Glossary extracted starting with manual seeds, with BOW for the domain gel and language EN

scrapers	aquatic invertebrates that feed by scraping the surface of rocks for algae
aerated lagoon	a 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.
hydrology	Science concerned with the occurrence, distribution, and circulation of water on the earth.
hydrologic cycle	natural 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
aquifer	A geological formation or group of formations capable of receiving, storing and transmitting significant quantities of water (Water and Rivers Commission 2000a).
meander width	Amplitude of a fully developed meander measured from midstream to midstream.
snag	Fallen trees and dead branches in the river channel.
environment	The sum total of all the external conditions that effect an organism, community, material, or energy.
soft water	Water that contains low concentrations of multivalent cations, such as calcium and magnesium
snow creep	A continuous, extremely slow, downhill movement of a layer of snow.
confined aquifer	an aquifer that lies between two rock layers of very low permeability
holding time	the maximum amount of time a sample may be stored before analysis.
recharge	Rainfall that drains past the root zone and reaches the groundwater.
delta	A delta is a large, silty area at the mouth of a river at which the river splits into many different slow-flowing channels that have muddy banks
dredging	Digging up and removing material from wetlands or waterways, usually to make them deeper or wider.
diversity	See Biodiversity
boiling point	The temperature at which a liquid changes to a vaporous state
hydraulic gradient	The change in hydraulic head over some specified distance.
slope stability	The resistance of a natural or artificial slope or other inclined surface to failure by landsliding (mass movement).
current	A horizontal movement of water, such as the Gulf Stream off the east coast of North America, or air, such as the jet stream.
bed sediment discharge	Part of the total sediment discharge that is composed of grain sizes found in the bed and is equal to the transport capability of the flow.
hec	Hydrologic Engineering Center; The part of the U.S
fid	=Flame Ionization Detector, a detector used in GC chromatography, very sensitive but destroys the sample due to combustion
hardpan	A layer of nearly impermeable soil beneath a more permeable soil, formed by natural chemical cementing of the soil particles.
stream	the 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.
transportation	A process where the river moves, or transports materials (it's load) from one place to another.
hydrologic unit	A distinct watershed or river basin defined by an eight-digit code.
transport capacity	the capacity of a river to carry sediment in suspension or to move sediment along the riverbed.
tonnes/d	Tonnes per day.
fishway	a structure designed to enable fish to move over a physical barrier (dam or weir) in a waterway.
land application	discharge of wastewater onto the ground for treatment or reuse.
secondary production	material that is transformed by consumers (eaten or decomposed)
hold	A feature common to thermometers allowing you to freeze the display at a given measurement without additional inputs for easier reading
critical shear stress	Minimum amount of shear stress required to initiate soil particle motion.
ephemeral streams	Streams that flow only in direct response to precipitation and whose channel is at all times above the water table.
stream segment	refers to the surface waters of an approved planning area exhibiting common biological, chemical, hydrological, natural, and physical characteristics and processes
cavitation	The boiling of a liquid caused by a decrease in pressure rather than an increase in temperature.
friction	In meteorology, it is the turbulent resistance of the earth on the atmosphere
weir	Usually a barrier constructed to catch upstream migrating adult fish.
macroinvertebrates	Invertebrates (animals without backbones) large enough to be seen without a microscope
biofilms	Layered groups or communities of microbial populations.
arctic air mass	An air mass that develops around the Arctic, it is characterized by being cold from surface to great heights
horsetail falls	A falls that descends a very nearly vertical rock face, maintaining some contact with it
effluent	Effluent is wastewater (like sewage water or factory runoff) that flows from a factory or other facility.
peak flow	The highest discharge achieved during a storm event.
hydraulic conductivity	the rate at which water can move through a permeable medium.
flood spawners	In the River Murray, include fish species of Golden perch and Silver perch which spawn and recruit following flow rises and during periods of floodplain inundation.
meridional flow	Atmospheric circulation in which the north and south, or meridional, component of motion is unusually pronounced
fahrenheit	A scale of temperature originally defined by having 0Â° as the lowest obtainable temperature with a mixture of water, ice and salt and 96Â° as the temperature of the human body
dissolved fraction	The part of a water sample passing through a 0.45 µm pore size filter paper
uv-vis spectroscopy	is a technique to investigate conjugation within molecules
butt end	The bottom end of a cutting taken from a riparian plant that will root if planted in soil (it is opposite the budding tip's end of the cutting).
prehistoric	before written historic records
depression	In meteorology, it is another name for an area of low pressure, a low, or trough
benthic	refers to the bottom of a body of water benthic macroinvertebrates: spineless animals that inhabit the bottom of streams and lakes; visible to the eye; aquatic worms, snails, clams, immature stages of aquatic insects
drainage area	of 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.
diluting water	distilled water that has been stabilized, buffered, and aerated
retention/retain	Retention is defined as the process of preventing rainfall runoff from being discharged into receiving water bodies by holding it in a storage area
water dependent ecosystems	Those parts of the environment, the species composition and natural ecological processes of which are determined by the permanent or temporary presence of water resources, including flowing or standing water and water within groundwater aquifers.
peak flow	in a wastewater treatment plant, the highest flow expected to be encoutered under any operational conditions, including periods of high rainfall and prolonged periods of wet weather.
bulking	Increasing the water discharge to account for high concentrations of sediment in the flow.
run-off	Water that runs off the soil's surface
ice	a solid form of water.
artesian well	a 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
dead end	the end of a water main that is not connected to other parts of the distribution system.
froude number	Dimensionless number expressing the ratio of inertial force to gravity force in a fluid.
algae	simple rootless plants that grow in sunlit waters in proportion to the amount of available nutrients
short circuiting	when 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.
halophytic	Refers to a plant that can tolerate or thrive in alkaline soil rich in sodium or calcium salts; tolerant of saline conditions.
aquifer	A body of rock that is sufficiently permeable to conduct groundwater and to yield significant quantities of water to wells and springs.
healthy working river	In the case of The Living Murray, a healthy working river is one that is managed to provide a compromise, agreed to by the community, between the condition of the river and the level of human use.
frost	The covering of ice crystals that forms by direct sublimation on exposed surfaces whose temperature is below freezing.
drainage basin	watershed
headcutting	The action of a bedscarp or headward erosion of a locally steep channel or gully.
macroinvertebrate	An invertebrate (animal without a backbone) that is larger than 1 mm.
lithosphere	The solid, outer portion of the earth's crust coupled to the rigid upper mantle
allochthonous	Derived from an external source, for example, organic matter entering a stream or lake but derived from adjacent terrestrial areas.
snowfall	The rate at which snow falls, usually expressed in inches of snow depth over a six hour period.
viscosity	A measure of the resistance of a fluid to flow
sediment	Soil or mineral material transported by water or wind and deposited in streams or other bodies of water.
channeled	Channeled means grooved or cut deeply.
freezing point	is the temperature at which a liquid becomes a solid
thermosphere	A thermal classification, it is the layer of the atmosphere located between the mesosphere and outer space
mixing zone	a limited volume of receiving water that is allocated for diluting a wastewater discharge without causing adverse effects to the overall water body.
catchment	(1) The catching or collecting of water, especially rainfall
publicly-owned treatment works	a wastewater treatment plant that is owned by a state, unit of local government or Indian tribe, usually designed to treat domestic wastewaters
glen	A long narrow valley, often U-shaped with small cliffs on the sides, carved by a stream
interface	the common boundary between two substances such as water and a solid, water and a gas, or two liquids such as water and oil.
groundwater	Subsurface water and underground streams that can be collected with wells, or that flow naturally to the earth's surface though springs.
water quality	the chemical, physical, biological, radiological, and thermal condition of water.
international date line	The line of longitude located at 180Â° East or West (with a few local deviations) where the date changes by a day
grab sample	a sample taken at a given place and time
oxbow lake	a U-shaped water body formed when a meander bend is cut off from the mainstem of a river or stream to create a lake.
eddy current	Vortex‑type motion of a fluid flowing contrary to the main current, such as the circular water movement that occurs when the main flow becomes separated from the bank.
economic values	Includes water body uses, stormwater use, economic values of the receiving environment (e.g
deglaciation	Disappearance by melting of ice covering an area
turbulent flow	Fluid flow in which the velocity at any point varies erratically in magnitude and direction
environment	aggregate of external conditions that influence the life of an individual organism or population.
dike	(1) (Engineering) An embankment to confine or control water, especially one built along the banks of a river to prevent overflow of lowlands; a levee
standard deviation	A measure of how much variation there is from the average across a data set.
filter fabric	Geosynthetic fabric that serves the same purpose as a granular filter blanket.
discharge	the volume of water that passes a given point within a given period of time
crossing	Relatively short and shallow reach of a stream between bends; also crossover or riffle.
ground water	its 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.
backwater pool	A pool that formed from an eddy along a channel margin as a result of an upstream obstruction like a large tree, rootwad, or boulder.
environmental water provisions	The water regimes that are provided as a result of the water allocation decision-making process taking into account ecological, social and economic impacts
mainstem survival	The proportion of anadromous fish that survive passage through the dams and reservoirs while migrating in the Columbia and Snake rivers.
dike	An impermeable linear structure for the control or containment of overbank flow
fogbow	A whitish semicircular arc seen opposite the sun in fog
milt	sperm-filled milky substance released by male fish to fertilize eggs
synthetic organic chemicals	man-made organic chemicals
dissolved oxygen	The amount of oxygen freely available in water and necessary for aquatic life and the oxidation of organic materials.
flow slide	Saturated soil materials which behave more like a liquid than a solid
streambed	part of the stream over which water moves; substrate
sandbar	An accumulation of alluvium - usually sand or gravel - caused by a decrease in sediment transport capacity in an overwide channel.
incised river	A river that erodes its channel by a process of degradation to a lower base level than existed previously or is consistent with the current hydrology.
habitat	an area where plants and animals live
geomorphology	Geomorphology is the scientific field that investigates how landforms are formed on the Earth (and other planets).
benthic	Of, or associated with, the bottom of a water body.
function	The physical, chemical and biological processes, services and values that occur in an ecosystem (e.g., floodplain, stream, wetland) as a result of their structure and composition.
acre	A measure of area equal to 43,560 square feet (4,046.87 square meters)
nutrient cycle	the cyclic conversions of nutrients from one form to another within biological communities
riffles	High points in a stream or river channel representing bedrock bars or accumulations of relatively coarse material
design flow	Discharge that is selected as the basis for the design or evaluation of a hydraulic structure.
isohel	A line drawn through geographic points having equal duration of sunshine or another form of solar radiation during a specified time period.
ukas	An acronym for United Kingdom Accreditation Service, the organization tasked by the British government with the maintenance and administration of national standards
macrophytes	Water plants that are not algae and which may either float or be attached to a substrate.
contraction scour	Contraction scour, in a natural channel or at a bridge crossing, involves the removal of material from the bed and banks across all or most of the channel width
sun dog	Either of two colored luminous spots that appear at roughly 22° on both sides of the sun at the same elevation
specific yield	the amount of water a unit volume of saturated permeable rock will yield when drained by gravity.
seagrass	Seagrasses are the 'grass meadows' of coastal waters.
coalescence	The merging of two water drops into a single larger drop.
speed	See response time.
redd	a nest in the streambed in which salmon and trout lay their eggs; the eggs incubate, then hatch in the gravel
haze	A suspension of fine dust and/or smoke particles in the air
e. coli	A group of bacteria, Escherichia, that reside in the intestinal tracts of humans and many animals and can cause food poisoning, urinary infections and enteritis.
key watershed	As defined by National Forest and Bureau of Land Management District fish biologists, a watershed containing (1) habitat for potentially threatened species or stocks of anadromous salmonids or other potentially threatened fish, or (2) greater than 6 square miles with high-quality water and fish habitat.
hydrocarbons	chemical compounds that consist entirely of carbon and hydrogen; also referred to as volatile organic compound.
drainage basin	The area drained by a river and its tributaries
target	A numerical concentration limit or descriptive statement relating to an aspect of water management aspired to as part of the LEWMP.
wastewater	water containing waste including greywater, blackwater or water contaminated by waste contact, including process-generated and contaminated rainfall runoff.
perennial stream	A stream that normally contains flowing water at all times.
watershed restoration	Improving current conditions of watersheds to restore degraded fish habitat and provide long-term protection to aquatic and riparian resources.
camba	The China Australia Migratory Bird Agreement, a treaty between Australia and China with the aim of preserving areas that provide habitat for internationally migrating birds within the tropics or the southern hemisphere.
riparian	Riparian means located by the banks of a river, stream, or other body of water.
anabatic wind	A wind that is created by air flowing uphill
periphyton	algae growing on surfaces in a stream, lake, or ocean
lagoon	(1) A shallow pond where sunlight, bacterial action, and oxygen work to purify wastewater
evapotranspiration	The loss of water from a land area through evaporation from the soil and through plant transpiration.
glide	A section of stream that has little or no turbulence.
well	a 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.
turbidity	a cloudy condition in water due to suspended silt or organic matter.
average annual recharge	amount of water entering the aquifer on an average annual basis
fresh water	Water found rivers, lakes, and rain, that is distinguished from salt water by its appreciable lack of salinity.
lock	An enclosed dam chamber with gates at each end that allow water to be admitted and released
combined sewer overflow	An outlet for stormwater and untreated sewage during large rainfall or runoff events.
normal operating zone	The elevation range within which main-river reservoirs are operated for power production and summer mosquito control
incubation	the process of keeping eggs in a favorable condition for hatching
waterproof	A non-technical term used to describe instruments that are protected from the ingress of liquids
organism	any form of animal or plant life.
fishways	Structures that provide fish with passage past an obstruction or stream.
sand	Small substrate particles, generally referring to particles less than 2 mm in diameter
cloud	A visible collection of minute particle matter, such as water droplets and/or ice crystals, in the free air
water surface elevation	the elevation of a water surface above or below an established reference level, such as sea level.
wild rivers	Rivers or sections of rivers that are free of impoundments and generally inaccessible except by trail, with watersheds or shorelines essentially primitive and waters unpolluted.
head	In the hydrological sense, refers to water pressure as a result of flow, usually as a result of a pressure gradient created by the movement of water.
current meter	Instrument used to measure flow velocity.
nocturnal thunderstorms	Thunderstorms which develop after sunset
tidal marsh	low, flat marshlands traversed by channels and tidal hollows, subject to tidal inundation; normally, the only vegetation present is salt-tolerant bushes and grasses.
biotechnical engineering	Countermeasure techniques that combine the use of vegetation with structural (hard) elements.
seepage	percolation of water through the soil from unlined canals, ditches, laterals, watercourses, or water storage facilities.
smolt	a juvenile anadromous fish that has undergone physical changes to prepare for life in saltwater
flash flood	A flood that crests in a short length of time and is often characterized by high velocity flows.
channelization	The process of changing (usually straightening) the natural path of a waterway.
vortex rocks	Rocks placed in a streambed to help direct flows for the formation of meanders and creation of riffles and pools
watershed	all the land area that drains into a particular body of water
salinity gradients	Changes in salt concentration.
infiltration	The movement of water from the surface to the subsoil and at times, ultimately to the underlying aquifer.
samphire	A leafless shrub that is tolerant of saline conditions
green filamentous algae	Hair-like filaments of algae often found floating on the surface of water or clumped on the stream bed.
vertical visibility	The distance an observer can see vertically into an undefined ceiling, or the height corresponding to the top of a ceiling light projector beam, or the height at which a ceiling balloon disappears during the presence of an indefinite ceiling.
snow devil	A small, rotating wind that picks up loose snow instead of dirt (like a dust devil) or water (like a waterspout)
foraging habitat	areas in which a fish searches for food
wet bulb depression	Dependent on the temperature and the humidity of the air, it is the difference between the dry bulb and the wet bulb readings.
molecule	the smallest division of a compound that still retains or exhibits all the properties of the substance.
bar	an 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.
estuary	an area of a river where the fresh water meets the salt water
stream	also 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.
water pollution	An unusually high amount of a chemical in a water body that has the potential to cause an environmental impact.
nist-traceable	Indicates that a given instrument has been calibrated using standards that have an accuracy certified by the National Institute of Standards and Technology (NIST).
crib	Frame structure filled with earth or stone ballast, designed to reduce energy and to deflect streamflow away from a bank or embankment.
stagnation	lack of motion in water that holds pollutants in place.
fauna	A living organism characterised by voluntary movement.
gauging station	A point of demarkation along the route of a stream or river, used for reference marking or water monitoring.
