to salt water to spawn or reproduce such as the American eel.
perennial streamone that flows all year round
evapotranspirationThe total amount of water that is transferred from the earth's surface to the atmosphere
whole-effluent toxicitythe aggregate toxic effect of an effluent measured directly by a toxicity test.
wilting pointthe point at which water losses due to transpiration are greater than gains through the roots
interstate wateraccording to law, interstate waters are defined as (1) rivers, lakes and other waters that flow across or form a part of state or international boundaries; (2) waters of the Great Lakes; (3) coastal waters whose scope has been defined to include ocean waters seaward to the territorial limits and waters along the coastline (including inland streams) influenced by the tide.
mesoscale convective complexA cluster of thunderstorms covering an area of 100,000 kilometers or more
tankAn artificial pool, pond, reservoir, cistern, or large container for holding and storing water for drinking or irrigation.
driftEarly writers assumed that glacial deposits had drifted in with the Great Flood.
frontal inversionA transition zone between 2 different air masses
cumulus cloudPuffy clouds with relatively flat bases
hydrologic balancean accounting of all water inflow to, water outflow from, and changes in water storage within a hydrologic unit over a specified period of time.
windwardUpwind side or side directly influenced to the direction that the wind blows from
frost pointIs the temperature at which water vapor saturates from an air mass into solid usually forming snow or frost
hrlThe Hydrological Research Laboratory at the Office of Hydrology (OH).
cone of influenceThe depression, roughly conical in shape, produced in a water table, or other piezometric surface, by the extraction of water from a well at a given rate
cctvSewer inspection method that uses a remote controlled color television camera to capture and transmit images from the inside of a sewer.
vested water rightthe right granted by a state water agency to use either surface or ground water.
sewageWaste fluid in a sewer system.
energy dissipater  A structure which slows fast-moving spillway flows in order to prevent erosion of the stream channel.
observation wellA well used to monitor changes in water levels of an aquifer and to obtain samples for water quality analyses.
effective porositythe portion of pore space in saturated permeable material where the movement of water takes place.
cokriging  A technique for estimating values of a spatial process (e.g., a precipitation field) given point observations of the process (e.g., rain gage observations) and possibly auxiliary observations (e.g., radar and satellite observations).
flash floodA rapid and short-lived increase in the amount of runoff water entering a stream resulting in a flood.
channel routingThe process of determining progressively timing and shape of the flood wave at successive points along a river.
nonpoint sourcesource of pollution in which wastes are not released at one specific, identifiable point but from a number of points that are spread out and difficult to identify and control
flurries  Light snowfall that generally does not produce a measurable accumulation.
desertificationConversion of marginal rangeland or cropland to a more desert like land type
temperatureThe degree of hotness or coldness.
french drain  An underground passageway for water through the interstices among stones placed loosely in a trench.
snowFrozen precipitation in the form of white or translucent ice crystals in complex branched hexagonal form
barAn obstacle formed at the shallow entrance to the mouth of a river or bay which empties into the ocean.
intermittent streamA stream which flows for only a part of the time
sea iceIce that is formed by the freezing of sea water
el niño currentAn intermittent warm water current that originates from the tropics and overrides the normal cold water currents that persist along the Pacific coast, resulting in warmer than normal ocean conditions.
inchoate water rightAn unperfected water right.
bayA bay is a body of water that is partly enclosed by land (and is usually smaller than a gulf).
showalter stability indexA measure of the local static stability of the atmosphere
diffuse ice  Poorly defined ice edge limiting an area of dispersed ice; usually on the leeward side of an area of floating ice.
sediment storage capacityThe volume of a reservoir planned for the deposition of sediment.
flood forecastingPrediction of stage, discharge, time of occurrence, and duration of a flood, especially of peak discharge at a specified point on a stream, resulting from precipitation and/or snowmelt.
quarry waterthe moisture content of freshly quarried stone, esp
sanitary sewerA pipe or network of pipes which transport only municipal, commercial, or industrial wastewater (sewage) and not rain or storm waters from streets.
perched streamsPerched streams are either Losing Streams or Insulated Streams that are separated from the underlying ground water by a zone of aeration.
firnOld snow on top of glaciers, granular and compact and not yet converted into ice
lacustrinePertaining to, produced by, or inhabiting a lake.
food webThe complex intermeshing of individual food chains in an ecosystem.
vadose waterWater occurring in the Unsaturated Zone (Vadose Zone) between the land surface and the water table.
terminusThe end of the glacier
ice shelfA large flat-topped sheet of ice that is attached to land along one side and floats in an ocean or lake
habitatLocation where a plant or animal lives.
central pressureThe atmospheric pressure at the center of a high or low
bernoulli effectThe phenomenon of internal pressure reduction with increased stream velocity in a fluid
dykeThin vertical veins of igneous rock that form when magma enters and cools in fractures found within the crust
precipitateA solid which forms from a liquid suspension as a result of a chemical reaction
phytoplanktonMicroscopic floating plants, mainly algae, that live suspended in bodies of water and that drift about because they cannot move by themselves or because they are too small or too weak to swim effectively against a current.
injection zoneA geological formation receiving fluids trough a well.
contaminantAny physical, chemical, biological, or radiological substance or matter that has an adverse affect on air, water, or soil.
plastic solidA perfectly plastic solid yields after a critical threshold of stress has been exceeded
transpirationthe cyclic transfer of water from       the Earth's surface via evapotranspiration into the atmosphere, from the atmosphere via       precipitation back to earth, and through runoff into streams, rivers, and lakes and ultimately       into the oceans, (see water cycle).
ground water divide  A line on a water table where on either side of which the water table slopes downward
river statement  A NWS product issued to communicate notable hydrologic conditions which do not involve flooding, i.e., within river bank rises, minor ice jams, etc.
atmospheric pressureThe pressure exerted by the atmosphere at a given point.
medial moraineDeposit of material found down the center of a glacier
risk assessmentA methodology used to examine all possible risks involved with a particular product or organism
freezup jam  Ice jam formed as frazil ice accumulates and thickens.
salt-water intrusionThe invasion of a body of fresh water by a body of salt water, due to its greater density
hydrologic conditionThe runoff potential of a particular cropping practice
calmAtmospheric conditions devoid of wind or any other air motion
hillA hill is a raised area or mound of land.
groundwater flowUnderground topographic flow of groundwater because of gravity.
aquatic life usea beneficial use designation in which the water body provides suitable habitat for survival and reproduction of desirable fish, shellfish, and other aquatic organisms.
acrotelmthe upper layer of peat deposits
humiditythe amount of moisture in the air as measured by a percentage.
density altitudeThe altitude at which a given density is found in the standard atmosphere
bottom bergsIcebergs which originate from near the base of a glacier
total gross reservoir capacityThe total amount of storage capacity available in a reservoir for all purposes from the streambed to the normal water or normal water or normal pool surface level
dischargeIn the simplest form, discharge means outflow of water
hydrologic balanceAn accounting of all water inflows to, water outflows from, and changes in water storage within a hydrologic unit over a specified period of time.
stabilitywhen the DALR and SALR are both higher than the ELR then an air mass will be cooler than its surroundings and will sink back to its original position once the upward forces on it have ceased e.g
glacial retreatwhen ablation exceeds accumulation causing a net loss of ice from the glacier
dischargeFlow of surface water in a stream or canal.
snow grainsPrecipitation of very small, white, and opaque grains of ice
breakup period  The period of disintegration of an ice cover.
coalescenceThe process by which water droplets in a cloud collide and come together to form raindrops.
fathomThe common unit of depth in the ocean for countries using the English system of measurement
national meteorological centerNow incorporated into the National Centers for Environmental Prediction, it was the division of the National Weather Service that produced, processed, handled, and distributed meteorological and oceanographic information to users throughout the Northern Hemisphere, specifically U.S
poolA deep reach of a stream
high cloudsA term used to signify cirriform clouds that are composed of ice crystals and generally have bases above 20,000 feet
bed loadSediment that moves near the streambed.
moisture(1) Diffuse wetness that can be felt as vapor in the atmosphere or condensed liquid on the surface of objects; dampness
well monitoringmeasurement by on-site instruments or laboratory methods of well water quality.
thermal gradienttemperature difference between two areas.
salt waterThe water of the ocean, distinguished from fresh water by its appreciable salinity.
generationAct or process of producing electric energy from other forms of energy
ice blocksChunks of the glacier remain as ice blocks after glacial outburst floods which may remain as kettle lakes.
bow echoA radar echo signature often associated with severe thunderstorms, especially those that produce wind damage
competencein rivers, the maximum particle diameter that can be carried at a given velocity.
hsbThe Hydrologic Systems Branch in the Office of Hydrology (OH).
pitchIn climbing, a unit of measure approximately equal to the length of your rope, or the distance between fixed anchor positions
systemany set of components which are gathered into a working whole.
aquicludea formation which, although porous and capable of absorbing water slowly, will not transmit water fast enough to furnish an appreciable supply for a well or a spring.
helicityA property of a moving fluid, such as air, representing the potential for helical flow (flow that follows a corkscrew pattern)
snow pelletsFrozen precipitation in the form of white, round or conical opaque grains of ice
meteorA body of matter that enters the Earth's atmosphere from space
fenA habitat composed of woodland and swamp.
rampingControlling streamflow so that flow changes are gradual and do not adversely impact safety and property downstream.
length  The distance in the direction of flow between two specific points along a river, stream, or channel.
floodan overflow or inundation that comes from a river or other body of water and causes or threatens damage
water column(see hydrophobic).
current meterDevice used to measure the water velocity or current in a river.
megawattA unit of electricity equivalent to 1000 kilowatts.
snow creepA continuous, extremely slow, downhill movement of a layer of snow.
aboveground sewerAn unburied sewer (generally a sanitary sewer), supported on piers, pedestals or bents to provide a suitable grade line.
biospherethe earth and all its ecosystems.
indicator parametersmeasurable physical or chemical characteristics or attributes of water or soil-pore moisture used to indicate the possible presence of waste constituents, or the effects of waste constituents on waters.
vicinityA proximity qualifier used to indicate weather phenomena observed between 5 and 10 statue miles of the usual point of observation, but not at the station.
geographic information systemA computer system capable of storing and manipulating spatial data.
federal snow samplerA snow sampler consisting of five or more sections of sampling tubes, one which has a steel cutter on the end
coastal convergence  The convergence or running together of land and se winds, creating a stronger band of windnear the shore.  Factors such as the shape of the shoreline and the angle between the wind and the shore determine the severity of this effect.
coliform bacteriaA group of bacteria used as an indicator of sanitary quality in water
anaerobicalso refers to metabolic activities, glycolysis, in the       absence of oxygen which occurs in some microorganisms.
gustA sudden significant increase in or rapid fluctuations of wind speed
rain gaugeAn instrument used to measure the amount of rain that has fallen
capillary attractionThe force that results from greater adhesion of a liquid to a solid surface than internal cohesion of the liquid itself and that causes the liquid to be raised against a vertical surface, as water is in a clean glass tube
diffuse icePoorly defined ice edge limiting an area of dispersed ice; usually on the leeward side of an area of floating ice.
temperate glaciera glacier in which the ice reaches the pressure melting point.
tarna lake in a corrie.
lacustrinePertaining to lakes
equatorThe line at 0 degrees latitude
inflowentry of rainwater into a sewer system from sources other than infiltration, such as basement drains, manholes, storm drains, and street washing.
whirlwindA small-scale, rapidly rotating column of wind, formed thermally and most likely to develop on clear, dry, hot afternoons
fractureWall of sewer visibly separated along the length and/or circumference of the sewer with the pieces of the sewer wall in place
ground water basinA ground-water reservoir together with all the overlying land surface and the underlying aquifers that contribute water to the reservoir
gaining streamA stream or reach of a stream, the flow of which is being increased by the inflow of ground water seepage or from springs in, or alongside, the channel.
nonpotablenot suitable for drinking
oceanThe intercommunicating body of salt water occupying the depressions of the earth's surface, or one of its major primary subdivisions, bounded by the continents, or the equator, and other imaginary lines
injection wellRefers to a well constructed for the purpose of injection treated wastewater directly into the ground
hsb  The Hydrologic Systems Branch in the Office of Hydrology (OH).
hazeA suspension of fine dust and/or smoke particles in the air
bankthe sloping land bordering a stream channel that forms the usual boundaries of a channel
conductivityThe amount of electricity the water can conduct
erraticA large rock boulder that has been transported by glaciers away from its origin and deposited in a region of dissimilar rock.
crystallizationThe process of a substance going directly from a vapor form (water vapor) to a solid (ice) at the same temperature, without going through the liquid phase (water)
infiltrationThe movement of water into soil or porous rock
foliar leachingProcess in which water from precipitation removes plant nutrients from the surface of leaves.
sandstormParticles of sand carried aloft by strong wind
erosionthe degradation and removal of rock material by an agent (water, wind or ice)
nonuniform flow(Hydraulics) Flow in which the mean velocity or cross-sectional area vary at successive channel cross-sections
oceanographyThe study of the ocean, embracing and integrating all knowledge pertaining to the ocean's physical boundaries, the chemistry and physics of sea water, and marine biology.
edwards outcropwhere the Edwards and associated limestone formations are found at the surface
tropical disturbanceAn organized group of thunderstorms often found over a tropical ocean that generates a slight cyclonic flow of less than 37 kilometers per hour
coastlineThe line that separates a land surface from an ocean or sea.
hummockA hillock of broken ice which has been forced upward by pressure.
saltsnutrients, pesticide chemicals or contaminants, are       washed into a lower layer of soil or are dissolved and carried away by water.
minimum flow appropriationAn appropriation designed to preserve a specified minimum flow in a stream
d-valueThe deviation of actual altitude along a constant pressure surface from the standard atmosphere altitude of that surface.
cut bankThe outside bank of a bend, often eroding opposite a point bar.
intersticesthe void or empty portion of rock or soil occupied by air or water.
cloud-ground lightningLightning occurring between cloud and ground.
solutionthe taking of minerals into water and removing them through flow.
brash ice  Accumulation of floating ice made up of fragments not more than 2 meters across; the wreckage of other forms of
river cliffsteep slope on the outer bend of a river where erosion allows for undercutting.
urban runoffstorm water from city streets and adjacent domestic or commercial properties that carries pollutants of various kinds into the sewer systems and receiving waters.
baya curved indent to the coastline, usually created by greater erosion rates than neighbouring parts of the coast
satisficingaccepting what is satisfactory rather than chasing the maximum possible outcome.
consumptive wasteWater that returns to the atmosphere without providing benefit to humans.
10-year 1-hour designThis design criteria is used for determining storm sewer size, and assumes 1.25" falling in 1 hour in a SCS Type II storm event.
receiving watersa river, ocean, stream, or other watercourse into which wastewater or treated effluent is discharged.
top of bankThe break in slope between the bank and the surrounding terrain.
valley winds  Valley winds encompass several effects, the first of which is the tendency of wind wind to funnel down a pronounced valley.  The term also refers to the movement of airdown the slopes of a valley at night (katabatic winds) or up the slopes of valley during the day (anabatic winds).
control structurea structure on a stream or canal that is used to regulate the flow or stage of the stream or to prevent the intrusion of salt water.
low tidethe lowest point to which the sea falls against the land in its daily vertical movement.
combined sewer system A one-pipe sewer system in which a single pipe collects both sewage and stormwater
low pressureAn area of atmospheric pressure within the Earth's atmosphere that is below average
sedimentary rockrock formed of sediment, and specifically: (1) sandstone and shale, formed of fragments of other rock transported from their sources and deposited in water; and (2) rocks formed by or from secretions of organisms, such as most limestone
headwatersUpper portion of stream's drainage system.
demographic transition modela theory of population change over time
moraineA hill of glacial till deposited directly by a glacier.
wet floodproofingAn approach to floodproofing which usually is a last resort
in-situ flushingintroduction of large volumes of water, at times supplemented with cleaning compounds, into soil, waste, or groundwater to flush hazardous contaminants from a site.
medial moraineA moraine—situated well away from a glacier's edges—formed by the intersection of two lateral moraines when a substantial tributary glacier meets and joins a tributary glacier.
evaporitesSediments deposited from an aqueous (water) solution as a result of extensive or local evaporation of a solvent, such as salts in the Great Salt Lake in the western United States.
glacial outburst floodA sudden release of melt water from a glacier or glacier-dammed lake sometimes resulting in a catastrophic flood, formed by melting of a channel or by subglacial volcanic activity.
rotenoneA substance derived from the Derris root that is commonly used to kill fish during lake rehabilitation programs.
backwashingReversing the flow of water back through the filter media to remove entrapped solids.
zonalMovement of wind or ocean waters in a direction that is roughly parallel to the lines of latitude.
recirculationWater reused within a plant unit
aquaculturefarming of plants and animals that live in water.
total dissolved solidsA quantitative measure of the residual minerals dissolved in water that remain after evaporation of a solution
seismologyA branch of science focused on the study of earthquakes and seismic activity.
stabilityThe capability of a system to tolerate or recover from disturbance or an environmental stress.
channelAn area that contains continuously or periodically flowing water that is confined by banks and a stream bed.
recessional moraineMoraine that is created during a pause in the retreat of a glacier
brash iceAccumulation of floating ice made up of fragments not more than 2 meters across; the wreckage of other forms of ice.
conservation easementEasement restricting a landowner to land uses that that are compatible with long-term conservation and environmental values.
stratocumulusA low cloud composed of layers or patches of cloud elements
intermittentin rivers, flowing most of the time but seasonally or occasionally ceasing to flow in response to decreased water availability e.g
sillHorizontal planes of igneous rock that run parallel to the grain of the original rock deposits.They form when magma enters and cools in bedding planes found within the crust
horizonOne of several lines or planes used as reference for observation and measurement relative to a given location on the surface of the earth
well pluga seal installed in a borehole or well preventing movement of fluids.
pagophobia  The fear of ice or frost.
polygenetic landformLandform that shows the influence of two or more major geomorphic processes
equatorial climatewithin 5-to 10-of the equator at elevations up to 1000m
sanitary landfilllandfill that is lined with plastic or concrete or located in clay-rich soils to prevent hazardous substances from leaking into the environment.
outplantingHatchery reared fish released into streams for rearing and maturing away from the hatchery sites.
stratiformDescriptive of clouds of extensive horizontal development, as contrasted to the more narrow and vertically developed cumuliform type.
greenfield siteone on which no building has taken place.
flowmeterA gauge indicating the velocity of wastewater moving through a treatment plant or of any liquid moving through various industrial processes.
carbamatesa class of new-age pesticides that attack the nervous system of organisms.
bow echoA rapidly moving crescent shaped echo on a radar which is convex in the direction of motion
water quality criteriascientifically derived ambient limits developed and updated by EPA, under section 304(a)(1) of the Clean Water Act, for specific pollutants of concern
black iceTransparent ice formed in rivers and lakes, or on roads and bridges.
polynyaThe open seawater between pack-ice and the land or the edge of a glacier.
storm beachthe highest part of a beach, created by a strong storm, which rests above the usual high water mark.
tropospherethe layer of atmosphere closest to the Earth, extending seven to ten miles above the surface, containing most of the clouds and moisture.
snowpack  The total snow and ice on the ground, including both the new snow and the previous snow and ice which has not
light breezeWind felt on face; leaves rustle; wind vanes moved by wind; small wavelets form on water, still short, but more pronounced; crests have glassy appearance.
cwmsee corrie
reservationA withdrawal usually of a more or less permanent nature; also, any federal lands of the U.S
solifluctionForm of mass movement in environments that experience freeze-thaw action
temperatemoderate or mild conditions as found between 23.5˚ and 66.5˚ of latitude.
pulseA short burst of electromagnetic energy that a radar sends out in a straight line to detect a precipitation target
hydraulic earthfill damAn embankment built up from waterborne clay, sand, and gravel carried through a pipe or flume.
trophic structurethe feeding relationships among species within a food web.
dendrogramA branching diagram, sometimes resembling a tree, that provides one way of visualizing similarities between different groups or samples.
fitnessA measure of the health of a species in terms of physiology and future reproductive success.
water withdrawalThe removal of water from some type of source, like groundwater, for some use by humans
mesophytePlants that have moderate water requirements.
snow linetwo types:
salt lakeinland body of water with a high salinity
frazil iceDisorganized, slushy ice crystals in the water column, usually near the water surface
median particle sizevalue for which half the particles in a sample have a greater diameter and half a lesser diameter.
fjordA fjord is a long, narrow sea inlet that is bordered by steep cliffs.
graupelVariations in temperature, migration of liquid and vapor water, and pressure of snow cover may result in rounded snow pellets from 2 to 5 mm diameter
gray waterwastewater from household tubs, showers, sinks and washing machines, but not from kitchen sinks and dishwashers can be reused.
stationary frontA transition zone in the atmosphere where there is little movement of opposing air masses and winds blow towards the front from opposite directions.
desalinationthe process of salt removal from sea or brackish water.
fjordA narrow, steep-sided, elongated estuary formed from a glacial trough inundated by seawater.
wall cloudIt is formed in a supercell thunderstorm.  A localized, persistent, often abrupt lowering from a rain-free base
neap tideA minimum tide occurring at the first and third quarters of the moon.
black iceThin, new ice on fresh or salt water that appears dark in color because of its transparency
forest canopyThe cover of branches and foliage formed collectively by the crowns of adjacent trees and other woody growth.
pool height  The height of the water behind a dam
bermLow hill of sand that forms along coastal beaches.
foredeepening topographyThe ground below an ice sheet may be bowl-shaped with the inner part being deeper than the ground around the edges because glaciers erode preglacial material and subsidence due to the weight of the ice.
glazeCoating of ice that forms when rain falls on a surface with a temperature below freezing.
stair steppingThe process of continually updating river forecasts for the purpose of incorporating the effects rain that has fallen since the previous forecast was prepared
comma cloud  A synoptic scale cloud pattern with a characteristic comma-like shape, often seen on satellite photographs associated with large and intense
pressure characteristicThe pattern of the pressure change during the specified period of time, usually the three hour period preceding an observation
equatorThe geographic circle at 0 degrees latitude on the earth's surface
tail water(1) In Hydraulics, water, in a river or channel, immediately downstream from a structure
colloidsfinely divided solids which will not settle but which may be removed by coagulation or biochemical action.
troposphereThe lowest layer of the atmosphere located between the earth's surface to approximately 11 miles (17 kilometers) into the atmosphere
river reachAny defined length of river.
bank  The margins of a channel
total sediment loadThe sum of the bedload and the suspended sediment load.
seepage  The interstitial movement of water that may take place through a dam, its foundation, or abutments.
hanging damA mass of ice composed mainly of frazil or broken ice deposited underneath an ice cover in a region of low flow velocity.
mean annual floodThe average of all the annual flood stages or discharges of record
firn limitThe dividing line between old ice and new snow at the end of the melting season.
braided streamShallow stream channel that is subdivided into a number of continually shifting smaller channels that are separated by bar deposits.
erosion controlThe application of necessary measures including artificial structures, vegetative manipulation, water control, or physical soil changes to minimize soil erosion.
      organellesthese species manufacture photosynthetic pigments but lack chloroplasts, the       specialized photosynthetic organelles in higher plants, in some situations an increase in       blue-green algae can indicate an environmental stress such as pollution.
symbolSomething on a map that stands for something else.
sediment yieldtotal amount of sediment moved by a river over time, usually in m3/km2/yr.
regelationThe process of localized melting and refreezing of ice, involving no overall change in glacier mass.
accessory cloud  A cloud which is dependent on a larger cloud system for development and continuance
insulated streamsStreams or a reach of a stream that neither contribute water to the zone of saturation nor receive water from it
névéPartially melted and compacted snow that has a density of at least 500 kilograms per cubic meter.
keetch-byram drought index  A soil/duff drought index that ranges from 0 (no drought) to 800 (extreme drought) and is based on a soil capacity of 8 inches of water
forebaythe water behind a dam.
withdrawalwater removed from a ground water or surface water source for use.
low cloudsA term used to signify clouds with bases below 6,000 feet and are of a stratiform or a cumuliform variety
improved irrigated acreageRefers to farm acreage which has been leveled, planed and serviced by improved conveyance and control structures.
z-listOSHA's Toxic and Hazardous Substances Tables (Z-1, Z-2, and Z-3) of air contaminants; any material found on these tables is considered hazardous.
dalton's lawStates that the total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of the gases
overflow rateone of the guidelines for design of the settling tanks and clarifiers in a treatment plant.
hardpanImpervious layer found within the soil
puddlea small pool of water, usually a few inches in depth and from several inches to several feet in its greatest dimension.
nephelometricmethod of measuring turbidity in a water sample by passing light through the sample and measuring the amount of light deflected.
subsidenceA sinking or downward motion of air, often seen in anticyclones
smoga mixture of smoke and fog produced by factory and domestic emissions which provide hygroscopic nuclei for condensation to occur onto.
thermal lowArea of low pressure in the atmosphere caused by the area having cooler temperatures relative to the air around it.
faceThe external surface of a structure, such as the surface of a dam.
inline reservoirA reservoir constructed in line with the canal used to regulate flow for a balanced operation.
upwellingThe movement of nutrient rich waters from the bottom of the ocean to the surface.
lateral moraineA moraine deposited along the side of a valley glacier.
kettle holeDepression found in glacial deposits
state water management agenciesState government agencies that regulate water resources
grounded iceIce that has run aground or is contact with the ground underneath it.
lagoon(1) A shallow lake or pond, especially one connected with a larger body of water
snow telemetryAn automated network of snowpack data collection sites
hydraulic radiusstream efficiency measured by dividing cross-sectional area of a stream by the wetted perimeter
smogOriginally smog meant a mixture of smoke and fog
tributaryA tributary is a stream or river that flows into a larger river.
microscaleThe smallest scale of meteorological phenomena that range in size from a few centimeters to a few kilometers
fish flows"Artificially increased flows in the river system called for in the fish and wildlife program to quickly move the young fish down the river during their spring migration period
bed stabilityoccurs when the average elevation of the streambed does not change significantly over time
plugcement, grout, or other material used to fill and seal a hole drilled for a water well.
calcium carbonateCACO3 - a white precipitate that forms in water lines, water heaters and boilers in hard water areas; also known as scale.
groundwater flowthe flow of water through the groundwater store.
groundwater runoffthe portion of runoff which has passed into the ground, has become ground water, and has been discharged into a stream channel as spring or seepage water.
pressure relief pipesPipes used to relieve uplift or Pore Pressure in a dam foundation or in the dam structure.
brineSeawater with a salinity greater than 35 parts per thousand
cleavagethe line of weakness in a rock along which it will break when put under stress.
snow meltConversion of snow into runoff and groundwater flow with the onset of warmer temperatures.
separate sewera sewer system that carries only sanitary sewage, not stormwater runoff
mud slideFast moving soil, rocks and water that flow down mountain slopes and canyons during a heavy a downpour of rain.