langelier saturation index	an index reflecting the equilibrium pH of a water with respect to calcium and alkalinity; used in stabilizing water to control both corrosion and scale deposition.
re-snagging	Refers to the process of placing woody debris back into channels to improve aquatic fauna habitat.
mattress	Blanket or revetment of materials interwoven or otherwise lashed together and placed to cover an area subject to scour.
tcd	=Thermal Conductivity Detector, less sensitive than FID, but allows to collect sample
freezing	the change of a liquid into a solid as temperature decreases
overbank flows	the component of an instream flow regime that represents infrequent, high flow events that exceed the normal channel
boundary layer	The thin layer of the water column immediately above the stream bed where friction virtually stops the current.
united states weather bureau	The official name of the National Weather Service prior to 1970.
weather surveillance radar	The newest generation of Doppler radars, the 1988 Doppler weather radar
biological oxidation	decomposition of complex organic materials by microorganisms
sandstorm	A strong wind carrying sand particles through the air
larva	the first mobile stage of life after hatching
recruitment	addition of new fish to a population, usually through natural reproduction or stocking
embankment	An artificial deposit of material that is raised above the natural surface of the land and used to contain, divert, or store water, support roads and railways, or for other similar purposes.
rapids	Rapids are fast-flowing stretches of water formed where the river surface breaks up into waves because rocks are near to the surface.
crustaceans	Aquatic organisms with a shell
convergence	Wind movement that results in a horizontal net inflow of air into a particular region
streambank stabilization	The lining of streambanks with riprap, matting, etc., or other measures intended to control erosion.
river channels	Natural or artificial open conduits which continuously or periodically contain moving water, or which forms a connection between two bodies of water.
top of bank	The break in slope between the bank and the surrounding terrain.
lumo	lowest unoccupied molecular orbital
fill	(Geology) Any sediment deposited by any agent such as water so as to fill or partly fill a channel, valley, sink, or other depression.
algae	Microscopic plants that grow in sunlit water containing phosphates, nitrates, and other nutrients
volcano	An opening in the earth's crust through which steam and lava are forced out.
aquiculture	the raising or fattening of fish in enclosed ponds
noncontact recreation	recreational pursuits not involving a significant risk of water ingestion, including fishing, commercial and recreational boating, and limited body contact incidental to shoreline activity
homo	is the highest occupied molecular orbital in a molecule
whirlwind	A small-scale, rapidly rotating column of wind, formed thermally and most likely to develop on clear, dry, hot afternoons
drainage basin	the area of land drained by a major river system
canyon	A very wide and deep chasm with sides comprised of a series of cliffs, carved by a river.
cobble	rocks with a grain size between 2.5 to 10 inches
headwater	The upstream portion of a watershed.
water recycling	the treatment of urban wastewater to a level rendering it suitable for a specific, direct, beneficial use.
mesosphere	The layer of the atmosphere located between the stratosphere and the ionosphere, where temperatures drop rapidly with increasing height
stream bed	The bottom of a stream.
stream flow	volume of water carried by a stream
rain	Water falling to earth in drops that have been condensed from moisture in the atmosphere.
auto-range	A feature on some thermometers that automatically changes the resolution of the display over a specified range.
heat lightning	Lightning that appears as a glowing flash on the horizon
soft water	Water that contains low concentrations of metal ions such as calcium and magnesium
climate	The historical record and description of average daily and in seasonal weather events that help describe a region
economic demand	The consumer's willingness and ability to purchase some quantity of a commodity based on the price of that commodity.
caviar	ripe sturgeon eggs which are processed and salted to be eaten as a spread or used as a garnish
load	The amount of electric power that is drawn from TVA’s electric system at a given point in time.
open system	system in which energy and matter are exchanged between the system and its environment, for example, a living organism.
salt	generally potassium or ammonium is the cation, used to coagulate particles in water treatment.
run	a part of the stream with smooth, slow to moderate flow, deeper than a riffle
freeboard	Vertical distance above a design stage that is allowed for waves, surges, drift, and other contingencies.
sediment	Soil particles (sand, silt, clay) that have been transported away from their previous location by the action of water.
granular activated carbon	pure carbon heated to promote "active" sites which can adsorb pollutants
species composition	that portion of an Index of Biotic Integrity that is a metric measuring the number and identity of species.
runoff	Water that flows over the ground and reaches a stream as a result of rainfall or snowmelt.
cut bank	Concave wall of a meandering stream.
erosion	the wearing away of the land surface by wind, water, ice or other geologic agents
drainage well	a well drilled to carry excess water off agricultural fields
jar test	a 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.
dust	Small particles of earth or other matter suspended in the air
acidic	The condition of water or soil that contains a sufficient amount of acid substances to lower the pH below 7.0.
neat	a term often used in IR spectroscopy, means that only the pure compound was place in the IR beam
collada	A strong, steady wind blowing from the north or northwest in the upper part of the Gulf of California and from the northeast in the lower part.
millibar	The standard unit of measurement for atmospheric pressure used by the National Weather Service
robust brown algae	Large brown macroalgae (Phaeophyta) that are found in marine habitats with hard substrate where seagrasses cannot grow
trihalomethanes	chemical compounds in which three of the four hydrogen atoms of methane (CH4) are replaced by halogen atoms
runoff	Runoff is water that drains into a river (or other body of water) from uncontrolled streams, drains, or sewage lines
debris torrent	Rapid movement of a large quantity of materials (wood and sediment) down a stream channel during storms or floods
carbamates	a class of new-age pesticides that attack the nervous system of organisms.
flanking line	A line of attached cumulus or towering cumulus clouds of descending height, appearing as stair steps (usually on the southwest side) of the most active part of a supercell.
methyl orange alkalinity	A measure of the total alkalinity in a water sample in which the color of methyl orange reflects the change in level.
stream reach	An individual first order stream or a segment of another stream that has beginning and ending points at a stream confluence
riparian buffer	An undisturbed, vegetated strip of land adjacent to a water course.
woody weeds	Introduced shrub like plants which can become pests, such as gorse and blackberries.
wetlands	Areas of seasonally, intermittently or permanently waterlogged or inundated land, whether natural or otherwise, including lakes and floodplains.
lakes	Inland water bodies that have little or no flow
key watershed	As defined by National Forest and Bureau of Land Management District fish biologists, a watershed containing (1) habitat for potentially threatened species or stocks of anadromus salmonids or other potentially threatened fish, or (2) greater than six square miles with high-quality water and fish habitat.
anti-degradation clause	part of federal and water quality requirements prohibiting deterioration where pollution levels are above the legal limit.
groundwater storage capacity	The space or voids contained in a given volume of soil and rock deposits.
kalema	a violent surf that occurs on the coast of the Guinea region, West Africa.
retention time	is the time interval that passed between the sample injection and the appearance of the peak maximum
disinfection byproducts	halogenated organic chemicals formed when water is disinfected.
water quality standards	laws or regulations, promulgated under Section 303 of the Clean Water Act, that consist of the designated use or uses of a waterbody or a segment of a waterbody and the water quality criteria that are necessary to protect the use or uses of that particular waterbody
meander cut-off	A channel cut across the neck of a bend (often as a result of movement of a channel over time).
base floodplain	Floodplain associated with the flood with a 100-year recurrence interval.
mudflats	Mudflats are large area of mud that the tide washes over twice each day
alberta clipper	A fast moving, snow-producing weather system that originates in the lee of the Canadian Rockies
acid rain	the acidic rainfall which results when rain combines with sulfur oxides emissions from combustion of fossil fuels.
nick point	A usually less erosive material, such as bedrock or a fallen log, that tends to slow the downward erosion of the stream channel and the upstream migration of a headcut.
vested water right	the right granted by a state water agency to use either surface or ground water.
acidic	The condition of water or soil in which the amount of acid substances are sufficient to lower the pH below 7.0.
contaminant	An undesirable substance not normally present or an unusually high concentration of a naturally occurring substance
primary production	organic material produced by plants from inorganic material and sunlight
dry slot	An area of dry, and usually cloud-free, air that wraps into the southern and eastern sections of a synoptic scale or mesoscale low pressure system
overbank flow	Water movement that overtops the bank either due to stream stage or to overland surface water runoff.
sac fry	newly hatched fish that have not yet absorbed their yolk sac
surface erosion	The detachment and transport of soil particles by wind, water, or gravity
hydraulic problem	An effect of streamflow, tidal flow, or wave action such that the integrity of the highway facility is destroyed, damaged, or endangered.
alluvium	Unconsolidated material deposited by a stream in a channel, floodplain, alluvial fan, or delta.
calibration	The process of adjusting an instrument to be more accurate by comparing it to a reliable standard
non-cohesive soil	Soil particles that have no natural resistance to being pulled apart at their point of contact, for example, silt, sand, gravel.
bathythermograph	A device used to obtain a record of temperature against depth (pressure) in the ocean
upflow	an upward flow.
headcutting	Channel degradation associated with abrupt changes in the bed elevation (headcut) that generally migrates in an upstream direction.
arrhenius equation	predicts that the rate of reaction increases if the temperature is raised
stream order	A hydrologic system of stream classification
thaw	A warm spell of weather when ice and snow melt
air pollution	The 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.
pool	A river feature where above average depth and/or width and below average velocity create a calm river section.
certificate of water right	an official document which serves as court evidence of a perfected water right.
catchment	Area of land from which all surface water drains to a common destination, such as a lake of a river.
prograding	A formation or geological complex that forms by the deposition of mud and sand at the mouth of a river system during relatively low sea level.
minimum streamflow	the specific amount of water reserved to support aquatic life, to minimize pollution, or for recreation
channel scour	The erosive action of water and sediment that removes and carries away bed and bank material.
riprap	rock covering used to protect stream banks from erosion
mesotrophic	reservoirs and lakes that contain moderate quantities of nutrients and are moderately productive in terms of aquatic animal and plant life.
casing	a 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.
refraction	The bending of light or radar beam as it passes through a zone of contrasting properties, such as atmospheric density, water vapor, or temperature.
invert	Lowest point in the channel cross section or at flow control devices such as weirs, culverts, or dams.
aquiclude	a 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.
regulated	A river or creek where water is released from storage to meet diversion requirements downstream, or to reduce flooding.
type t	A more specialized thermocouple sensor pairing two wires made mostly of copper and constantan and using variance in voltage to calculate temperaturesâknown for greater accuracy and durabilityâtypical in medical or pharmaceutical applications.
epa	Environmental Protection Agency. The federal regulatory agency responsible for protecting environmental quality throughout the nation
evaporation	The physical process by which a liquid (or a solid) is transformed to the gaseous state
swamp	Low, wet land on which grass and trees grow.
mathematical model	Numerical representation of a flow situation using mathematical equations (also computer model).
aquatic ecosystem	Any body of water, such as a stream, lake, or estuary, and all organisms and nonliving components within it, functioning as a natural system.
straight-line winds	Any surface wind that is not associated with rotation
instream use	Use of water that does not require diversion from its natural watercourse
cloudburst	a torrential downpour of rain, which by it spottiness and relatively high intensity suggests the bursting and discharge of water from a cloud all at once.
washboarding	When a stream descends a rock face in many small and rather evenly spaced drops.
response time	The length of time a given instrument requires to reach a specified percentage of its final reading value
guide bank	Dike extending upstream from the approach embankment at either or both sides of the bridge opening to direct the flow through the opening
reservoir operations study	A study carried out by TVA to determine whether changes in its reservoir operating policies would produce greater overall public value
creek	a small stream of water which serves as the natural drainage course for a drainage basin
average	A measure of the mean, or middle-point, of a data set when there is more than one measurement taken.
mitigation	To alleviate, or compensate for, the impact of environmental degradation, often through replacement of lost ecological functions or values at a nearby location.
exclusion rule	describes the fact that a molecule with a center of inversion has peaks either in the IR or in the Raman spectrum, but not in both.
bed load	the particles in a stream channel that mainly move by bouncing, sliding, or rolling on or near the bottom of the stream.
relative humidity	A type of humidity that considers the ratio of the actual vapor pressure of the air to the saturation vapor pressure
boiling point	The temperature at which a substance in the liquid phase transforms to the gaseous phase
rapids	A reach of stream that is characterized by small falls and turbulent high velocity water.
in-situ vitrification	technology that treats contaminated soil in place at high temperatures, at 3,000 degrees Fahrenheit or more.
settleable solids	in sewage, suspended solids that will settle when the sewage is brought to a quiet state for a reasonable length of time, usually two hours.
celsius	A metric scale of temperature, originally defined as having the freezing point of water as 0Â° and its boiling point as 100Â°, at standard atmospheric pressure
superheating	the process at which a liquid is heated above its boiling point without vaporization
drainage basin	The area of land that is drained by a river and its tributaries
attainment	Meeting the Biocriteria standards for the designated aquatic life use.
vapor pressure	The pressure exerted by the molecules of a given vapor
westerlies	Usually applied to the broad patterns of persistent winds with a westerly component
virgin flow	the streamflow which exists or would exist if man had not modified the conditions on or along the stream or in the drainage basin.
sediment	Sediment is small particles of soil or rocks that are transported by water or the wind.
cordwood	wood pile
drifts	Normally used when referring to snow or sand particles are deposited behind obstacles or irregularities of the surface or driven into piles by the wind.
sluiceway	Vertical slots, generally located near the bottom of a dam, which can be opened to release water from the upstream reservoir without passing it through the turbines
municipal sewage	sewage from a community which may be composed of domestic sewage, industrial wastes or both.
lake	separated by the fairly thin thermocline zone, from the upper, warmer, less dense zone, the epilimnion.
diversity	number of species in a particular community or habitat
solvent	Substances (usually liquid) capable of dissolving or dispersing one or more other substances.
coliform bacteria	non-pathogenic microorganisms used in testing water to indicate the presence of pathogenic bacteria.
clear-water scour	Scour at a pier or abutment (or contraction scour) when there is no movement of the bed material upstream of the bridge crossing at the flow causing bridge scour.
scenic rivers	Rivers or sections of rivers that are free of impoundments, with shorelines or watersheds still largely primitive, and shorelines largely undeveloped but accessible in places by roads.
hygroscopic nuclei	piece of dust or other particle around which water condenses in the atmophere
spawning	The production and/or deposition of eggs by a fish or other aquatic animal.
herbland	Extensive community or herbaceous plant species (that is, with non-woody stems).
flood	excess water from a river which spills over its banks
restoration	Bring back to a former, natural condition
marine waters	Marine waters include coastal environments such as beaches and bays.
yield	the quantity of water expressed either as a continuous rate of flow (cubic feet per second, etc.) or as a volume per unit of time
unravel	The lose material from the edges of a revetment.
sediment	soil particles, sand, and minerals washed from the land into aquatic systems as a result of natural and human activities.
base flow	The sustained portion of stream discharge that is drawn from natural storage sources, and not affected by human activity or regulation.
inorganic	Matter other than plant or animal and not containing a combination of carbon, hydrogen, and oxygen, as in living things.
amprometric titration	a way of measuring concentrations of certain substances in water using the electric current that flows during a chemical reaction.
cirrostratus	A cirriform cloud that develops from cirrus spreading out into a thin layer, creating a flat sheetlike appearance
surge	The increase in sea water height from the level that would normally occur were there no storm
secchi depth	A relatively crude measurement of the turbidity (cloudiness) of surface water
abrasion	Abrasion is a form of erosion caused by rubbing of fine particles against an object
model	A simulation, by descriptive, statistical, or other means, of a process or project that is difficult or impossible to observe directly.
hydrological cycle	The continual cycle of water between the land, the ocean and the atmosphere.
sole-source aquifer	an aquifer that supplies 50 percent or more of the drinking water of an area.
wastewater	The used water, liquid waste, or drainage from a community, industry, or institution.
hydrology	The properties, distribution, and effects of water on the earth's surface, below the earth's surface, and in the atmosphere.
windthrow	A tree or trees uprooted or felled by the wind.
brackish	water that is not fresh but is not fully salt water
pupa	stage of a life cycle between larva and adult
sediment trapping efficiency	the ratio of sediment retained within the reservoir to the sediment inflow to the reservoir.
velocity	The speed at which water is flowing, typically reported in feet per second
wettable powder	dry formulation that must be mixed with water or other liquid before it is applied.
flood stage	The gage height at which the stream begins to overflow its banks.
scutes	small, bony plates on the outside of the sturgeon that is for protection
toxicity reduction evaluation	a study conducted to determine the source(s) of toxicity in a discharge effluent so that these sources can be controlled sufficiently to allow a discharger to comply with their permit limits.