heat capacityIs the ratio of the amount of heat energy absorbed by a substance compared to its corresponding temperature rise.
vapor flowThe gaseous flow of water vapor in soils from a moist or warm zone of higher potential to a drier or colder zone of lower potential.
water purveyora public utility, mutual water company, county water district, or municipality that delivers drinking water to customers.
artesian wella water well drilled into a confined aquifer where enough hydraulic pressure exists for water rise in the well to a height above the top of the aquifer in the subsurface
floeAn accumulation of frazil flocs (also known as a "pan") or a single piece of broken ice.
thermokarstin periglacial areas, the melting of ground ice causes subsidence and creates a very uneven surface.
fluoridated      chlorinated or brominated, (see adsorption, halides).
barrageAny artificial obstruction placed in water to increase water level or divert it
ice lenseHorizontal accumulation of permanently frozen ground ice.
prevailing windthe direction from which wind most frequently blows in a particular place.
convective temperatureIt is the surface temperature that must be reached to start the formation of convective clouds by solar heating of surface-air layer.
glacier tableA rock sitting on top of a pillar of ice shielded from insolation by the rock's mass.
fringe waterWater occurring in the Capillary Fringe.
regolithrock material that has been weathered from the original bedrock
radarsonde observationAn upper air observation used to determine winds and other meteorological data, by tracking the range, elevation, and azimuth of a radar target carried aloft
valleyA valley is a low place between mountains.
mean sea-levelThe average height of the ocean surface as determined from the mean of all tidal levels recorded at hourly intervals.
sea stackA steep pillar of rock located in the ocean a short distance from the coastline
stream-maturingSteelhead that enter fresh water in a sexually immature condition and require several months in fresh water to mature and spawn, commonly referred to as summer steelhead.
streamalso a relatively high flow as measured by either gauge height or discharge       quantity.
projectRun-of-river or storage dam and related facilities; also a diversion facility.
pacific rimthe countries at the margins of the Pacific ocean.
ground water prime supplyThe long-term average annual percolation to the major ground water basins from precipitation falling on the land and from flows in rivers and streams
continental air massAn air mass with continental characteristics
green movementnon-governmental organizations, political parties and, increasingly, public opinion which propose that care for the environment should inform and mould our behaviour much more than it has historically.
stratosphereAtmospheric layer found at an average altitude of 11 to 50 kilometers above the Earth's surface
capillary fringe  The soil area just above the water table where water can rise up slightly through the cohesive force of capillary action
combined sewera sewer system that carries both sanitary sewage and stormwater runoff
operational lossesLosses of water resulting from evaporation and seepage.
snow showerFrozen precipitation in the form of snow, characterized by its sudden beginning and ending
drawdownthe local lowering of the water table around a pumping well.
freezing point/freezeThe process of changing a liquid to a solid
diversion  The taking of water from a stream or other body of water into a canal, pipe, or other conduit.
warm frontA transition zone in the atmosphere where an advancing warm air mass displaces a cold air mass.
raob  An acronym for Radiosonde Observation.  See Radiosonde.
toe drain and outfallA drainage conduit from a dam's structure used to carry seepage water away from the dam and can allow seepage quantities to be measured.
pathogenic bacteriacysts or viruses, potable       water, fit to drink, potable water that has or is to be treated additionally, to enhance aesthetic       quality and/or reduce mineral content plus other known or unknown, undesirable substances: by       one or more point-of-use water processing devices or systems or purified bottled water.
hydrologic regionA study area, consisting of one or more planning subareas, that has a common hydrologic character.
deglaciationthe removal of glacier cover (glacial retreat) when ablation outstrips accumulation.
yellow snow  Snow given a golden or yellow appearance by the presence in it of pine, cypress pollen, or anthropogenic material or animal-produced material.  Compare with Brown Snow.
directional shearThe shear created by a rapid change in wind direction with height.
flowing artesian wella special case of an artesian well where a water well drilled into a confined aquifer has enough hydraulic pressure for the water to rise to a height above ground surface and to flow at the surface without pumping.
hanging valleya small glacial valley entering a larger one someway up the side of the latter
bioassaya test to determine the relative strength of a substance by comparing its effect on a test organism with that of a standard preparation.
lenticCharacterizing aquatic communities found in standing water.
sand dunea mound of sand deposited by wind in desert areas and along shore lines.
system lossAn amount of water, expressed as a percentage, lost to leaks, seepage and unauthorized use.
bioaccumulantionThe increase in concentration of a substance in living organisms, as they take in contaminated air, water, or food, due to slow metabolization and excretion.
dissolved loadthose minerals that have been taken into solution and are carried along by a river.
pump stationmechanical device installed in sewer or water system or other liquidcarrying pipelines to move the liquids to a higher level.
edgeWhere plant communities meet or where successional stages or vegetative conditions with plant communities come together.
macrophytemacroscopic plants in the aquatic environment
distilled waterwater that has been treated by boiling and condensation to remove solids, inorganics, and some organic chemicals.
standard atmosphereA standard atmosphere has been defined by the International Civil Aeronautical Organization (ICAO)
environmenttwo meanings:
littoral zoneThe zone along a coastline that is between the high and low-water spring tide marks.
undertowthe current beneath the surface that sets seaward or along the beach when waves are breaking on the shore.
oceanlake, or other body of water into which light can penetrate, also       known as the zone of photosynthesis.
oceanAn ocean is a large body of salt water that surrounds a continent
intermittent streamA stream that flows only for short periods over a year
hard waterWater that contains a great number of positive ions
storm scale  Referring to weather systems with sizes on the order of individual thunderstorms
rock stepThe step-like mountainside profile (in the postglacial landscape) often created as an eroding alpine glacier moved downslope.
proglacialThe area in front of, or just at the outer edge of a glacier.
watershed approacha coordinated framework for environmental management that focuses public and private efforts on the highest priority problems within hydrologically defined geographic areas.
frostThe covering of ice crystals that forms by direct sublimation on exposed surfaces whose temperature is below freezing.
drains  A vertical well or borehole, usually downstream of impervious cores, grout curtains or cutoffs, designed to collect and direct seepage through or under a dam to reduce uplift pressure under or within a dam
ice agesee glacial.
percolationthe movement of water through the subsurface soil layers, usually continuing downward to the groundwater or water table reservoirs.
moraineUnsorted till (diamicton) deposited either along the sides (lateral moraine) or the ends of an ablating glacier (end or terminal moraine); or the material below a retreating glacier (ground moraine).
underflowmovement of water through subsurface material.
grounded ice  Ice that has run aground or is contact with the ground underneath it.
liquor(Water Quality) A liquid solution containing dissolved substances
waveAn identifiable, periodic disturbance or motion in a medium that shows displacement
calorieQuantity of energy
oligotrophic lakeDeep, clear lakes with low nutrient supplies
drifting icePieces of floating ice moving under the action of wind and/ or currents.
eutrophicationan excess of plant nutrients from natural erosion and runoff from the land in an aquatic ecosystem supporting a large amount of aquatic life that can deplete the oxygen supply.
aggressive waterWater that is soft and acidic and can corrode plumbing, pipes and appliances.
clear air turbulenceName given to turbulence that may occur in perfectly clear air without any visual in warning in the form of clouds
ice fallThe reaction of glacial snow and ice to subglacial changes in gradient
subsoilSoil material underlying the surface soil.
tapA physical connection made to a public water distribution system that provides service to an individual customer.
water cyclenatural pathway water follows as it changes between liquid, solid, and gaseous states; biogeochemical cycle that moves and recycles water in various forms through the ecosphere
raw waterIntake water before any treatment or use.
land farmingA technique for the controlled biodegradation of organic waste that involves the mixture of waste sludges with soil
mistLiquid particles measuring 40 to 500 micrometers, are formed by condensation of vapour
infiltration ratethe rate at which water moves into the soil
wave troughArea in between wave crests.
medial morainesConcentrations of till in septa dividing ice streams deposits as medial moraines after complete ablation
earthen dam   An embankment dam in which more than 50% of the total volume is formed of compacted fine-grained material
upstream controlControl structure adjustments based on information from upstream
horizontal integrationthe merging of firms at the same stage of production.
tolerancePermissible residue level for pesticides in raw agricultural produce and processed foods
kilowatt-hourA basic unit of electrical energy that equals one kilowatt of power applied for one hour.
water equivalentThe amount of water, in inches, obtained by melting a snow sample.
fjordA glacial valley or glacial trough found along the coast that is now filled with a mixture of fresh water and seawater.
phytoplanktonFree-floating, mostly microscopic aquatic plants.
leachingThe removal of soluble organic and inorganic substances from the topsoil downward by the action of percolating water.
recharge boundaryAn aquifer system boundary that adds water to the aquifer
dip slopethe gentle slope formed by the upper plane of the dipping, harder bed of rock in a cuesta.
urban flooding  Flooding of streets, underpasses, low lying areas, or storm drains
barrageany artificial obstruction placed in water to increase water level or divert it
discharge permita permit issued by a state or the federal government to discharge effluent into waters of the state or the United States
lough(Irish) (1) A lake
isobaric chart  Same as a constant pressure chart.
solution loadthat portion of a river load held in solution.
thermal lowsAreas of low pressure that are shallow in vertical extent and are produced primarily by warm surface temperatures.
sewageThe waste and wastewater discharged into sewers from homes and industry.
adhesionthe molecular attraction asserted between the surfaces of bodies in contact
service hydrologist  The designated expert of the hydrology program at a WFO.
residual saturationsaturation level below which fluid drainage will not occur.
mean annual floodover a series of years, the mean average of the maximum flood discharges experienced in a particular river
riparian water rightthe legal right held by an owner of land contiguous to or bordering on a natural stream or lake, to take water from the source for use on the contiguous land.
artesian wellA well drilled into a confined aquifer.
aqueoussomething made up of water.
national estuary programa program established under the Clean Water Act Amendments of 1987 to conserve and manage estuaries, restore and maintain their chemical, physical, and biological integrity, and control point and nonpoint pollution sources.
irrigation releasesRefers to those waters released from storage primarily for irrigation
effective porosity  The ratio, usually expressed as a percentage, of the volume of water or other liquid which a given saturated volume of rock or soil will yield under any specified hydraulic condition, to the given volume of soil or rock.
adfluvialPossessing a life history trait of migrating between lakes or rivers and streams.
dissolved solidsVery small pieces of organic and inorganic material contained in water
basalt plateauExtensive continental deposits of basaltic volcanic rock.
marineWith reference to ocean environments and processes.
slushSnow or ice on the ground that has been reduced to a softy watery mixture by rain and/or warm temperatures.
esp  Extended Streamflow Prediction.
conveyance lossWater loss in pipes and channels by leakage or evaporation.
estuarine zonearea near the coastline that consists of estuaries and coastal saltwater wetlands.
nutrientsprimarily nitrate and phosphate, content of natural       waters, usually resulting in an increase in biomass and productivity of algae which may result       in the depletion of the oxygen concentration in the water leading to a fish kill, from natural       erosion and runoff from the land or from anthropogenic sources.
outfallThe place where effluent is discharged into receiving waters.
moraineA ridge or mound of glacial debris deposited during the melting phase of a glacier.
topographic mapMap that displays topography through the use of elevation contour lines
firn lineSee firn limit.
backingIt is the counterclockwise turning of the wind direction as we move up through the atmosphere
fossil waterwater that has become detached from the hydrological cycle having lain, untouched and without addition, in deep aquifers since prehistoric times.
gaining streamA river, or reach of a stream or river, that gains flow from ground water seepage or from springs in, or alongside, the channel--sometimes called an effluent stream.
riftA shallow or rocky place in a stream, forming either a ford or a rapid.
flooded ice  Ice which has been flooded by melt water or river water and is heavily loaded by water and wet snow.
zone of saturation  The locus of points below the water table where soil pores are filled with water
leachingextraction or flushing out of dissolved or suspended materials from the soil, solid waste, or another medium by water or other liquids as they percolate down through the medium to groundwater.
outlet glaciersValley glaciers which permit ice to move from accumulation areas through mountainous terrain to the sea.
leeward/windwardLeeward is on the side facing the direction toward which the wind is blowing
sustainable agriculturethe increase in food yields without damage to the environment.
very windy  30 to 40 mph winds
rockA naturally formed mass of minerals.
annual flood  The maximum discharge peak during a given water year (October 1 - September 30).
weirsA regulating device in a sewer that permits dry weather flow in a combined sewer to enter an interceptor, but causes the storm flow to leap over for a controlled overflow.
scs  The Soil Conservation Service.
absolute recruitmentThe number of fish which grow into the catchable size range in a unit of time (usually a year).
electrofishinga biological collection method that uses electric current to facilitate capturing fishes.
rearing pondAn artificial impoundment in which juvenile salmon and steelhead are raised prior to release into the natural habitat.
sewage treatmentThe processing of wastewater for the removal or reduction in the level of dissolved solids or other undesirable constituents.
atollAn atoll is a ring (or partial ring) of coral that forms an island in an ocean or sea
beginning of the breakupDate of definite breaking, movement, or melting of ice cover or significant rise of water level.
terminusThe leading edge of a glacier; also known as the glacier snout.
aestheticsaquatic life and wildlife, (see contact recreation, non-contact       recreation).
dykeAn artificial embankment constructed to prevent flooding.
riffleBar deposit found on the bed of streams
stream orderclassification of streams within a drainage basin so that it can be compared with another
mista light fog
salt waterWater which contains a relatively high percentage of sodium chloride.
submersible traveling screenA wire mesh screen that acts like a conveyor belt when installed in the intakes of turbines at dams guiding and transporting juvenile fish into bypass channels.
downwelling currentOcean current that travels downward into the ocean because of the convergence of opposing horizontal currents or because of an accumulation of seawater.
flotationA solids-liquid or liquid-liquid separation procedure, which is applied to particles of which the density is lower than that of the liquid they are in
environmental impact statementa document that analyzes the effects of major federal projects on the environment
scheduled deliveryOperation of a water delivery system to meet predetermined needs, generally based on user water orders.
forfeited water righta water right canceled because of several consecutive years of nonuse.
hydraulic fill dam  A dam constructed of materials, often dredged, that are conveyed and placed by suspension in flowing water.
earthquake focusPoint of stress release in an earthquake.
sheet flowUnrestricted glaciers including ice caps and ice sheets flow independently of underlying topography
sanitary sewersunderground pipes that carry off only domestic or industrial waste, not storm water.
surface water disposalRefers to the release of reclaimed water or treated effluent directly into a surface body of water (including marshes and wetlands)
tephrasee pyroclastic cloud.
bar screenin wastewater treatment, a device used to remove large solids from the incoming wastewater stream.
lakeshore statement  The local National Weather Service Offices with Great Lakes responsibility will issue this product to alert the public when their is either a potential or actual reports of minor Great Lakes lakeshore flooding and erosion.  This means that the lakeshore flooding or erosion would not cause too much damage to property, but it would be an inconvenience to living or driving in those areas.
blustery  15 to 25 mph winds
interglacialPeriod of time during an ice age when glaciers retreated because of milder temperatures.
subtropical airAn air mass that forms over the subtropical region
supraglacialThe area on top of the glacier which may be snow, ice, rock fragments or covered with soil, plants or forests.
snow grainsFrozen precipitation in the form of very small, white, opaque grains of ice
dewateringElimination of water from a lake, river, stream, reservoir, or containment.
ablationIn glaciers, refers to melting, erosion and evaporation which reduces the area of the ice.
loading capacityThe greatest amount of chemical materials or thermal energy that can be added to a stream without exceeding water quality standards established for that stream.
mountain breezeA katabatic wind, it is formed at night by the radiational cooling along mountainsides
storm tracking information  This WSR-88D radar product displays the previous, current, and projected locations of storm centroids (forecast and past positions are limited to one hour or less).  Forecast tracks are based upon linear extrapolation of past storm centroid positions, and they are intended for application to individual thunderstorms not lines or clusters.  It is used to provide storm movement:  low track variance and/or 2 or more plotted past positions signify reliable thunderstorm movement.
field capacitywater in the soil once gravitational water has fully drained out i.e
tertiary treatmentremoval from wastewater of traces or organic chemicals and dissolved solids that remain after primary treatment and secondary treatment.
land breezeThe land-to-sea surface wind that occurs in coastal areas at night
icelandic lowSubpolar low pressure system found near Iceland
kameA steep conical hill composed of glaciofluvial sediments
foldWavelike layers in rock strata that are the result of compression.
velocity of a streamRate of motion of a stream measured in terms of the distance its water travels in a unit of time, usually in feet per second.
chalkForm of limestone
breakup dateDate on which a body of water is first observed to be entirely clear of ice and remains clear thereafter.
peak loadThe maximum load in a stated period of time
raw sewageUntreated domestic or commercial wastewater.
certified water rightA state-issued document that serves as legal evidence that an approved application has been physically developed and the water put to beneficial use
trunk myomeres of lampreysThe number of body segments between the last gill opening and the cloacal slit.
refraction of waves  The change in the direction of movement of waves which encounter shallow water.  See Reflection of Waves.
valleyLow land between hills and mountains.
heavy waterwater in which all the hydrogen atoms have been replaced by deuterium.
anchor ice  Submerged Frazil ice attached or anchored to the river bottom, irrespective of its formation.
viscosityThe syrupiness of water and it determines the mobility of the water
valley trainMeltwater-deposited alluvium in a glacial trough; derived from the morainal material left behind by a receding mountain glacier.
equi-potential line  A line, in a field of flow, such that the total head is the same for all points on the line, and therefore the direction of flow is perpendicular to the line at all points.
canal prismThe cross-sectional shape of a typical canal.
cumulonimbus cloudThey are the ultimate manifestation of instability
attenuationthe process whereby the magnitude of a flood event is reduced by slowing, modifying, or diverting the flow of water.
"repurified water"Denotes reclaimed or recycled wastewater that is treated far beyond the most stringent standards current in force and then remixed with fresh water to augment existing water supplies
temperate climateClimates with distinct winter and summer seasons, typical of regions found between the Tropics of Cancer and Capricorn and the Arctic and Antarctic Circles
composite hydrograph  A stream discharge hydrograph which includes base flow, or one which corresponds to a net rain storm of duration longer than one unit period.
rimeIce deposits formed when supercooled water droplets freeze on contact with an object (deposition).
operable unita term used by the Superfund program to describe a discrete action that comprises an incremental step toward comprehensively addressing site problems
cross-connectionany actual or potential connection between a drinking water system and an unapproved water supply or other source of contamination.
epicentrethe point on the surface directly above the focus of an earthquake.
terminal moraineMoraine that marks the maximum advance of a glacier.
initial lossIn hydrology, rainfall preceding the beginning of surface runoff
channel leadAn elongated opening in the ice cover caused by a water current.
periglacialThe area around a glacier often characterized by harsh climate.
external costcost of production or consumption that must be borne by society; not by the producer.
avalancherapid, down slope mass movement of ice and/or snow due to a trigger overcoming reduced friction in an unstable accumulation.
field capacitythe amount of water held in soil against the pull of gravity.
meltwaterThe water from melted snow or ice.
fena type of wetland that accumulates peat deposits, but not as much as a bog
aridA term used for an extremely dry climate
streamflowThe discharge that occurs in a natural channel
planktonany drifting biota inhabiting the pelagic (non-bottom) zones of seas and lakes
hornA high mountain peak that forms when the walls of three or more glacial cirques intersect.
isostatic depressionLarge scale sinking of the crust into the asthenosphere because of an increase in weight on the crustal surface
notch width  The 3 dB band width of a rejection filter.
geohydrologyThat branch of hydrology relating to subsurface, or subterranean waters.
diffractionThe result of light waves interfering with other after passing through a narrow aperture, causing them to bend or spread.
cryostatic pressurePressure exerted on a substance by ice at rest.
seepagepercolation of water through the soil from unlined canals, ditches, laterals, watercourses, or water storage facilities.
influent stream  Any watercourse in which all, or a portion of the surface water flows back into the ground namely the, vadose zone, or zone of aeration.
climatic cycleThe periodic changes of climate, including a series of dry years following a series of years with heavy rainfall.
rissEuropean glaciation related to North American Illinoian glaciation.
lake-effect snow advisory  This product is issued by the National Weather Service when pure lake effect snow (this is where the snow is a direct result of lake effect snow and not because of a low pressure system) may pose a hazard or it is life threatening.  The criteria for this advisory varies from area to area.  In Michigan, the criteria for its issuance is a pure lake effect snow event that is forecasted to produce snow (average of forecast range) greater than 3 inches, but less than warning criteria (6 inches in Lower Michigan and 8 inches in Upper Michigan) in 12 hours.  If the forecaster feels that it is warranted, he or she can issued it for amounts less than the minimum criteria.  For example, it may be issued for the first snow of the season or when snow has not fallen in long while.  In cases where you have a system snow  transitioning to a pure lake effect snow, the criteria for defining this transition is when the mid and high clouds have been stripped away leaving only the stratocumulus clouds behind.
long wave troughA wave in the prevailing westerly flow aloft which is characterized by a large length and amplitude
slush limitThe highest point from which runoff occurs.
diluting waterdistilled water that has been stabilized, buffered, and aerated
wastesexcessive dissolved solids make water       unsuitable for drinking or industrial uses, (see TDS, total dissolved solids).
permeabilitythe ability of a water bearing material to transmit water
hydrologic benchmarkA hydrologic unit, such as a basin or a ground-water body, that because of its expected freedom from the effects of man, has been designated as a benchmark
epilimnionThe upper region of a thermally stratified lake, above the thermocline, and generally warm and well oxygenated.
meltingAn endothermic physical process in which solid ice changes into liquid water (0° C at 1 atm)
taxonA classification category for a group of organisms.
rivuletA small stream or brook; a streamlet.
saturation pointThe point when the water vapor in the atmosphere is at its maximum level for the existing temperature.
tributarya stream that contributes its water to another stream or body of water.
subsistence flowsthe component of an instream flow regime that represents infrequent, naturally occurring low flow events that occur for a seasonal period of time
watershedAn area from which water drains and contributes to a given point on a stream or river.
parametric testsStatistical tests that assume the sample data is normally distributed.
clarifiera tank in which solids settle to the bottom and are subsequently removed as sludge.
deisDraft Environmental Impact Statement.
rockfallType of mass movement that involves the detachment and movement of a small block of rock from a cliff face to its base
declinationthe latitude where, on any particular day, the sun is 90˚ above the horizon at solar noon i.e
compact callThe requirement that an upstream state cease or curtail diversions of water from the river system that is the subject of the compact to satisfy the downstream state's compact entitlements.
tabular icebergA flat-topped iceberg, usually formed by breaking off an ice shelf.
tropopauseThe boundary zone or transition layer between the troposphere and the stratosphere
coalescenceProcess where two or more falling raindrops join together into a single larger drop because of a midair collision.
reservoirpond, lake or basin (natural or artificial) for the storage and control of water.  Lake Pleasant, Saguaro, Apache, Canyon and Roosevelt Lakes are some of the reservoirs for storing the Valley's water.
galleryA passageway within the body of a dam or abutment.
distributarya stream which splits away from the main channel and never rejoins it
reclaimed waterdomestic wastewater that is under the direct control of a treatment plant owner/operator which has been treated to a quality suitable for a beneficial use.
bypass flowWater that is allowed to flow past a diversion structure or storage facility.
middle latitudesThe latitude belt roughly between 35 and 65 degrees North and South
capillary forcesforces that cause ground water to rise above the surface of the saturated zone into the spaces between soil particles in the unsaturated zone.
non-transient non-community water systemA public water system that regularly serves at least 25 of the same non-resident persons per day for more than six months per year.
manholeVertical openings that serve as access holes for maintenance in sanitary or storm drain infrastructure
mean velocityThe average cross-sectional velocity of water in a stream channel
dischargeSee stream discharge.
breakpoint chlorinationaddition of chlorine to the point where all organic matter and ammonia compounds have been destroyed and any additional chlorine becomes a free chlorine residual available for disinfection.
algal bloomrapid growth of phytoplankton in water bodies usually in the surface layers
cumuliformClouds composed of water droplets that exhibit vertical development
evaporationThe process of the passage of water from liquid to vapour.
dioxinAny of a family of compounds known chemically as dibenzo-p-dioxins
riskA measure of the chance that damage to life, health, property, or the environment will occur.
manning's roughnessa coefficient in Manning's equation that accounts for energy loss due to the friction between the channel and the water
embankment  Fill material, usually earth or rock, placed with sloping sides and usually with length greater than height.  All dams are types of embankments.
turbiditya cloudy condition in water due to suspended silt or organic matter.
normal daily temperatureThe average daily mean temperature for a given date, computed for a specific 30-year period.
stormwater dischargeprecipitation that does not infiltrate into the ground or evaporate due to impervious land surfaces but instead flows onto adjacent land or water areas and is routed into drain/sewer systems.
ground moraineA continuous layer of till deposited beneath a steadily retreating glacier.
indian summerA period of abnormally warm weather in mid to late autumn with clear skies and cool nights
seismographInstrument that measures the energy contained in seismic waves from an earthquake or other type of ground displacement.
meander benda windings or sinuous section of a stream channel
latent heat of condensationThe amount of heat released by a unit mass of substance, without change in temperature, while passing from the vapor to the liquid state.
productivitythe efficiency with which a company turns inputs into outputs.
populationThe number of people living in a certain area.
groundwater dischargeGround water entering coastal waters, which has been contaminated by land-fill leachates, deep well injection of hazardous wastes and septic tanks.
frontal passageIt is the passage of a front over a specific point on the surface
near galeWhole trees in motion; inconveniences felt against wind; sea heaps up and white foam from breaking waves begins to be blown in streaks along the direction of the wind.
non-potableWater not suitable for drinking
osmosisthe passage of a liquid from a weak solution to a more concentrated solution across a semi-permeable membrane that allows passage of the solvent (water) but not the dissolved solids.
water cyclesee hydrological cycle.
ephemeral streamsStreams that flow only in direct response to precipitation and whose channel is at all times above the water table.
cutoffwhere the stream cuts through the neck of a meander bend.
sprayAn ensemble of water droplets torn by the wind from the surface of the of an extensive body of water, generally from crests of waves, and carried a short distance into the air.
maintainable yield"""The largest catch that can be maintained from the population, at whatever level of stock size, over an indefinite period
detergentsynthetic washing agent that helps remove dirt and oil
flash flood warning  This warning signifies a short duration of intense flooding of counties, communities, streams, or urban areas with high peak rate of flow.  Flash floods may result from such things as torrential downpours, dam breaks, or ice jam breaks.
convergence precipitationThe formation of precipitation due to the convergence of two air masses
continental divideAn imaginary boundary line that runs north to south through the Rocky Mountains, separating rivers that flow west to the Pacific Ocean from those that flow south and east toward the Gulf of Mexico and the Atlantic Ocean.