digester	in wastewater treatment, a unit in which anaerobic bacterial action is induced and accelerated in order to break down and stabilize organic matter removed from the treatment process.
soil stabilisation	The use of measures or materials, such as rock lining or vegetation, to prevent the movement of soil when loads are applied to the soil.
extirpated	Describes a local population of a species that has been eliminated because of loss of habitat, a catastrophic event, or chronic impairment, but still can be found in another location.
hydrological	Refers to the study associated with water and the hydrological cycle-the way in which water circulates through the atmosphere and biopshere.
tropical wave	Another name for an easterly wave, it is an area of relatively low pressure moving westward through the trade wind easterlies
buffer strip	Areas of vegetation through which runoff passes while travelling to a discharge point and which are therefore aligned perpendicular to the direction of flow.
barotropy	The state of a fluid in which surfaces of constant density or temperature are coincident with surfaces of constant pressure
mud slide	Fast moving soil, rocks and water that flow down mountain slopes and canyons during a heavy a downpour of rain.
rearing habitat	places in a stream that provide food, resting places, and shelter for young fish
evapotranspiration	combination of evaporation and transpiration of water into the atmosphere from living plants and soil
island	A permanently vegetated area, emergent at normal stage, that divides the flow of a stream
hydrologic unit	is a geographic area representing part or all of a surface drainage basin or distinct hydrologic feature.
recharge rate	the quantity of water per unit of time that replenishes or refills an aquifer.
turbidimeter	a device that measures the cloudiness of suspended solids in a liquid; a measure of the quantity of suspended solids.
assemblage	an organism group of interacting species in a given ecosystem, for example, a fish assemblage or a benthic macroinvertebrate assemblage.
piezometric surface	the imaginary surface to which groundwater rises under hydrostatic pressure in wells or springs.
hydrosphere	region that includes all the earth's liquid water, frozen water, floating ice, frozen upper layer of soil, and the small amounts of water vapor in the Earth's atmosphere.
mackerel sky	The name given to cirrocumulus clouds with small vertical extent and composed of ice crystals
coriolis force	Inertial force caused by the Earth's rotation that deflects a moving body to the right in the Northern Hemisphere.
loading	The total mass of a contaminant discharged during a runoff event
water table	The water table is the natural level of water in a soil or rock
snag	fallen trees and dead branches in the river channel.
boulders	large rocks with grain size greater than ten inches in diameter
ecosystem	the interacting system of a biological community and its non-living environmental surroundings; a complex system composed of a community of fauna and flora, taking into account the chemical and physical environment with which the system is interrelated.
ecliptic	The sun's apparent path across the sky that tracks a circle through the celestial sphere.
bridge opening	Cross‑sectional area beneath a bridge that is available for conveyance of water.
alluvium	Sediment or loose material such as clay, silt, sand, gravel, and larger rocks deposited by moving water.
base flows	the component of a flow regime that represents normal flow conditions between precipitation events
sleet	precipitation which is a mixture of rain and ice.
liquid	a state of matter, neither gas nor solid, that flows and takes the shape of its container.
critical flow	The flow regime at a given discharge for which the specific energy (i.e., combination of velocity energy and depth) are a minimum (Froude number = 1)
contact load	Sediment particles that roll or slide along in almost continuous contact with the streambed (bed load).
gabion	A wire basket or cage that is filled with gravel and generally used to stabilize stream banks and improve degraded aquatic habitat.
distillation	water treatment method where water is boiled to steam and condensd in a separate reservoir
lotic	Meaning or regarding things in running water.
underdrain	a concealed drain with openings through which the water enters when the water table reaches the level of the drain.
percolation	the movement of water through the subsurface soil layers, usually continuing downward to the groundwater or water table reservoirs.
sanitary landfill	landfill that is lined with plastic or concrete or located in clay-rich soils to prevent hazardous substances from leaking into the environment.
countermeasure	Measure intended to prevent, delay or reduce the severity of hydraulic problems.
accuracy	"The closeness of the agreement between the result of a measurement and the value of the quantity being measured and or ""true value."" Usually expressed as Â± a certain number of degrees or Â± a certain percentage of the full reading."
ecological water requirements	The water regimes needed to maintain ecological values of water dependent ecosystems at a low level of risk
drawdown	Lowering of the water table, surface water, or piezometric surface resulting from the withdrawal of water from a well or drain; the elevation of the static water level (at the well) at a given discharge.
restoration	The renewing or repairing of a natural system so that its functions and qualities are comparable to its original, unaltered state.
groundwater hydrology	the branch of hydrology that deals with groundwater; its occurrence and movements, its replenishment and depletion, the properties of rocks that control groundwater movement and storage, and the methods of investigation and utilization of ground water.
armor	Surfacing of channel bed, banks, or embankment slope to resist erosion and scour
depletion curve	in hydraulics, a graphical representation of water depletion from storage stream channels, surface soil, and groundwater
triple point	The point at which any three atmospheric boundaries meet
buffer zone	The band of vegetation that can reduce the amount of runoff entering a stream and provide vegetative corridors for the terrestrial life stages of aquatic organisms
macroinvertebrates	Macroinvertebrates are aquatic animals without backbones that are large enough to be seen with the naked eye
holding pond	a 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.
backscatter	A radar echo that is reflected, or scattered, at 180 degrees to the direction of the incident wave
hydraulic radius	Cross‑sectional area of a stream divided by its wetted perimeter.
aeration tank	a chamber used to inject air into water.
environmental impact statement	a document that analyzes the effects of major federal projects on the environment
capillary forces	forces that cause ground water to rise above the surface of the saturated zone into the spaces between soil particles in the unsaturated zone.
snow depth	The actual depth of snow on the ground at any instant during a storm, or after any single snowstorm or series of storms.
bioaccumulation	A term used to describe a process that occurs when levels of toxic substances increase in an organism over time, due to continued exposure.
undercutting	The process by which the lower portion or "toe" of the streambank is eaten away by erosion leaving a concave, overhanging section of stream bank
instrument shelter	A 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.
chlorine contact chamber	the part of a wastewater treatment plant where treated water is disinfected by chlorine.
d-value	The deviation of actual altitude along a constant pressure surface from the standard atmosphere altitude of that surface.
recharge	Water infiltrating to replenish an aquifer.
evaporation	The physical process by which a liquid, such as water is transformed into a gaseous state, such as water vapor
ground water	or aquifer, storage from surface water supplies such as irrigation water, reclaimed wastewater or induced infiltration from streams or wells.
wall cloud	An abrupt lowering of a cloud from its parent cloud base, a cumulonimbus or supercell, with no visible precipitation underneath
piercers	predators that feed by sucking fluids out of their prey
wave attack	Impact of waves on a stream bank.
tributary	A stream that contributes its water to another stream or body of water.
instream use	use of water that does not require withdrawal or diversion from its natural watercourse; for example, the use of water for navigation, recreation, and support of fish and wildlife.
denitrification	The reduction of nitrate or nitrite to nitrogen gas, in the absence of oxygen (ARMCANZ & ANZECC 2000).
normal stage	Water stage prevailing during the greater part of the year.
mesocyclone	A area of rotation of storm size that may often be found on the southwest part of a supercell
canopy	the overhanging cover formed by branches and foliage.
cold air funnel	Funnel clouds, usually short-lived, that develop from relatively small showers or thunderstorms when the air aloft is very in cold
precipitation	rain, snow, hail, or sleet falling to the ground
thermocline	A vertical negative temperature gradient in some layer of a body of water which is appreciably greater than the gradients above and below it
instream flows	See flows.
saltation	Particles bouncing down a river bed
puddle	a small pool of water, usually a few inches in depth and from several inches to several feet in its greatest dimension.
windward	The direction from which the wind is blowing
landfall	The point at which a tropical cyclone's eye first crosses a land mass.
flash flood	A sudden flood of great volume, usually caused by a heavy rain
intermountain high	An area of high pressure that occurs during the winter between the Rocky Mountains and the Sierra-Cascade ranges
die-back	Loss of biodiversity due to environmental pressures such as weed invasion, nutrient-laden run-off or sedimentation.
recharge	The processes involved in the addition of water to the zone of saturation; also the amount of water added.
supercritical water	a type of thermal treatment using moderate temperatures and high pressures to enhance the ability of water to break down large organic molecules into smaller, less toxic ones
moisture	Refers to the water vapor content in the atmosphere, or the total water, liquid, solid or vapor, in a given volume of air.
eddy current	A circular current of water, usually resulting from an obstruction, that develops when the main flow becomes separated from the bank.
oxygen demanding waste	organic water pollutants that are usually degraded by bacteria if there is sufficient dissolved oxygen (DO) in the water.
silt	Tiny pieces of sand or rocks
phreatic line	Upper boundary of the seepage water surface landward of a streambank.
effluent limitation	restrictions established by a a regulating agency such as a State or the EPA in an NPDES permit on quantities, rates, and concentrations in wastewater discharges.
hydrology	The study of the distribution and movement of water.
hardpoint	Streambank protection structure whereby "soft" or erodible materials are removed from a bank and replaced by stone or compacted clay
impoundment	A body of water, such as a pond, lake or reservoir, formed by confining a stream or other surface flow.
boundary conditions	definition or statement of conditions or phenomena at the boundaries of a model; water levels, flows, and concentrations that are specified at the boundaries of the area being modeled.
hudson bay low	An 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.
tuberculation	development or formation of small mounds of corrosion products on the inside of iron pipe
baseflow	The underlying flow rate that cannot be directly attributed to storm events (ARMCANZ & ANZECC 2000)
decomposition	The breakdown of matter by bacteria and fungi, changing the chemical makeup and physical appearance of materials.
wasatch winds	Strong winds blowing easterly out of the Wasatch Mountains in Utah, sometimes reaching speeds greater than 75 miles per hour.
escarpment	the topographic expression of a fault.
dissolved oxygen	The amount of free (not chemically combined) oxygen dissolved in water, wastewater, or other liquid, usually expressed in milligrams per liter, parts per million, or percent of saturation.
eutrophic	having a large or excessive supply of plant nutrients (nitrates and phosphates)
threat	An activity or land use with potential to damage the local or receiving environment's social/cultural, ecological or economic values.
active storage capacity	The total usable storage capacity available for seasonal or cyclic water storage
decomposable waste	waste that under suitable natural conditions can be transformed through biological and chemical processes into compounds that do not impair water quality.
threshold pollutant	substance that is harmful to a particular organism only above a certain concentration, or threshold level.
continental shelf	The zone around the continents extending from the low-water mark seaward, typically ending in steep slope to the depths of the ocean floor.
siltation	the deposition or accumulation of fine soil particles.
bacteria	plants and animals.
hydrologic regime	A description of the variation of flow rate or water level over time.
geomorphology	A branch of both physiography and geology that deals with the form of the earth, the general configuration of its surface, and the changes that take place due to erosion of the primary elements and the buildup of erosional debris.
base	accept an unshared pair of electrons from a base or react with a base to form a salt, a substance that has more free hydrogen ions, H+, than hydroxyl ions, OH-, (see alkaline).
floodplain	area along a stream or river subject to flooding; often the location of human development
riffle	A reach of stream that is characterised by shallow, fast-moving water broken by the presence of rocks and boulders.
type k	A common thermocouple sensor pairing two wires made mostly of nickel and chromium and using variance in voltage to calculate temperaturesâknown for its wide temperature range and affordabilityâtypical in industrial applications.
erosion	The movement of soil or rock from one area to another by the action of the sea, running water, moving ice, precipitation, or wind.
equator	The equator is an imaginary circle around the earth, halfway between the north and south poles.
canopy	A layer of continuous foliage in a forest stand
emissivity	A measure of the energy-emitting propensity of a surface, usually measured at a specific wavelength
nutrient recycling	The process of nutrients being passed between biosphere and atmosphere.
advanced wastewater treatment	any 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.
eddy viscosity	a model parameter that reproduces the effects of turbulent mixing in fluid flow.
base flow	The sustained low flow of a stream, usually resulting from groundwater inflow to the stream channel rather than surface water run-off.
reflux	implies that a solution/solvent is heated to a boil while maintaining its volume constant
ph	measure of the hydrogen ion activity; measures the acidity or alkalinity of a solution: the pH scale ranges from 1 (strong add) to 14 (strong base), with 7.0 as neutral
smoke	Small particles produced by combustion that are suspended in the air
sustainable management	method of exploiting a resource that can be carried on indefinitely
dam	a structure of earth, rock, or concrete designed to form a basin and hold water back to make a pond, lake, or reservoir.
trophic composition	that portion of an Index of Biotic Integrity that is a metric measuring the proportion of species and proportions of omnivores, insectivores, and omnivores.
initial dilution	the process that results in the rapid and irreversible turbulent mixing of effluent and receiving water around the point of discharge.
rapid drawdown	Lowering the elevation of water against a bank faster than the bank can drain, leaving a pressure imbalance that may cause the bank to fail.
snag	Any standing dead, partially dead, or defective (cull) tree at least 10 in
mahd	Elevation in metres according to Australian Height Datum.
ecotone	a transition zone between two distinctly different ecosystems or communities.
choke	Refers to the `Barmah Choke'
nutrients	Essential chemicals such as nitrogen (N) and phosphorus (P) needed by plants and animals for growth
channel storage	Simply water storage within the banks of the channel.
nutrients	Nutrients include several naturally occurring chemicals that animals and plants need to grow
rtd	Resistance Thermometer Detection probes use variance in resistance (typically in platinum) to calculate temperaturesâknown for high accuracy over a wide range of temperatures and low driftâtypical in high-precision applications like calibration.
black ice	Thin, new ice on fresh or salt water that appears dark in color because of its transparency
adhesion	the molecular attraction asserted between the surfaces of bodies in contact
ecosystem management	A strategy or plan to manage ecosystems to provide for all associated organisms, as opposed to a strategy or plan for managing individual species.
lake	or other body of water into which light can penetrate, also known as the zone of photosynthesis.
natural levee	Low ridge that slopes gently away from the channel banks that is formed along streambanks during floods by deposition.
conjunctive management	integrated management and use of two or more water resources, such as an aquifer and a surface water body.
migration	Change in position of a channel by lateral erosion of one bank and simultaneous accretion of the opposite bank.
plunge	See Leap.
hydrometer	an instrument used to measure the density of a liquid.
mouth	The point where a stream ends as it flows into another stream, or body of water.
terrestrial radiation	Long wave radiation that is emitted by the earth back into the atmosphere
culvert	A pipe that carries a stream from one above-ground section to another above-ground section
habitat	The native environment where a plant or animal naturally grows or lives.
zone of aeration	a region in the Earth above the water table
ph	A measure of the acidity or alkalinity of a substance, using numerical values from 0 (maximum acidity) through 7 (neutral) to 14 (maximum alkalinity).
flow augmentation	the addition of water to meet flow needs.
thermocline	fairly thin zone in a lake that separates an upper warmer zone (epilimnion) from a lower colder zone (hypolimnion).
cold advection	The horizontal movement of colder air into a location
perched water table	groundwater standing unprotected over a confined zone.
drainage	An area (basin) mostly bounded by ridges or other similar topographic features, encompassing part, most, or all of a watershed and enclosing some 5,000 acres.
biomaster	An anti-microbial additive to the plastic housing of some ThermoWorks products containing silver ions shown to actively inhibit bacterial growth up to 99.9% over the life of the instrument
basin	a bowl shaped land formation usually caused by a glacier
stormwater discharge	precipitation 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.
appropriative rights	"first in time, first in right” principle of allocating water rights based
hydraulic model	Small‑scale physical or mathematical representation of a flow situation.
clean water act	federal legislation enacted in 1972 to restore and maintain the chemical, physical and biological integrity of the surface waters of the United States
photosphere	The intensely bright portion of the sun visible to the unaided eye; the "surface" of the sun
stream gage	A device used to measure the water surface elevation in relation to an established datum.
irrigation return flow	water which is not consumptively used by plants and returns to a surface or ground water supply
circulation cells	Large areas of air movement created by the rotation of the earth and the transfer of heat from the equator toward the poles
current	Water flowing through a channel.
turbidity	degree to which light penetration is blocked because water is cloudy; measure of sediment suspended in water
kelvin	An absolute, thermodynamic temperature scale using as its null point absolute zero and the triple point of water at 273.16 K (0.01 Â°C; 32.02 Â°F)
bank-full channel depth	the maximum depth of a channel within a rifle segment when flowing at a bank-full discharge.
sewage	The waste and wastewater produced by residential and commercial establishments and discharged into sewers.