caveA cave is a large hole in the ground or in the side of a hill or mountain.
percolation rateThe rate, usually expressed as a velocity, at which water moves through saturated granular material
administrative ordera legal document signed by U.S
streamthe volume of water that passes a given point within a given period of time,       an all-inclusive outflow term, describing a variety of flows such as from a pipe to a stream or       from a stream to a lake or ocean, usually expressed in cubic feet per second.
suspended loadPortion of the stream load that is carried almost permanently suspended in flowing water.
geysera periodic thermal spring that results from the expansive force of super heated steam.
pedogenic regimeThe particular soil forming process that operates in a certain climate
alberta clipperA fast moving, snow-producing weather system that originates in the lee of the Canadian Rockies
pondA pond is a small body of water surrounded by land
couplet  Adjacent maxima of radial velocities of opposite signs.
physiographic provincean area with similar characteristics based on geology, soil type, and topography.
dental fluorosisdisorder caused by excessive absorption of fluorine and characterized by brown staining of teeth.
climatic yeara period used in meteorological measurements
aerated lagoona holding and/or treatment pond that speeds up the natural process of biological decomposition of organic waste by stimulating the growth and activity of bacteria that degrade organic waste.
constant pressure chartA chart of a constant pressure surface in which atmospheric pressure is uniform everywhere at any given moment
fewThe amount of sky cover for a cloud layer between 1/8th and 2/8ths, based on the summation layer amount for that layer.
driftsNormally used when referring to snow or sand particles are deposited behind obstacles or irregularities of the surface or driven into piles by the wind.
hypolimnionbottom layer of cold water in a lake
salt water intrusionthe invasion of fresh surface or ground water by salt water
aggressive waterwater which is soft and acidic and can corrode plumbing, piping, and appliances.
band width  The number of cycles per second between the limits of a frequency band.
exogenicRefers to a system that is external to the Earth.
hoarfrostA light, feathery coating of ice.
cold frontA transition zone in the atmosphere where an advancing cold air mass displaces a warm air mass.
fish screenA screen across the turbine intake of a dam, designed to divert the fish into the bypass system.
peak flowthe maximum instantaneous discharge of a stream or river at a given location
mass movementthe downslope movement en masse of rock, earth or water
cisterna tank used to collect rainwater runoff from the roof of a house or building.
subpolar lowsSurface zone of atmospheric low pressure located at about 60° North and South latitude
frozen precipitationPrecipitation that reaches the ground in a frozen state
frontal liftingLifting of a warmer or less dense air mass by a colder or more dense air mass at a frontal transitional zone.
bioaccumulationuptake and retention of substances by an organism from its surrounding medium (usually water) and from food.
subsurface seepageSubsurface seepage is movement of water through soils from above-lying bodies of water.
headwatersthe uppermost portion of a river course close to the source.
jar testA laboratory test procedure with differing chemical doses, mix speeds, and settling times, to estimate the minimum or ideal coagulant dose required to achieve water quality goals.
ice pushCompression of an ice cover particularly at the front of a moving section of ice cover.
hanging valleyA valley formed by the intersection of a tributary glacier with a trunk glacier; when the Ice melts away, the tributary valley floor usually is at a higher elevation and thus “hangs” above the main valley's floor.
flow boundariesAnything which inhibits ground water flow, such as a ground water divide or an impermeable geologic unit.
light icing  The rate of ice accumulation that may create a problem if the flight is prolonged in this environment (over one hour).  Occasional use of de-icing equipment removes/prevents accumulation.  It does not present a problem if de-icing/anti-icing equipment is used.  This standard of reporting this type of icing was based on a recommendation set forth by the subcommittee for Aviation Meterorological Services in the Office of the Federal Coordinator for Meteorology in November 1968.  The convetion has been to designate icing intensity in terms of its operational effect upon reciprocating engine, straight wing transport aircraft as used by commuter operators.
bed loadPortion of the stream load that is carried along the stream bed without being permanently suspend in the flowing water.
basal slidingThe sliding of a glacier over the ground on a layer of water.
meander beltThe area between lines drawn tangential to the extreme limits of fully developed meanders.
sheet erosionThe removal by surface runoff of a fairly uniform layer of soil from a bank slope from "sheet flow" or runoff that flows over the ground surface as a thin, even layer not concentrated in a channel.
climatologyThe study of climate
samplebacterial       colonies on laboratory media resulting from filtering and culturing bacteria from a water       sample, each colony in the laboratory culture is presumed to have arisen from the multiplication       of a single bacterium in the original sample.
haines index  This is also called the Lower Atmosphere Stability Index.  It is computed from the morning (12Z) soundings from RAOB stations across North America
mesocyclone  It is a sufficiently strong circulation detected on two or more elevation angles which are symmetrically linked within a thunderstorm.  It is indicated on the radar display as a thick yellow circle.
coefficient of transmissivityThe rate at which water of the prevailing kinematic viscosity is transmitted through a unit width of the aquifer under a unit Hydraulic Gradient
speciesA group of closely related individuals that can interbreed and produce fertile offspring.
dependable supplyThe annual average quantity of water that can be delivered during a drought period.
halogenated organic compoundsparticularly that are fluoridated,       chlorinated or brominated, (see adsorption, halides).
phnumeric value that describes the intensity of the acid or basic (alkaline) conditions of a solution
shoreThe land area bordering a relatively large water body like a lake or ocean.
violent stormWidespread damage; exceptionally high waves (small and medium-sized ships might be for a time lost to view behind waves); the sea is completely covered with long white patches of foam lying along the direction of the wind; everywhere the edges of the wave crests are blown into froth; visibility affected.
potentiometric surfacethe surface to which water in an aquifer can rise by hydrostatic pressure
snowfieldAn area of permanent snow accumulation
quarryopen-air works where rock is removed for commercial use.
sanitary sewerA sewer intended to carry only sanitary or sanitary and industrial wastewater from residences, commercial buildings, industrial parks, and institutions.
iceThe solid form of water is called ice.
stationary frontA front that barely moves with winds blowing in almost parallel, but in opposite directions on each side of the front
tillHeterogeneous sediment deposited directly by a glacier
chionophobia  Fear of snow.
hungry waterClear water minus its expected suspended sediment load, usually released from an impoundment that has excess energy, which erodes sediment from the downstream channel.
forest landLand that is now, or is capable of becoming, at least 10 percent stocked with forest trees and that has not been developed for nontimber use.
canopyA layer of foliage in a forest stand
marine-based ice sheetA large mass of ice with its base grounded below sea level.
floodplainland next to a river that becomes covered by water when the river overflows its banks .
receiving watersA lake, river, pond or creek that receives stormwater runoff from storm drainpipe.
water cycleThe cycle of evaporation and condensation that controls the distribution of the earth's water as it evaporates from bodies of water, condenses, precipitates, and returns to those bodies of water.
sediment storageThe accumulation, in a reservoir, of sediment that would normally be carried downstream without the project.
right bankThe right-hand side of a stream, river, or channel when facing in the direction of the flow.
flood probabilityThe statistical probability that a flood of a given size will be equaled or exceeded in a given period of time.
streamflow regulationThe artificial manipulation of the flow of a stream.
blind spotsAny place on a filter medium where fluids cannot flow through.
beheaded streamThe lower section of a stream that has lost its upper portion through diversion or Stream Piracy.
revetmentA facing of stone, bags, blocks, pavement, etc., used to protect a bank against erosion.
hydrologic services  A general Term referring to the operations, products, verbal communications, and related forms of support provided by the NWS for the Nation's streams, reservoirs, and other areas affected by surface water.
freezingAn exothermic physical process in which liquid water changes into solid ice (0C at 1 atm)
stream dischargeA river or stream's rate of flow over a particular period of time
parrThe developmental life stage of salmon and trout between alevin and smolt, when the young have developed parr marks and are actively feeding in fresh water.
sea-levelThe average surface elevation of the world's oceans.
bogA type of wetland that accumulates appreciable peat deposits
platformHorizontal sedimentary deposits found on top of continental shield deposits.
glazeIce formed by freezing precipitation covering the ground or exposed objects.
dredgingremoval of mud from the bottom of water bodies
ecologyThe study of the inter-relationships of living things to one another and to the environment.
bridgeAn over the lake, stream or river structure built so that people can get from one side to the other.
cryology  The science of the physical aspects of snow, ice, hail, and sleet and other forms of water produced by temperatures below Zero degrees Celsius.
eisEnvironmental Impact Statement.
stratospherelayer of the atmosphere from approximately 12 to 50km
wettable powderdry formulation that must be mixed with water or other liquid before it is applied.
cold glacierGlacier in which the ice found from the its surface to base has a temperature as cold as -30° Celsius throughout the year
leveea natural or man-made earthen obstruction along the edge of a stream, lake, or river
ice agePeriod of time when glaciers dominate the landscape of the Earth
interceptor sewersLarge sewer lines that, in a combined system, control the flow of sewage to the treatment plant
water managementthe attempt to provide the right quality of water for a variety of uses in the places where it is required
upriver stocksSalmon and steelhead stocks that spawn in the Columbia River or its tributaries above Bonneville Dam.
leachingProcess in which water removes and transports soil humus and inorganic nutrients in solution.
supply managementMethods by which a utility maximizes use of available untreated water.
truncated spursTriangular hillside features due to glacial erosion of the headlands between two former streams.
rope stage  The dissipating stage of a tornado, characterized by thinning and shrinking of the condensation funnel into a rope (or rope funnel)
deformed ice  A general term for ice which has been squeezed together and forced upwards and downwards in places.  Subdivisions are rated ice, ridge ice, hummocked ice, and other similar deformations.
air quality standardsThe maximum level which will be permitted for a given pollutant
macrointervebratean animal without a backbone, large enough to be seen without magnification and unable to pass through a 0.595 mm mesh.
backwater valveA backwater valve is a backflow prevention valve designed to prevent sanitary sewage from backing up through your floor drain from the sanitary system into a building.
chemical weatheringattack and dissolving of parent rock by exposure to rainwater, surface water, oxygen, and other gases in the atmosphere, and compounds secreted by organisms
megawatt-hourA unit of electrical energy equal to one megawatt or power applied for one hour.
windthe horizontal movement of air created by differing pressures of adjacent air masses
snow crustThe crisp, almost icy, surface on fallen snow, usually formed by the slight melting and refreezing of the surface snow.
boreal forestHigh to mid-latitude biome dominated by coniferous forest
subcritical flowflow characterized by low velocity and a Froude number less than 1
residuethe dry solids remaining after the evaporation of a sample of water or sludge.
canyona large-scale, steep-sided valley which is deeper than it is wide.
runoffThat part of precipitation that flows toward streams on the surface of the ground or within the ground
freshwater(1) Of, relating to, living in, or consisting of water that is not salty
climax communityThe stage in community succession where the community has become relatively stable through successful adjustment to its environment.
lagoonA shallow pond where sunlight, bacterial action, and oxygen work to purify wastewater.
waterwater which is applied to assist crops in areas or during times where rainfall is inadequate.
environmentaggregate of external conditions that influence the life of an individual organism or population.
floodproofingFloodproofing is making efforts to prevent moisture from forming, or preventing water from entering, your home.
ice-wedge castsA vertical structure that results from cracks in frozen ground (by means of ice wedging) which are later filled by sediment
soluteMatter dissolved in a liquid, such as water.
transparentA condition where a material is clear enough not to block the passage of radiant energy, especially light.
glaciationThe transformation of the landscape through the action of glaciers.
fog bankA fairly well-defined mass of fog observed in the distance
corrie glacierthe glacier found in a corrie which has been responsible for its formation.
confined aquiferAn aquifer which is bounded above and below by formations of impermeable or relatively impermeable material
seismicShaking displacement usually caused by an earthquake.
reuse waterWater used repeatedly.
water vapor plumeThis appear in the water vapor satellite imagery
springAn issue of water from the earth; a natural fountain; a source of a reservoir of water.
macroburstA large downburst with an outflow diameter of 2.5 miles (4 kilometers) or larger and damaging winds.
ground frostFrost that penetrates the soil surface in response to freezing temperatures.
river milesGenerally, miles from the mouth of a river to a specific destination or, for upstream tributaries, from the confluence with a main river to a specific destination.
municipal sewageSewage (mostly liquid) originating from a community which may be composed of domestic sewage, industrial wastes, or both.
migrationThe movement of oil, gas, contaminants, water, or other liquids through porous and permeable rock.
oh  The Office of Hydrology, located in Silver Springs, MD.
groundwater reservoiran aquifer or aquifer system in which ground water is stored
liningA protective covering over all or part of the perimeter of a reservoir or a conduit to prevent seepage losses, withstand pressure, resist erosion, reduce friction, or otherwise improve conditions of flow.
varianceA statistical measure of the dispersion of observation values in a data set
equatorLocation on the Earth that has a latitude of 0°.
water lossesWater which is unavailable or lost from a particular containment system.
hydroserea freshwater environment in which primary plant succession takes place.
net demandThe water demand that is expected to occur in the future after reductions for natural replacement and conservation
estuarine(1) Of, pertaining to, or formed in, an Estuary
percolating waterswaters passing through the ground beneath the Earth's surface without a definite channel.
columbia river systemThe Columbia River and its tributaries.
continental riseThick layers of sediment found between the continental slope the ocean floor.
frazil slush  An agglomerate of loosely packed frazil which floats or accumulates under the ice cover.
meltwaterliquid water that has come from melting snow or ice.
critical flow  A condition of flow where the mean velocity is at one of the critical values; ordinarily at Belanger's critical depth and velocity
specific yieldthe amount of water a unit volume of saturated permeable rock will yield when drained by gravity.
fracturingDeformation process whereby ice is permanently deformed, and fracture occurs.
attritiona process of erosion where the collisions between parts of the load lead to comminution.
zone of aerationThe comparatively dry soil or rock located between the ground surface and the top of the Water Table
hydrologic unitis a geographic area representing part or all of a surface drainage basin or distinct hydrologic feature.
filtera device used to remove solids from a mixture or to separate materials
firnNévé on a glacier that survives the year's ablation season
pingo  a dome-shaped hill in a flat tundra plain, often having a depression in the summit
thalweg  The line of maximum depth in a stream
headworksThe diversion structures at the head of a conduit.
reachin general, a length of stream with relatively homogenous characteristics.
storm hydrographA hydrograph representing the total flow or discharge past a point.
valley glacierA stream of ice flowing down gradient.
recycled waterused more than one time before it passes back into the hydrologic system.  (See gray water, reclaimed water.)
pilot balloonA small balloon whose ascent is used to determine the direction and speed of low level atmospheric winds
tropical rainforestForested biome found near the equator and dominated by evergreen vegetation.
groundwater hydrologyThe branch of hydrology that deals with the occurrence, movements, replenishment and depletion, properties and methods of investigation and utilisation of groundwater.
receiving watersA river, lake, ocean, stream or other watercourse into which wastewater or treated effluent is discharged.
hydrologic cycleThe constant circulation of water from the sea, through the atmosphere, to the land, and back to the sea by over-land, underground, and atmospheric routes.
glacierA huge mass of ice, formed on land by the compaction and recrystallization of snow, that moves very slowly downslope or outward due to its own weight.
differential motion  Cloud motion that appears to differ relative to other nearby cloud elements, e.g
cold air advection  Transport of cold air into a region by horizontal winds.
land breezeA diurnal coastal breeze that blows offshore, from the land to the sea
tidal marshlow, flat marshlands traversed by channels and tidal hollows, subject to tidal inundation; normally, the only vegetation present is salt-tolerant bushes and grasses.
hydraulic radiusThe right cross-sectional area of a stream of water divided by the length of that part of its periphery in contact with its containing conduit; the ratio of area to wetted perimeter
fahrenheitAn older form of temperature measurement
lagoona shallow pond where sunlight, bacterial action, and oxygen work to purify wastewater
mixed precipitationAny of the following combinations of freezing and frozen precipitation: snow and sleet, snow and freezing rain, or sleet alone
pool heightThe height of the water behind a dam
lithometeorAtmospheric phenomena which affect the state of the atmosphere
tuleFall chinook stock native to the Columbia River tributaries.
grazing food chainModel describing the trophic flow of organic energy in a community or ecosystem.
bound waterWater molecules that are held tightly to soil or other solids
flow metera gauge indicating the velocity and/or volume of a flowing liquid.
milligramOne-thousandth of a gram.
oxidation pondA man-made body of water in which waste is consumed by bacteria.
tropical air massAn air mass that forms in the tropics or subtropics over the low latitudes
upstreamToward the source or upper part of a stream; against the current
husbandryThe scientific management and control of the hatchery environment for the production of fish or wildlife.
psammoseresuccession of plants in a sandy environment such as coastal dunes.
groundwater rechargethe inflow to a ground water reservoir.
ground water divideA line on a water table on either side of which the water table slopes downward
hanging valleyA shallow glacial trough that leads into the side of a larger, main glacial trough.
rawinsonde observationA radiosonde observation which includes wind data.
creeka small stream of water which serves as the natural drainage course for a drainage basin
rainsplashSoil erosion caused from the impact of raindrops.
mesospherethe layer of the atmosphere above the stratosphere
spring tideextremely high and low tides which occur twice a month when the sun and moon align on the same side of the earth and exert a combined gravitational pull on the oceans.
mammatus clouds  Rounded, smooth, sack-like protrusions hanging from the underside of a cloud (usually a thunderstorm anvil)
multicell thunderstormsThese thunderstorms are organized in clusters of at least 2-4 short-lived cells
water table aquiferan aquifer confined only by atmospheric pressure (water levels will not rise in the well above the confining bed).
rain shadowAlso referred to as a precipitation shadow, it is the region on the lee side of a mountain or similar barrier where the precipitation is less than on the windward side
retrogression  Movement of a weather system in a direction opposite to that of the basic flow in which it is embedded, usually referring to a closed low or a longwave trough which moves westward.
presedimentation(Water Quality) A pretreatment process used to remove gravel, sand, and other gritty material from raw water before it enters the main treatment plant
neveThe upper area of accumulation in a glacier where firn is found.
potential evapotranspirationtheoretical amount of moisture that could be lost from the surface to the atmosphere if it were available.
kelp bedssignificant aggregations of a large, fast growing marine algae throughout the water column.
iflowsThe Integrated Flood Observing and Warning System.
forebay guidance netA large net placed in the forebay of a dam to guide juvenile fish away from the powerhouse.
cbodCarbonaceous Biochemical Oxygen Demand.  A BOD test in which a nitrification inhibitor is added, so that only the carbonaceous oxygen demanding compounds are measured. 
potable waterWater that is safe for drinking and cooking.
soundingA plot of the atmosphere, using data rom upper air or radiosonde observations
appropriateTo authorize the use of a quantity of water to an individual requesting it.
reservoirA body of water used to collect and store water, or a tank or cistern used to store potable water.
wasatch windsStrong winds blowing easterly out of the Wasatch Mountains in Utah, sometimes reaching speeds greater than 75 miles per hour.
bias  A systematic difference between an estimate of and the true value of the parameter.
millibarThe standard unit of measurement for atmospheric pressure used by the National Weather Service
plateauA plateau is a large, flat area of land that is higher than the surrounding land.
trimlinesSharp boundaries in vegetation abundance or community type showing the upper margin of a former glaciation
influentwater, wastewater, or other liquid flowing into a reservoir, basin, or treatment plant.
colA connection across the rock arête dividing two cirques.
seepa spot where water contained in the ground oozes slowly to the surface and often forms a pool; a small spring.
optimum yield(OY) The yield from a fishery which provides the greatest overall benefit to the nation with particular reference to food production and recreational opportunities; it is based on MSY as modified by economic, social or ecological factors
condensationthe change of state from a gas to a liquid
closed basinA basin is considered closed with respect to surface flow if its topography prevents the occurrence of visible outflow
trajectoryThe curve that a body, such as a celestial object, describes in space
foodweba model structure used to represent the links between organisms within an environment, based upon the order in which various organisms consume one another.
environmentAll of the external factors, conditions, and influences that affect an organism or a community.
grease iceThin plates of organized ice crystals on the surface of water.
backflow  The backing up of water through a conduit or channel in the direction opposite to normal flow.
faceThe external surface of a structure, such as the surface of an appurtenance or a dam.
infiltration capacityThe ability of a soil to absorb surface water.
environmentalismthe politicization of concern for the environment and demands for action to protect and conserve it.
hydraulic fill damA dam constructed of materials, often dredged, that are conveyed and placed by
bed loadthe particles in a stream channel that mainly move by bouncing, sliding, or rolling on or near the bottom of the stream.
diffluenceA rate at which wind flow spreads apart along an axis oriented normal to the flow in question
pressure zoneGeographical area within a water distribution system defined by a number of valves with at least two feeds.
homeowner water systemA water system that supplies piped water to a single residence.
pumping-generating plantA plant at which the turbine-driven generators can also be used as motor-driven pumps.
saline waterwater containing more than 1,000 parts per million (ppm) of dissolved solids of any type
saprophytic      pathogenic or parasitic.
arêteA knife-edged rock divide between two glacial cirques.
oligotrophic lakesDeep clear lakes with few nutrients, little organic matter and a high dissolved-oxygen level.
coalescenceThe merging of two water drops into a single larger drop.
point-bargently sloping inner bank of a meander
river channelsNatural or artificial open conduits which continuously or periodically contain moving water, or which forms a connection between two bodies of water.
kettleA shallow basin or bowl shaped depression formed when a large block of ice is buried in outwash or diamicton during ablation
nutrientssuch as potassium,       sulfur, magnesium, calcium, copper and zinc, soil that is lacking in these substances can be       fertilized with biosolids which also improve soil properties and plant productivity reducing       dependence on inorganic fertilizers.
cola saddle-like landform between mountain peaks where two corrie glaciers have back-eroded an ar皻e.
anvil  The flat, spreading top of a Cumulonimbus Cloud (Cb)
ice waterChilled or iced water, especially served as a beverage.
salt flatA salt-encrusted flat area resulting from evaporation of a former body of water.
granular activated carbonpure carbon heated to promote "active" sites which can adsorb pollutants
drainage windA wind common to mountainous regions that involves heavy cold air flowing along the ground from high to low elevations because of gravity
gradient windHorizontal wind in the upper atmosphere that moves parallel to curved isobars
subtropical jet streamRelatively fast uniform winds concentrated within the upper atmosphere in a narrow band
hydropower systemThe hydroelectric dams on the Columbia River and its tributaries.
free ground water  Unconfined ground water whose upper boundary is a free water table.
station pressureThe atmospheric pressure with respect to the station elevation.
solifluctionA slow, viscous, downslope flow of saturated sediment and rock debris especially in areas underlain by frozen ground.
hazardous materialsAnything that poses a substantive present or potential hazard to human health or the environment when improperly treated, stored, transported, disposed of, or otherwise managed.
flocA cluster of frazil particles.
gage datumThe arbitrary zero datum elevation which all stage measurements are made from.
thalwegthe line of maximum depth in a stream
downstream  In the same direction as a stream or other flow, or toward the direction in which the flow is moving.
rock flourFine-grained rock material produced when a glacier abrades or scrapes rock beneath it.
hydrometeorological prediction center  This is one of 9 centers that comprises the National Centers for Environmental Prediction (NCEP, formerly the National Meteorological Center)
gravitational waterthe water in the soil that is unavailable to plants and which flows out of the soil as throughflow to the river channel or percolates into the rock below.
outwashStratified sands and gravels washed out from glaciers by meltwater streams and deposited in the proglacial environment, or beyond the active glacial margin.
fissureA deep, long and narrow opening such as a crevasse in a glacier.
irrigated areaThe area upon which water is artificially applied
ground water overdraft  Pumpage of ground water in excess of safe yield.
continental slopeSteeply sloping portion of continental crust found between the continental shelf and continental rise.
regelationthe refreezing of water into ice after pressure which caused it to melt is released.
fetchdistance wind has travelled over open water to create waves.
water year  The time Period form October 1 through September 30.
deep seepage  Infiltration which reaches the water table.
septic systeman on-site system designed to treat and dispose of domestic sewage
average power  Pulsed radars transmit over a very low duty cycle; i.e., many intense but short and widely separated pulses
sea mileA unit of length distinguished from a nautical mile
floodHigh water flow or an overflow of rivers or streams from their natural or artificial banks, inundating adjacent low lying areas.
dorsal fin rayRefers to one of the cartilaginous rays (stiff rods) located in the membrane of a dorsal fin.
ion exchange treatmentA common water-softening technique often found on a large scale at water purification plants that remove some organics and radium by adding calcium oxide or calcium hydroxide to increase the pH to a level where the metals will precipitate out.
natural controlA stream-gaging control which is natural to the stream channel, in contrast to an artificial control constructed by man.
left mover  A thunderstorm which moves to the left relative to the steering winds, and to other nearby thunderstorms; often the northern part of a splitting storm
wave steepness  The ratio of wave heights to wave length.
anaerobica life or process that occurs in, or is not destroyed by, the absence of oxygen.
transpirationThe process by which water vapour is released into the atmosphere after transpiring of living plants.
saturated zoneThe zone in the earth's crust, extending from the water table downward, in which all open pore spaces in the soil or rock are filled with water at greater than atmospheric pressure
leached layerA soil layer or an entire soil profile from which the soluble materials (CaCO3 and MgCO3 and material more soluble) have been dissolved and washed away by percolating waters.
epidemicwidespread occurrence of a disease in a particular area or population.
water storage pondAn impound for liquid wastes designed to accomplish some degree of biochemical treatment.
closed basin  A basin draining to some depression or pond within its area, from which water is lost only by evaporation or percolation
bergschrunda large crevasse at the upper portion of a corrie glacier, close to the back-wall.
snow rollerThe product of moist, cohesive snow that when initiated by wind rolls across the landscape, gathering snow until it can no longer move
accumulation zoneThe area of a glacier where mass is increased through snowfall at a greater rate than snow and ice is lost through ablation.
fresh water inflow requirementsfreshwater flows required to maintain the natural salinity, nutrient, and sediment delivery in a bay or estuary that supports their unique biological communities and ensures a healthy ecosystem.
supercoolingThe reduction of the temperature of any liquid below the melting point of that substance's solid phase
arroyoA water-carved channel or gully in arid country, usually rather small with steep banks, dry most of the time, due to infrequent rainfall and the shallowness of the cut which does not penetrate below the level of permanent ground water.
snow packThe combined layers of snow and ice on the ground at any one time
katabatic windA wind that flows from a glacier, caused by air cooled by the ice becoming heavier than surrounding air, then draining down-valley.
hydraulic gradientThe slope or the water surface
uncorrelated shear  It is a sufficiently strong circulation detected on only one elevation angle within a thunderstorm.
headward erosionErosion which occurs in the upstream end of the valley of a stream, causing it to lengthen its course in that direction.
valley breezeLocal thermal circulation pattern found in areas of topographic relief
longitudeLongitude is the angular distance east or west from the north-south line that passes through Greenwich, England, to a particular location
flocGenerally, a very fine, fluffy mass formed by the aggregation of fine suspended particles, as in a precipitate
residualamount of a pollutant remaining in the environment after a natural or technological process has occurred.
riveran overland flow of water which forms a vital link in the hydrological cycle.
atolla ring-shaped coral reef.
ice runFlow of ice in a river
rock flour **Pulverized rock of the smaller size sediment classes (silts and clays) produced by glacial milling can give outwash streams a milky appearance.
lentic watersPonds or lakes (standing water).
stream powera measure of energy available to move sediment, or any other particle in a stream channel
medial moraineA moraine formed when two adjacent glaciers flow into each other and their lateral moraines are caught in the middle of the joined glacier.
firm annual yieldThe yearly amount of water that can be dependably supplied from the raw water sources of a given water supply system.
monomicticlakes and reservoirs that are relatively deep, do not freeze over during winter, and undergo a single stratification and mixing cycle during the year (usually in the fall).
flooded iceIce which has been flooded by melt water or river water and is heavily loaded by water and wet snow.
inter-basin transferthe transfer of water between drainage basins by humans.
pressure gradientThe change in pressure with distance, from lower to higher pressure, or vice versa.
unconfined aquiferan aquifer containing water that is not under pressure; the water level in a well is the same as the water table outside the well
biogeochemical cyclingthe flow of chemical substances to and from the major environmental reservoirs (atmosphere, hydrosphere, lithosphere, and biosphere).
mineral waterContains large amounts of dissolved minerals such as calcium, sodium, magnesium, and iron
gully reclamationuse of small dams of manure and straw; earth, stone,or concrete to collect silt and gradually fill in channels of eroded soil.
derecho(Pronounced day-RAY-cho) A widespread and usually fast-moving windstorm associated with convection
field moisture deficiencyThe quantity of water, which would be required to restore the soil moisture to field moisture capacity.
avalancheA mass of snow, rock, and/or ice falling down a mountain or incline
glacial driftA general term for all material transported and deposited directly by or from glacial ice.
bank-full channel depththe maximum depth of a channel within a rifle segment when flowing at a bank-full discharge.
nutrientAny food, chemical element or compound an organism requires to live, grow, or reproduce.
anticycloneAn area of high pressure around which the wind blows clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere
settleable solidsThose suspended solids in wastewater that will settle over a certain period of time and are removed in that way.
downburstA strong down draft, initiated by a thunderstorm, that induces an outburst of damaging straight line winds on or near the ground
prevailing visibilityIt is considered representative of visibility conditions at the observation station
convection plumethe upwelling part of a convection cycle in the mantle.
bioaccumulationA term used to describe a process that occurs when levels of toxic substances increase in an organism over time, due to continued exposure.
optimumThe level of an abiotic factor or condition in the environment within the tolerance range at which a species or population can function most efficiently or with the greatest positive effect to its physiological or reproductive fitness.
desert pavementA veneer of coarse particles left on the ground after the erosion of finer particles by wind.
zone of accumulationArea of a glacier where additions of snow exceed losses of ice from melting, evaporation, and sublimation.
sustainable managementA method of exploiting a resource that can be carried on indefinitely
algaesimple rootless plants that grow in sunlit waters in proportion to the amount of available nutrients
fracture  Any break or rupture formed in an ice cover or floe due to deformation.
physical weatheringbreaking down of parent rock into bits and pieces by exposure to temperature and changes and the physical action of moving ice and water, growing roots, and human activities such as farming and construction
dispersionthe movement and spreading of contaminants out and down in an aquifer.
primary spillway  The spillway which would be used first during normal inflow and flood flows.
megawattsA megawatt is one million watts or one thousand kilowatts, a measure of electrical power or generating capacity
return flowThe part of a diverted flow which is not consumptively used and which returns to a water body.
percolation pathThe course followed by water moving or percolating through any other permeable material, or under a dam which rests upon a permeable foundation.
z/r relationship  An empirical relationship between radar reflectivity factor z (in mm^6 / m^3 ) and rain rate ( in mm / hr ), usually expressed as Z = A R^b; A and b are empirical constants.
non-parametric statistical testStatistical tests that do not assume the sample data is normally distributed.
permanent monument  Fixed monuments placed away from the dam which allow movements in horizontal and vertical control points on the dam to be monitored by using accurate survey procedures.
in-line filtrationa pretreatment method in which chemicals are mixed by flowing water; commonly used in pressure filtration installations.
whalebacksElongated mounds or hills shaped by glacier movement may indicate direction of ice flow.
locational factorany factor which has an influence in an entrepreneurial decision to locate industry in a particular place.
sluman area of old, rundown housing where living and social conditions are very poor.
soft waterany water that does not contain a significant amount of dissolved minerals such as salts of calcium or magnesium.
ice sheetA dome-shaped glacier covering an area greater than 50,000 square kilometers
gullychannel formed on a poorly vegetated hillside by soil erosion
static water level(1) The elevation or level of the water table in a well when the pump is not operating
satellite imagesImages taken by a weather satellite that reveal information, such as the flow of water vapor, the movement of frontal system, and the development of a tropical system
density of snowThe ratio, expressed as a percentage, of the volume which a given quantity of snow would occupy if it were reduced to water, to the volume of the snow
rifflea bar-shaped deposit on a channel bed, midstream.
imperviousthe quality or state of being impermeable; resisting penetration by water or plant roots
clearThe state of the sky when no clouds or obscurations are observed or detected from the point of observation.
point barStream bar deposit that is normally located on the inside of a channel bend.
concentrateThe totality of different substances that are left behind in a filter medium after filtration.
tropical disturbanceAn area of organized convection, originating in the tropics and occasionally the subtropics, that maintains its identity for 24 hours or more
porosityThe void spaces found in rock, sediment, or soil
nonwithdrawal useUse which does not require diversion
precipitatea solid which has come out of an aqueous solution
field-moisture capacityThe quantity of water which can be permanently retained in the soil in opposition to the downward pull of gravity.
zooplanktontiny aquatic animals eaten by fish.
high seas  The major oceans of the world including, for National Weather Service purposes, the coastal and offshore areas.  Areas of responsibility for the United States are determined by international agreements under the auspices of the World Meteorological Organization (WMO).
gulf streamWarm ocean current that originates in and around the Caribbean and flows across the North Atlantic to northwest Europe.
composite volcanoVolcano created from alternate layers of flows and exploded rock
fractureAny break or rupture formed in an ice cover or floe due to deformation.
groundwater monitoringThe periodic measurement of ground water levels
hatchery stockA stock that depends upon spawning, incubation, hatching, or rearing in a hatchery or other artificial production facility.
overdraftpumping water from a groundwater basin or aquifer in excess of the supply flowing into the basin; results in a depletion or "mining" of the groundwater in the basin.
food processingpreserving food through canning, freezing, refrigeration, salting, smoking or vacuum packing
remote-sensingthe study of the surface from data gathered at high altitude by photography and other technology carried on aircraft and satellites.
leaching fieldThe area used for disposal of liquid through a non-water-tight artificial structure, conduit, or porous material by downward or lateral drainage, or both, into the surrounding permeable soil.
detachmentOne of three distinct processes involved in erosion
gorgedeep, narrow, steep (often vertical) -sided valley which usually has a river occupying its entire floor.
tropics/tropicalThe region of the earth located between the Tropic of Cancer, at 23.5 degrees North latitude, and the Tropic of Capricorn, at 23.5 degrees South latitude
corrosivityAbility of water to dissolve or break down certain substances, particularly metals.
weighing-type precipitation gageA rain gage that weighs the rain or snow which falls into a bucket set on a platform of a spring or lever balance
instabilityA state of atmosphere in which the vertical distribution of temperature allows rising, warm air to continue to rise and accelerate
reachIn both streams and glaciers, stretches of the flowing material which are different from those above and below.
threshold velocitythe velocity required for particles of a certain size to be taken into transport by an agent of erosion (entrainment).
periglacialLandforms created by processes associated with intense freeze-thaw action in an area high latitude areas or near an alpine or continental glacier.
tolerance rangeLimits of tolerance a species has to an abiotic factor or condition in the environment.
affluentA stream or river that flows into a larger one; a Tributary.
confined aquiferan aquifer that lies between two rock layers of very low permeability
gravity feed systemA system that provides flow in a channel or conduit through the use of gravity.
nature reservean area of land set aside to protect the environment for its own sake
runoffsurface water entering rivers, freshwater lakes, or reservoirs.
conduit(1) A natural or artificial channel through which fluids may be conveyed
infiltrationpaving, roofs,       roadways or other human structures, impervious cover increases runoff and affects the       quantity and composition of non-point source pollution, the quality or state of being       impermeable, resisting penetration by water or plant roots.
snow flurriesThey are intermittent light snowfalls of short duration (generally light snow showers) with no measurable accumulation.
membraneA plastic material used in the electrodialysis and reverse osmosis processes
globeA round model of the earth.
inflow & infiltrationI & I occurs when groundwater and stormwater enters the sanitary sewer system.
biosphereThe transition zone between the earth and the atmosphere within which most terrestrial life forms are found
plug flowtype of flow that occurs in tanks, basins, or reactors when a slug of water moves through without ever dispersing or mixing with the rest of the water flowing through.
latitudeThe measurement of distance north or south of the equator.
cirqueA steep-walled semicircular basin in a mountain caused by glacial erosion
specific humidityMeasurement of atmospheric humidity
craterCircular depression in the ground surface created by volcanic activity or asteroid impact.
outburst floodSee Jokulhlaup.
nitrificationThe biochemical oxidation of ammonium to nitrite and nitrite to nitrate
weathering landformIs a landform created by the physical or chemical decomposition of rock through weathering
pluckingThe process of loosening and lifting pieces of rock by a flowing glacier
subpolar glacierGlacier in which the ice found from the its surface to base has a temperature as cold as -30° Celsius throughout the year
pavementA rock surface, often eroded or striated, which underlies glacial till and is exposed in sufficient quantity to resemble a sidewalk or open plaza.
deflationProcess where wind erosion creates blowout depressions or deflation hollows by removing and transporting sediment and soil.
rippleStream bed deposit found streams
barrier windsRefers to the westerly flow of air along the northern slope of the Brooks Range in northern Alaska that precedes the arrival of colder air from the north.
pressure gradientThe amount of pressure change that occurs over a fixed distance at a fixed altitude.
imhoff coneA clear, cone-shaped container used to measure the volume of settle able solids in a specific volume of water.
seismic waveSuccessive wave-type displacement of rock usually caused by an earthquake.
flood plainLevel land that may be submerged by flood waters.
cooling towerlarge tower used to transfer the heat in cooling water from a power or industrial plant to the atmosphere either by direct evaporation or by convection and conduction.
stratopauseThe stratopause is a relatively thin atmospheric transition layer found between the stratosphere and the mesosphere
drainage patternGeometric pattern that a stream's channels take in the landscape
oxbow lakea U-shaped water body formed when a meander bend is cut off from the mainstem of a river or stream to create a lake.
diversionto remove water from a water body
vapor pressure  The partial pressure of water vapor in an air-water system.
froude numbera dimensionless number comparing inertial and gravitational forces
habitat diversityThe number of different types of habitat within a given area.
cloudA visible collection of minute particle matter, such as water droplets and/or ice crystals, in the free air
heavy waterWater in which all the hydrogen atoms have been replaced by deuterium.
hydrometeran instrument used to measure the density of a liquid.
water columnan imaginary column extending through a water body from its floor to its surface
prognostic chartA chart of forecast predictions that may include pressure, fronts
epilimnionwarm, less dense top layer in a stratified lake
afforestationplanting of trees on previously un-wooded land.
funnelling  The process whereby wind is forced to flow through a narrow opening between adjacent land areas, resulting in increased wind speed.
internal deformationOne of the ways glaciers flow is by movement across the faces of the ice crystals that make the glacier.
ice stormA severe weather condition characterized by falling freezing precipitation
eastern north pacific basin  The region north of the Equator east of 140W
sewageWaste matter carried off by sewers and drains.
gas chromatographan instrument that identifies the molecular composition and concentrations of various chemicals in water and soil samples.
flood of recordThe highest observed river stage or discharge at a given site during the period of record keeping
methoxychlorpesticide that causes adverse health effects when found in domestic water supplies
isothermal layerVertical layer in the atmosphere where temperature remains unchanged
ventifactA loose piece of rock that has been polished smooth by wind transported particles
pondA body of water smaller than a lake, often artificially formed.
relative humidityThe ratio between the actual amount of water vapor held in the atmosphere compared to the amount required for saturation
circulation cellsLarge areas of air movement created by the rotation of the earth and the transfer of heat from the equator toward the poles
incidental waste water reclamationTreated waste water returned to fresh-water streams or other water bodies
ground wateror aquifer, storage from surface water       supplies such as irrigation water, reclaimed wastewater or induced infiltration from streams       or wells.
ground water divideA line on a water table where on either side of which the water table slopes downward
meta-populationA population comprising local populations that are linked by migrants, allowing for recolonization of unoccupied habitat patches after local extinction events.
lowland flooding  Inundation of low areas near the river, often rural, but may also occur in urban areas.
imhoff conea clear, cone-shaped container used to measure the volume of settleable solids in a specific volume of water.
inselbergA German term used to describe a steep-sided hill composed of rock that rises from a pediplain.
thalwegLine of deepest water in a stream channel as seen from above
infiltrationthe penetration of water through the ground surface into sub-surface soil or the penetration of water from the soil into sewer or other pipes through defective joints, connections, or manhole walls.
forfeited water rightA water right that is no longer valid because of five or more consecutive years of nonuse.
municipal dischargedischarge of effluent from treatment plants that receive wastewater from households, commercial establishments, and industries.
permeameterA laboratory instrument for determining permeability by measuring the discharge through a sample of the material when a known hydraulic head is applied.
indian summerA warm, calm spell of weather occurring in autumn, especially in October and November
soil-moisture depletionThe process where soil water is removed by crops through Evapotranspiration.
sulfate aerosolType of solid compound commonly found in the atmosphere
hydrographA graph showing the stage, flow, velocity, or other property of water with respect to the passage of time
reach(1) Most generally, any specified length of a stream or conveyance
sea-levelaverage elevation of the surface of the oceans.
asthenospherelayer of rock in the mantle approximately 80km deep and at a temperature of 1400°C
tailraceThe channel that is downstream of the draft tube that carries the water discharged from a turbine
lakeor other body of water into which light can penetrate, also       known as the zone of photosynthesis.
natural precipitationRepresents the average annual precipitation (rainfall, snow, and sleet) measured at a number of different weather stations.
      surfacewaterground water).
upwellingThe movement of nutrient-rich deep seawater to the ocean's surface.
spawning channelAn artificial gravel-bed area in which flow, depth and velocity are controlled at ideal levels for spawning by a particular species of salmon or steelhead.
spring tideTide that occurs every 14 to 15 days and coincides with the new and full moon
tropopause jetsJet streams found near the tropopause
terminal moraineA ridge formed by the accumulation of glacial deposits at the point marking the furthest advance of an ablating glacier.
infiltrationmovement of water from the surface into the soil.
valley breezeAn anabatic wind, it is formed during the day by the heating of the valley floor
zone of ablationThe termini of glaciers where loss of ice occurs through calving, melting or evaporation.
conjunctive managementintegrated management and use of two or more water resources, such as an aquifer and a surface water body.
suspended-sediment dischargethe quantity of suspended sediment passing a point in a stream over a specified period of time
tube settlerdevice using bundles of tubes to let solids in water settle to the bottom for removal by conventional sludge collection means
hydrologic cycleThe movement of water from the atmosphere to the Earth and back
evapotranspirationThe loss of water from the soil through vaporizing, both by direct evaporation and by transpiration from plants.
lake/land breezeA lake breeze occurs when prevailing winds blow off the water, while a land breeze indicates winds blowing from land to sea
hydrologyField of physical geography that studies the hydrosphere.
freezing rainA type of precipitation
forecast point  A location that represents an area (reach of a river), where a forecast is made available to the public
degradationReadjustment of the stream profile where the stream channel is lowered by the erosion of the stream bed
pascalThe unit of pressure produced when one newton acts on about one square meter.
clarificationClearing action that occurs during wastewater treatment when solids settle out
lakeseparated by the fairly thin thermocline       zone, from the lower, colder, denser zone of water, the hypolimnion.
frost/freeze advisory  This product is issued by the National Weather Service when freezing temperatures or conditions conducive to the formation of frost occur during the growing season.
lagoonA lagoon is a shallow body of water that is located alongside a coast.
boundary waterA river or lake that is part of the boundary between two or more countries or provinces that have rights to the water.
subimpoundmentAn isolated body of water created by a dike within a reservoir or lake.
per capita useThe average amount of water used per person during a standard time period, generally per day.
critical depthThe depth of water flowing in an open channel or conduit, partially filled, corresponding to one of the recognized critical velocities.
condensationsublimation,       vapourization, transpiration, evapotranspiration, volatilization).
base width(1) The time interval between the beginning and end of the direct runoff produced by a storm
ccl  An acronym for Convective Condensation Level.  See Convective Condensation Level.
pater noster lakesA string of glacial lakes along the path of a mountain glacier
bio-monitorplant/animal used to alert scientists to a change in environment.
in-situ oxidationtechnology that oxidizes contaminants dissolved in groundwater, converting them into insoluble compounds.
altitudeheight above sea-level.
hygroscopicSubstances that have the ability to absorb water and therefore accelerate the condensation process.
gaging stationA particular site in a stream, lake, reservoir, etc., where hydrologic data are obtained.
phytoplanktona miniscule plant which grows and lives in the upper layers of the ocean and which forms the basis of the marine food chain or web.
infiltration indexAn average rate of infiltration, in inches per hour, equal to the average rate of rainfall such as that the volume of rainfall at greater rates equals the total direct runoff.
high-yield varietygrain crop which has been selectively bred to produce seeds which produce far more than otherwise.
effluentWastewater--treated or untreated--that flows out of a treatment plant, sewer, or industrial outfall
tillA random mixture of finely crushed rock, sand, pebbles, and boulders deposited by a glacier.
focusin an earthquake, the actual point within the crust where the energy was released.
rope  A narrow, often contorted condensation funnel usually associated with the decaying stage of a tornado
ground waterits occurrence and movements, its       replenishment and depletion, the properties of rocks that control ground water movement and       storage and the methods of investigation and utilization of ground water.
canyonA canyon is a deep valley with very steep sides - often carved from the Earth by a river.
onshoreComing or moving from the water toward or onto the shore, as a breeze or prevailing wind.
potential energyIs the energy that a body possesses by virtue of its position and that is potentially transformable into another form of energy.
mesotrophicreservoirs and lakes that contain moderate quantities of nutrients and are moderately productive in terms of aquatic animal and plant life.
strayingA natural phenomena of adult spawners not returning to their natal stream, but entering and spawning in some other stream.
snoutFront end of a glacier
greenhouse effectThe heating effect caused by gases in the atmosphere absorbing heat (solar radiation) instead of letting it escape back into space
longitudeLongitude is a west-east measurement of position on the Earth
ground water overdraftPumpage of ground water in excess of safe yield.
reference files systemAn OPP database that provides data on pesticide active ingredients, registrants, and products (including product types, formulations, transfers, etc.) registrant - A pesticide manufacturer that has registered a pesticide product. 
codChemical Oxygen Demand.  A measure of the oxygen equivalent of the organic matter content of a sample that is susceptible to oxidation by a strong chemical oxidation.  Differs from the BOD test in that COD uses oxygen derived from chemicals, while BOD uses oxygen derived from air dissolved in water. 
sunriseMoment of time when the Sun's edge first appears above the Earth's horizon.
mean low waterThe average height of the daily low tides recorded over a 19-year period at a specific location.
biomonitoringThe use of living organisms to test the suitability of effluents for discharge into receiving waters and to test the quality of such waters downstream from the discharge.
rotten iceIce in an advanced stage of disintegration.
hydrologythe science dealing with the properties, distribution, and circulation of water.
landlocked(1) Enclosed or nearly enclosed by land, as a landlocked country without access to the sea or ocean
farm headgate deliveryThat amount of water in acre feet (AF) delivered through a farm headgate.
aqueous solubilityThe maximum concentration of a chemical that dissolves in a given amount of water.
closed lowA region of low pressure distinguished by a center of counterclockwise circulation (in the Northern Hemisphere), and is surrounded by one or more isobars or height contours
maximumThe greatest value attained by a function, for example, temperature, pressure, or wind speed
injection zonea geological formation receiving fluids through a well.
limnophobia  The fear of lakes.
rain gageany instrument used for recording and measuring time, distribution, and the amount of rainfall.
tower   Short for towering cumulus.   A cloud element showing appreciable upward vertical development.
glacial surgeThe rapid forward movement of a glacier.
ice tongueA long, narrow projection of ice which points out for the coastline where a valley glacier flows rapidly into the sea or a lake.
sky condition  Used in a forecast to describes the predominant/average sky condition based upon octants (eighths) of the sky covered by opaque (not transparent) clouds.
municipal sewagesewage from a community which may be composed of domestic sewage, industrial wastes or both.
limnologyThe branch of hydrology that pertains to the study of lakes.
unambiguous range  See maximum unambiguous range.
desalinationThe removal of salt from seawater or brackish water to produce drinking water, using various techniques.
severe icing  The rate of ice accumulation on an aircraft is such that de-icing/anti-icing equipment fails to reduce or control the hazard.  Immediate diversion is necessary.  This standard of reporting this type of icing was based on a recommendation set forth by the subcommittee for Aviation Meterorological Services in the Office of the Federal Coordinator for Meteorology in November 1968.  The convection has been to designate icing intensity in terms of its operational effect upon reciprocating engine, straight wing transport aircraft as used by commuter operators.
point barThe convex side of a meander bend that is built up due to sediment deposition.
raw sludgeThe material settled out during the primary clarification of sewage.
aerated lagoonA water treatment pond that speeds up biological decomposition of organic waste by stimulating the growth and activity of bacteria, which are responsible for the degradation.
opaqueA condition where a material, such as a cloud, blocks the passage of radiant energy, especially light
marine(1) Of or pertaining to the sea; having to do with the ocean or the things peculiar to the ocean
emergency services  Services provided in order to minimize the impact of a flood that is already happening
pressure tendencyThe character and amount of atmospheric pressure change during a specified period of time, usually 3-hour period preceding an observation.
dam failure  Catastrophic event characterized by the sudden, rapid, and uncontrolled release of impounded water.
piezometric surfacethe imaginary surface to which groundwater rises under hydrostatic pressure in wells or springs.
ponding  In flat areas, runoff collects, or ponds in depression and cannot drain out
peritoneumMembrane lining the body cavity.
steady-state mass balancethe mathematical concept that the sum of upstream pollutant loads, each determined by the product of their concentration times flow, equals a resultant downstream load after mixing.
late seral conditionSynonymous with good ecological conditions.
receiving watersA river, ocean, stream, or other watercourse into which wastewater or treated effluent is discharged.
critical slopeThat slope that will sustain a given discharge at uniform, Critical Depth in a given channel.
benthic invertebratesAquatic animals without backbones that dwell on or in the bottom sediments of fresh or salt water
recreational riversRivers or sections of rivers that are readily accessible by road or railroad, that may have some development along their shoreline, and that may have undergone some impoundment or diversion in the past.
anti-degradation clausepart of federal and water quality requirements prohibiting deterioration where pollution levels are above the legal limit.
rip currentA strong, narrow current of surface water that flows seaward through the surf into deeper water
water pollutiondegradation of a body of water by a substance or condition to such a degree that the water fails to meet specified standards or cannot be used for a specific purpose.
tuberculationdevelopment or formation of small mounds of corrosion products on the inside of iron pipe
large water systemA water system that services more than 50,000 customers.
contaminantAny foreign component in a substance, for example in water.
normal faultVertical fault where one slab of the rock is displaced up and the other slab down
densitya measure of how heavy a specific volume of a solid, liquid, or gas is in comparison to water.
linkagesrelationships between industries.
impermeableUnable to transmit water; not easily penetrated
scatteringthe diffusion of insolation by particles in the atmosphere
alvusiona sudden or perceptible change in a river's margin, such as a change in course or loss of banks due to flooding.
troughAn elongated area of low atmospheric pressure that is associated with an area of minimum cyclonic circulation
migrantLife stage of anadromous and resident fish species which moves from one locale, habitat or system (river or ocean) to another.
sea(1) One of the larger bodies of salt water, less than an ocean, more or less landlocked and generally forming part of, or connecting with, an ocean or a larger sea
spillway  A structure over or through which excess or flood flows are discharged
assimilative capacitythe capacity of a natural body of water to receive and dilute wastewaters or toxic materials without damage to aquatic life or humans who consume the water.
firn snow  Old snow on top of glaciers, granular and compact and not yet converted into ice
ssoSanitary Sewer Overflow: Untreated or partially treated sewage overflows from a sanitary sewer collection system.
mesosphereAtmospheric layer found between the stratosphere and the thermosphere
shield areaancient, stable area of crust away from plate margins and therefore unaffected by volcanic or earthquake activity.
evaporationA process by which liquid changes into a gas or vapor.
reefA ridge of rocks found in the tidal zone along a coastline
quantitative precipitation forecastA forecast of rainfall, snowfall or liquid equivalent of snowfall.
wet-bulb temperatureThe lowest temperature that can be obtained by evaporating water into air.
deadmanA log, block of concrete, rebar, or other object buried in a stream bank that is used to tie in revetment with cable or chain.
hydropowerelectrical energy produced by falling water.
catalina eddyA weak low pressure circulation that may form off the Southern California coast.
transporttwo types:         In human geography, the movement of goods or people by vehicle         In physical geography, the movement of sediment load by water, wind or ice.
till plainA gently irregular plain of till deposited by an actively retreating glacier.
habitatThe local environment in which a organism normally lives and grows.
underflowThe lateral motion of water through the upper layers until it enters a stream channel
saltationthe transport of load by bouncing along the bed of a river channel.
pluvialpertaining to precipitation.
profundal zonea lake's deep-water region that is not penetrated by sunlight.
meltwaterwater that comes from the melting ice of a glacier or a snowbank.
continental shelfshallow sea floor fringing continents
grab samplea sample taken at a given place and time
rock flourThe very finely-ground up debris carried downslope by a mountain glacier; when deposited, often blown away by the wind.
water yeara division based on a general pattern of annual wet and dry periods rather than a calendar year
transmissibilitythe capacity of a rock to transmit water under pressure
sedimentary rockRocks formed by the deposition, alteration and/or compression, and lithification of weathered rock debris, chemical precipitates, or organic sediments
hydraulic permeabilityThe flow of water through a unit cross-sectional area of soil normal to the direction of flow when the hydraulic gradient is unity.