drift	The change in the readings or measurement values of an instrument at a set point over time
soil erosion	the 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.
tertiary treatment	The treatment of wastewater beyond the secondary or biological stage
sounding	A plot of the atmosphere, using data rom upper air or radiosonde observations
inflow	Water that flows into a reservoir or forebay during a specified period.
profiler	A type of Doppler radar that typically measures both wind speed and direction from the surface to 55,000 feet in the atmosphere.
ocean	An ocean is a large body of salt water that surrounds a continent
elevation	The measure of height with respect to a point on the earth's surface above mean sea level
washout	(1) Erosion of a relatively soft surface, such as a roadbed, by a sudden gush of water, as from a downpour or floods
channel	A channel is an area that contains flowing water confined by banks.
saline water	water containing more than 1,000 parts per million (ppm) of dissolved solids of any type
asymmetrical	not symmetrical
macrointervebrate	an animal without a backbone, large enough to be seen without magnification and unable to pass through a 0.595 mm mesh.
snow	precipitation in the form of branched hexagonal crystals, often mixed with simple ice crystals, which fall more or less continuously from a solid cloud sheet
cliff	A very steep slope of rock or soil.
aquatic habitat	Habitat that occurs in free water.
augmentation	Increasing stream flow under normal conditions, by releasing storage water from reservoirs.
ephemeral streams	Streams which flow only in direct response to precipitation and whose channel is at all times above the water table.
aerobic treatment	process by which microbes decompose complex organic compounds in the presence of oxygen and use the liberated energy for reproduction and growth
newton	The unit of force giving a mass of about one kilogram (2.205 pounds) an acceleration of about one meter (1 yard) per second per second.
anvil	The upper portion of a cumulonimbus cloud that becomes flat and spread-out, sometimes for hundreds of miles downstream from the parent cloud
estuarine	Refers to the water quality of an estuary, being influenced by both salt and fresh water.
woody debris	Generally referring to naturally occurring wood in streams.
natural flow	The flow past a specified point on a natural stream that is unaffected by stream diversion, storage, import, export, return flow, or change in use caused by modifications in land use.
community	the plants and animals that interact in a habitat; the community of people who influence a habitat
heterogeneity	Diversity
rotation	The spinning of a body, such as the earth, about its axis.
scenic rivers	Rivers or sections of rivers that are free of impoundments, with shoreline and watersheds still largely primitive, and shorelines largely undeveloped, but accessible in places by roads.
outwash	a deposit of sand and gravel formed by streams of meltwater flowing from a glacier.
cascading	When a stream descends a very steep rock face somewhat smoothly or in a series of small individual drops, or any combination of these.
fluvial	Relating to a stream or river; produced by stream action.
naturalized conditions	an estimate of natural conditions obtained by attempting to remove effects of human activities from a set of measured conditions.
silt	Silt is very tiny particles of soil or rocks that are 3 to 60 micrometers in diameter.
hydraulics	The study of the properties, movement and behavior of water flowing in open channels or pipes.
gravel	rock 0.5 to 7 cm (0.2 to 3 inches) in diameter
baseline monitoring	Development of a system for continuous or periodic assessment, and recording of existing conditions that will be compared to future observations.
resolution	The smallest detectable increment of measurement on an instrument
cliff	A cliff is a steep face of rock and soil.
infiltration	The movement of water into soil or porous rock
spawning	behavior and actions of male and female animals for the purposes of reproduction
aggradation	a 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.
backfill	Material used to refill a ditch or other excavation, or the process of doing so.
green flash	A brilliant green coloration of the upper edge of the sun, occasionally seen as the sun's apparent disk is about to set below a clear horizon.
enantiomer	is a molecule that is not superimposable on its mirror image, related to chirality
toxicity test	the means to determine the toxicity of a chemical or an effluent using living organisms
water pollution	Generally, the presence in water of enough harmful or objectionable material to damage the water's quality.
volatile organic compounes	a group of chemicals that react in the atmosphere with nitrogen oxides, heat and sunlight to form ozone; VOCs are referred to as hydrocarbons.
sustainability	the long-term capacity of an ecosystem to maintain ecological processes and functions, biological diversity, and productivity.
invertebrates	animals without backbones including zooplankton, shellfish, worms, insects, shrimp, crabs and snails.
equilibrium scour	Scour depth in sand-bed stream with dune bed about which live bed pier scour level fluctuates due to variability in bed material transport in the approach flow.
sublimation	the transition of water directly from the solid state to the gaseous state, without passing through the liquid state; or vice versa
engulfers	predators that eat their prey whole
spring melt/thaw	the process whereby warm temperatures melt winter snow and ice
haboob	Sudanese name for duststorm or sandstorm with strong winds that carry small particles of dirt or sand into the air, particularly severe in areas of drought.
inert waste	waste that does not contain hazardous waste or soluble pollutants at concentrations in excess of applicable water quality objectives, and does not contain significant quantities of decomposable waste.
stream bank	The side slopes of an active channel between which the streamflow is normally confined.
wind wave	An ocean or lake wave resulting from the action of wind on the water's surface
weathering	The decay and breakup of rocks on the earth's surface by natural chemical and mechanical processes
groundwater	Water that soaks into the soil and then flows within the matrix of soil or rock particles.
fry	A recently hatched fish.
broken	The amount of sky cover for a cloud layer between 5/8ths and 7/8ths, based on the summation layer amount for that layer.
watershed	A watershed is the term given to the land that drains water into a particular stream, lake, or river.
whiteout	When visibility is near zero due to blizzard conditions or occurs on sunless days when clouds and surface snow seem to blend, erasing the horizon and creating a completely white vista.
salmonella	A rod-shaped bacteria common to food, particularly chicken and chicken products like eggs
municipal discharge	discharge of effluent from treatment plants that receive wastewater from households, commercial establishments, and industries.
swamp	a type of wetland dominated by woody vegetation but without appreciable peat deposits
rain forest	A forest which grows in a region of heavy annual precipitation
river stage	The elevation of the water surface at a specified station above some arbitrary zero datum (level).
flow	The amount of water passing a particular point in a stream or river, usually expressed in cubic-feet per second (cfs).
leaching	extraction 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.
embankment	An artificial deposit of material that is raised above the natural surface of the land and used to contain, divert, or store water, support roads or railways, or for other similar purposes.
hard water	water containing a high level of calcium, magnesium, and other minerals
psychrometer	An instrument used to measure water vapor content of the atmosphere
ecoregion	A region defined by similarity of climate, landform, soil, natural vegetation, hydrology or other relevant variables.
hydrologic model	a computer model of a watershed used to evaluate how precipitation contributes to flow in streams
hydrograph	a chart that measures the amount of water flowing past a point as a function of time.
sand	Small substrate particles, generally from 0.6 to 2.0 mm in diameter
advisory	Statements that are issued by the National Weather Service for probable weather situations of inconvenience that do not carry the danger of warning criteria, but, if not observed, could lead to hazardous situations
transparent	A condition where a material is clear enough not to block the passage of radiant energy, especially light.
blackwater	wastewater from toilet, latrine, and agua privy flushing and sinks used for food preparation or disposal of chemical or chemical-biological ingredients.
cap	Composed of a layer of warmer, dryer air aloft which may suppress or delay the development of thunderstorms
critical habitat	Under the Endangered Species Act, critical habitat is defined as(1) the specific areas within a geographic area occupied by a federally listed species on which are found physical and biological features essential to the conservation of the species, and that may require special management considerations or protections; and (2) specific areas outside the geographic area occupied by a listed species, when it is determined that such areas are essential for the conservation of the species.
rock	A naturally formed mass of minerals.
thermal plant	A power plant that produces electricity from heat energy released by the combustion of a fossil fuel (coal, oil, or gas) or the consumption of a fissionable material (nuclear fuel).
mean column velocity	the average velocity of fluid flow measured in a column extending from the surface of the water to the bed of the channel
stage	The height of water above an established datum
extraction	water taken from rivers for off stream use or consumption
particulates	the 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.
trickling filter	a 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.
bank slumping	An indication of the degree of bank erosion
armoring	Natural armoring is the formation of a resistant layer of relatively large particles resulting from removal of finer particles by erosion
environmental analysis	An analysis of alternative actions and their predictable short-term and long-term environmental effects, incorporating physical, biological, economic, and social considerations.
entrenchment ratio	The ratio between the flood-prone width and the bankfull width.
goals or aims	General descriptions of what a project will achieve (Woodhill & Robins 1998).
fill	Soil or other material placed as part of a construction activity
estuarine zone	area near the coastline that consists of estuaries and coastal saltwater wetlands.
mortality	death
leaching	The removal of soluble organic and inorganic substances from the topsoil downward by the action of percolating water.
injection zone	a geological formation receiving fluids through a well.
influent	water, wastewater, or other liquid flowing into a reservoir, basin, or treatment plant.
zooplankton	tiny aquatic animals eaten by fish.
off-site enhancement	The improvement in conditions for fish and wildlife species away from the site or development activities that may have detrimental effects on fish and/or wildlife, as part or total compensation for those effects.
enteric viruses	a category of viruses related to human excreta found in waterways.
hardpan	a shallow layer of earth material which has become relatively hard and impermeable, usually through the deposition of minerals
le châtelier principle	describes equilibrium reactions and how to influence them
angle of repose	The maximum slope at which unconsolidated material remains stable.
time of concentration	The time required for water to flow from the farthest point in the watershed to the gaging station.
heat balance	The equilibrium which exists on the average between the radiation received by the earth and atmosphere from the sun and that emitted by the earth and atmosphere
check dam	a small dam constructed in a gully or other small water course to decrease the streamflow velocity, minimize channel erosion, promote deposition of sediment and to divert water from a channel.
in-line filtration	a pretreatment method in which chemicals are mixed by flowing water; commonly used in pressure filtration installations.
biodiversity	Refers to variety of organisms, their genetic information and the biological communities where they live.
floodplain	land next to a river that becomes covered by water when the river overflows its banks .
contaminant	A substance that presents or has the potential to present a risk of harm to human health, the environment or any environmental value .
meander	A bend in a river - usually in the middle or lower course
kilowatt	A unit of electrical power equal to 1000 watts or 1.341 horsepower.
sleet	Also 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
evaporation	the change by which any substance is converted from a liquid state and carried of in vapor
ravine	A steep sided depression cut by a stream, smaller than a valley and larger than a gully.
meander length	The lineal distance downvalley between two corresponding points of successive meanders of the same phase.
parallel	Another word for latitude lines.
load	Amount of sediment being moved by a stream.
local scour	Removal of material from around piers, abutments, spurs, and embankments caused by an acceleration of flow and resulting vortices induced by obstructions to the flow.
physical weathering	breaking 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
cod	Chemical 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.
confluence	Junction of two or more streams.
quarry water	the moisture content of freshly quarried stone, esp
runoff	That portion of total rainfall that eventually enters a river
hurricane watch	A formal advisory issued by forecasters at the National Hurricane Center when they have determined that hurricane conditions are a potential threat to a coastal area or group of islands within a 24 to 36 hour period
recrystallization	is a technique used to purify solids based on different solubilities of the impurity and the target compound.
minimum operations guide	The system minimum operations guide is a seasonal guide based on the sum of the storage in 10 tributary projects
tropic of cancer	The most northern point on the earth where the sun is directly overhead, located at approximately 23.5 degrees North latitude.
duststorm	A severe weather condition characterized by strong winds and dust-filled air over a large area
regulators	Structural works that control flow.
biomass	The amount of living matter, usually given in weight per unit area of habitat.
comma cloud	A feature seen on satellite images with a distinctive comma-shape
prior appropriation	a doctrine of water law that allocates the rights to use water on a first in time, first in right, basis.
hurricane warning	A 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
effluent stream	A stream that takes source water from the water table.
surface runoff	Surface runoff is water flow on the land that occurs when the soil is saturated with water and the excess water (from precipitation or snowmelt) runs over the surface.
headworks	Structural works designed to induce a pressure gradient or move water in a particular way
sample	bacterial 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.
zone of saturation	the space below the water table in which all the interstices (pore spaces) are filled with water
carbon adsorption	a treatment system that removes contaminants from ground water or surface water by forcing it through tanks containing activated carbon treated to attract the contaminants.
hydrostatic head	a 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.
check dam	Low dam or weir across a channel used to control stage or degradation.
scour	The erosive action of running water in streams, which excavates and carries away material from the bed and banks
nutrient depletion	Detrimental changes at a site in the total amount of nutrients and/or their rates of input, uptake, release, movement, transformation, or export.
benthic	associated with the bottom of a water body
loading	The influx of pollutants to a selected water body.
stone	Rock fragments larger than 25.4 cm (10 inches) but less than 60.4 cm (24 inches).
chute spillway	the overall structure which allows water to drop rapidly through an open channel without causing erosion
alevin	newly hatched fish with yolk sac attached, larva
density	The ratio of the mass of a substance to the volume it occupies
furrow irrigation	irrigation method in which water travels through the field by means of small channels between each group of rows.
eutrophic lake	Shallow, murky bodies of water that have excessive concentrations of plant nutrients causing excessive algal production.
discount rate	The interest rate used in evaluating water (and other) projects to calculate the present value of future benefits and future costs or to convert benefits and costs to a common time basis.
connate water	water trapped in the pore spaces of a sedimentary rock at the time it was deposited
standard surface pressure	The measurement of one atmosphere of pressure under standard conditions
salt water intrusion	the invasion of fresh surface or ground water by salt water
on-site sewage treatment	any individual residential sewage treatment and wastewater dispersal system, such as a septic system.
nonalluvial channel	Channel whose boundary is in bedrock or non-erodible material.
recession curve	That part of a hydrograph after the flow peak showing decreasing runoff or discharge following a period of rain or snowmelt.
adsorb pollutants	used in some water treatment systems to remove certain organic chemicals and radon gas.
planform	The shape of an object as viewed from above
degree	A unit of measurement of temperature on any of several scales, such as Celsius or Fahrenheit.
channelization	The process of changing and straightening the natural path of a waterway.
dalton's law	States that the total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of the gases
embeddedness	a measure of the degree that gravel and larger substrates are surrounded by fine particles (silt and sand).
condensation	The process by which water vapor undergoes a change in state from a gas to a liquid
mother liquor	the solution that was separated from the crystals
substrate	The composition of a streambed, including either mineral or organic materials.
flood-prone area	A term coined by Rosgen (1996) to describe the area flooded at flows twice the maximum depth of flow at the effective discharge.
finite difference	a method of solving the governing equations of a numerical model by dividing the spatial domain into a mesh of nodes
poles/polar	The poles are the geographic point at 90 degrees latitude North and South on the earth's surface
oxbow	Abandoned former meander loop that remains after a stream cuts a new, shorter channel across the narrow neck of a meander
satellite images	Images 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
current	the portion of a stream or body of water which is moving with a velocity much greater than the average of the rest of the water
kinetic energy	energy possessed by a moving object or water body.
sheet flooding	Run-off or artificially induced run-off that flows over the ground surface as a thin, even layer not concentrated in a channel.
confining bed or unit	a body of impermeable or distinctly less permeable material stratigraphically adjacent to one or more aquifers.
hyporheic zone	the zone under a river or stream comprising substrate whose interstices are filled with water.
mariculture	cultivation of fish and shellfish in estuarine and coastal areas
biological monitoring	Sampling the biota of a place (e.g., stream) repetitively to monitor change over time.
diversion	to remove water from a water body
thermistor	A common thermal sensor that uses the predictable variance in the resistance to an electrical current with changes in temperature to calculate temperatures
riparian area of influence	transition area between riparian area and upland vegetation
fabric mattress	Grout-filled mattress used for streambank protection.
overland flow	a land application technique that cleanses wastewater by allowing it to flow over a sloped surface
balancing guide	The elevation that is used to help maintain a relative balance among tributary storage reservoirs
showalter stability index	A measure of the local static stability of the atmosphere
septic tank	underground receptacle for wastewater from a home
hydropneumatic	a water delivery system, usually small, that maintains water pressure in the distribution system by means of pressure in a compressed air tank.
stationary front	A front which is nearly stationary or moves very little since the last synoptic position
trigger event	Environmental conditions (which may be flow or non-flow) that initiate an event
dyke	An artificial embankment constructed to prevent flooding.
diffraction	The result of light waves interfering with other after passing through a narrow aperture, causing them to bend or spread.
undercurrent	a current below the upper currents or surface of a fluid body.
wetland specialists	Refers to flora or fauna who forage for food, recruit or carry out their life cycle within wetland habitats.
ice storm	A severe weather condition characterized by falling freezing precipitation
suspended sediment	Sediment suspended in a fluid by the upward components of turbulent currents, moving ice, or wind.
monitoring	Assessing the short- or long-term and localised change in environmental or river condition as a result of specific actions.
pesticide	A substance or mixture of substances intended for preventing, destroying, repelling, or mitigating any pest
jet stream	a long narrow meandering current of high-speed winds near the tropopause blowing from a generally westerly direction and often exceeding a speed of 250 miles per hour.
freezing drizzle	Drizzle, falling as a liquid, but freezing on impact with the colder ground or other exposed surfaces
resistance	The resistance to the flow of electric current measured in ohms
calorie	In meteorology, it is the amount of heat required to raise the temperature of one (1) gram of water one (1) degree Celsius
supercooling	The reduction of the temperature of any liquid below the melting point of that substance's solid phase
wild rivers	Rivers or sections of rivers that are free of impoundments and generally inaccessible except by trail, with watersheds or shorelines essentially primitive and water unpolluted.
cascade	The sudden descent of a stream primarily over a very steep slope in its stream bed
contiguous habitat	Habitat suitable to support the life needs of a species that is distributed continuously across the landscape.
mesohabitat	basic structural elements of a river or stream such as pools, backwaters, runs, glides, and riffles.
static water level	elevation or level of the water table in a well when the pump is not operating; the level or elevation to which water would rise in a tube connected to an artesian aquifer or basin in a conduit under pressure.
icicle	Ice that forms in the shape of a narrow cone hanging point down
attrition	The wearing away of particles of rock as they bounce along the riverbed or knock against each other and wear away becoming more rounded.
din	An acronym for Deutsche Industrial Norm
drifting snow	Snow particles blown from the ground by the wind to a height of less than six feet.
type j	A specialized thermocouple sensor pairing two wires made mostly of iron and constantan and using variance in voltage to calculate temperaturesâmore limited in its range to higher temperatures but known for its sensitivity.
pool/riffle ratio	The ratio of surface area or length of pools to the surface area or length of riffles in a given stream reach; frequently expressed as a relative percentage of each category
pumped storage project	A hydroelectric power plant and reservoir system in which water released for generating energy during peak load periods is stored and pumped back into the upper reservoir, usually during periods of reduced power demand.
adiabatic process	A thermodynamic change of state in a system in which there is no transfer of heat or mass across the boundaries of the system
aeration	Any active or passive process by which intimate contact between air and liquid are assured, generally by spraying liquid in the air, bubbling air through water, or mechanical agitation of the liquid to promote surface absorption of air.
erosion	Displacement of soil particles due to water or wind action.
drought	Abnormal dry weather for a specific area that is sufficiently prolonged for the lack of water to cause serious hydrological imbalance.
anabranched stream	Stream whose flow is divided at normal and lower stages by large islands or, more rarely, by large bars; individual islands or bars are wider than about three times water width; channels are more widely and distinctly separated than in a braided stream.
delta	a collection of rocks and soil at the mouth of a river
gradient	degree of slope, or steepness of a geographic feature
drought	Generally, the term is applied to periods of less than average or normal precipitation over a certain period of time sufficiently prolonged to cause a serious hydrological imbalance resulting in biological losses (impact flora and fauna ecosystems) and/or economic losses (affecting man)
alkaline	the condition of water or soil that contains a sufficient amount of alkali substance to raise the pH above 7.0.
streambank stabilization	Natural geological tendency for a stream to mold its banks to conform with the channel of least resistance to flow
rinsing/rinse	refers to the washing of a solid with small amounts of cold solvent to remove mother liquor and impuries from the surface
invertebrate drift	Stream and terrestrial invertebrates that float with the current.
sublimation	The process of a solid (ice) changing directly into a gas (water vapor), or water vapor changing directly into ice, at the same temperature, without ever going through the liquid state (water)
groundwater recharge	Increases in groundwater storage by natural conditions or by human activity
apron	Protective material placed on a streambed to resist scour.
turbidity	Cloudiness caused by the presence of suspended sediments in water, typically measured with a Secchi disk or turbidity tube.
bed roughness	A measure of the irregularity of the streambed as it contributes to flow resistance
peaked stone dike	Riprap placed parallel to the toe of a streambank (at the natural angle of repose of the stone) to prevent erosion of the toe and induce sediment deposition behind the dike.
fen	a type of wetland that accumulates peat deposits, but not as much as a bog
braided stream	Stream whose flow is divided at normal stage by small mid‑channel bars or small islands; the individual width of bars and islands is less than about three times water width; a braided stream has the aspect of a single large channel within which are subordinate channels.
fluvial geomorphology	Science dealing with morphology (form) and dynamics of streams and rivers.
cotyledon	The `seed leaves' produced by the embryo of a seed plant that serve to absorb nutrients packaged in the seed, until the seedling is able to produce its first true leaves and begin photosynthesis
subsidence	sinking down of part of the earth's crust due to underground excavation, such as removal groundwater.
well monitoring	measurement by on-site instruments or laboratory methods of well water quality.
emergent plants	Emergent vegetation includes aquatic plants which have roots in the sediment of a stream but stems which extend through and above the water
impervious	the quality or state of being impermeable; resisting penetration by water or plant roots
mist	A collection of microscopic water droplets suspended in the atmosphere
altimeter setting	The 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.
bank revetment	Erosion‑resistant materials placed directly on a streambank to protect the bank from erosion.
closed low	A 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
crown cover	The degree to which the crowns of trees are nearing general contact with one another.
wetland	land inundated wish temporary or permanent water that is usually slow moving or station, shallow, and either fresh, brackish or saline.
sea mile	A unit of length distinguished from a nautical mile
bedrock	the solid rock or geologic surface underlying unconsolidated surface materials (e.g., water, soil, alluvium).
clinometer	An instrument used to measure angles of inclination
wellhead protection area	a protected surface and subsurface zone surrounding a well or well field supplying a public water system to keep contaminants from reaching the well water.
entrenched channel	A channel that has eroded downward or was constructed such that it no longer has access to its original floodplain during moderate flow events.
distance to target ratio	"Indicates the diameter of the surface area an infrared thermometer will measure at a given distance
sludge digester	tank in which complex organic substances like sewage sludge are biologically dredged
stream morphology	The form and structure of streams.
redd	Shallow depression in the streambed gravel in which a female salmonid (e.g., trout) deposits her eggs
instream cover	The layers of vegetation, like trees, shrubs, and overhanging vegetation, that are in the stream or immediately adjacent to the wetted channel.
protozoans	A single-celled organism.
enantiomeric excess	is the ratio of one enantiomer to the other enantiomer in a mixture (abbreviated: e.e
tertiary treatment	In sewage, the additional treatment of effluent beyond that of secondary treatment to obtain a very high quality of effluent for reuse.
flash flood	A flood that rises and falls quite rapidly with little or no advance warning, usually as the result of intense rainfall over a relatively small area
chlorination	the adding of chlorine to water or sewage for the purpose of disinfection or other biological or chemical results.
cobble	Substrate particles that are smaller than boulders and larger than gravels, and are generally 64-256 mm in diameter
directional shear	The shear created by a rapid change in wind direction with height.
calorie	amount of energy required to raise the temperature of 1 gram of water 1 degree Celsius.
aquifer	An underground layer of rock or soil containing ground water.
tailrace	The channel that is downstream of the draft tube that carries the water discharged from a turbine
drainage reuse	reuse of agricultural drainage on salt-tolerant crops.
groundwater recharge	Water that is returned to subsurface flow from surface flow.
hydrograph	A chart that measures the amount of water flowing past a point as a function of time.
armoring	A natural or artificial process where an erosion-resistant layer of relatively large particles is established on the surface of the streambed through the removal of finer particles by stream flow
method blank	laboratory grade water taken through the entire analytical procedure to determine if samples are being accidentally contaminated by chemicals in the lab
urban	Land used for residential, rural-residential, commercial or industrial development (includes regional towns).
tropic of capricorn	The most southern point on the earth where the sun is directly overhead, located at approximately 23.5 degrees South latitude.
southern oscillation	A periodic reversal of the pressure pattern across the tropical Pacific Ocean during El NiÑo events
permeability	The capability of soil or other geologic formations to transmit water.
sediment load	The soil particles transported through a channel by stream flow.
calibration	to check, adjust, or determine by comparison that a computer model will produce results that meet or exceed some defined criteria within a specified degree of confidence.
trunk	The trunk is the main course of river.
critical habitat	Areas containing physical and biological features essential to the conservation of a species, and that may require special management considerations or protections.
key habitats	flow-sensitive habitats as well as habitats that support key species.
concrete revetment	Unreinforced or reinforced concrete slabs placed on the channel bed or banks to protect it from erosion.
trickle irrigation	method in which water drips to the soil from perforated tubes or emitters.
crest	the top of a dam, dike, or spillway, which water must reach before passing over the structure; the summit or highest point of a wave; the highest elevation reached by flood waters flowing in a channel.
zooplankton	floating microscopic animals.
baseline	Establishing the current status of the system.
pluvial	pertaining to precipitation.
discharge	Volume of water passing through a channel during a given time.
causeway	Rock or earth embankment carrying a roadway across water.
migration	the movement of oil, gas, contaminants, water, or other liquids through porous and permeable rock.
plankton	Tiny plants and animals that live in water.
haccp	An acronym for Hazard Analysis Critical Control Point
eutrophication	The process of enrichment of water bodies by nutrients.
meander ratio	Ratio of meander width to meander length.
water pollution	degradation 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.
eutrophication	an 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.
critical low flow	low flow conditions below which some standards do not apply
bmp	Best Management Practice
colloids	finely divided solids which will not settle but which may be removed by coagulation or biochemical action.
deposit	something dropped or left behind by moving water, as sand or mud.
aerobic	Characterizing organisms able to live only in the presence of air or free oxygen, and conditions that exist only in the presence of air or free oxygen
meander belt	Distance between lines drawn tangent to the extreme limits of successive fully developed meanders.
opaque	A condition where a material, such as a cloud, blocks the passage of radiant energy, especially light
aeration	Any active or passive process by which intimate contact between air and liquid is assured, generally by spraying liquid in the air, bubbling air through water, or mechanical agitation of the liquid to promote surface absorption of air.
adjudication	a court proceeding to determine all rights to the use of water on a particular stream system or ground water basin.
vapor trail	A cloudlike streamer or trail often seen behind aircraft flying in clear, cold, humid air
listeria	A rod-shaped bacteria common to food.
cement grout	a mixture of water and cement in the ratio of not more than 5-6 gallons of water to a 94 pound sack of portland cement which is fluid enough to be pumped through a small diameter pipe.
risk assessment	The process of risk analysis and risk evaluation.
squall line	A narrow band or line of active thunderstorms that is not associated with a cold front
salt water	The water of the ocean, distinguished from fresh water by its appreciable salinity.
detritus	decaying organic matter (mostly leaves and other matter from vegetation).
slope stability	The resistance of a natural or artificial slope or other inclined surface to failure by mass movement.
flow-sensitive habitats	habitats that show hydraulic response to relatively small changes in streamflow
ocean	lake, or other body of water into which light can penetrate, also known as the zone of photosynthesis.
day-second-feet	A measure of the volume of water accumulated at a flow rate of one cubic foot per second running for one day
surcharging	In this case, refers to the filling of groundwater, surface water or a structural feature such as a dam.
rain gauge	An instrument used to measure the amount of rain that has fallen
coupling constant	characterizes the line spacing within a multiplet in a 1H-NMR spectrum, which permits conclusions about the distance and the angle of interaction of the coupling partners
snowburn	A burn of the skin, like a sunburn, but caused by the sun's rays reflected off the snow surface.
background noise	The total noise floor from all sources of interference in a measurement system, independent of the presence of a data signal.
recruitment	Increment to a natural population, usually from young animals or plants entering the adult population.
hydrology	The 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.
hydrograph	A graph showing flow, stage, velocity or discharge with respect to time, for a given point in the stream.
plate tectonics	refers to the folding and faulting of rock and flow of molten lava involving lithospheric plates in the earth's crust and upper mantle.
radiation	The process by which energy is propagated through any medium by virtue of the wave motion of that medium
dynamic equilibrium	The state at which the channel exhibits patterns of erosion and deposition but there is not net change in the input and output of materials
stream gradient	A general slope or rate of change in vertical elevation per unit of horizontal distance of the water surface of a flowing stream.
dilution ratio	the critical low flow of the receiving water at the point of recycled water discharge divided by the flow of the discharge. Is used in the biomonitoring test to simulate in-stream conditions that organisms will be exposed to during critical low-flow times.
draft	the act of drawing or removing water from a tank, reservoir or groundwater supply.
discharger	any person who discharges waste that could affect the quality of state waters
whitewater	Swift moving water, whose surface has become foamy and turbulent because of passing over or around rocks.
revetment	A facing of stone, rootwads, cut trees, or other durable material used to protect a streambank against erosion.
run-of-river reservoir	A project that relies on the flow of a stream or river to produce hydropower but has little or no capacity to store water
biota	The flora/plants and fauna/animals of an area.
mare's tail	The name given to thin, wispy cirrus clouds composed of ice crystals that appear as veil patches or strands, often resembling a horse's tail.
nondegradation	an environmental policy that does not allow any lowering of naturally occurring water quality regardless of pre-established health standards.
gale warning	A warning for marine interests for impending winds from 28 to 47 knots (32 to 54 miles per hour).
vanes	An artificial structure used to direct flows in a stream.
piping	Removal of soil material through subsurface flow of seepage water that develops channels or "pipes" within the soil bank.
microbarograph	A instrument designed to continuously record a barometer's reading of very small changes in atmospheric pressure.
tide	The periodic rising and falling of the earth's oceans and atmosphere
pollutant retention	The proportion of pollutant load intercepted and retained by a device, either on an event or annual basis (ARMCANZ & ANZECC 2000).
canyon	walls of rock along a river, sometimes very steep
restoration	The return of an ecosystem to a close approximation of its condition prior to disturbance.
rain rejection events	See rain rejection.
multiple use corridors	Facilities performing a range of functions (e.g
connectivity	Refers to the water-mediated transfer of matter, energy and organisms between elements of the hydrologic cycle eg
base level	The elevation to which a stream-channel profile has developed.
plume	the area taken up by contaminant(s) in an aquifer.
aeration	The mixing of air and water, usually by bubbling air through water or by contact of water with air.
setback	Denotes the positioning of a levee or structure in relationship to a stream bank
suspended sediment	Refers to small solid particles which remain in suspension in the water column and cause poor water clarity.
wildlife tree	A live tree retained to become future snag habitat.
bloom	a 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.
tailings pond	An excavated or diked area that is intended to contain liquid and solid wastes from mining and milling operations.
ecological values	Particular values or uses of the environment important for a healthy ecosystem or for public benefit, welfare, safety or health and economic activities, and which require protection from the effects of pollution, waste discharges and deposits (ARMCANZ & ANZECC 2000) and from the effects of altered water regimes.
uncertainty	An expression of the possible measurement error for a given instrument over a specified range
vapor plumes	flue gases that are visible because they contain water droplets.
constantan	A copper-nickel alloy used as the negative lead in Type E, Type J, and Type T thermocouples.
talus	A chaotic accumulation of large rocks at the base of a cliff or steep slope.
chlorine demand	the 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
immiscibility	the inability of two or more substances or liquids to readily dissolve into one another, such as soil and water.
forebay	A reservoir or pond situated at the intake of a pumping plant or power plant to stabilize water levels; also, a storage basin for regulating water for percolation into groundwater basins.
perennial yield	The maximum quantity of water that can be annually withdrawn from a groundwater basin over a long period of time (during which water supply conditions approximate average conditions) without developing an overdraft condition
indicator organisms	microorganisms, such as coliforms, whose presence is indicative of pollution or of more harmful microorganism.
environmental outcomes	Project outcomes that benefit the ecological health of the river system.
radionuclide	a radioactive particle, man-made or natural, with a distinct atomic weight number
baseflow	The sustained portion of stream discharge that is drawn from natural storage sources, and not affected by human activity or regulation.
translucent flood	Flow that is allowed to spill over a dam wall, not necessarily as a result of exceeding the height of the dam.
base flow	The sustained portion of stream discharge that is drawn from natural storage sources, and not effected by human activity or regulation.
mean annual discharge	Daily mean discharge averaged over a period of years
cavern	a large underground opening in rock (usually limestone) which occurred when some of the rock was dissolved by water
live-bed scour	Scour at a pier or abutment (or contraction scour) when the bed material in the channel upstream of the bridge is moving at the flow causing bridge scour.