recharge ratethe quantity of water per unit of time that replenishes or refills an aquifer.
advanced wastewater treatmentany treatment of sewage that goes beyond the secondary or biological water treatment stage and includes the removal of nutrients such as phosphorus and nitrogen and a high percentage of suspended solids.
gaging stationa site on a stream, lake, reservoir or other body of water where observations and hydrologic data are obtained
settlementa location where people have built structures to use as a base for their existence.
erosionThe removal of weathered sediment or rocks by the forces of wind, water, and ice.
storm hydrographA hydrograph representing the flow or discharge of water past a point on a river.
casinga tubular structure intended to be watertight installed in the excavated or drilled hole to maintain the well opening and, along with cementing, to confine the ground waters to their zones of origin and prevent the entrance of surface pollutants.
urban floodingFlooding of streets, underpasses, low lying areas, or storm drains
convectiontransfer of heat in a gas or liquid by upward movement of the hotter, less dense portion
breachThe failed opening in a dam.
bergschrundThe ice wall commonly found at the head of a glacier which has separated slightly from the rock wall of its cirque.
mediaMaterials that form a barrier to the passage of certain suspended solids or dissolved liquids in filters.
chart datumA plane of reference, established by the National Ocean Survey (NOS), as a mean low water level for each of the Great Lakes
gondwanalanda supercontinent proposed by Alfred Wegener after the breakup of Pangaea (the single continent) into two
river floodingThe rise of a river to an elevation such that the river overflows its natural banks causing or threatening damage.
soil moisture rechargeThe process of water filling the pore space found in a soil (storage).
woody debrisReferring to wood in streams.
hydroelectricHaving to do with production of electricity by water power from falling water.
effluentany substance, particularly a liquid, that enters the environment from a point source
short waveA small wave in the polar jet stream and the westerlies that extends from the middle to the upper troposphere
flow duration curvea measure of the range and variability of a stream's flow
anabranch  A diverging branch of a river which re-enters the main stream.
mineral waterNaturally occurring or prepared water that contains dissolved mineral salts, elements, or gases, often used therapeutically.
stream piracythe tendency of one stream to capture the flow of another by eroding a channel that intercepts the other stream's flow.
gravity damA concrete structure proportioned so that its own weight provides the major resistance to the forces exerted on it.
floodThe inundation of a normally dry area caused by high flow, or overflow of water in an established watercourse,
hygroscopica substance that attracts water.
black ice  Thin, new ice on fresh- or saltwater, appearing dark in color because of its transparency; also popularly applied to thin hazardous ice coverings on roads.
pressure gradientin the atmosphere, the rate at which pressure changes across space
anadromousFish that hatch rear in fresh water, migrate to the ocean (salt water) to grow and mature, and migrate back to fresh water to spawn and reproduce.
detritivoreHeterotrophic organism that feeds on detritus
interglacial periodsTimes between recognized advances of the ice
venturi meterA meter, developed by Clemens Herschel, for measuring flow of water or other fluids through closed conduits or pipes
industrial estateplanned area of integrated buildings and roads for industrial use, especially by modern industrial businesses
in-situ vitrificationtechnology that treats contaminated soil in place at high temperatures, at 3,000 degrees Fahrenheit or more.
sewera system of underground pipes that collect and deliver wastewater to treatment facilities or streams.
shear stressthe frictional force per unit area exerted on a streambed by flowing water
tidethe periodic rise and fall of sea level due to the gravitational pull of the sun and moon
adsorptionthe adhesion of a substance to the surface of a solid or liquid
cirrus cloudsHigh altitude cloud composed of ice crystals
storeta national U.S
magnetic reversalA change in the polarity of the Earth's magnetic field
snowfallThe amount of snow which has accumulated since the last observation
sealthe impermeable material, such as cement grout bentonite, or puddling clay placed in the annular space between the borehole wall and the casing of a water well to prevent the downhole movement of surface water or the vertical mixing of artestian waters.
stable/stabilityOccurs when a rising air parcel becomes denser than the surrounding air
flow-sensitive habitatshabitats that show hydraulic response to relatively small changes in streamflow
sawrs-ii  Indicates automated observations taken by a commissioned Automated Surface Observing System
sewageThe liquid waste from domestic, commercial, and industrial establishments.
swellOcean waves that have traveled out of their generating area
crevasseElongated open cracks in glacial ice, usually nearly vertical, and subject to change at any moment
closed basin lake floodingFlooding that occurs on lakes with either no outlet or a relatively small one
water tableThe level of groundwater; the upper surface of the Zone of Saturation for underground water
hydrogeologythe geology of groundwater, with particular emphasis on the chemistry and movement of water.
river statementA product issued to communicate notable hydrologic conditions which do not involve flooding, i.e., within river bank rises, minor ice jams, etc.
hanging glacierIce moving out of high cirques can carve hanging valleys unconnected to a lower glacial mass on steep slopes.
mackerel skyThe name given to cirrocumulus clouds with small vertical extent and composed of ice crystals
altocumulus castellanusA middle cloud with vertical development that forms from altocumulus clouds
climatologyScientific study of the Earth's climate over long time spans (greater than several days)
fjordA deep glacial trough submerged with seawater.
clean water actfederal legislation enacted in 1972 to restore and maintain the chemical, physical and biological integrity of the surface waters of the United States
saline/poor quality aquiferAn aquifer containing water that is high in total dissolved solids, and is unacceptable for use as drinking water.
subirrigated landLand with a high water table condition, either natural or artificially controlled, that normally supplies a crop irrigation requirement.
storm sewerAny underground pipe or conduit designed to carry only stormwater to a known outfall
dynamic metamorphismForm of metamorphism that causes only the structural alteration of rock through pressure
national priorities listEPA's list of the most serious uncontrolled or abandoned hazardous waste sites identified for possible long-term remedial action under Superfund
nonconsumptive useusing water in a way that does not reduce the supply
snow advisoryA statement or advisory issued when snow is expected to create hazardous travel conditions
blooma proliferation of algae and/or higher aquatic plants in a body of water; often related to pollution or excessive nutrients, especially when they accelerate growth.
pluvial  In hydrology, anything that is brought about directly by precipitation.
ancraophobia  The fear of the wind.  See Anemophobia.
groundwaterThe supply of fresh water found beneath the earth's surface (usually in aquifers) that is often used for supplying wells and springs.
sublimationthe transition of water directly from the solid state to the gaseous state, without passing through the liquid state; or vice versa
cultivationthe preparation and use of land for crop growing.
firnpartially packed snow which lasts through at least one summer
man entry sewersThose sewers considered to be large enough for safe manual (physical) inspection, survey and work activities (e.g., manual renovation and repair)
coagulationin water treatment, the use of chemicals to make suspended solids gather or group together into small flocs.
fresh waterWater that generally contains less than 1000 milligrams per litre of dissolved solids such as salts, metals, nutrients, etc.
glacial troughA deep U-shaped valley with steep valley walls that was formed from glacial erosion
springGround water seeping out of the earth where the water table exceeds the ground surface.
csi  An acronym for Conditional Symmetric Instability.  See Conditional Symmetric Instability. 
snow telemetry  An automated network of snowpack data collection sites
interbasin transferThe diversion of water from one drainage basin to one or more other drainage basins.
collector wella well located near a surface water supply used to lower the water table and thereby induce infiltration of surface water through the bed of the water body to the well.
zonal indexThe measure of the strength of the westerly winds of the middle latitudes
doldrumsArea of low atmospheric pressure and calm westerly winds located at the equator
thunderThe sound emitted by rapidly expanding gases along the channel of a lightning discharge
nitrous oxideGas found in the atmosphere that contributes to the greenhouse effect
advection fogIt is formed as warmer, moist air moves over a cold ground
mcs  An acronym for Mesoscale Convective System.  See Mesoscale Convective System.
streamflowThe discharge that occurs in a natural channel of a surface stream course.
pluviometerA Rain Gauge.
firn line  The highest level to which the fresh snow on a glacier's surface retreats during the melting season
ice sizzleSounds made by glaciers which sound like carbonated soda.
conservationThe continuing protection and management of natural resources in accordance with principles that assure their optimum long-term economic and social benefits.
mitigationMeasures taken to reduce adverse impacts on the environment.
continentone of the seven largest pieces of land on earth.
basin rechargeRainfall that adds to the residual moisture of the basin in order to help recharge the water deficit
ice twitch  Downstream movement of a small section of an ice cover
sewageThe waste and wastewater produced by residential and commercial sources and discharged into sewers.
perched groundwaterGroundwater supported by a zone of material of low permeability located above an underlying main body of groundwater with which it is not hydrostatically connected.
smpdbk  The Simplified Dam Break (DAMBRK) Model
ablationThe process by which ice and snow waste away as a result of melting and/or evaporation.
water tableTop surface of groundwater.
shore iceAn ice sheet in the form of a long border attached to the bank or shore; border ice.
glacial lakeA natural impoundment of meltwater at the front of a glacier.
free ground waterUnconfined ground water whose upper boundary is a free water table.
mangroveTreed wetlands located on the coastlines in warm tropical climates.
power peakingThe generation of electricity to meet maximum instantaneous power requirements; usually refers to daily peaks.
core areaThe area of habitat essential in the breeding, nesting, and rearing of young, up to the point of dispersal of the young.
marshA type of wetland that does not accumulate appreciable peat deposits and is dominated by herbaceous vegetation
meander  The winding of a stream channel.
publicly-owned treatment worksa wastewater treatment plant that is owned by a state, unit of local government or Indian tribe, usually designed to treat domestic wastewaters
water yieldRunoff, including ground water outflow that appears in the stream, plus ground water outflow that leaves the basin underground
effluent exchangeThe practice of using wastewater effluent as a replacement source for diversion of water upstream.
net balanceThe change in the amount of mass of a glacier from one year to the next.
chezy's equationthe empirical equation used to estimate the hydraulic conditions of flow within a channel cross section
biological integritythe ability to support and maintain balanced, integrated functionality in the natural habitat of a given region
intermittentAlternately containing and empty of water as an intermittent lake.
recirculationRecycling water after it is used
terraceAn abandoned floodplain that is located at a higher elevation than the current active floodplain.
heatA form of energy transferred between two systems by virtue of a difference in temperature
zwitter ionsAct as cations or as anions according to the environment in which they find themselves
current meterAn instrument for measuring the velocity of water flowing in a stream, open channel, or conduit by ascertaining the speed at which elements of the flowing water rotate a vane or series of cups.
ridgeAn elongated area of high atmospheric pressure that is associated with an area of maximum anticyclonic circulation
ice fogA fog that is composed of small suspended ice crystals
leaf dripThe rain water that fall to the ground surface from plant leaves after it has been intercepted by these structures.
focusSee earthquake focus.
glideA section of stream that has little or no turbulence.
bankfull stage/elevation  An established river stage/water surface elevation at a given location along a river which is intended to represent the maximum water level that will not overflow the river banks or cause any significant damages from flooding.
ice fogOccurs when the temperature is much below freezing and water vapor condenses directly as ice crystals (sublimation)
collar cloud  A generally circular ring of cloud that may be observed on rare occasions surrounding the upper part of a wall cloud.  This term sometimes is used (incorrectly) as a synonym for wall cloud.
floodway  1) A part of the flood plain, otherwise levied, reserved for emergency diversion of water during floods
plumeThe area of the Pacific Ocean that is influenced by discharge from the Columbia River, up to 500 miles beyond the mouth of the river.
live moisture maps  These maps portray experimental live vegetation moisture with values ranging from 50 to 250 percent of dry weight.
importWater piped or channeled into an area.
hydrographyThe study, description, and mapping of oceans, lakes, and rivers, especially with reference to their navigational and commercial uses.
specific conductanceMethod to estimate the dissolved solid content of a water supply by testing its conductivity.
compressionOne of the three forces (see tension and shear), compression applied to an object causes deformation parallel and perpendicular to the constricting force.
snowfallThe rate at which snow falls, usually expressed in inches of snow depth over a six hour period.
semi-diurnal tideTides that have two high and two low waters per tidal period.
ferrel cellThree-dimensional atmospheric circulation cell located at roughly 30 to 60° North and South of the equator.
river banksThe portion of the channel cross section that restricts lateral movement of water at normal discharges
horizontwo uses:
continental crustis the layer of granitic, sedimentary, and metamorphic rocks which form the continents and the areas of shallow seabed close to their shores, known as continental shelves.
blowout depressionSaucer shaped depressions created by wind erosion
nomada person without a permanent home who moves from place to place throughout the year seeking subsistence
eyeThe relatively calm center in a hurricane that is more than one half surrounded by wall cloud
esker fanA small plain of sand and gravel built at the mouth of a subglacial stream and associated with an esker formed simultaneously.
estuarya place where fresh and salt water mix, such as a bay, salt marsh, or where a river enters an ocean.
total totalsThis index estimates the potential for severe convection
french drainAn underground passageway for water through the interstices among stones placed loosely in a trench.
quasi-stationary  Describes a low or high pressure area or a front that is nearly stationary.
irrigation requirement  The quantity of water, exclusive of precipitation, that is required for crop production
confined ground waterGround water held under an aquiclude or an aquifuge called artesian if the pressure is positive.
aeration zone  A portion of the lithosphere in which the functional interstices of permeable rock or earth are not filled with water under hydrostatic pressure
cured-in-placeA pipe rehabilitation system in which a flexible lining (either epoxy resin or polyester resin) is inserted into an existing sewer and heat cured
contract farmingwhere large agribusinesses, usually food processing companies or supermarket chains, contract farmers to provide them with particular types of produce.
hydraulic modela computer model of a segment of river used to evaluate hydraulic conditions
ablation zoneThe area of a glacier where mass is lost through melting or evaporation at a greater rate than snow and ice accumulate.
arcticOf or relating to the area around the geographic North Pole, from 90° North to the Arctic Circle at approximately 66 1/2 North latitude.
transpirationdirect transfer of water from the leaves of living plants to the atmosphere
epiphyteType of vegetation that gets its physical support from the branches of other plants
hydrostatic pressureForce caused by water under pressure.
aqueous solubilitythe maximum concentration of a chemical that will dissolve in pure water at a reference temperature.
oxbowAn abandoned meander in a river or stream, caused by cutoff
stock statusThe current condition of a stock, which may be based on escapement, run size, survival, or fitness level.
fecal coliform bacteriaBacteria that are present in the gut or the feces of warm blooded animals; they are indicators of possible sewage pollution.
bcwmcBassett Creek Watershed Management Commission
condensation funnelA funnel-shaped cloud consisting of condensed water drops that has possible rotation.
rossby wavesThe movement of ridges and troughs in the upper wind patterns, primarily the jet stream, circling the earth
ice capsSmaller ice sheets which cap many islands in the Arctic Ocean and in and near Iceland.
perennial streamsStreams that flow continuously.
ice fallAn area of crevassed ice on a glacier
meteoric watergroundwater which originates in the atmosphere and reaches the zone of saturation by infiltration and percolation.
water quality-based toxics controlan integrated strategy used in NPDES permitting to assess and control the discharge of toxic pollutants to surface waters
rime ice  It is a rough, milky, opaque ice formed by the instantaneous freezing of small supercooled droplets as they strike the aircraft.  The fact that droplets maintain their nearly spherical shape upon freezing and thus trap air between them gives the ice its opaque appearance and makes it porous and brittle.
distributionThe spatial arrangement of a species within its range.
gallery  A passageway within the body of a dam or abutment.
gaging stationthe site on a stream, lake or canal where hydrologic data is collected.
erosionThe wearing away of the land surface by wind, water, ice or other geological agents
fluvioglacial landformsmeltwater transports and deposits material both in and adjacent to glacial environments
slurryA pumpable mixture of solids and fluid.
wetting and dryingPhysical weathering process where rocks are mechanically disintegrated by the accumulation of successive layers of water molecules in between the mineral grains of a rock
ribbon fallsSpectacular narrow waterfalls that occur at the edge of a hanging valley.
perched water tablegroundwater standing unprotected over a confined zone.
evaporationThe physical process by which a liquid, such as water is transformed into a gaseous state, such as water vapor
wind erosionthe removal of particles from the surface by wind, and the degrading processes caused when these particles are thrown against rock.
woody debrisGenerally referring to naturally occurring wood in streams.
quickwaterthe part of a stream that has a strong current; an artificial current or bubbling patch of water just astern of a moving boat.
drought indexComputed value which is related to some of the cumulative effects of a prolonged and abnormal moisture deficiency
gelifluctiona form of mass movement in which thawed upper soil layers move over permafrost.
stratosphereThe layer of the atmosphere located between the troposphere and the mesosphere, characterized by a slight temperature increase and absence of clouds
organicany chemical containing the element carbon overdraft - condition that occurs in a groundwater basin when pumping exceeds the amount of replenishment over a period of years ozone - a gas that is bubbled through water to kill germs
detection limitthe lowest level that can be determined by a specific analytical procedure or test method.
algal blooma phenomenon whereby excessive nutrients within a river, stream or lake cause an explosion of plant life which results in the depletion of the oxygen in the water needed by fish and other aquatic life
hudson bay lowAn area of low pressure over or near the Hudson Bay area of Canada that often introduces cold air to the north central and northeast United States.
mucape  CAPE calculated using a parcel from a pressure level that results in the Most Unstable CAPE possible.  See Convective Available Potential Energy (CAPE).
rex blockA blocking pattern where there is an upper level high located directly north of a closed low.
soil-moisture deficiencyThe difference between the water-holding capacity of the soil and the instantaneous soil moisture.
pressure falling rapidlyA decrease in station pressure at a rate of 0.06 inch of mercury or more per hour which totals 0.02 inch or more.
subtropical jetMarked by a concentration of isotherms and vertical shear, this jet is the boundary between the subtropical air and the tropical air
pesticideA substance or mixture of substances intended for preventing, destroying, repelling, or mitigating any pest
fluvialMigrating between main rivers and tributaries
evapotranspirationThe loss of water from a land area through evaporation from the soil and through plant transpiration.
sleetprecipitation which is a mixture of rain and ice.
particulatesthe mechanical process which removes       particulate matter by separating water from solid material, by passing it through a filter such as       sand in many water filtration plants.
humidityThe degree of moisture in the air.
sea archA coastal landform composed of rock that resembles an arch
humidityA general term used to describe the amount of water vapor found in the atmosphere.
spatial isolationReproductive isolation of two or more populations of a species by distance or physical barriers
annual operating planA yearly plan for operating reservoirs on the Columbia River
sanitary sewerA sanitary sewer is a pipe located in a street or easement that is designed to transport wastewater away from sanitary fixtures inside your house or place of business.
ice jam  A stationary accumulation that restricts or blocks streamflow.
run-offall water leaving a drainage basin.
river stageThe elevation of the water surface at a specified station above some arbitrary zero datum (level).
routing parameterscoefficients that, along with mathematical routing equations, can be used to estimate the attenuation and lag (time delay) associated with the movement of flow through a length of stream channel.
ground water runoffA portion of runoff which has passed into the ground, has become ground water, and has been discharged into a stream channel as spring or seepage water.
hod  1) The Hydrologist on Duty at an RFC.  2) The Hydrologic Operations Division of the Office of Hydrology (OH).
unloadingThe releasing of downward pressure on rocks because of removal of overlying material by erosion
isohyetThe line drawn through geographic points recording equal amounts of rainfall during a given time or for a given of storm.
turbidimetera device that measures the cloudiness of suspended solids in a liquid; a measure of the quantity of suspended solids.
leadsLong, narrow openings or fractures in sea ice.
instream flow work groupAn interagency group that simulated the effects of various fish flow regimes by using hydropower regulation computer models
deepeningUsed in describing the history of a low pressure system or an area of cyclonic circulation, it means a decrease in the central pressure of the system
leaky aquiferAn artesian or water table aquifer that loses or gains water through adjacent semipermeable Confining Units.
aggradationa progressive build up of a channel bed with sediment over several years due to a normal sequence of scour and deposition, as distinguished from the rise and fall of the channel bed during a single flood.
snow coreA sample of either freshly fallen snow, or the combined old and new snow on the ground
bottomset bedHorizontal deltaic deposit of alluvial sediment composed of fine silt and clay.
deflationwind removal of small, grain-size rock particles such as sand. 
weather vaneOriginally used as a wind vane, it is an instrument that indicates the wind direction
epiphytesplants in tropical rainforest which live on the branches or trunks of larger trees
nmc  National Meteorological Center, with headquarters near Washington D.C.; now known as NCEP.
pressure tendencyThe pressure characteristic and amount of pressure change during a specified time period, usually the three hour period preceding the observation.
isotachA line connecting equal wind speeds.
diversionThe taking of water from a stream or other body of water into a canal, pipe, or other conduit.
weatheringThe decay and breakup of rocks on the earth's surface by natural chemical and mechanical processes
hydrostatic loadsForces imposed on a flooded structure due to the weight of the water.
streamriver or lake that is covered       by water during a flood, land next to a river that becomes covered by water when the river       overflows its banks.
cohesiona molecular attraction by which the particles of a body are united throughout the mass whether like or unlike
driftmaterial deposited by glacial and fluvioglacial processes.
gaging stationA particular site on a watercourse where systematic observations of stage and/or flow are measured.
scourThe erosive action of running water in streams, which excavates and carries away material from the bed and banks
pelagicOf or in the open ocean or open water.
outletAn opening through which water can be freely discharged from a reservoir.
note  HPC was formerly called the National Meteorological Center (NMC) and it is located in Washington DC.
beach erosionThe carrying away of beach materials by wave action, currents, tides, or wind.
cavea recess in the ground.
stream long profileVertical and horizontal profile of the stream
pingoA large conical mound that contains an ice core
ice boom  A floating structure designed to retain ice.
geographic information systemA computer system capable of storing and manipulating spatial (i.e., mapped) data.
worker protection standardsStandards designed to reduce the risks of illness or injury resulting from workers' and handlers' occupational exposures to pesticides used in the production of agricultural plants on farms or in nurseries, greenhouses, and forests and also from the accidental exposure of workers and other persons to such pesticides
flowThe amount of water passing a particular point in a stream or river, usually expressed in cubic-feet per second (cfs).
escarpmentthe topographic expression of a fault.
varveA thin yearly deposit of sediment found on the bottom of a lake
bioassessmentmonitoring the aquatic environment to determine the health of a stream.
cold vapormethod to test water for the presence of mercury.
constant pressure surfaceA surface along which the atmospheric pressure is equal everywhere.
turbulent flowMovement of water within a stream that occurs as discrete eddies and vortices
temperature-gradient metamorphismProcess of firnification when large temperature gradients exist within the snowpack, such as within adjacent layers of snow
snow squallsThey are intense, but limited duration, periods of moderate to heavy snowfall
basinA segment or portion of a larger watershed area, based on the natural water drainage pattern.
weira wall or plate placed in an open channel to measure the flow of water; a wall or obstruction used to control flow from settling tanks and clarifiers to ensure a uniform flow rate and avoid short-circuiting.
structural landformIs a landform created by massive Earth movements due to plate tectonics
primary treatmentFirst stage of wastewater treatment in which solids are removed by screening and settling.
erosionThe movement of soil or rock from one area to another by the action of the sea, running water, moving ice, precipitation, or wind.
hydroelectric power water useThe use of water in the generation of electricity at plants where the turbine generators are driven by falling water.
floodproofingThe process of protecting a building from flood damage on site
santa ana windA warm, dry chinook like wind that occurs in southern California
vaporizeConversion of a liquid into vapour.
sandstormA strong wind carrying sand particles through the air
hardwood bottomlandhardwood forested lowlands adjacent to some rivers, especially valuable for wildlife breeding, nesting, and habitat.
non-aqueous phase liquidcontaminants that remain undiluted as the original bulk liquid in the subsurface, such as spilled oil.
abutment  The part of a valley or canyon wall against which a dam is constructed
fuelwoodas it suggests, the use of wood as a fuel
polarizationIn the context of particles in an electric field, it is the displacement of charged centers within a particle in response to the electrical forces acting thereon.
stationary frontA front which is nearly stationary or moves very little since the last synoptic position
open river channelA navigation channel in a natural river with improvements limited to removal of obstructions and dredging to obtain adequate depths.
hemispherehalf of a sphere; half of the earth
isoplethA line connecting equal points of value
deltaA deposit of sediment that occurs at a river mouth, usually triangular, named after the Greek letter "delta."
climateThe historical record and description of average daily and in seasonal weather events that help describe a region
meteoric waterWater derived from precipitation.
detritusdecaying organic matter (mostly leaves and other matter from vegetation).
echoEnergy back scattered from a target (precipitation, clouds, etc.) and received by and displayed on a radar screen.
kettleholea small depression usually found on the outwash plain of a glacial area and sometimes containing a small lake
smoke management  Conducting a prescribed fire or slash burn with firing techniques and meteorological conditions that keep the smoke's impact on the environment with acceptable limits.
fresh wateran increasingly popular way of providing fresh water to coastal       populations.
fetchThe distance of open water in one direction across a body of water over which wind can blow.
chinook windThe name of a North American wind that occurs on the leeward side of mountains
aggradationA progressive buildup or raising of the channel bed and floodplain due to sediment deposition
waterspoutA violently rotating column of air, usually a pendant to a cumulus or cumulonimbus cloud, over a body of water with its circulation reaching the water
outlet  An opening through which water can be freely discharged from a reservoir.
glaciofluvialGeomorphic feature whose origin is related to the processes associated with glacial meltwater.
snow depthThe combined total depth of both the old and new snow on the ground.
temperature rangethe difference between maximum and minimum temperature
glaciera huge mass of land ice that consists of recrystallized snow and moves slowly downslope or outward.
filtersa screening device or porous substance used as a strainer       for removing solid material from liquids.
maximum probable floodThe largest flood for which there is any reasonable expectancy.
rockfill damAn embankment dam of earth or rock in which the material is placed in layers and compacted by using rollers or rolling equipment
saltsminerals that cause salinity
earthquakeIs a sudden motion or trembling in the Earth
floodplainthe part of the valley floor occasionally flooded by the river
environmental evaluationThat part of the planning process by governmental agencies that inventories and estimates the potential effects on the human environment of alternative solutions to resource problems, determines the need for an Environmental Assessment (EA) or an Environmental Impact Statement (EIS), and aids in the consideration of alternatives and the identification of available resources.
erodeWind, water, and movement of glaciers remove material from (erode) the surface of the earth.
unconstrained demandThe demand that would be experienced were it not for conservation and natural replacement
cycloneAn area of closed pressure circulation with rotating and converging winds, the center of which is a relative pressure minimum
mean column velocitythe average velocity of fluid flow measured in a column extending from the surface of the water to the bed of the channel
non-irrigated croplandThose non-irrigated cultivated lands that are used for the production of grain crops (harvested and/or grazed), orchard, and field crops.