riffle	relatively fast flowing, shallow water in a stream
sediment	Solid fragment of organic and inorganic material that is transported, suspended and/or deposited by water and wind.
static water depth	the 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.
tube settler	device using bundles of tubes to let solids in water settle to the bottom for removal by conventional sludge collection means
ripple	(1) To form or display little undulations or waves on the surface, as disturbed water does
stream	A general term for a body of water flowing by gravity; natural watercourse containing water at least part of the year
range resolution	The ability of radar to distinguish between targets on the same azimuth but at different ranges.
contact recreation	activities involving a significant risk of ingestion of water, such as wading by children, swimming, water skiing, diving and surfing
base flow	the water that flows in a river during the dry periods between rainstorms
landslide	A movement of earth down a steep slope.
fetch	Area in which waves are generated by wind having a rather constant direction and speed; sometimes used synonymously with fetch length.
adjustable emissivity	A setting on many infrared thermometers allowing you to help the thermometer calculate a more accurate temperature reading for a given material based on an estimate of its ability to emit infrared energy
blue-green algae	also known as cyanobacteria
hydrosphere	Considered as the water portion of the earth's surface
rapid	A reach of stream that is characterized by small falls and turbulent, high-velocity water.
vacuum filtration	is a filtration technique that permits to separate a solid from a liquid
abandoned water right	a water right which was not put to beneficial use for a number of years, generally five to seven years.
aqueous solubility	the maximum concentration of a chemical that will dissolve in pure water at a reference temperature.
toxic hot spot	location in enclosed bay, estuary, or any adjacent waters that has toxic pollution problems in the water or sediment in excess of applicable standards.
landslide	a movement of earth mass down a steep slope.
erosion	movement of soil by water and wind
bank-full width	the width of a river or stream channel between the highest banks on either side of a stream.
aggradation	A progressive buildup or raising of the channel bed and floodplain due to sediment deposition
face	The vertical surface of a waterfall found between its crest and its base.
tractive force	The drag or shear stress on a stream bank or stream bed caused by passing water which tends to pull soil particles along with the stream flow.
shear line	A line of maximum horizontal wind shear
freeboard	the 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.
rearing pond	An artificial impoundment in which juvenile fish are raised prior to release into the natural habitat.
drainage basin	Area confined by drainage divides, often having only one outlet for discharge (catchment, watershed).
filter	Layer of fabric (geotextile) or granular material (sand, gravel, or graded rock) placed between bank revetment (or bed protection) and soil for the following purposes: (1) to prevent the soil from moving through the revetment by piping, extrusion, or erosion; (2) to prevent the revetment from sinking into the soil; and (3) to permit natural seepage from the streambank, thus preventing the buildup of excessive hydrostatic pressure.
background level	the concentration of a substance in an environmental media (water or soil) that occurs naturally or is not the result of human activities.
eutrophic	Usually refers to a nutrient-enriched, highly productive body of water.
artificial discharge	Addition of surface water to a groundwater reservoir by human activity, such as putting surface water into spreading basins
aerobic or oxic zone	An environment in which there is free oxygen (ARMCANZ & ANZECC 2000).
aurora	It is created by the radiant energy emission from the sun and its interaction with the earth's upper atmosphere over the middle and high latitudes
mixed layer	It is the upper portion of the boundary layer in which air is thoroughly mixed by convection
dredging	removal of mud from the bottom of water bodies
potable water	Water generally considered suitable for human consumption.
geographic information system	A computer system capable of storing and manipulating spatial data.
groundwater	Groundwater is water that percolates down the soil profile
condensation	water vapor that is forming droplets
best management practice	Conservation measures intended to minimize or mitigate impacts from a variety of land-use activities.
night	The period of the day between dusk and dawn.
soluble minerals	Naturally occurring substances capable of being dissolved.
channelization	natural or intentional straightening and/or deepening of streams so water moves faster and causes less flooding. Channelization can sometimes exacerbate flooding in other downstream areas.
flocculation	large scale treatment process involving gentle stirring whereby small particles in flocs are collected into larger particles so their weight causes them to settle to the bottom of the treatment tank.
average velocity	Velocity at a given cross section determined by dividing discharge by cross sectional area.
homogenous aquifer	an aquifer that has similar forms or characteristics throughout, such as a uniform gravel aquifer
river miles	Miles from the mouth of a river to a specific destination or, for upstream tributaries, from the confluence with the main river to a specific destination.
sewage	The liquid waste from domestic, commercial, and industrial establishments.
subwatershed	A small area of a larger watershed for which surface runoff drains to a particular point
head	the pressure of a fluid owing to its elevation, usually expressed in feet of head or in pounds per square inch, since a measure of fluid pressure is the height of a fluid column above a given or known point.
confluence	(1) The act of flowing together; the meeting or junction of two or more streams; also, the place where these streams meet
riffles	A river feature where below average depth and above average velocity create small cresting waves.
impermeable	material that does not permit fluids to pass through.
spawning	The depositing and fertilizing of eggs (or roe) by fish and other aquatic life.
circulation	The flow or motion of a fluid in or through a given area or volume
cheyenne fog	An upslope fog formed by the westward flow of air from the Missouri River Valley, producing fog on the eastern slopes of the Rockies.
leaching	The flushing of minerals or pollutants from soil or other material by the percolation of applied water.
photosynthesis	manufacture of carbohydrates by plants using energy from light.
visitor-day	See recreation-day.
outfall	The mouth or outlet of a river, stream, lake, drain or sewer.
charles' law	States that when the pressure is held constant, the volume of a gas varies directly with the temperature
emulsion	is a suspension of finely divided particles in a continuous medium in which the particles are approximately 5 to 5,000 Å in size, do not settle out of the substance rapidly, and are not readily filtered i.e
laminar flow	Streamline or parallel flow near a solid boundary
geosphere	Considered the solid portions of the earth, including the hydrosphere and the lithosphere, as opposed to the atmosphere, which lies above it
gradient	Vertical drop per unit of horizontal distance.
snow blindness	Temporary blindness or impaired vision that results from bright sunlight reflected off the snow surface
gas chromatograph	an instrument that identifies the molecular composition and concentrations of various chemicals in water and soil samples.
hook echo	A radar reflectivity pattern observed in a thunderstorm, appearing like a fish hook and indicating favorable conditions for tornadic development
entrain	to trap bubbles in water either mechanically through turbulence or chemically through a reaction.
frost	a covering of minute ice crystals on a cold surface.
few	The amount of sky cover for a cloud layer between 1/8th and 2/8ths, based on the summation layer amount for that layer.
weir	a construction across a river that dams the water but may be removable during times of flood.
middens	A mound of domestic refuse containing shells and animal bones marking the site of an Indigenous settlement.
visibility	A measure of the opacity of the atmosphere, and therefore, the greatest distance one can see prominent objects with normal eyesight
thalweg	The path connecting the deepest points along a stream channel.
nominal diameter	Equivalent spherical diameter of a hypothetical sphere of the same volume as a given sediment particle.
infrared	The long wave, electromagnetic radiation of radiant heat emitted by all hot objects
dissolved gas concentrations	The amount of chemicals normally occurring as gases, such as nitrogen and oxygen, that are held in solution in water, expressed in units such as milligrams of the gas per liter of liquid
maximum	The greatest value attained by a function, for example, temperature, pressure, or wind speed
effluent	waste liquid from a house, industry, sewage treatment plant, etc.
abyssal plain	The flat, gently sloping or nearly level region of the sea floor.
brackish water	Generally, water containing dissolved minerals in amounts that exceed normally acceptable standards for municipal, domestic, and irrigation uses
median particle size	value for which half the particles in a sample have a greater diameter and half a lesser diameter.
instream cover	overhanging or instream structure, such as tree roots, undercut streambanks, boulders, or aquatic vegetation that offer protection for aquatic organisms.
meltwater	water that comes from the melting ice of a glacier or a snowbank.
bank-full capacity	the rate of water flow that completely fills a channel; the flow rate at which the water surface is level with the flood plain.
aquatic	refers to water aquatic insect: insect species whose larval stages live in water
wildlife	any animal that is not tamed or domesticated
riprap	Rock or other material with a specific mixture of sizes referred to as a "gradation" used to stabilize streambanks or riverbanks from erosion or to create habitat features in a stream.
hygrometer	An instrument that measures the humidity of the air or other gases, especially the relative humidity.
rill	A rill is a very small channel of water, caused mainly by runoff water that eroded the soil.
bed-forms	Topography of the riverbed: the sediment formed structures on the bed.
pressure tendency	The pressure characteristic and amount of pressure change during a specified time period, usually the three hour period preceding the observation.
seasonal application efficiency	The sum of evapotranspiration of applied water and leaching requirement divided by the total applied water, expressed as a percentage: SAE=(ETAW+LR)/AW.
shear stress	the frictional force per unit area exerted on a streambed by flowing water
levees	An artificial or natural bank or length of raised ground, constructed along a swamp or river to confine flood water to the main channel.
thalweg	the line of maximum depth in a stream
deposition	depositing of material by a stream, generally at points of reduced stream flow
litterfall	Leaves, branches or other material having fallen from vegetation.
nonpoint source	source 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
conveyance	Continuous transport of water.
environmental flows	Any river flow pattern provided with the intention of maintaining or improving river health.
water recycling	the treatment of wastewater making it suitable for reuse.
anaerobic	a life or process that occurs in, or is not destroyed by, the absence of oxygen.
diastereomer	is a stereoisomer of a compound having two or more chiral centers that is not a mirror image of another stereoisomer of the same compound i.e borneol and isoborneol
well plug	a seal installed in a borehole or well preventing movement of fluids.
divergence	Wind movement that results in a horizontal net outflow of air from a particular region
transport capacity	The ability of a stream, for a given flow condition, to transport a volume (or weight) of sediment material of a specific size per unit time.
nowcast	A short-term weather forecast for expected conditions in the next few hours.
radius of influence	the 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.
reach	A length of channel uniform with respect to discharge, area and slope
tornado	A violently rotating column of air in contact with and extending between a convective cloud and the surface of the earth
flood guide level	The elevation of a reservoir above which the space is reserved for temporary storage of water to help reduce downstream flooding.
unsaturated zone	the area above the water table where soil pores are not fully saturated, although some water may be present.
aggradation	The process by which streams and other water bodies are raised in elevation by the deposition of material eroded and transported from other areas
aquifer	a geologic formation that will yield water to a well in sufficient quantities to make the production of water from this formation feasible for beneficial use; permeable layers of underground rock or sand that hold or transmit groundwater below the water table.
ion	an electrically charged atom or molecule
cross-connection	any actual or potential connection between a drinking water system and an unapproved water supply or other source of contamination.
non-aqueous phase liquid	contaminants that remain undiluted as the original bulk liquid in the subsurface, such as spilled oil.
groundwater table	The upper surface of the zone of saturation, except where the surface is formed by an impermeable body.
percolating waters	waters passing through the ground beneath the Earth's surface without a definite channel.
correlative rights	rights that are coequal or that relate to one another, so that any one owner cannot take more than his share.
fog bank	A fairly well-defined mass of fog observed in the distance
gray water	Waste water from a household or small commercial establishment which specifically excludes water from a toilet, kitchen sink, dishwasher, or water used for washing diapers.
erosion	the wearing away of a riverbank caused by continuous movement of water and wind.
confluence	Where two rivers or streams meet.
macrophytes	literally ‘big plants
genetics	the science of heredity and variation in living organisms
riffle	Shallow, steeper, section of stream with fast currents at low flow
isodrosotherm	The line drawn on a weather map connecting points of equal dew point.
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
saltation	The leaping movement of sand or soil particles as they are transported in a fluid medium over an uneven surface.
drainage area	The total surface area that drains to a point of interest, typically reported in acres (small watersheds) or square miles.
watermaster	An employee of a water department who distributes available water supply at the request of water right holders and collects hydrographic data.
discharge permit	a permit issued by a state or the federal government to discharge effluent into waters of the state or the United States
pond	a body of water usually smaller than a lake and larger than a pool either naturally or artificially confined.
volatility	the tendency of a liquid to evaporate.
externally	on the outside of the sturgeon body
understorey	Ground cover and below ground biomass (roots, bulbs and the seed bank).
subtropical air	An air mass that forms over the subtropical region
lock	Consists of a rectangular chamber of concrete with gates at each end to regulate flow and permit boats to move from one water level to another.
hydraulic gradient	the direction of groundwater flow due to changes in the depth of the water table.
catalina eddy	A weak low pressure circulation that may form off the Southern California coast.
floods	flows that are high enough at their peak to overrun river banks.
west virginia high	An area of stagnant high pressure located over West Virginia during Indian Summer.
aggressive water	water which is soft and acidic and can corrode plumbing, piping, and appliances.
interbasin transfer	the physical transfer of water from one watershed to another; regulated by the Texas Water Code.
watershed	land area from which water drains toward a common watercourse in a natural basin.
quarternary	A geological name given to the period of time that covers the last 2 million years.
aggradation	The accumulation of stratigraphic sequences by deposition that stacks beds atop each other, building upwards during periods of balance between sediment supply and accommodation.
reservoir	A reservoir is an artificial lake created by building a dam across a river.
levee	An embankment constructed to prevent a river from overflowing (flooding).
stream channel	A long narrow depression shaped by the concentrated flow of a stream and covered continuously or periodically by water.
silt	A soil separate consisting of particles between 0.002 and 0.02 mm in equivalent diameter.
infrared	A type of thermometry that measures the amount of infrared energy being emitted by a substance and compares that value to a predictable curve to calculate temperature.
total drop or height	The total vertical distance, from the first crest to the last base, of a close series of waterfalls
primary treatment	mechanical treatment in which large solids are screened out and suspended solids in the sewage settle out as sludge
transpiration	direct transfer of water from the leaves of living plants to the atmosphere
cutoff wall	Wall, usually of sheet piling or concrete, that extends down to scour‑resistant material or below the expected scour depth.
fill slope	Side or end slope of an earth‑fill embankment
precipitation	A general term for all forms of water particles rain, snow, sleet, dew, hail etc.
channel	Bed and banks that confine surface flow of a stream.
teflon	A registered trademark
salinity	amount of dissolved salts in a given volume of water.
zenith	The point which is elevated 90 degrees from all points on a given observer's astronomical horizon
return period	See Recurrence Interval.
oligotrophic	Lacking in plant nutrients and having a large amount of dissolved oxygen throughout.
riprap	Usually refers to rocks or concrete structures used to stabilize stream or river banks from erosion.
stage-discharge relationship/curve	A graph showing the relation between gage height (or stage) and the amount of water flowing in the channel.
dental fluorosis	disorder caused by excessive absorption of fluorine and characterized by brown staining of teeth.
bar	A shoal that develops at the mouth of a river as sediment carried by the river is deposited as the current slows or is impedded by wave action
rawinsonde	An upper air observation that evaluates the winds, temperature, relative humidity, and pressure aloft by means of a balloon-attached radiosonde that is tracked by a radar or radio direction-finder
nadir	The point on any given observer's celestial sphere diametrically opposite of one's zenith.
escarpment	A long, cliff-like ridge of land or rock
disinfectant	killing 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.
weather	day to day variation in atmospheric conditions
hyperchromic	Increased absorption of UV-Vis light (opposite: hypochromic)
bedrock	Solid rock exposed at the surface of the earth or overlain by soils and unconsolidated material.
erosion	Wearing 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.
irrigation	diversion of waterway to water agricultural crops
pebble count	Method for determination of the size distribution of channel bed materials.
collector well	a 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.
erosion	The process by which the land surface is detached and transported away by the action of water, wind, ice or gravity.
water cycle	The water cycle the natural cycle in which the sun's energy evaporates water into the atmosphere, and the water vapor condenses, returning to the Earth as precipitation (rain, snow, sleet, etc.).
hemisphere	half of a sphere; half of the earth
condensation	The process by which a vapour becomes a liquid or solid; the opposite of evaporation
phenols	organic compounds that are byproducts of petroleum refining; tanning; and textile, dye, and resin manufacturing
navier-stokes equations	a set of equations that describe the physics governing the motion of a fluid
spoil	Dirt or rock that has been removed from its original location.
pyrolysis	is the process where organic compounds decompose when heated without burning.
bank	the sloping land bordering a stream channel that forms the usual boundaries of a channel
semi-confined aquifer	an aquifer partially confined by soil layers of low permeability in which recharge and discharge can still occur.
zaitsev rule	predicts the formation of an alkene based on thermodynamic stability: the alkene with the highest the degree of substitution is preferentially formed under thermodynamic conditions.
chromophore	is a chemical group that absorbs light at a specific wavelength and so imparts color to a molecule i.e
zodiac	The position of the sun during the course of the year as it appears to move though successive constellations
mesoscale convective complex	A large mesoscale convective system (MCS) which is about the size of the state of Ohio or Iowa and lasts at least 6 hours
leachate	water containing contaminants which leaks from a disposal site such as a landfill or dump.
frontal passage	It is the passage of a front over a specific point on the surface
peat	Partially decomposed plants and other organic material that build up in poorly drained wetland habitats.
national response team	representatives of 13 federal agencies that, as a team, coordinate federal responses to nationally significant incidents of pollution and provide advice and technical assistance to the responding agencies.
precautionary principle	If there are threats of serious or irreversible environmental damage, lack of full scientific certainty should not be used as a reason for postponing measures to prevent environmental degradation.
backsiphonage	reverse seepage of water in a distribution system.
fluvial	From the Latin word fluvius, meaning river.
cutoff	(A) Direct channel, either natural or artificial, connecting two points on a stream, thereby shortening the original length of the channel and increasing its slope; (B) natural or artificial channel which develops across the neck of a meander loop (neck cutoff) or across a point bar (chute cutoff).
active floodplain	The level area adjacent to a stream channel that is subject to frequent overflow.
data buoys	Buoys 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.
ocean	The 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
distilled water	water that has been treated by boiling and condensation to remove solids, inorganics, and some organic chemicals.
water quality	A term used to describe the physical, chemical and biological characteristics of water with respect to its suitability for a particular use.
effectiveness	The extent to which project outcomes (see 'outcomes') are achieving project objectives.
rossby waves	The movement of ridges and troughs in the upper wind patterns, primarily the jet stream, circling the earth
pollutant	or the pollutant or substance itself, such that the final concentration after mixing is lower than that in the effluent or of the pure substance.
cohesion	a molecular attraction by which the particles of a body are united throughout the mass whether like or unlike
hypsochromic shift	is the shift to lower wavelength in the UV-Vis spectrum (opposite: bathochromic)
biota	All living organisms of a region, as in a stream or other body of water.
bulk density	Density of the water sediment mixture (mass per unit volume), including both water and sediment.
flow meter	a gauge indicating the velocity and/or volume of a flowing liquid.
hydraulic gradient	The slope or the water surface
main stem	The principal channel of a drainage system into which other smaller streams or rivers flow.
geomorphology	Of, or relating to, the forms of the earth's surface and the processes associated with them (e.g
meander amplitude	Distance between points of maximum curvature of successive meanders of opposite phase in a direction normal to the general course of the meander belt, measured between center lines of channels.
ml/d	Megalitres per day.
density	a measure of how heavy a specific volume of a solid, liquid, or gas is in comparison to water.
growing season	Considered the period of the year during which the temperature of cultivated vegetation remains sufficiently high enough to allow plant growth
water year	a division based on a general pattern of annual wet and dry periods rather than a calendar year
silt	tiny, fine particles suspended in or deposited by water
conservation	to protect from loss and waste
beaufort wind scale	A system of estimating and reporting wind speeds
geyser	A geyser is a natural hot spring that occasionally sprays water and steam above the ground.
sheet erosion	The 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.
skew t-log p diagram	A thermodynamic diagram, using the temperature and the logarithm of pressure as coordinates
ambient medium	material surrounding or contacting an organism (e.g., outdoor air, indoor air, water, or soil through which chemicals or pollutants can reach the organism.
air mass thunderstorm	A thunderstorm that is produced by convection within an unstable air mass through an instability mechanism
drainage network	The system of channels and pipes and overland flow pathways which drain a catchment area (ARMCANZ & ANZECC 2000).
easterly wave	An inverted, migratory wave-like disturbance or trough in the tropical region that moves from east to west, generally creating only a shift in winds and rain
minimum	The least value attained by a function, for example, temperature, pressure, or wind speed
augmentation	Increasing steam flow under normal conditions, by releasing storage water from reservoirs.
channel	An area containing continuously or periodically flowing water that is confined by banks and a streambed.
pressure change	The 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.
anaerobic or anoxic zone	An environment devoid of oxygen (ARMCANZ & ANZECC 2000).
ecosystem	An ecological community together with its environment, functioning as a unit.
hydroelectricity	Electric energy produced by water-powered turbine generators.
thunder snow	A wintertime thunderstorm from which falls snow instead of rain
off-takes	Flow of water that is separated from a main body by a channel or diversion structure.
troposphere	the layer of atmosphere closest to the Earth, extending seven to ten miles above the surface, containing most of the clouds and moisture.
watershed	An area of land whose total surface drainage flows to a single point in a stream.
cataract	The descent of a very large volume of water over any combination of rapids, cascades, and falls, often through a narrow gorge.
conduction	The transfer of heat through a substance by molecular action or from one substance by being in contact with another.
drainage basin	The total area of land from which water drains into a specific river.
water conservation	Reduction in applied water due to more efficient water use such as implementation of Urban Best Management Practices or Agricultural Efficient Water Management Practices
pool	A reach of stream that is characterized by deep low velocity water and a smooth surface.
vortex	Any circular or rotary flow in the atmosphere that possesses vorticity.
reforestation	The natural or artificial restocking of an area with forested trees.
hydrologic balance	an accounting of all water inflow into, outflow from and changes in water storage within a hydrologic unit over a specified period of time
dams	earth or other construction along a river to control water flow
stream order	A method for classifying streams as part of a drainage network
abrasion	Removal of streambank material due to entrained sediment, ice, or debris rubbing against the bank.
population	group of individuals of a specific kind, in a given area, at a given time
benthos	All plants and animals living on or closely associated with the bottom of a body of water.
municipal sludge	semi-liquid residue remaining from the treatment of municipal water and wastewater.
glacier	a body of snow and ice that moves like a river
tilt	The inclination to the vertical of a significant feature of the pressure pattern or of the field of moisture or temperature
grassed waterway	natural or constructed watercourse or outlet that is shaped or graded and planted in suitable vegetation for the disposal of runoff water without erosion.
population	The total number of a single species (i.e., group of interbreeding organisms) inhabiting a particular locality.
flowing artesian well	a 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.
macroburst	A large downburst with an outflow diameter of 2.5 miles (4 kilometers) or larger and damaging winds.
ph	The negative logarithm of the molar concentration of the hydrogen ion, or, more simply acidity.
first step decision	A decision announced in November 2003 by the Murray-Darling Basin Ministerial Council.
riffle	A reach of stream that is characterized by shallow, fast moving water broken by the presence of rocks and boulders.
time constant	As defined by engineering sciences, a time constant is the actual time that a physical system requires to reach 62.3% of its total value
drift	Alternate term for vegetative "debris."
food-web	A conceptual way of showing how plants and animals in a habitat depend on each other.
lottic	Moving water.
conservation area	Designated land where conservation strategies are applied for the purpose of attaining a viable plant or animal population.
levee	Embankment, generally landward of top bank, that confines flow during high-water periods, thus preventing overflow into lowlands.
embeddedness	The degree to which the coarse channel bed materials (boulders, cobble, gravel, sand) are surrounded or covered by fine sediments, usually measured as percent coverage by finer sediments.
piping	The process by which water forces an opening around or through a supposedly sealed structure, such as a check dam or levee
benthic macroinvertebrate	Backboneless aquatic animals that dwell on or in the bottom sediments of a stream channel that are large enough to be seem by the unaided eye.
bioaccumulation	Process in which the level of toxic substances in an organism increase over time due to continued exposure.
total dissolved solids	A quantitative measure of the residual minerals dissolved in water that remain after evaporation of a solution
pollutant	Particles, gases, or liquid aerosols in the atmosphere which have an undesirable effect on humans or their surroundings
flood storage	The volume, or capacity, in a reservoir that is reserved for the storage of floodwater.
water regime	Refers to flow pattern and timing of flows.
unclassified waters	those waters for which no classification has been assigned and which have not been identified in Appendix A of 31 Texas Administrative Code, Chapter 307.10 of Title 31 (relating to definitions).
outfall	the place where a wastewater treatment plant discharges treated water into the environment.
spot size	The diameter of the circle formed by the intersection of the field of view of an infrared thermometer with the surface being measured
tidal flats	Saltwater wetlands that are characterized by mud or sand and daily tidal fluctuations.
clear	To restore a device to a its initial state, usually the zero state.
heat exhaustion	The effect of excessive heat, particularly when combined with high humidity, on a human being
greywater	wastewater from clothes washing machines, showers, bathtubs, handwashing, lavatories and sinks that are not used for disposal of chemical or chemical-biological ingredients.
habitat indicator	a physical attribute of the environment measured to characterize conditions necessary to support an organism, population, or community in the absence of pollutants
ecological modelling	A representation of an ecological system, either qualitative or quantitative, that can predict, simulate or identify a response as a result of perturbation from an environmental process outside of the ecological system identified.
energy dissipation	The loss of kinetic energy of moving water due to internal turbulence, bottom friction, large rocks, debris, or other obstacles that impede flow.
isotherm	line that connects points of equal temperature.
guild	a 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.
producers	plants that manufacture food from inorganic nutrients
outcrop	exposed at the surface
national priorities list	EPA's list of the most serious uncontrolled or abandoned hazardous waste sites identified for possible long-term remedial action under Superfund
headcut	A break in the slope at the top of a gully or section of a gully that forms a "waterfall" which in turn causes the underlying soil to erode and the gully to expand uphill.
recurrence interval	The interval of time, on average, between occurrences of a hydrologic event of a certain magnitude.
gravel	See cobble.
bioclastic	Sediment or rock formations developed as a result of expulsion from a volcano.
dissolved oxygen	amount of oxygen gas dissolved in a given quantity of water at a given temperature and atmospheric pressure
performance monitoring	Gathering of information to measure the success of strategies implemented when compared to objectives (see 'objectives').
abrasion	Removal of stream-bank soil as a result of sediment-laden water, ice, or debris rubbing against the bank.
earthquake	A 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.
wave cyclone	A cyclone which forms and moves along a front
temperature stratification	The variation of water temperature at different depths in a reservoir
woody debris	Any large, relatively stable woody material that intrudes into the stream channel.
flow-control structure	Structure either within or outside a channel that acts as a countermeasure by controlling the direction, depth, or velocity of flowing water.
lock-and-key method	describes the selectivity of enzymes towards certain substrates over others
state revolving funds	a 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.
filling	Used 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
erosion	the movement of rock and soil
runoff	Water that flows over the surface of a catchment area.
polar air mass	An air mass that forms over a high latitude region
blackbody	A theoretical material that absorbs all incident electromagnetic radiation and reflects none
social/cultural values	Social values include public health and safety, recreational uses and visual amenity
filter fabric	A polypropylene textile used to keep soil separate from water
environmental monitoring	The process of checking, observing, or keeping track of something for a specified period of time or at specified intervals.
magnetic poles	Either of the two points on the earth's surface where the magnetic meridians converge
effluent	(1) Something that flows out or forth, especially a stream flowing out of a body of water
kilolitre	one thousand litres
discharge	The volume of water passing through a channel during a given time, usually measured in cubic feet per second.
recharge	refers to water entering an underground aquifer through faults, fractures, or direct absorption.
demand	the number of units of something that will be purchased at various prices at a point in time
molluscs	Fresh and marine organisms which usually have a shell
stream order	a system used to classify (and analyze) streams
mg/l	Milligrams per litre.
in-situ	refers to the synthesis of a reactive intermediate, which is not isolated since it is too difficult or too dangerou
recaptured	to find and capture the same fish consecutive times
habitat	the type of environment in which a given animal or plant lives and grows, including physical and biological conditions.
map scale	The relationship between the actual size of a place and its size as shown on a map.
crystallization	The 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)
wettability	the degree to which a fluid will spread into or coat a solid surface in the presence of other fluids into which it will not dissolve.
soil erodibility	An indicator of a soil's susceptibility to raindrop impact, runoff, and other eroding processes.
meander belt width	The distance between lines drawn tangential to the extreme limits of fully developed meanders
triple-bottom-line assessment	A process which uses multi-criteria analysis to evaluate the economic, social and ecological costs and benefits of possible Best Management Practices.
effluent	The sewage or industrial liquid waste that is released into natural water by sewage treatment plants, industry, or septic tanks.
ceiling light	An instrument consisting of a drum and an optical system that projects a narrow vertical beam of light onto a cloud base.
radius of curvature	The radius of the circular arc that best describes the outside bend of a stream meander.
field capacity	the amount of water held in soil against the pull of gravity.
suspended sediments	particles carried in water without being dissolved
ecological indicator	An attribute of an ecosystem whose presence or absence, quantity, level, pattern, or etc
turbidity	A measure of the content of suspended matter that interferes with the passage of light through the water or in which visual depth is restricted
ecosphere	total of all the ecosystems on the planet, along with their interactions; the sphere of air, water, and land in which all life is found.
toxaphene	chemical that causes adverse health effects in domestic water supplies and is toxic to fresh water and marine aquatic life.
environmental assessment	The critical appraisal of the likely effects of a proposed project, activity, or policy on the environment, both positive and negative.
colorado low	A low pressure disturbance that forms in the lee of the Rocky Mountains, usually in southeastern Colorado.
technology-based treatment requirements	NPDES permit requirements based on the application of pollution treatment or control technologies including BTP (best practicable technology), BCT (best conventional technology), BAT (best available technology economically achievable), and NSPS (new source performance standards).
pollutant	(1) Something that pollutes, especially a waste material that contaminates air, soil, or water
acre	A measure of area equal to 43,560 ft2 (4,046.87 m2)
riparian	Located on the banks or a stream or other body of water.
moisture holding capacity	the amount of liquid that can be held against gravity, by waste materials or soil, without generating free liquid.
contaminant	organism, 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.
hydraulics	The physical forces that interact between the river and it's surrounding landscape.
angle of repose	Maximum angle (as measured from the horizontal) at which gravel or sand particles can stand.
efficiency	The extent to which project outputs (see 'outputs') are maximised for the given level of inputs
point bars	The convex side of a meander bend that is built up due to sediment deposition.
fine sediment load	That part of the total sediment load that is composed of particle sizes finer than those represented in the bed (wash load)
soft water	any water that does not contain a significant amount of dissolved minerals such as salts of calcium or magnesium.
canyon	A canyon is a deep valley with very steep sides - often carved from the Earth by a river.
limnology	scientific study of physical, chemical, and biological conditions in lakes, ponds, and streams.
storage reservoir	A reservoir that can be used to store water for a variety of purposes, such as flood damage reduction, power production, navigation, water supply, and recreation.
reservoir	a pond, lake, tank, or basin (natural or human made) where water is collected and used for storage
hygrograph	An instrument that records the hygrometer's measure of water vapor.
decant	the process in the laboratory when a liquid is transferred into a different container and the solid is left behind
wasteload allocation	term used in conjunction with the TMDL Program, a WLA is the portion of a receiving water's loading capacity that is allocated to one of its existing or future point sources of pollution
freshet	a sharp rise in discharge or a flood event associated with rainfall or snow melt
cobble	Fragment of rock whose diameter is in the range of 64 to 250 mm.
catchment	A topographically defined area draining surface water to a single outlet point.
glide	Shallow, low gradient stream sections with slow current and fine substrate.
sun pillar	Horizontal 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.
resolution	In relation to radar, it is the ability to read two distinct targets separately
cross-sectional area	The area of cross-section below the water surface perpendicular to the direction of flow.
ph	A measure of the hydrogen ion concentration of water or wastewater; expressed as the negative log of the hydrogen ion concentration [H+]
streambank erosion	The wearing away of streambanks by flowing water.
phragmites	A common reed found on the edges of creeks and rivers, especially near coast.
cold low	A 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
saline	Salty water - water from the sea is known as saltwater, or saline
riffles	Sections of flowing water in a stream
dissolved solids	inorganic material contained in water or wastes
mass wasting	Large slope failures associated with downcutting stream channels and undermined support of steep slopes
opportunistic macroalgae	Large algae (eg Ulva, Hincksia, etc) that grow rapidly in marine waters when nutrients are high.
microscale	The smallest scale of meteorological phenomena that range in size from a few centimeters to a few kilometers
floodplain	the area on either side of the bankfull channel that carries the flow greater than the bankfull flow, that is, all storms greater than the one-to-two year storm
blowdown	Trees felled at the base by high winds.