smokeA suspension in the air of small particles produced by combustion
bankfull stageAn established river stage at a certain point along a river which is intended to represent the maximum safe water level which will not overflow the river banks or cause any significant damage within the reach of the river.
decomposable wastewaste that under suitable natural conditions can be transformed through biological and chemical processes into compounds that do not impair water quality.
palouserA strong, dangerous, katabatic wind that descends from the mountains into the Palouse River valley in northern Idaho and eastern Washington
ground moraineBlanket of unsorted glacial till that was laid down at the base of a melting glacier.
rangeA statistical measure of the dispersion of observation values in a data set
mud balls(Water Quality) Accretions of siliceous incrustations on the exterior of sand grains in a rapid sand filter; typically removed by backwashing
agent of erosionthe direct source of movement that can cause erosion through the transfer of energy or transport of rock material: water (rivers and waves), wind and ice.
reclaimed waterRefers to water that has received at least Secondary Wastewater Treatment and is reused after flowing out of a wastewater treatment facility.
geostrophic windA steady horizontal motion of air along straight, parallel isobars or contours in an unchanging pressure or contour field
net water useRefers to water withdrawals plus or minus water transfers
standard deviationA statistical measure of the dispersion of observation values in a data set
littoralmost properly the area at a coast between the highest and lowest tides
nutrientas a pollutant, any element or compound, such as phosphorous or nitrogen, that fuels abnormally high organic growth in aquatic ecosystems
blackwaterWater that contains waste of humans, animals or food.
density of snow  The ratio, expressed as a percentage, of the volume which a given quantity of snow would occupy if it were reduced to water, to the volume of the snow
aquiculturethe raising or fattening of fish in enclosed ponds
polar frontA semipermanent, semicontinuous front that separates tropical air masses from polar air masses.
drawdownthe drop in the water table or level of groundwater when water is being pumped from a well; the amount of water used from a tank or reservoir; the drop in the water level of a tank or reservoir.
dynamic icePressure due to a moving ice cover or drifting ice.
el ni隳Name given to the occasional development of warm ocean surface waters along the coast of Ecuador and Peru
forebay  The water behind (upstream) of the dam.
salt lakeA landlocked body of water that has become salty through evaporation.
snow stickA portable rod used to measure snow depth.
jetterone (as a geyser) that sends out a jet.
chemosphereA vaguely defined region of the upper atmosphere in which photochemical reactions take place
isothermal atmosphere  An atmosphere in hydrostatic equilibrium in which the temperature is constant with altitude and in which, the pressure decreases exponentially upward.
wedgePrimarily refers to an elongated area of shallow high pressure at the earth's surface
nimbostratus cloudsDark, gray low altitude cloud that produces continuous precipitation in the form of rain or snow
probable maximum floodThe largest flood for which there is any reasonable expectancy in a particular climatic era.
polar frontWeather front located typically in the mid-latitudes that separates arctic and polar air masses from tropical air masses
corrie glaciersLarger than niche glaciers, smaller than valley glaciers, they occupy hollows on bedrock faces in mountain regions.
sun pillarHorizontal ice crystals in the form of plates, which occur in clouds and ice fog near the earth's surface, reflect sunlight into vertical sun pillars for a spectacular display.
water equivalentThe liquid content of solid precipitation that has accumulated on the ground (snow depth)
hydraulic gradientIn general, the direction of groundwater flow due to changes in the depth of the water table.
truncated spurSpurs of hillsides that have been cut off by a glacier, thereby straightening the glacially eroded valley.
caverna large underground opening in rock (usually limestone) which occurred when some of the rock was dissolved by water
melting pointThe temperature at which a solid substance undergoes fusion, changing from a solid to a liquid state
secondary treatmentTreatment of wastewater to a non-Potable level so that it may be returned to the stream
glacial troughA U-shaped valley carved out of a V-shaped stream valley by the movement of a valley glacier.
fresh(1) Not saline or salty
wastewater treatmentAny of the mechanical or chemical processes used to modify the quality of waste water in order to make it more compatible or acceptable to man and his environment.
i & iInflow and Infiltration
calibrationThe process of using historical data to estimate parameters in a hydrologic forecast technique such as SACSMA, routings, and unit hydrographs.
ffg  An acronym for Flash Flood Guidance.  See Flash Flood Guidance.
bouldera size-classification of rock pieces
aftershockground tremors occurring after a major earthquake but associated with the same focus point.
intakeopening through which a fluid is admitted into a container or conduit.
channel routing  The process of determining progressively timing and shape of the flood wave at successive points along a river.
doldrumssee intertropical convergence zone.
mcc  An acronym for Mesoscale Convective Complex.  See Mesoscale Convective Complex.
plastic flowIn glaciers, plastic flow in ice begins at 50 meters (165 feet) from the top of the ice surface.
twisterA slang term used in the United States for a tornado.
beginning of the breakup  Date of definite breaking, movement, or melting of ice cover or significant rise of water level.
deep percolation loss  Water that percolates downward through the soil beyond the reach of plant roots.
erosionthe wearing away of the land surface by wind, water, ice or other geologic agents
dry crack  Crack visible at the surface but not going right through the ice cover, and therefore it is dry.
bedding planeA layer in a series of sedimentary beds that marks a change in the type of deposits.
static water depththe vertical distance from the centerline of the pump discharge down to the surface level of the free pool while no water is being drawn from the pool or water table.
urban flash flood guidance  A specific type of flash flood guidance which estimates the average amount of rain needed over an urban area during a specified period of time to initiate flooding on small, ungaged streams in the urban area.
waterfalla sudden, nearly vertical drop in a stream, as it flows over rock.
floodwayThe channel of a river or stream and those parts of the adjacent floodplain adjoining the channel that are required to carry and discharge the base flood.
blizzardWinter severe weather condition characterized by strong wind, blowing snow, and cold temperatures.
indicator teststests for a specific contaminant, group of contaminants, or constituent which signals the presence of something else (ex., coliforms indicate the presence of pathogenic bacteria).
confluent growth(Water Quality) A continuous bacterial growth covering all or part of the filtration area of a membrane filter in which the bacteria colonies are not discrete
ground(1) The solid surface of the earth
spring melt/thawthe process whereby warm temperatures melt winter snow and ice
cu  An acronym for Cumulus.  See Cumulus.
lindanea pesticide that causes adverse health effects when present in domestic water supplies and is toxic to freshwater fish and aquatic life.
superrefractionBending of the radar beam in the vertical which is greater than sub-standard refractive conditions
litterAccumulation of leaves, twigs and other forms of organic matter on the soil surface
lateral moraineMoraine that is found along the sides of a glacier
inversionSee temperature inversion.
sewerA channel or conduit that carries wastewater and storm water runoff from the source to a treatment plant or receiving stream.
evaporation panA pan used to hold water during observations for the determination of the quantity of evaporation at a given location
deposition nucleiSix-sided microscopic particle that allows for deposition of water as ice crystals in the atmosphere
coromellThe prevailing evening land breeze which takes place from November to May in the vicinity of La Paz, at the southern tip of Baja California, Mexico.
infiltration index  An average rate of infiltration, in inches per hour, equal to the average rate of rainfall such as that the volume of rainfall at greater rates equals the total direct runoff.
tiltIt describes a storm in which a line connecting the centroid of a mid level storm component to the centroid of the lowest storm component is to the right or the rear of the direction of motion.
false ogivesLight and dark bands on the glacier formed by rock avalanching.
hydraulic permeabilityThe flow of water through a unit cross-sectional area of soil normal to the direction of flow when the Hydraulic Gradient is unity.
swampa type of wetland dominated by woody vegetation but without appreciable peat deposits
poroussomething which allows water to pass through it
infrastructureThe massive foundation or basic framework of pipes, wells, storage tanks, treatment facilities, and pump stations that are mostly below ground.
erosionWearing away of rock or soil by the gradual detachment of soil or rock fragments by water, wind, ice, and other mechanical, chemical, or biological forces.
basal meltingKnown specific melting rates for different substances including ice
ocean currentlarge-scale movement of water within the oceans
physical weatheringBreaking down of rock into bits and pieces by exposure to temperature and changes and the physical action of moving ice and water, growing roots, and human activities such as farming and construction.
basal slidingThe sliding of a glacier over the surface it rests on
face  The external surface of a structure, such as the surface of a dam.
meltwaterWater that comes from the melting ice of a glacier or a snow bank.
old growth forestClimax forests dominated by late successional species of trees that are hundreds to thousands of years old
saturated zoneThe area below the water table where all open spaces are filled with water.
sea-floor spreadingthe widening of an ocean basin by the creation of new crust at a divergent margin.
irrigation return flowwater which is not consumptively used by plants and returns to a surface or ground water supply
game fisha species such as trout, salmon, or bass, caught for sport.
swashthe running of water up a beach under the momentum of a breaking wave.
iceThe solid form of water
mesosphereThe layer of the atmosphere located between the stratosphere and the ionosphere, where temperatures drop rapidly with increasing height
swampan area, usually vegetated, permanently flooded or at least saturated by groundwater.
groundwater lawthe common law doctrine of riparian rights and the doctrine of prior appropriation as applied to ground water.
stormwater runoffwhen sewers are       constructed this way, wastewater treatment plants have to be sized to handle stormwater       flows and often some of the water receives little or no treatment during overflows or bypasses       during extreme storm events, (see separate sewer).
lakeseparated by the fairly thin thermocline zone,       from the upper, warmer, less dense zone, the epilimnion.
crucial habitatHabitat that is basic to maintaining viable populations of fish and wildlife during certain seasons of the year or specific reproduction periods.
adiabaticchange in temperature due to expansion or contraction of a parcel of air which thus change the pressure and therefore the temperature
depletionThat part of a withdrawal that has been evaporated, transpired, incorporated into crops or products, consumed by man or livestock, or otherwise removed.
upwelling  The process by which cold waters from the depths of a lake or ocean rise to the surface.
zone of aerationThe locus of points just above the water table where soil pores may either contain air or water
planktonmicroscopic floating plant and animal organisms of lakes, rivers, and oceans.
tectonicsSee plate tectonics.
carbon adsorptiona treatment system that removes contaminants from ground water or surface water by forcing it through tanks containing activated carbon treated to attract the contaminants.
percolation pondRefers to a pond (usually man-made) designed to allow treated wastewater effluent to percolate slowly into the ground
cone of influence  The depression, roughly conical in shape, produced in a water table, or other piezometric surface, by the extraction of water from a well at a given rate
swaleSmall depressions, natural or artificial, that carry water only after a rainfall.
base flowthat portion of river discharge derived from groundwater flow.
annulusA mark or ring that forms annually on the otoliths, scales, and other bones of fish, that correspond to the annual period of slow growth that fish go through
urban floodingNuisance flooding of streets, underpasses, basements and other low-lying urban areas
emergenceThe process during which fry leave their gravel spawning nest and enter the water column.
climap projectMultiuniversity research project that reconstructed the Earth's climate for the last million years by examining proxy data from ocean sediment cores.
phreatophytesplants that send their roots into or below the capillary zone to use ground water.
upgradient wellA groundwater monitoring well, such as those required at facilities that treat, store, or dispose of hazardous waste using surface impoundments or landfills, that allows sampling and analysis of groundwater that is upstream from the facility, before the groundwater is possibly affected by any escaping contaminants
meridional flowAtmospheric circulation in which the north and south, or meridional, component of motion is unusually pronounced
pentachorophenoltoxic substance usually used as a wood preservative.
diluting waterDistilled water that has been stabilized, buffered, and aerated
circulationThe flow or motion of a fluid in or through a given area or volume
fresh:salt water interfacethe region where fresh water and salt water meet
ultra-violet oxidationA process using extremely short wave-length light that can kill micro-organisms (disinfection) or cleave organic molecules (photo oxidation) rendering them polarized or ionized and thus more easily removed from the water.
aquitardgeological formation that may contain groundwater but is not capable of transmitting significant quantities of it under normal hydraulic gradients
flowing well  A well drilled into a confined aquifer with enough hydraulic pressure for the water to flow to the surface without
bernoulli's theoremA statement of the conservation of energy for a steady, nonviscous, incompressible level flow
sludgesolid matter that settles to the bottom of sedimentation tanks in a sewage treatment plant and must be disposed of by digestion or other methods or recycled to the land.
turbidity  The thickness or opaqueness of water caused by the suspension of matter
assaya test for a specific chemical, microbe, or effect.
variable ceilingOccurs when the height of a ceiling layer increases and decreases rapidly, The ascribed height is the average of all the varying values.
tidal zoneArea along the coastline that is influence by the rise and fall of tides.
sediments(see hydrophyllic).
climax communityPlant community that no longer undergoes changes in species composition due to succession.
on-site sewage treatmentany individual residential sewage treatment and wastewater dispersal system, such as a septic system.
anvilThe upper portion of a cumulonimbus cloud that becomes flat and spread-out, sometimes for hundreds of miles downstream from the parent cloud
public water systemby law, a drinking water system that serves 15 or more connections or 25 or more people; must meet EPA standards for treatment and water quality.
crevassea deep crack in the surface, usually in a glacier.
lengthThe distance in the direction of flow between two specific points along a river, stream, or channel.
scsThe Soil Conservation Service, now known as the NRCS (National Resources Conservation Services).
stoplogsLarge logs, timbers or steel beams placed on top of each other with their ends held in guides on each side of a channel or conduit providing a temporary closure versus a permanent bulkhead gate.
magmaMolten rock originating from the Earth's interior.
fallowCropland, either tilled or untilled, allowed to lie idle, during the whole or the greater part of the growing season.
coarse woody debrisPortion of a tree that has fallen or been cut and left in the woods
snow showerIt is a moderate snowfall of short duration
iceThe solid form of water.
supercooledSupercooled water remains in the liquid state even though the its temperature is below its freezing point.
permeameter  A laboratory instrument for determining permeability by measuring the discharge through a sample of the material when a known hydraulic head is applied.
transmissometerAn electronic instrument system which provides a continuous record of the atmospheric transmission between two fixed points
droughtA long period of below-average precipitation.
holding ponda small basin or pond designed to hold sediment laden or contaminated water until it can be treated to meet water quality standards or be used in some other way.
thawA warm spell of weather when ice and snow melt
embankment damA dam structure constructed of fill material, usually earth or rock, placed with sloping sides and usually with a length greater than its height.
environmentThe sum total of all the external conditions that effect an organism, community, material, or energy.
floodThe temporary inundation of normally dry land areas resulting from the overflowing of the natural or artificial confines of a river or other body of water.
smokeSmall particles produced by combustion that are suspended in the air
erosionThe gradual wearing away of Earth surfaces through the action of wind and water.
drifting ice  Pieces of floating ice moving under the action of wind and/ or currents.
alkalinethe condition of water or soil that contains a sufficient amount of alkali substance to raise the pH above 7.0.
environmental monitoringThe process of checking, observing, or keeping track of something for a specified period of time or at specified intervals.
raw waterIntake water prior to any treatment or use
hydromancyDivination by the observation of water.
resource monitoringThe act of continually or periodically observing resources to determine changes and trends in their status and condition.
assemblagean organism group of interacting species in a given ecosystem, for example, a fish assemblage or a benthic macroinvertebrate assemblage.
freezup jamIce jam formed as frazil ice accumulates and thickens.
bed formsthree-dimensional configurations of bed material, which are formed in streambeds by the action of flowing water.
baran accumulation of alluvium (usually gravel or sand) caused by a decrease in sediment transport capacity on the inside of meander bends or in the center of an overwide channel.
soil conservationthe protection of a soil from erosion plus the maintenance of its fertility so that its productivity is maintained.
gulf streamA warm, swift, narrow ocean current flowing along the East Coast of the United States.
geyserA geyser is a natural hot spring that occasionally sprays water and steam above the ground.
residual depression storageDepression storage existing at the end of a period of excess rain.
wave cycloneA cyclone which forms and moves along a front
glacial retreatThe backwards movement of the snout of a glacier.
watershedland area from which water drains toward a common watercourse in a natural basin.
terrestrial radiationLong wave radiation that is emitted by the earth back into the atmosphere
sand ripplesAnother term used for wind ripples.
polar cellone of the cells of atmospheric circulation in the tri-cellular model.
fena wetland area composed of swamp and some low density woodland
flood fringeThe portion of the floodplain where water depths are shallow and velocities are low.
floe  An accumulation of frazil flocs (also known as a "pan") or a single piece of broken ice.
oxbowa U-shaped bend in a river or stream that may or may not be cut off from the mainstem.
ground water outflow  That part of the discharge from a drainage basin that occurs through the ground water
landwardPositioned or located away from a water body but towards the land.
stream segmentRefers to the surface waters of an approved planning area exhibiting common hydrological, natural, physical, biological, or chemical processes
phiezometer  An instrument used to measure pressure head in a conduit, tank, soil, etc
species compositionthat portion of an Index of Biotic Integrity that is a metric measuring the number and identity of species.
glacier  Bodies of land ice that consist of recrystallized snow accumulated on the surface of the ground, and that move slowly downslope.
flood control poolReservoir volume reserved for flood runoff and then evacuated as soon as possible to keep that volume in readiness for the next flood.
arctic jetThe jet stream that is situated high in the stratosphere in and around the Arctic or Antarctic Circles
oceanographyThe scientific study of phenomena found in the world's oceans.
municipal dischargeThe discharge of effluent from waste water treatment plants which receive waste water from households, commercial establishment, and industries
basic volcanowhere low viscosity, extremely hot lava flows from a vent it will spread rapidly to form a shallow sloped, low altitude cone.
basal iceThe basal layer is the part of the glacier in which the nature of the ice is directly affected by proximity to the glacier bed
showerIt implies short duration, intermittent, and scattered precipitation (rain, snow, ice pellet) of a more unstable, convective nature.
interbasin transferThe physical transfer of water from one watershed to another.
hydrometric networkNetwork of stations at which measurement of hydrological parameters is performed.
bureau of reclamationAn agency that administers some parts of the federal program for water resource development and use in western states
drifting snowSnow particles blown from the ground by the wind to a height of less than six feet.
concordant flowsFlows at different points in a river system that have the same Recurrence Interval, or the same frequency of occurrence
precipitateSolidification of a previously dissolved substance from a solution.
firn lineThe highest level to which the fresh snow on a glacier's surface retreats during the melting season
ice contact depositThe multiple types of accumulated stratified sediment left behind when meltwater flows over, within, and at the base of a motionless, melting terminus
climatic optimumWarmest period during the Holocene epoch
fabricIn tills which have been oriented by flowing water, fabric indicates the preferred orientation of the grains
free-flowing streamA stream or a portion of a stream that is unmodified by the works of man or, if modified, still retains its natural scenic qualities and recreational opportunities.
point velocityvelocity measured at a single point in the water column of flowing water
secondary treatmentThe removal or reduction of contaminants and BOD of effluent from primary wastewater treatment.
conjunctive operationThe operation of a ground water basin in combination with a surface water storage and conveyance system
peclet numberthe relationship between properties of the mesh, fluid velocity, and eddy viscosity for a hydraulic computer model.
stalagmitea similar feature to a stalactite, formed by the same process, but found on the cave floor beneath the stalactite above
ogives *A series of ice waves or bands of lighter and darker material formed below ice falls in some glaciers
steam fogSee evaporation fog.
meridianA circular arc that meets at the poles and connects all places of the same longitude.
storm windsOn the Beaufort Wind Scale, a wind with speeds from 56 to 63 knots (64 to 72 miles per hour).
natal streamStream of birth.
turbidthick or opaque with matter in suspension
flow augmentationIncreased flow from release of water from storage dams.
short circuitingwhen some of the water in tanks or basins flows faster than the rest; shortcircuiting may result in shorter contact, reaction, or settling times than calculated or presumed.
rainWater falling to earth in drops that have been condensed from moisture in the atmosphere.
exotic streamA stream that has a course that begins in a humid climate and end in an arid climate
sedimentationa large scale water treatment process where heavy solids settle out to the bottom of the treatment tank after flocculation.
natural selectionEnvironment's influence on the reproductive success of individuals in a population
blowing snow  Wind-driven snow that significantly reduces surface visibility to less than 7 miles.
conservationObtaining the benefits of water more efficiently, resulting in reduced demand for water
critical flowA condition of flow where the mean velocity is at one of the critical values; ordinarily at Belanger's critical depth and velocity
sand duneA hill or ridge of aeolian sand deposits with a minimum height of less than one meter and a maximum height of about 50 meters
frenumReferring to the membrane that binds the lip to the snout or lower jaw.
ice pelletsPrecipitation of transparent and translucent pellets of ice, which are round or irregular, rarely conical, and which have a diameter of 0.2 inch (5 mm), or less
river recreation statementA statement released by the NWS to inform river users of current and forecast river and lake conditions
sausage damA dam composed of loose rock that has been wrapped with wire into cylindrical bundles and laid in a horizontal or vertical position.
intermountain highAn area of high pressure that occurs during the winter between the Rocky Mountains and the Sierra-Cascade ranges
nivationProcess where snow patches initiate erosion through physical weathering, meltwater flow, and gelifluction.
subsidencea dropping of the land surface as a result of ground water being pumped
protistaGroup, at the kingdom level, in the classification of life
smoltRefers to the salmonid or trout developmental life stage between parr and adult, when the juvenile is at least one year old and has adapted to the marine environment.
range resolutionThe ability of radar to distinguish between targets on the same azimuth but at different ranges.
longshore currentA water current that moves parallel to the shoreline.
riverA large stream of water that flows along a certain path.
sloughA shallow backwater inlet that is commonly exposed at low flow or tide.
steam fogIt forms as cold air moves over warm water
pollutantParticles, gases, or liquid aerosols in the atmosphere which have an undesirable effect on humans or their surroundings
backwashingreversing the flow of water through a home treatment device filter or membrane to clean and remove deposits.
glacial lakeProglacial lakes form the angle of the land and the angle of the glacier are opposite or in the superglacial/englacial environment
green revolutionmost properly refers to the development of higher yield varieties of maize (Mexico) and rice (India) in the 1960s
corner effects  A small-scale convergence effect that can be quite severe.  It occurs around steep islands and headlands.
seracsUnstable ice pinnacles formed by intersecting crevasse planes, usually in areas of fast glacier movement.
hail spikeWhen looking at a WSR-88D Cross-Section, one will occasionally see a distinctive spike above the actual top of the thunderstorm
right of capturethe idea that the water under a person's land belongs to that person and they are free to capture and use as much as they want
station elevationThe vertical distance above mean sea level that is the reference level for all current measurements of atmospheric pressure at that station.
plainA broad and flat area that usually has low elevation.
coliform bacterianon-pathogenic microorganisms used in testing water to indicate the presence of pathogenic bacteria.
river systemAll of the streams and channels draining a river basin.
nowcastA short-term weather forecast for expected conditions in the next few hours.
ice shelfLarge flat layer of ice that extends from the edge of the Antarctic ice cap into the Antarctic Ocean
v-shaped valleythe V-shape of the cross profile of a river valley in its upper course
quantitative precipitation forecastA forecast of the amount of precipitation which will fall during a specific time period
ephemeral streamA stream that flows only in direct response to precipitation, and thus discontinues its flow during dry seasons
return flow(1) That part of a diverted flow which is not consumptively used and returns to its original source or another body of water
specific drawdownThe drawdown in a well per unit discharge.
isothermLines on a map joining points of equal temperature.
protonA sub-particle of an atom that contains a positive charge.
cirrocumulus standing leticularThese clouds are formed on the crests of waves crested by barriers in the wind flow
lateral plate marginsee conservative plate margin.
dendrites  Thin branch-like growth of ice on the water surface.
rilla small channel eroded into the soil by surface runoff; can be easily smoothed out or obliterated by normal tillage.
water tableThe upper surface of zone of saturation
duration of ice coverThe time from freeze-up to break-up of an ice cover.
ecosystemA system formed by the interaction of a group of organisms and their environment.
abyssal plainThe flat, gently sloping or nearly level region of the sea floor.
central north pacific basin  The region north of the Equator between 140W and the International Dateline
zooplanktonSmall aquatic animals that are suspended or swimming in water.
streamafter complete treatment       steps which meet current effluent water quality standards, effluent water is often recycled       as irrigation water for golf courses, parklands and some agricultural applications, particularly a       liquid, that enters the environment from a point source, generally refers to wastewater from a       sewage treatment or industrial plant.
mean annual temperatureThe average of the daily maximum and minimum temperatures.
subtropical jetThis jet stream is usually found between 20o and 30o latitude at altitudes between 12 and 14 km.
wellfieldarea containing one or more wells that produce usable amounts of water or oil.
flowin streams and rivers, it is equal to a volume of water one       foot high and one foot wide flowing a distance of one foot in one second, one cfs is equal to       7.48 gallons of water per second.
black bodyIs a body that emits electromagnetic radiation, at any temperature, at the maximum possible rate per unit surface area
abatementReducing the degree or intensity of, or eliminating, pollution.
flumeA sloped channel that is utilized to convey water and is commonly constructed of wood or concrete
vertical aerial photographPhotograph taken from a overhead or near overhead angle from a platform in the atmosphere.
yieldthe quantity of water expressed either as a continuous rate of flow (cubic feet per second, etc.) or as a volume per unit of time
point-source pollutionwater pollution coming from a single point, such as a sewage-outflow pipe.
interbasin transfer of waterSee Water exports; Water imports.
settleable solidsin sewage, suspended solids that will settle when the sewage is brought to a quiet state for a reasonable length of time, usually two hours.
accumulation area or zoneWhere snow falls on a glacier, commonly on a snowfield or cirque.
united states weather bureauThe official name of the National Weather Service prior to 1970.
morphoedaphic indexThe most widely used index of potential fish production in lakes
temperatureThe measure of molecular motion or the degree of heat of a substance
receiving watersA river, lake, ocean, stream, or other body of water into which wastewater or treated effluent is discharged.
sublimationProcess where ice changes into water vapor without first becoming liquid
roll cloudA relatively rare, low-level, horizontal, tube-shaped cloud
topographyThe shape of a landscape, composed of its relief and position of natural and man-made features.
droughtAbnormal dry weather for a specific area that is sufficiently prolonged for the lack of water to cause serious hydrological imbalance.
septic tankunderground receptacle for wastewater from a home
sewerA channel or conduit that carries wastewater and stormwater to a treatment plant or receiving waters
zone of aerationa region in the Earth above the water table
high wind advisory  This product is issued by the National Weather Service when high wind speeds may pose a hazard.  The criteria for this advisory varies from state to state.  In Michigan, the criteria is sustained non-convective (not related to thunderstorms) winds greater than or equal to 30 mph lasting for one hour or longer, or winds greater than or equal to 45 mph for any duration.
velocity barrierA physical structure, such as a barrier dam or floating weir, built in the tailrace of a hydroelectric powerhouse, which blocks the tailrace from further adult salmon or steelhead migration to prevent physical injury or migration delay.
headgatethe gate that controls water flow into irrigation canals and ditches
trickle irrigationmethod in which water drips to the soil from perforated tubes or emitters.
squallA sudden onset of strong winds with speeds increasing to at least 16 knots (18 miles per hour) and sustained at 22 or more knots (25 miles per hour) for at least one minute
streamflowthe water discharge that occurs in a natural channel
fish ladderSee Fishway.
subtropicalThe region between the tropical and temperate regions, an area between 35° and 40° North and South latitude
lotic systemA flowing body of fresh water, such as a river or stream.
springthe emergence of water from the ground, usually leading to the formation of a channel flow.
drainage areaSee watershed.
flowThe discharge rate of a resource, expressed in volume during a certain period of time.
nuclear energyuranium is processed into uranium dioxide, which undergoes nuclear fission
duplicatestwo separate samples with separate containers taken at the same time at the same place.
main stemThe reach of a river/stream formed by the tributaries that flow into it.
diurnal tideTides that have one high and one low water per tidal period.
laminar flowMovement of water within a stream that occurs as uninterrupted parallel flows
neo-colonialismthe holding of political or economic influence (or both) by one country over another.
streamflow depletionThe amount of water that annually flows into a valley or onto a particular land area minus the amount that flows out of the valley or away from the particular land area
tropopauseThe tropopause is a relatively thin atmospheric transition layer found between the troposphere and the stratosphere
homingThe ability of a salmon or steelhead to correctly identify and return to their natal stream, following maturation at sea.
rainwaterWater that has fallen as rain and contains little dissolved mineral matter.
phreaticOf or relating to ground water.
perched groundwater  Local saturated zones above the water table which exist above an impervious layer of limited extent.
sedimentary cyclebiogeochemical cycle in which materials primarily are moved from land to sea and back again.
transpirationAn essential physiological process in which plant tissues give off water vapor to the atmosphere.
mass balanceThe balance of glacial input (accumulation), throughput (transport), and output (ablation) of snow and ice.
driftAny material deposited by a glacier.
sea breezea wind blowing from the sea to the land.
potentiometric surfaceAn imaginary surface representing the static head of ground water in tightly cased wells that tap a water-bearing rock unit (aquifer); or in the case of unconfined aquifers, the water table.
chemical weatheringBreakdown of rock and minerals into small sized particles through chemical decomposition.
oregon production indexAn annual index to the measurable number of 3-year-old adult coho salmon south of Illwaco, Washington.
specific conductancea measure of the ability of a water to conduct an electrical current
cryophobia  Fear of extreme cold, ice, or frost.
mariculturecultivation of fish and shellfish in estuarine and coastal areas
mainstem passageThe movement of salmon and steelhead around or through the dams and reservoirs in the Columbia and Snake rivers.
mistralthe French term for a katabatic wind.
conveyance losswater loss in pipes, channels, conduits, and ditches by leakage or evaporation.
centralized headquartersControl of a canal project from a central location generally by a master station, communications network, and one or more remote terminal units (RTUs).
swim-up fryA salmonid fry that is swimming in the water column in search for food.
grounding lineThe place where a glacier extending into the sea or a lake loses contact with the seafloor and begins to float as an ice shelf
cryosphereThe perennially frozen regions of the planet, including land-ice, sea-ice, permanent snow cover and permafrost
water disposal systemThe complete system for removing excess water from land with minimum erosion
recumbent foldA fold in which the axial plane is almost horizontal.
duplicatesTwo separate samples with separate containers taken at the same time and at the same place.
stageThe level of the water surface above a given datum at a given location along a river or stream.
euphotic zonesurface layer of an ocean, lake, or other body of water through which light can penetrate
contact recreation      non-contact recreation).
sedimentSediment is material suspended in water, that consists mostly of soil, but can also contain cigarette butts, litter, etc., which is carried by stormwater into the city's storm drain system and eventually into a body of water.
multiple-vortex tornado  A tornado in which two or more condensation funnels or debris clouds are present at the same time, often rotating about a common center or about each other
knickpointthe point where an old profile meets a new profile in a rejuvenating river.
cycleThe length of time a filter can be used before it needs cleaning, usually including cleaning time.
overrunningThis occurs when a relatively warm air mass is forced above a cooler air mass of greater density
radius of influenceThe radial distance from the center of a well bore to the point where there is no lowering of the water table or Potentiometric Surface (the edge of its Cone of Depression).
dropsondeA radiosonde dropped with a parachute from an aircraft rather than lifted by a balloon to measure the atmosphere below.
blackwaterwastewater from toilet, latrine, and agua privy flushing and sinks used for food preparation or disposal of chemical or chemical-biological ingredients.
background levelthe concentration of a substance in an environmental media (water or soil) that occurs naturally or is not the result of human activities.
hydrologic equationThe water inventory equation: Inflow = [Outflow + Change in Storage], which balances the Hydrologic Budget and expresses the basic principle that during a given time interval the total inflow to an area must equal the total outflow plus the net change in storage.
non-consumptive useWater drawn for use that is not consumed, such as water diverted for hydroelectric generation
trap efficiency of reservoirsRatio of sediment retained to sediment inflow expressed as a percentage.
springan issue of water from the earth; a natural fountain; a source of a body or reservoir of water.
glacial driftA generic term applied to all glacial and glaciofluvial deposits.
transmissibilityThe rate at which water at the prevailing water temperature is transmitted through a unit width of the aquifer under a unit hydraulic gradient
flare echoThis image will once in awhile appear on the WSR-88D reflectivity product
air massAn extensive body of air throughout which the horizontal temperature and moisture characteristics are similar.
fountainhead  The upper end of a confined-aquifer conduit, where it intersects the land surface.
sewage sludgeSludge produced in a public sewer.
metamorphic rockrocks created by the chemical alteration of existing rocks under the influence of temperature, pressure, or both.
snow pelletsA form of precipitation also known as graupel
mercalli scaleA scale for rating the power of an earthquake.
low flowlow flow conditions below which some standards do not apply
firnA permeable aggregate of small ice grains with densities greater than 0.55 up to 0.82 where begins glacial ice.
rift valleya valley created by the subsidence of land between two parallel faults undergoing tensile forces which pull them apart.
aquifugeA geologic formation which has no interconnected openings and cannot hold or transmit water.
greenhouse gasesGases responsible for the greenhouse effect
hydrologyThe science of waters of the earth, their occurrence, distribution, and circulation; their physical and chemical properties; and their reaction with the environment, including living beings.
ehi  An acronym for Energy Helicity Index.  See Energy Helicity Index.
perviousallowing water to flow along cracks or joints.
adiabatic processA thermodynamic change of state in a system in which there is no transfer of heat or mass across the boundaries of the system
bathymetric chart  A map delineating the form of the bottom of a body of water, usually by means of depth contours (see Isobaths).
flowThe amount of water passing a particular point in a stream or river, usually expressed in cubic feet per second (cfs).
artesian watergroundwater that is under pressure and rises to the land surface when tapped by a well.
coagulant(1) An agent that causes a liquid or sol to coagulate
holding timethe maximum amount of time a sample may be stored before analysis.
foldingThe deformation of rock layers because of compressive forces to form folds.
data buoysBuoys placed throughout the Gulf of Mexico and along the Atlantic and Pacific coasts of the United States that relay information on air and water temperature, wind speed, air pressure, and wave conditions via radio signals.
mechanical bypass systemsSee bypass system.
river basinthe area drained by a river and its tributaries.
pectoral finsThe anterior(front) paired fins, attached to pectoral (shoulder) girdle.
cloud-air lightningStreaks of lightning which pass from a cloud to the air, but do not strike the ground.
hydroelectric powerElectric energy generated by means of a power generator coupled to a turbine through which water passes.
archipelagoAn archipelago is a group or chain of islands clustered together in a sea or ocean.
border iceAn ice sheet in the form of a long border attached to the bank or shore.; shore ice.
blowdownthe water drawn from boiler systems and cold water basins of cooling towers to prevent the buildup of solids.
frictional forceForce acting on wind near the Earth's surface due to frictional roughness
katabatica wind flowing down valley sides and floors, usually as air cools, condenses and sinks at night.
precipitable waterThe total water vapor contained in an atmospheric column of unit cross-sectional area; expressed in terms of water of the same cross-sectional area.
upper air westerliesConsistent winds that exist in the upper troposphere that flow east to west from about 20° of latitude to the poles.
overproductionusually applied to food yields exceeding the needs of the area in which they are produced
solonetzic soilSoil order (type) of the Canadian System of Soil Classification
erosion controlMaterials, structures, and actions utilized and taken to reduce or prevent erosion.
bed(1) An underwater or intertidal area in which a particular organism is established in large numbers
drainsA vertical well or borehole, usually downstream of impervious cores, grout curtains or cutoffs, designed to collect and direct seepage through or under a dam to reduce uplift pressure under or within a dam
energy helicity index  An index that incorporates vertical shear and instability, designed for the purpose of forecasting supercell thunderstorms.  It is related directly to storm-relative helicity in the lowest 2 km (SRH, in m2/s2) and CAPE (in j/kg) as follows:
hillSmaller than a mountain, a raised part of the earth.
bailTo remove water, as from the bottom of a boat or other vessel.
positive-tilt trough  An upper level system which is tilted to the east with increasing latitude (i.e., from southwest to northeast)
ice brecciaLarge angular ice fragments embedded in finer ice or snow record abrupt changes.
showerPrecipitation from a convective cloud that is characterized by its sudden beginning and ending, changes in intensity, and rapid changes in the appearance of the sky
groundwaterWater that flows below the ground surface through saturated soil, glacial deposits or rock.
annual floodThe maximum discharge peak during a given water year (October 1 - September 30).
glacial troughA valley that has been eroded by a glacier; distinctively U-shaped in cross-sectional profile.
conservationto protect from loss and waste
bed materialThe sediment mixture of which a streambed, lake, pond, reservoir, or estuary bottom is composed.
pirate streamOne of two streams in adjacent valleys that has been able to deepen its valley more rapidly than the other, has extended its valley headward until it has breached the divide between them, and has captured the upper portion of the neighboring stream.
hydraulic gradientThe gradient or slope of the water table or potentiometric surface in a specific direction.
tensionOne of the three forces (see compression and shear); in ice, tension creates crevasses.
run-of-river damA hydroelectric generating power plant that operates based only on available streamflow and some short-term storage (hourly, daily, or weekly)
ppmor as a       percentage of saturation.
rainPrecipitation in the form of liquid water droplets greater than 0.5 mm
carrying capacityThe maximum number of organisms that a certain habitat can sustain over the long term.
snow stick  A portable rod used to measure snow depth.
velocity zonesAreas within the floodplain subject to potential high damage from waves
cutoff lowA closed low which has become completely displaced (cut off) from basic westerly current, and moves independently of that current
kamea short ridge, hill, or mound of stratified drift deposited by glacial meltwater.
recolonizationThe reestablishment of an organism in a habitat that it previously occupied.
flood plainLowland, bordering a river, that is usually dry, but which is subject to flooding.
thermosphereAtmospheric layer above the mesosphere (above 80 kilometers) characterized by air temperatures rising rapidly with height
heterotrophOrganism that must consume energy rich organic molecules for survival
saturated(1) Generally, filled to capacity; having absorbed all that can be taken up; soaked through with moisture
plan position indicatorAlso known as a PPI Scope, it is a radar indicator scope displaying range and azimuth of targets in polar coordinates.
kelvin temperature scaleA temperature scale with the freezing point of +273°K (Kelvin) and the boiling point of +373° K
ice storm warning  This product is issued by the National Weather Service when freezing rain produces a significant and possibly damaging accumulation of ice.  The criteria for this warning varies from state to state.  In Michigan, the criteria is normally an ice accumulation of 1/4 inch or greater.
headwaterReferring to the source of a stream or river
frontthe boundary where two air masses meet.
glacierA large body of ice that formed on land by the compaction and recrystallization of snow, survives year to year, and shows some sign of movement downhill due to gravity.
chinook windA warm, dry wind that descends the eastern slope of the Rocky Mountains
parametric data  Data such as rating curves, unit hydrographs, and rainfall/runoff curves which define hydrologic variables in models.
tributaryA stream that contributes its water to another stream or body of water.
hydrologyThe study of the waters of the earth, especially with relation to the effects of precipitation and evaporation upon the occurrence and character of water in streams, lakes, and on or below the land surface.
lateral lineA series of sensory pores along the head and sides of fish and some amphibians by which water currents, vibrations, and pressure changes are detected.
volatile organic compoundsAny organic compound which evaporates readily to the atmosphere
combined sewerA sewer that conveys both stormwater and sanitary sewage in the same pipe.
glacial diversionsee diffluence.
migrationthe movement of oil, gas, contaminants, water, or other liquids through porous and permeable rock.
colSaddle like depression found between two mountain peaks
droughta sustained period of under-average precipitation.
recyclableRefers to such products as paper, glass, plastic, used oil, and metals that can be reprocessed instead of being disposed of as waste.
palustrineof bogs, marshes or swamps.
zooplanktonSmall heterotrophic organisms found inhabiting aquatic ecosystems
continental shelfThe zone around the continents extending from the low-water mark seaward, typically ending in steep slope to the depths of the ocean floor.
transmissibilityThe capacity of a rock to transmit water under pressure
filtrationSeparation of a solid and a liquid by using a porous substance that only lets the liquid pass through.
acid rainRain that has a flamboyantly low pH, due to contact with atmospheric pollutants such as sulphuric oxides.
velocity zones  Areas within the floodplain subject to potential high damage from waves
agglomerateAn ice cover of floe formed by the freezing together of various forms of ice.
turbidityThe thickness or opaqueness of water caused by the suspension of matter
streamerA channel of very high ion density which propagates through the air by the continual establishment of an electron avalanche ahead of its tip.
turbidityThe opaqueness or reduced clarity of a fluid due to the presence of suspended matter.
minimal flood hazard areasAreas between the 100-year and the 500-year flood boundaries are termed Moderate Flood Hazard Areas
detritus(1) the heavier mineral debris moved by natural watercourses, usually in bed-load form
low cloudsThe bases of these clouds range from near the surface to about 6,500 feet in middle latitudes
wastewater infrastructureThe plan or network for the collection, treatment, and disposal of sewage in a community.
condensation funnel  A funnel-shaped cloud associated with rotation and consisting of condensed water droplets (as opposed to smoke, dust, debris, etc.).
zone of ablationArea of a glacier where losses of ice from melting, evaporation, and sublimation exceed additions of snow annually.
corrie glaciationThe development of ice fields between peaks, the growth and coalescence of mountain ice caps into regional ice caps, and the growth of these regional caps into ice sheets.
ocean currentLarge scale horizontal flow of ocean water that is persistent and driven by atmospheric circulation.
ice fogFog that is composed of minute ice particles
ice bridgeA continuous ice cover of limited size extending from shore to shore like a bridge.
mesoscale convective complexA large mesoscale convective system (MCS) which is about the size of the state of Ohio or Iowa and lasts at least 6 hours
potable waterWater that is safe and palatable for human consumption.
bottled waterWater that is sold in plastic containers for drinking water and/ or domestic use.
perched water tableThe top of a Zone of Saturation that bottoms on an impermeable horizon above the level of the general water table in the area
source regionArea where air masses originate and come to possess their moisture and temperature characteristics.
percolation  The movement of water, under hydrostatic pressure, through the interstices of a rock or soil, except the movement through large openings such as caves.  In other words, the movement of water within the soil.
net penA fish rearing enclosure used in lakes and marine areas.
brackish iceIce formed from Brackish water.
hydraulic gradientThe slope of the water table or aquifer
geologic erosionnormal or natural erosion caused by geological processes acting over long geologic periods and resulting in the wearing away of mountains, the building up of floodplains, coastal plains, etc.
hydraulic gradientthe direction of groundwater flow due to changes in the depth of the water table.
hrl  The Hydrological Research Laboratory at the Office of Hydrology (OH).
indicator organismsMicrorganisms, such as coliforms, whose presence is indicative for pollution or for the presence more harmful microrganisms.
fill dam  Any dam constructed of excavated natural materials or of industrial wastes.
effluentThe sewage or industrial liquid waste that is released into natural water by sewage treatment plants, industry, or septic tanks.
wetlandarea that is regularly wet or flooded and has a water table that stands at or above the land surface for at least part of the year, such as a bog, pond, fen, estuary, or marsh.
perched water table  The water table of a relatively small ground-water body supported above the general ground water body.
electromagnetic radiationAlso called radiation, it is waves of energy propagated though space or through a material media.
estuarine watersdeepwater tidal habitats and tidal wetlands that are usually enclosed by land but have access to the ocean and are at least occasionally diluted by freshwater runoff from the land (such as bays, mouths of rivers, salt marshes, lagoons).
gelifluctionForm of mass movement in periglacial environment where a permafrost layer exists
convergenceWind movement that results in a horizontal net inflow of air into a particular region
conduitA 24-inch or larger diameter pipe carrying raw or potable water from or to treatment facilities, reservoirs and delivery points feeding a distribution system.
kame-terraceFlat-topped ridges built of stratified sand and gravel deposed by a melt water stream between an ablating glacier or a stagnant ice lobe and a higher wall or lateral moraine
stratified driftLayered and sorted sediments deposited by meltwater streams or bodies of water adjacent to the ice.
fohnwarm, dry wind descending in the Alps
infiltrationWater entering sewers and manholes via defective joints and connections, broken pipes, fractured manholes, etc.
peak gustThe highest instantaneous wind speed observed or recorded.
yieldThe weight or number of fish removed by fishing during a defined time period.
phosphorousa plant nutrient that can cause an overabundance of bacteria and algae when high amounts are present, leading to a depletion of oxygen and fish kills
reverse faultThis vertical fault develops when compressional force causes the displacement of one block of rock over another.
potential(1) (Hydrology and Hydraulics) Any of several scalar variables, each involving energy as a function of position or condition; of relevance here is the fluid potential of ground water
vapor blanketThe layer of air which overlies a body of water and, due to its proximity to the water, has a water vapor content higher than that of the surrounding atmosphere.
specific dischargeFor ground water, the rate of discharge per unit area, measured at right angles to the direction of flow.
zone of saturationthe space below the water table in which all the interstices (pore spaces) are filled with water
limestone pavementa lagstone-pattern appearing on exposed, flat upper surfaces of a mass of limestone
conjunctive water useCombined use of ground water and surface water.
topset bedHorizontal deltaic deposit composed of coarse alluvial sediment
glaciera mass of ice formed through the accumulation of multiple years of snow input causing compaction and thus the expulsion of air from within the mass.
chlorinationthe adding of chlorine to water or sewage for the purpose of disinfection or other biological or chemical results.
floodplainLand built of sediment that is regularly covered with water as a result of the flooding of a adjacent stream.
entrance headThe Head required to cause flow into a conduit or other structure, including both entrance loss and Velocity Head.
flowGlacial ice flows in two ways
conduitA natural or artificial channel through which fluids may be transported.
hydrostatic heada measure of pressure at a given point in a liquid in terms of the vertical height of a column of the same liquid which would produce the same pressure.
backflow preventionPrevention of the flow of any foreign liquids, gases or substances into the distribution pipelines of a potable water supply; accomplished by an air gap or mechanical backflow obstacle.
facultative bacteriabacteria that can live under aerobic or anaerobic conditions.
convective condensation levelThe height at which a parcel of air, if heated sufficiently from below, will rise adiabatically until it is just saturated.
municipal sludgeSemi liquid residue that remains from the treatment of municipal water and wastewater.
freshetA rapid temporary increase in stream flow due to heavy rains or snow melt.
northeast trade windsSee trade winds.
rimevery heavy frost created when fog touches surfaces which are below 0˚C
high flow pulsesthe component of an instream flow regime that represents short-duration, in-channel, high flow events following storm events
sub-basinin general, a portion of a river basin.
mprbMinneapolis Park and Recreation Board
field diversionAn interception channel near the contour to carry runoff to a waterway
glacierA large long lasting accumulation of snow and ice that develops on land
valley glaciera glacier which extends from a larger body of ice, often in a corrie, and moves downslope, initially following existing river channels but increasingly cutting its own bigger, straighter trough.
headcuttingThe action of a bedscarp or headward erosion of a locally steep channel or gully.
glacial troughGlaciers transform v-shaped stream valleys to u-shaped glacial troughs by erosion.
air pressurethe force of the atmosphere on the surface.
jettya structure (as a pier or mole of wood or stone) extending into a sea, lake, or river to influence the current or tide or to protect a harbor.
assimilationThe ability of water to purify itself of pollutants.
instream useUse of water that does not require diversion from its natural watercourse
floodplainRelatively flat area found alongside the stream channel that is prone to flooding and receives alluvium deposits from these inundation events.
contaminationthe introduction into water of sewage or other foreign matter that will render the water unfit for its intended use.
zone of fractureThe upper 50 meters of glacial ice is brittle and is carried by the ice below it.
key habitatsflow-sensitive habitats as well as habitats that support key species.
upper air/upper levelThe portion of the atmosphere which is above the lower troposphere
euryhalineHaving a wide tolerance to salinity.
groundwater rechargeThe inflow to an aquifer.
degradationwhen high discharge creates a high energy environment in a river channel leading to a lowering of the channel bed.
atmosphereThe gaseous or air portion of the physical environment that encircles a planet
side channel spillway  A spillway whose crest is roughly parallel to the channel immediately downstream of the
storm drain outfallA storm drain outfall is the point where a storm system discharges into a body of water
stratusIt is a low, uniform sheet-like cloud
reserve capacityExtra treatment capacity built into solid waste and wastewater treatment plants and interceptor sewers to accommodate flow increases due to future population growth.
hydroelectric powerPower (hydroelectricity) produced using water power as a source of energy
toe drainA drain which carries seepage away from the dam and can allow seepage quantities to be measured.
closed basin lake flooding  Flooding that occurs on lakes with either no outlet or a relatively small one
nitrogen cycleModel that describes the movement of nitrogen in its many forms between the hydrosphere, lithosphere, atmosphere and biosphere.
undercurrenta current below the upper currents or surface of a fluid body.
environmental assessmentThe critical appraisal of the likely effects of a proposed project, activity, or policy on the environment, both positive and negative.
inversionA departure from the usual increase or decrease of an atmospheric property with altitude
genetic integrityThe ability of a breeding population or group of breeding populations to remain adapted to its natural environment.
catchment areaThe area draining into a river, reservoir, or other body of water.
noctilucent cloudsRarely seen clouds of tiny ice particles that form approximately 75 to 90 kilometers above the earth's surface
adult fish laddersThe main-stem hydroelectric dams on the Columbia and lower Snake Rivers have fish ladders that allow adults to pass the dams on their upstream spawning migration.
windwardThe direction from which the wind is blowing
nuee ardenteA glowing cloud of dense hot volcanic gas and ash that moves downslope at high speeds, incinerating the landscape.
deep seepageInfiltration which reaches the water table.
rechargewater added to an aquifer
hadley cellThree-dimensional atmospheric circulation cell located at roughly 0 to 30° North and South of the equator
varvea two-layered deposit in a lake near to a glacial area
supercritical flowflow characterized by high velocity and a Froude number greater than 1
upriver bright stockA stock of fall chinook destined for the Columbia River and several tributaries upstream from The Dalles Dam
calvingThe loss of glacier mass when ice breaks off into a large water body like an ocean or a lake.
snow stakeA 1-3/4 inch square, semi-permanent stake, marked in inch increments to measure snow depth.
base flowsthe component of a flow regime that represents normal flow conditions between precipitation events
westerliesUsually applied to the broad patterns of persistent winds with a westerly component
matric forceForce that holds soil water from 0.0002 to 0.06 millimeters from the surface of soil particles
reachAn expanse of a stream channel.
acclimation pondConcrete or earthen pond or a temporary structure used for rearing and imprinting juvenile fish in the water of a particular stream before their release into that stream.
soil permeabilityThe rate at which water and air move vertically through a soil.
rockfill dam  An embankment dam of earth or rock in which the material is placed in layers and compacted by using rollers or rolling equipment.
unsteady flowFlow that is changing with respect to time.
wilting pointThe point at which the rate of water leaving a plant's leaves is greater than the water uptake by the roots
co-managersFederal, state, county, local, and tribal agencies that cooperatively manage salmonids in the Pacific Northwest.
compressive flowThe body of the glacier is shortened and thickened (not elastically compressed) in reaches where velocity is decreasing.
sediment storageThat portion of total reservoir storage dedicated for sediment deposition and encroachment
riparian landLand situated along the bank of a stream or other, generally flowing bodies of water.
tricellular modelthe basis of the modern understanding of the general circulation of the atmosphere as it relates to the troposphere
lentic watersponds or lakes (standing water).
west virginia highAn area of stagnant high pressure located over West Virginia during Indian Summer.
quench tankA water-filled tank used to cool incinerator residues or hot materials during industrial processing.
ice cliffWalls of ice where glaciers meet the sea, such as at the edge of land or the edge of an ice shelf.
total water usedTotal water withdrawal which does not include recirculation.
assimilationthe ability of a water body to purify itself of pollutants.
water yearA continuous 12-month period for which hydrologic records are compiled and summarized.
overflow(1) To flow or run over the top, brim, or banks
water yieldThe quantity of water derived from a unit area of watershed.
currentThe portion of a stream or body of water, which is moving much faster than the rest of the water
anchor iceSubmerged Frazil ice attached or anchored to the river bottom, irrespective of its formation.
rift valleySteep sided valley found on the Earth's surface created by tectonic rifting.
plateauA high area with a flat top that may have deep canyons.
tsunamiAn ocean wave with a long period that is formed by an underwater earthquake or landslide, or volcanic eruption
cold frontthe boundary between a warm and a cold air mass where the cold mass is undercutting the warm, causing the latter to rise
periglacialthe area at the edge of a glacier or ice sheet which is not covered by ice but experiences very cold conditions
corrugation irrigationSpreading water by directing it into small channels across the field.
sinuosityThe amount of bending, winding and curving in a stream or river.
wastewaterWastewater (mostly water, with a small portion of dissolved and suspended solids) is water that has been used and discharged by homes, businesses and industries
band  See frequency band.
altitudeHow high a place is above sea level.
scatteredThe amount of sky cover for a cloud layer between 3/8ths and 4/8ths, based on the summation layer amount for that layer.
perchloroethylenea chlorinated solvent commonly used in dry cleaning
coveA cove is small, horseshoe-shaped body of water along the coast; the water is surrounded by land formed of soft rock.
mare nostrumA navigable body of water, such as a sea, that is under the jurisdiction of one nation or that is shared by two or more nations.
core-periphery modela model seeking to explain a spatial pattern of economic growth in which one centre or region in a country develops an economic advantage over the rest of the country
ground water reservoirprimarily from the surface, infiltration of rain       and snowfall and its movement to the water table is one form of natural recharge, the volume of       water added by this process, (see ground water).
backflowthe backing up of water through a conduit or channel in the direction opposite to normal flow
sheet flowSee overland flow.
irrigation requirementThe quantity of water, exclusive of precipitation, that is required for crop production
gentle breezeLeaves and small twigs in constant motion; wind extends light flag; large wavelets on water; waves crests begin to break; water has a foam of glassy appearance; scattered whitecaps appear on lakes.
scalein general use refers to the size of an area or time period
diablo windsDry winds in the Diablo mountain range in central California that can exceed 60 miles per hour
recruitmentThe amount of fish added to the exploitable stock each year due to growth and/or migration into the fishing area
hydraulic controla feature in a stream (such as a constriction or a weir) that controls the upstream water surface elevation.
cold core lowA low pressure area which is colder at its center than at its periphery
mclThe maximum permissible level of a contaminant in water delivered to any user of a public system
erosionused in mining some       placer deposits to wash the unconsolidated deposits into sluice boxes.
climategeneralized weather at a given place on earth over a fairly long period; a long term average of weather
striations  Grooves or channels in cloud formations, arranged parallel to the flow of air and therefore depicting the airflow relative to the parent cloud
secondary substanceOrganic chemical produced by a plant that has no direct function in its metabolism
air pollutionThe soiling of the atmosphere by contaminants to the point that may cause injury to health, property, plant, or animal life, or prevent the use and enjoyment of the outdoors.
filterA device used to remove solids from a mixture or to separate materials
ppmSee parts per million.
ceiling lightA type of cloud-height indicator that uses a focused light to project vertically a narrow beam of light onto a cloud base.
rain barrelRain barrels collect rainwater, which can be used in gardens and lawns, as well as preventing excessive runoff.
interceptor tunnelsAny large volume pipe or conduit having a deeper invert elevation to accept or intercept the sewer flow of smaller sanitary sewers
columnar iceIce consisting of columnar shaped grain
glacialof or pertaining to:          or         a cooler period of climate during which glaciers advance (ice age)
population crashSudden decline in the number of individuals found in a population because of a scarcity of environmental resources that are required for survival, growth, and reproduction.
biologically activated carbonActivated carbon that supports active microbial growth, in order to aid in the degradation of organics that have been absorbed on its surface and in its pores.
boundary conditionsFlow conditions imposed at the ends of a pipeline or canal reach by various physical structures, which must be described mathematically to solve the general equation of flow for hydraulic transient computer models.
maximum spillway dischargeSpillway discharge (cfs) when reservoir is at maximum designed water surface elevation.
condensation nucleiA particle upon which condensation of water vapor occurs
affinityThe keenness with which an ion exchanger takes up and holds on to a counter-ion
suspended sedimentSediment that is transported in suspension by a stream
average yearly supplyThe average annual supply of a water development system over a whole hydrologic system.
streamflow  Water flowing in the stream channel
water tablelevel below the earth's surface at which the ground becomes saturated with water
csoCombined Sewer Overflows occurs when heavy rain or melting snow causes sanitary sewers to overflow into stormwater drainpipes
rankine vortex  Velocity profile for a symmetric circulation in which the inner core is in solid rotation and tangential winds outside the core vary inversely with radial distance from the center.
crackA separation formed in an ice cover of floe that does not divide it into two or more pieces.
ground water runoff  The part of runoff, caused by precipitation and/or snowmelt, that passes into the ground, becomes ground water, and gets discharged into a stream or river as spring or seepage water.
english heritagein England, a private body, originating from central government, charged with regeneration and conservation of buildings considered to have a high historical value and thus maintenance of the cultural landscape.
suncupA melted bowl-shaped depression in ice due to insolation.
diversionA turning aside or alteration of the natural course of a flow of water, normally considered physically to leave the natural channel
crevasseA deep, nearly vertical crack that develops in the upper portion of glacier ice.
heat waveA period of abnormally and uncomfortably hot weather
circulation cell  A "package" of air with a distinct circulation pattern, i.e., a lake breeze.
specific capacityIn ground water hydrology, the yield of a well in gallons per minute per foot of drawdown after a period of sustained pumping.
sediment poolThe reservoir space allotted to the accumulation of submerged sediment during the life of the structure.
nearshore watersThe waters of The Great Lakes extending out to five miles from shore.
jointsnatural crack in a rock running vertically between bedding planes.
cold lowA low pressure system that has its coldest temperatures at or near the center of circulation, and is thermally barotropic with respect to a horizontal plane
wella hole dug or drilled into the ground to allow access to groundwater.
fresh-salt water interfaceThe region where fresh water and salt water meet.
alberta clipperA fast moving low pressure system that moves southeast out of Canadian Province of Alberta (southwest Canada) through the Plains, Midwest, and Great Lakes region usually during the winter
rossby wavesthe wave-pattern of flow of the westerly winds which blow in the upper atmosphere
groundwater infiltrationWater entering sewers and manholes via defective joints and connections, broken pipes, fractured manholes, etc., due to the effects of a high ground water table.
medium-size water systemA water system that serves 3,300 to 50,000 customers.
critical sewersThe major sewers in a wastewater network that would result in the most significant consequences in the event of structural collapse.
fjordsSteep-sided inlets of the sea which occur in flooded glacial troughs.
tideThe periodic rising and falling of the earth's oceans and atmosphere
freeze-thaw actionProcesses associated with daily and seasonal cycles of freezing and melting.
ablationDepletion of snow and ice by melting and evaporation.
in-line filtrationA pre-treatment method in which chemicals are mixed by the flowing water; commonly used in pressure filtration installations
snow depth  The combined total depth of both the old and new snow on the ground.
hydrologyThe science of waters of the earth; water's properties, circulation, principles, and distribution.
conduita natural or artificial channel through which fluids may be conveyed.
quotaa limit to production or trade
updraft  Current(s) of air with marked vertical upward motion.  If the air is sufficiently moist, then the moisture condenses to become a cumulus cloud or an individual tower of
back-building thunderstorm  A thunderstorm in which new development takes place on the upwind side (usually the west or southwest side), such that the storm seems to remain stationary or propagate in a backward direction.
cloudA visible aggregate of minute water droplets or ice particles in the atmosphere above the Earth's surface.
beaufort wind scaleDescriptive system that determines wind speed by noting the effect of the wind on the environment
sustainable resourcesthose resources which can be managed to provide an ongoing yield
coronaA pastel halo around the moon or sun created by the diffraction of water droplets
unsaturated zonethe area above the water table where soil pores are not fully saturated, although some water may be present.
thalwegthe deepest part of the river channel.
iceFrozen form of the water molecule
vertical temperature profileA series of temperature measurements taken at various levels in the atmosphere that show the thermal structure of the atmosphere over a specific location
conveyance lossThe loss of water from a conduit due to leakage, seepage, evaporation, or evapo-transpiration.
sludge digestertank in which complex organic substances like sewage sludge are biologically dredged
climatic yearA period used in meteorological measurements
underflow(1) (Surface and Groundwater) The downstream flow of water through the permeable deposits underlying a stream
thermoclinefairly thin zone in a lake that separates an upper warmer zone (epilimnion) from a lower colder zone (hypolimnion).
rock knobCarved by the forward advance of the glacier, these knobs have a smooth side and a plucked side
quartza mineral commonly found in continental crust.
gendarmesIce towers such as seracs and penitantes.
sand wedgeA form of ice wedge that contains accumulations of wind blown sand in long vertical layers
minimum operating poolThe lowest water level of an impoundment at which navigation locks can still operate.
moraineA general term for a ridge or mound of till deposited by a glacier.
fluxThe rate at which a Reverse Osmosis Membrane allows water to pass through it.
geographic information systemthe creation of a database of geographic information from a variety of sources which allow the cross-referencing and compilation of different data sets so that relationships may be observed or postulated.
unsaturated zonethe zone immediately below the land surface where the pores contain both water and air, but are not totally saturated with water
bed loadSand, silt, gravel, or soil and rock detritus carried by a stream on or immediately above its bed
sea surface temperatureThe temperature of the water's surface
alluvial fana fan-shaped deposit of river load where energy has been lost due to the river exiting abruptly from a narrow upland valley to a lowland plain.
clear wellA reservoir containing potable water which has been previously treated before entering the distribution lines.
filter cake(1) The solids or semisolids deposited on a filter as a fluid is moved through it
wave refractionThe re-orientation of a wave so that it approaches a shoreline at a more perpendicular angle
tsunamiAn ocean wave produced by a sub-marine earthquake, landslide, or volcanic eruption
benthic depositsBottom accumulations which may contain bottom-dwelling organisms and/or contaminants in a lake, harbor, or stream bed.
septic systemAn on-site system designed to treat and dispose of domestic sewage
corn snow ice  Rotten granular ice.
wastewaterThe spent or used water from a home, community, farm, or industry that contains dissolved or suspended matter.
ion exchangeThe substitution of one Ion for another in certain substances
centroidThe center of mass of a convective cell (storm) or other precipitation system.
pingo  A large frost mound of more than one-year duration.
nonporoussomething which does not allow water to pass through it
subpolarThe region bordering the polar region, between 50° and 70° North and South latitude
trickling filtera treatment system in which wastewater is trickled over a bed of stones or other material covered with bacteria that break down the organic waste and produce clean water.
ridge ice  Ice piled haphazardly one piece over another in the form of ridges or walls.
consolidated ice coverIce cover formed by the packing and freezing together of floes, brash ice and other forms of floating ice.
treated waterWater that has been filtered and disinfected
rainWater falling to earth in drops that have been condensed from moisture in the atmosphere
hurricane warningA formal advisory issued by forecasters at the National Hurricane Center when they have determined that hurricane conditions are expected in a coastal area or group of islands within a 24 hour period
drizzleSlowly falling precipitation in the form of tiny water droplets with diameters less than 0.02 inches or 0.5 millimeters
icebergA mass of ice found floating in the ocean or a lake
grout curtainA barrier produced by injecting grout into a vertical zone, usually narrow (horizontally), and in the foundation to reduce seepage under a dam.
irrigated areaThe gross area upon which water is artificially applied.
end-of-pipe techniquesTechniques for water purification that serve the reduction pollutants after they have formed.
outwasha deposit of sand and gravel formed by streams of meltwater flowing from a glacier.
freezing drizzleDrizzle, falling as a liquid, but freezing on impact with the colder ground or other exposed surfaces
icea solid form of water.
instrument shelterA boxlike structure designed to protect temperature measuring instruments from exposure to direct sunshine, precipitation, and condensation, while at the same time time providing adequate ventilation.
arctic air massAn air mass that develops around the Arctic, it is characterized by being cold from surface to great heights
meander beltThe zone along a valley floor that encloses a meandering river.
continental climatetypical climates of interior areas well away from the influence of the sea
abdominal pelvicsPelvic fins located on the abdomen far behind the pectoral fins; pelvic bones do not attach to pectoral girdle.
limestonerock that consists mainly of calcium carbonate and is chiefly formed by accumulation of organic remains.
water wellany artificial excavation constructed for the purpose of exploring for or producing ground water.
wave-cut notchA rock recess at the foot of a sea cliff where the energy of water waves is concentrated.
free ground waterWater in interconnected pore spaces in the Zone of Saturation down to the first impervious barrier, moving under the control of the water table slope.
groundwater rechargeIncreases in groundwater storage by natural conditions or by human activity
stratus cloudsLow altitude gray colored cloud composed of water droplets
ice islandsBodies of land ice calved from sheet or shelf.
connecting streamA stream connecting a lake with another lake or stream.
pluckinga form of glacial erosion in which ice freezes on to rock and pulls it away when the glacier moves on.
contentsThe volume of water in a reservoir
mean depth  The average depth of water in a stream channel or conduit
forebayThe water behind (upstream) of the dam.
effluent streamsEffluent streams are those leaving a lake.
k indexThe measure of thunderstorm potential based on the vertical temperature lapse rate, the moisture content of the lower atmosphere and the vertical extent of the moist layer.
undercurrent  A current below the upper currents or surface of a fluid body.
soil erosionthe processes by which soil is removed from one place by forces such as wind, water, waves, glaciers, and construction activity and eventually deposited at some new place.
water wellAn excavation where the intended use is for location, acquisition, development, or artificial recharge of ground water.
sludgeA semi-solid residue, containing microoroganisms and their products, from any water treatment process.
anchor ice damAn accumulation of anchor ice which acts as a dam and raises the water level.
hydrologic basinthe drainage area upstream from a given point on a stream.
confluence(1) The act of flowing together; the meeting or junction of two or more streams; also, the place where these streams meet
conservationPreserving and renewing, when possible, human and natural resources such as water
accas  An acronym for Altocumulus Castellanus.  See Altocumulus Castellanus.
millibar  Unit of atmospheric pressure
liquefactionTemporary transformation of a soil mass of soil or sediment into a fluid mass
elevation angleThe vertical pointing angle of the antenna
filtrationthe mechanical process which removes particulate matter by separating water from solid material, usually by passing it through sand.
game fishA fish that is regulated by law for recreational harvest.
forecast crestThe highest elevation of river level, or stage, expected during a specified storm event.
reservoira pond, lake, tank, or basin (natural or human made) where water is collected and used for storage
cold front  The leading edge of a relatively colder airmass which separates two air masses in which the gradients of temperature and moisture are maximized.  In the northern hemisphere winds ahead of the front will be typically southwest and shift into the northwest with frontal passage.
stalactitea spindly deposit of calcium carbonate found hanging from the ceilings of caves in limestone areas
ground water discharge(1) The flow of water from the Zone of Saturation
open lakeThe Great Lakes waters beyond 5 nautical miles from shore.
detritusShed tissues, dead body parts, and waste products of organisms
tractionthe rolling of load along the bed of a river channel.
dewCondensation in the form of small water drops that forms on grass and other small objects near the ground when the temperature has fallen to the dew point, generally during the nighttime hours.
outfallthe place where a wastewater treatment plant discharges treated water into the environment.
infiltration ratethe quantity of water that can enter the soil in a specified time interval.
loessDeposits of silt laid down by aeolian processes over extensive areas of the mid-latitudes during glacial and postglacial times.
glacial troughsee glacial valley.
pathogensAny agent that causes disease, such as a virus, protozoan, bacterium or fungus.
beginning of freezupDate on which ice forming a stable winter ice cover is first observed on the water surface.
anvil rollover  Slang for a circular or semicircular lip of clouds along the underside of the upwind part of a back-sheared anvil, indicating rapid expansion of the anvil
ground water velocityThe rate of water movement through openings in rock or sediment.
ice jamA stationary accumulation that restricts or blocks streamflow.
brinehighly salty and heavily mineralized water containing heavy metal and organic contaminants.
earthen damAn embankment dam in which more than 50% of the total volume is formed of compacted fine-grained material
salineof, containing, or concerned with salt (NaCl).     
wind vaneA mechanical device used to measure the direction of wind flow
flow augmentationThe addition of water to a stream, especially to meet instream flow needs.
wave heightVertical distance between a wave's trough and crest.
wave-cut notchthe undercut portion of a cliff where the base has been eroded by wave action.
flood capacityThe flow carried by a stream or floodway at bankfull water level
hoarfrostAnother name for frost
monitoringPeriodic or continuous surveillance or testing to determine the level of compliance with statutory requirements and/or pollutant levels in various media or in humans, plants, and animals.
beachThe terrestrial interface area in between land and a water body where there are accumulations of unconsolidated sediments like sand and gravel
pluvial lakeA lake formed during a pluvial (rainy) period.
vernal equinoxTaking place in the Northern Hemispheric spring, it is the point at which the ecliptic intersects the celestial equator
recoverable ground waterThe amount of water which may be physically and economically withdrawn from the ground water reservoir.
drawdowna lowering of the ground-water surface caused by pumping.
initial detentionThe volume of water on the ground, either in depressions or in transit, at the time active runoff begins.
mitigation(1) (Environmental, General) Actions designed to lessen or reduce adverse impacts; frequently used in the context of environmental assessment
groundwaterThe supply of fresh water found beneath the Earth's surface, usually in aquifers, which supply wells and springs
eskerA long, snakelike ridge of sediment deposited by a stream that ran under or within a glacier.
calorieamount of energy required to raise the temperature of 1 gram of water 1 degree Celsius.
sluicewayAn open channel inside a dam designed to collect and divert ice and trash in the river (e.g., logs) before they get into the turbine units and cause damage
wetted perimeterthat portion of a river? bed and sides which is in contact with the water.
eutrophicationThe natural process by which lakes and ponds become enriched with dissolved nutrients, resulting in increased growth of algae and other microscopic plants.
frosta covering of minute ice crystals on a cold surface.
guilda group of species or organisms that use the same environmental resources (habitat, food source, etc.) or life history strategy (such as reproduction) in the same way.
cold waveA rapid fall in temperature within twenty-four hours to temperatures requiring substantially increased protection to agriculture, industry, commerce, and social activities
outwashGlaciofluvial sediments deposited by meltwater streams at the edge of a glacier.
screehighly angular rock pieces produced by freeze-thaw weathering and found at the base of a steep or vertical cliff face.
developing stormUsed in the National Weather Service High Seas Forecast.  It refers to an extratropical low or an area in which storm force winds of 48 knots (55 mph) or greater are "expected" by a certain time period.  On surface analysis charts a developing storm indicates storm force winds forecast within the next 36 hours
masonry damA dam constructed mainly of stone, brick, or concrete blocks that may or may not be joined with mortar
interlocking spursthe landform resulting from the winding path of a river in its upper course cutting a V-shaped valley
threshold pollutantsubstance that is harmful to a particular organism only above a certain concentration, or threshold level.
hanging dam  A mass of ice composed mainly of frazil or broken ice deposited underneath an ice cover in a region of low flow velocity.
dissolved solidsinorganic material contained in water or wastes
downgradientthe direction that groundwater flows; similar to "downstream" for surface water.
ice shoveOn-shore ice push caused by wind, and currents, changes in temperature, etcetera.
groundwater rechargethe addition of water to the groundwater store.
ground water mining  Pumping ground water from a basin where the safe yield is very small, thereby extracting ground water which had accumulated over a long period of time.
dead endthe end of a water main that is not connected to other parts of the distribution system.
patterned groundPolygonal or circular ground patterns which develop from contrasting size/color soils in poorly drained areas subject to intensive frost action.
surgesPeriods of extremely rapid movements in glacial flow.
glazeA smooth, clear coat of ice on older ice, rock or any other surface.
irrigated croplandAll lands being supplied water by artificial means, excluding waterfowl refuges, that are being used for the production of orchard, field, grain crops and pasture.
net rainThe portion of rainfall during a storm which reaches a stream as direct surface flow.
espExtended Streamflow Prediction
mid-columbia coordinating committeeA committee whose primary purpose is to improve fish passage at the mid-Columbia dams
collector sewersPipes used to collect and carry wastewater from individual sources to an interceptor sewer that will carry it to a treatment facility.
pondA small natural body of standing fresh water filling a surface depression, usually smaller than a lake.
flood peakThe maximum instantaneous discharge of a flood at a given location
dredgingRemoving material (usually sediments) from wetlands or waterways, usually to make them deeper and wider.
eustacyVariations in sea-level that are related to changes in the volume of seawater in the oceans.
suspended sedimentSediment suspended in a fluid by the upward components of turbulent currents, moving ice, or wind.
isotopic datingDating technique used to determine the age of rock and mineral through the decay of radioactive elements.
prevailing visibilityThe visibility that is considered representative of conditions at the station; the greatest distance that can be seen throughout at least half the horizon circle, not necessarily continuous.
translucentNot transparent, but clear enough to allow light to pass through.
geographic isolationSee spatial isolation.
isostatic depressionthe sinking of a landmass due to the overlying weight of ice.
sewer inspectionViewing the sewer primarily with the aid of sewer CCTV equipment, and or manually, to assess overall condition
alluviumsediments deposited by erosional processes, usually by streams.
backwater floodingUpstream flooding caused by downstream conditions such as channel restriction and/ or high flow in a downstream confluence stream.
biotic potentialMaximum rate that a population of a given species can increase in size (number of individuals) when there are no limits on growth rate.
lakesponds and reservoirs.
streamflowthe discharge that occurs in a natural channel.
production capacityThe capacity of a water body or production facility to produce fish.
cone of depression  The depression, roughly conical in shape, produced in a water table, or other piezometric surface, by the extraction of water from a well at a given rate
outmigrationThe migration of fish down the river system to the ocean.
price at equilibriumwhere supply and demand curves intersect
snow coverThe areal extent of ground covered by the snow
pressure releasethe removal of overlying rock which releases pressure on underlying strata causing them to expand and crack.
cliffA cliff is a steep face of rock and soil.
toxaphenechemical that causes adverse health effects in domestic water supplies and is toxic to fresh water and marine aquatic life.
karstic riverA river which originates from a karstic spring or flows in a Karstic Region.
initial lossRainfall which precedes the beginning of surface runoff
back siphonageReverse seepage of water in a distribution system.
water tableThe boundary between the saturated and unsaturated zones
treatment plantA structure built to treat wastewater before discharging it into the environment.
run-byRun-by occurs when a high magnitude storm occurs and the flow in the street is going too fast to enter the storm drain inlet, usually a catch basin, and ‘runs by’.
confined groundwaterGroundwater trapped between two impervious layers of rock.
wella bored, drilled, or driven shaft or a dug hole whose depth is greater than the largest surface dimension and whose purpose is to reach underground water supplies or oil or to store or bury fluids below ground.
desalinationthe removal of salts from saline water to provide freshwater
subsidenceThe downwarping of Earth's crust due to additional weight (such as a glacier or a transgressing sea) being applied to it.
expanded towna town deliberately tagged for expansion to try and alleviate population pressure on a nearby, larger urban area
pressure altitudeThe altitude in standard atmosphere at which a given pressure will be observed
peak flowRefers to a specific period of time when the discharge of a stream or river is at its highest point.
thermosphereA thermal classification, it is the layer of the atmosphere located between the mesosphere and outer space
cirque glacierSmall glacier that just occupies a cirque.
green beltin the UK, an area of land surrounding an urban area in which planning restrictions severely curb new housing, commercial  and industrial developments
mouth of streamThe point of discharge of a stream into another stream, a lake, or the sea.
initial loss  In hydrology, rainfall preceding the beginning of surface runoff
energy content curvesA set of curves that establishes limits on the amount of reservoir draw-down permitted to produce energy in excess of FELCC.
thermal pollutionan increase in air or water temperature that disturbs the climate or ecology of an area.
navigational water useWater utilized as a means of commercial (and sometimes recreational) transportation
clarificationthe clearing action that occurs during wastewater treatment when solids settle out
phytoplanktonMinute plants, usually algae, that live suspended in bodies of water and that drift about because they are too small or too weak to swim effectively against the current.
flowing well/springa well or spring that taps ground water under pressure so that water rises without pumping
contour lineon topographical maps, the isolines connecting points of equal height above sea-level.
control systemAn arrangement of electronic, electrical, and mechanical components that commands or directs the regulation of a canal system.
gulf streama warm ocean current that originates in the Caribbean and flows north-east across the Atlantic where it becomes the North Atlantic Drift and is responsible for the mildness of the climate in the UK and Ireland.
salinity intrusionThe movement of salt water into a body of fresh water
sewer service conditionAssessment of the service condition of the sewer, reflecting the sewer conduit's capacity, potential for blockage, and water tightness.
soil absorption fieldA sub-surface area containing a trench or bed with clean stones and a system of piping through which treated sewage may seep into the surrounding soil for further treatment and disposal.
sealA tight and perfect closure as against the passage of water.
paleosolA soil exhibiting features that are the result of some past conditions and processes.
impermeablea rock which cannot absorb water and does not allow it to pass through.
conditional instabilitywhen the ELR is lower than the DALR but higher than the SALR then an air mass will initially be stable and may sink
snowpackThe total ice and snow on the ground, including fresh and older snow and ice.
pumpa device which moves, compresses, or alters the pressure of a fluid, such as water or air, being conveyed through a natural or artificial channel.
santa ana windsThe hot, dry winds, generally from the east, that funnel through the Santa Ana river valley south of the San Gabriel and San Bernadino Mountains in southern California, including the Los Angeles basin
pervious pavingPaving material that allows water to penetrate to the soil below.
valley wallThe side slope of a stream or glacial valley.
thermoelectric power water usewater used in the process of the generation of thermoelectric power
tillglacial deposits.
thermodynamicsStudy of the processes that involve the transformation of heat into mechanical work, of mechanical work into heat, or the flow of heat from a hotter body to a colder body.
rectangular coordinate systemSystem that measures the location of points on the Earth on a two-dimensional coordinate plane
moulinA vertical shaft at the downslope end of a transverse fissure
strike-slip faultFault that primarily displays horizontal displacement.
precipitatea solid that has formed out of dissolved state.
jugular pelvicsPelvic fins in front of the pectoral fins.
thalweg(1) The lowest thread along the axial part of a valley or stream channel
dry washA streambed that carries water only during and immediately following rainstorms.
ferricretesSedimentary rock created by the chemical precipitation of iron.
earthlightThe faint illumination of the dark part of the moon's disk produced by sunlight reflected onto the moon from the earth's surface and atmosphere.
shoaling  The process whereby waves coming into shallow waters are slowed by bottom friction and become closer together and steeper.
alpine glacierA relatively small glacier that forms in high elevations near the tops of mountains.
loadingThe influx of pollutants to a selected water body.
dripstonedeposits of calcium carbonate that include stalactites, stalagmites, columns, and cave pearls.
spring tideA tide higher than normal which occurs around the time of the new and full moon.
sedimentationcoagulation in water treatment uses alum to       congregate solids in the water into a mass that can be readily trapped by a filter, (see       flocculation).
recirculated waterWater that is used more than one time before it passes back into the natural hydrological system or discharged into a wastewater system
microbial growthThe multiplication of microrganisms such as bacteria, algae, diatoms, plankton, and fungi.
saturated zonethe area below the water table where all open spaces are filled with water under pressure equal to or greater than that of the atmosphere.
ebb tideTime during the tidal period when the tide is falling
ice twitchDownstream movement of a small section of an ice cover
polar easterliesWinds that originate at the polar highs and blow to the subpolar lows in a east to west direction.
mainstemThe major reach of a river or stream formed by the smaller tributaries which flow into it.
wall cloudAn abrupt lowering of a cloud from its parent cloud base, a cumulonimbus or supercell, with no visible precipitation underneath
potable waterWater that is safe for drinking or cooking.
droughtA continuous and lengthy period during which no significant precipitation is recorded.
ice jamAn accumulation of broken river ice caught in a narrow channel, frequently producing local flooding
shallow wellA well with a pumping head of 20 feet or less, permitting use of a suction pump.