unrestricted drawdown	The lowering of reservoir levels with no restrictions on the rate of change.
thermal pollution	an increase in air or water temperature that disturbs the climate or ecology of an area.
catchment	See drainage basin.
fetch length	Horizontal distance (in the direction of the wind) over which wind generates waves and wind setup.
condensation funnel	A funnel-shaped cloud consisting of condensed water drops that has possible rotation.
swell	Ocean waves that have traveled out of their generating area
k index	The 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.
basin	See Drainage Basin.
critical shear stress	The minimum amount of shear stress required to initiate substrate particle motion along the stream bed or banks.
fahrenheit temperature scale	A temperature scale where water at sea level has a freezing point of +32°F and a boiling point of +212°F
runoff	surface water entering rivers, freshwater lakes, or reservoirs.
national response center	The 24-hour a day federal operations center receives notifications of all releases of oil and hazardous substances into the environment
barrages	An artificial bar or obstruction placed in a river or water course to increase the depth of water or obstruct flow.
zooplankton	Small, free-floating or weakly swimming animals that are difficult to see with the naked eye.
load	What the river carries along with it - mud, sand, rocks, wood
well injection	the subsurface placement of fluids into a well.
artesian aquifer	a geologic formation in which water is under sufficient hydrostatic pressure to rise above the top of the aquifer in the subsurface
blowdown	the water drawn from boiler systems and cold water basins of cooling towers to prevent the buildup of solids.
bod	Biochemical Oxygen Demand
chenopod	From New Latin Chenopodiceae, meaning a small shrub or bush tolerant of dry and salty conditions, commonly found as an understorey species.
stratification	when the water in a dam or weir pool forms layers that do not readily mix with each other.
ambient bed elevation	Initial (unscoured) bed elevation.
eye	The center of a tropical storm or hurricane, characterized by a roughly circular area of light winds and rain-free skies
plunge pool	A deeply eroded depression in the stream bed, found at the base of some waterfalls.
range	The values that a particular instrument is intended to measure, usually noted in a specification table by upper and lower limits.
streambank protection works	Structure placed on or near a distressed stream bank to control bank erosion or prevent failure.
splash-proof	A non-technical term used to describe instruments that are protected from ingress caused by the splashing of liquids but not necessarily protected against immersion
dredging	The removal of material from the bottom of water bodies using a scooping machine
nephelometric	method of measuring turbidity in a water sample by passing light through the sample and measuring the amount of light deflected.
flow	in 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.
chromosphere	A thin layer of relatively transparent gases above the photosphere of the sun
interstitial flow	Water flow through bed (i.e., riffle) and bar materials.
distillation	is a technique to purify liquids based on different boiling points
backwater	Condition in which the water surface elevation is raised by downstream flow impediments.
scour pool	An area of deeper water created by the scouring action of water
bulkhead	Vertical, or near vertical, wall that supports a bank or an embankment; also may serve to protect against erosion.
effective discharge	The discharge that transports the largest fraction of the annual sediment load
hydrostatic pressure	pressure exerted by or existing within a liquid at rest with respect to adjacent bodies.
superfund list	A list of the hazardous waste disposal sites most in need of cleanup
ephemeral streams	ones that flow only during and shortly after extreme rainfall or snowmelt
streambank erosion	The removal of soil from streambanks by flowing water.
water table	level below the earth's surface at which the ground becomes saturated with water
evapotranspiration	water lost from plants through evaporation and photosynthesis
megawatt-hour	An amount of energy that equals one million watt-hours
retrofitting	installing modern pollution control devices at facilities without making major changes to the facility's design.
gravity	The force of attraction of the earth on an object
location	A place where something can be found.
organic compound	a ring molecule of six carbons and six hydrogens with three shared or resonant double carbon-to-carbon bonds, known as an aromatic compound.
lock	See hold.
frontogenesis	The birth or creation of a front
freezing fog	Used to describe the phenomena when fog is present and the air temperature is below 0°C
blinds	water samples containing a chemical of known concentration given a fictitious company name and slipped into the sample flow of the lab to test the impartiality of the lab staff.
dissolve	the process by which solid particles mix molecule by molecule with a liquid and appear to become part of the liquid.
depth of scour	Vertical distance a streambed is lowered by scour below a reference elevation.
ecosystem restoration	Restoration of all or part of the functions and structures of a previously degraded ecosystem.
celestial sphere	The apparent sphere of infinite radius having the earth as its center
boulder	A large substrate particle that is larger than cobble, 256 mm in diameter.
assay	a test for a specific chemical, microbe, or effect.
lentic	Of standing (or still) water.
nutrients	substances, such as phosphorus and nitrogen, that are necessary for plants (including algae) to grow.
seep	a spot where water contained in the ground oozes slowly to the surface and often forms a pool; a small spring.
pressure characteristic	The pattern of the pressure change during the specified period of time, usually the three hour period preceding an observation
ground water	water that sinks into the soil and collects over impermeable rode; it then flows laterally toward a stream, lake or ocean.
armoring	the formation of an erosion-resistant layer of relatively large particles on a streambed or bank resulting from removal of finer particles by erosion.
deep percolation	the percolation of water through the ground and beyond the lower limit of the root zone of plants into a groundwater aquifer.
river	A river is a naturally winding watercourse that drains surplus water from a drainage basin.
diatomaceous	consisting of or abounding in diatoms, a class of unicellular or colonial algae having a silicified cell wall that persists as a skeleton after death.
sills	Refers to the upper level of a levee, dam or regulator, above which flow spills into or out of the structure.
pilot balloon	A small balloon whose ascent is used to determine the direction and speed of low level atmospheric winds
current	The flow of the river.
median streamflow	the rate of discharge of a stream for which there are equal numbers of greater and lesser flow occurrences during a specified period.
riparian areas	An area of land directly influenced by water
aphelion	The point on the earth's orbit that is farthest from the sun
barbels	a whisker-like sensor that protrudes from the mouth area of a sturgeon and is used to sense food in murky water
treatment	any method, technique, or process designed to remove solids and/or pollutants from solid waste, waste-streams, and effluents.
geopressured reservoir	a geothermal reservoir consisting of porous sands containing water or brine at high temperature or pressure.
watershed	the geographic area that drains into a particular river.
subsistence flows	the component of an instream flow regime that represents infrequent, naturally occurring low flow events that occur for a seasonal period of time
channel	An area that contains continuously or periodically flowing water that is confined by banks and a streambed.
mermaid	a fabled marine creature usually represented as having the head, trunk, and arms of a woman and a lower part like the tail of a fish.
water quality	A term used to describe the chemical, physical, and biological characteristics of water, usually in respect to its suitability for a particular purpose.
monitoring well	a well used to obtain water quality samples or measure groundwater levels.
culvert	A buried pipe that allows flows to pass under a road.
management responses	Aquatic ecosystem condition reports include management responses that are being coordinated by community, industry and government sectors
rapids	Any descent of a stream over a moderately steep slope in its stream bed
nsf certified	This icon indicates that the design, materials, production process and quality controls used in the production of a product have been verified and certified for food safety by a highly respected third party non-profit organization, the National Sanitation Foundation (NSF).
finite volume	a method of solving the governing equations of a numerical model by dividing the spatial domain into a mesh of nodes and corresponding volumes around each node
mean temperature	The average of temperature readings taken over a specified amount of time
gabion	A wire basket or cage that is filled with gravel or cobble and generally used to stabilize streambanks.
gigalitre	one thousand million litres
cobble	rock from 7 to 30 an (3 to 12 inches) in diameter; rubble
electromagnetic radiation	Also called radiation, it is waves of energy propagated though space or through a material media.
pool	deeper and slower flowing water in a stream or river
meander radius of curvature	Radius of a circle inscribed on the centerline of a meander loop.
climatic cycle	the periodic changes climate displays, such as a series of dry years following a series of years with heavy rainfall.
cumulus fractus	Cumulus clouds that appear in irregular fragments, as if they had been shred or torn
flashiness	Where water levels rapidly peak and decline.
adaptive management	A type of management where the approach to managing resources evolves over time as new ideas, information, drivers for change and technologies emerge.
bifurcation	A fork into two or more streams.
equator	The geographic circle at 0 degrees latitude on the earth's surface
backpressure	a pressure that can cause water to backflow into the water supply when a user's wastewater system is at a higher pressure than the public system.
tsunami	An ocean wave with a long period that is formed by an underwater earthquake or landslide, or volcanic eruption
sewerage	the entire system of sewage collection, treatment, and disposal.
recharge	Water that infiltrates through the soil surface to the watertable.
leachate collection system	a system that gathers leachate and pumps it to the surface for treatment.
stream channel	The bed where a natural stream of water runs or may run; the long narrow depression shaped by the concentrated flow of a stream and covered continuously or periodically by water.
arid	A term describing a climate or region in which precipitation is so deficient in quantity or occurs so infrequently that intensive agricultural production is not possible without irrigation.
flood attenuation	To lessen the amount, force or severity of high flows.
reservoir	bay or other system, based upon flow rates into and out of the system, (see residence time).
surplus water	Developed water supplies in excess of contract entitlement or apportioned water.
zonal index	The measure of the strength of the westerly winds of the middle latitudes
barometer	An instrument used to measure atmospheric pressure
peclet number	the relationship between properties of the mesh, fluid velocity, and eddy viscosity for a hydraulic computer model.
storm winds	On the Beaufort Wind Scale, a wind with speeds from 56 to 63 knots (64 to 72 miles per hour).
longitudinal profile	Profile of a stream or channel drawn along the length of its centerline
helicity	A property of a moving fluid, such as air, representing the potential for helical flow (flow that follows a corkscrew pattern)
mesoscale convective system	A large organized convective weather system comprised of a number of individual thunderstorms
vegetative controls	non-point source pollution control practices that utilize vegetative cover to reduce erosion and minimize loss of pollutants.
cartilage	connective tissues without blood vessels
pool	A reach of a stream that is characterized by deep, low-velocity water and a smooth surface.
organic chemicals	chemicals containing carbon.
plunge pool	A pool at the foot of a small water-fall in a river
groundwater storage	the storage of water in groundwater reservoirs.
decomposition	breakdown of organic materials
ablation	The process by which ice and snow waste away as a result of melting and/or evaporation.
megalitre	one million litres (an Olympic swimming pool is about 2 megalitres).
pectoral fins	located directly behind the gill covers (operculum) on both sides of the sturgeon
enhancement	Emphasis on improving the value of particular aspects of water and related land resources.
siltation	the deposition of finely divided soil and rock particles upon the bottom of stream and river beds and reservoirs.
hydrograph	A curve showing stream discharge over time.
bedrock	consolidated rock beneath the surface of the earth
peak discharge	Maximum flow.
mesa	A mesa is a land formation with a flat area on top and steep walls - usually occurring in dry areas.
restricted drawdown	A lowering of reservoir pool levels that is limited by one or more restrictions on the rate of change.
breakpoint chlorination	addition 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.
racemic	a mixture that is composed of equal amounts of dextrorotatory and levorotatory forms of the same compound and is not optically active
flood stage	An above average elevation for the water level at high flows.
herbaceous	plants with soft rather than woody stems
outcomes	The results of the activities or products of a project
isohyet	The line drawn through geographic points recording equal amounts of rainfall during a given time or for a given of storm.
ppm	parts per million or milligrams per litre (mg/l)
habitat	Those parts of the environment on which particular plants or animals depend, directly or indirectly in order to carry out their life processes (modified from Newbury and Gaboury, 1993)
off-site enhancement	The improvement in conditions for fish or wildlife species away from the site of a hydroelectric project that had detrimental effects on fish and/or wildlife, as part or total compensation for those effects
ph	numeric value that describes the intensity of the acid or basic (alkaline) conditions of a solution
purgeable organics	volatile organic chemicals which can be forced out of the water sample with relative ease through purging.
tidal prism	The volume of water stored in an estuary or tidal lake between the high and low tide levels; the volume of water that moves into and out of the estuary over a tidal cycle.
velocity	In this concept, the speed of water flowing in a watercourse, such as a river.
diffluence	A rate at which wind flow spreads apart along an axis oriented normal to the flow in question
saturation	the condition of a liquid when it has taken into solution the maximum possible quantity of a given substance at a given temperature and pressure.
catchment	(1) the catching or collecting of water, especially rainfall
valley breeze	An anabatic wind, it is formed during the day by the heating of the valley floor
bow echo	A radar echo signature often associated with severe thunderstorms, especially those that produce wind damage
ephemeral	Temporary or intermittent; a creek or wetland that dries up intermittently.
flood plain	Level land that may be submerged by flood waters.
hydric soils	Soils that are ponded, flooded, or saturated long enough during the growing season to develop anaerobic conditions.
absolute zero	The coldest possible temperature, zero on the Kelvin scale, or approximately â'273.15 Â°C, â'459.67 Â°F
quantitative precipitation forecast	A forecast of rainfall, snowfall or liquid equivalent of snowfall.
advection	The horizontal transfer of any property in the atmosphere by the movement of air (wind)
heterogenic aquifer	an aquifer that has a variety of forms or characteristics, such as differering permeabilities
spurs	projection from the scutes of young sturgeon to deter predators
benthos	All the plant and animals living on or closely associated with the bottom of a body of water.
mainstem passage	The movement of salmon and steelhead around or through the dams and reservoirs in the Columbia and Snake rivers.
cold high	A high pressure system that has its coldest temperatures at or near the center of circulation, and horizontally, is thermally barotropic
large woody debris	Pieces of naturally occurring wood larger than 10 ft long and 6 in
precipitation	water that falls from the clouds - rain, snow, hail or sleet
parcel	A volume of air small enough to contain uniform distribution of its meteorological properties and large enough to remain relatively self-contained and respond to all meteorological processes.
zooplankton	Floating microscopic animals.
santa ana winds	The 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
bank stabilisation	See 'stabilisation'.
flora	plant population of a region.
weir	a 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.
gravel	Rock fragment whose diameter ranges from 2 to 64 mm.
moisture stress	A condition of physiological stress in a plant caused by lack of water.
riffle	A segment where the flow is shallower and more turbulent.
ecosystem	A term that describes all the organisms living in a particular area, as well as all the non-living, physical components of the environment with which the organisms interact, such as air, soil and water.
methoxychlor	pesticide that causes adverse health effects when found in domestic water supplies
resistance	The ease or difficulty of changing an ecosystem; how "resistant" it is to being changed
slough	A shallow backwater inlet that is commonly exposed at low flow or tide.
aquaduct	A pipe or conduit made to bring water from a source.
trade winds	Two belts of prevailing winds that blow easterly from the subtropical high pressure centers towards the equatorial trough
synoptic chart	Any map or chart that depicts meteorological or atmospheric conditions over a large area at any given time.
heat	A form of energy transferred between two systems by virtue of a difference in temperature
feeder bands	In tropical parlance, the lines or bands of thunderstorms that spiral into and around the center of a tropical system
riparian zone	The band of vegetation located adjacent to a stream
channel migration	Lateral or longitudinal (down-valley) migration of the stream channel within the valley by the process of erosion and deposition.
fry	young fish which have absorbed their yolk sac, during the larvae stage, and begin hunting for food
hydraulics	Applied science concerned with behavior and flow of liquids, especially in pipes, channels, structures, and the ground.
streamflow	The rate at which water passes a given point in a stream or river, usually expressed in cubic feet per second (cfs).
diadromous	Refers to fish that migrate between salt and fresh water.
chemical weathering	attack and dissolving of parent rock by exposure to rainwater, surface water, oxygen, and other gases in the atmosphere, and compounds secreted by organisms
geyser	a periodic thermal spring that results from the expansive force of super heated steam.
delta	A fan-shaped area of sediment built up at the mouth of a river.
volcano	A volcano is a mountainous vent in the Earth's crust
failure	Collapse or slippage of a large mass of bank material into a stream.
kame terrace	a terrace of stratified sand and and gravel deposited by streams between a glacier and an adjacent valley wall.
indicators	The specific characteristics or phenomena that tell you about the project and what impact it is having on the problem or issue it was set up to address.
electrodialysis	a process which uses an electrical current and an arrangement of permeable membranes to separate soluble minerals from water
habitat	A part of the environment that has well-defined physical characteristics and is inhabited by a particular species or group of animals or plants.
nutrients	such 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.
rain shadow	Also 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
ramsar convention	see Convention on Wetlands.
jamba	The Japan Australia Migratory Bird Agreement, a treaty between Australia and Japan to preserve habitat for migratory birds that are known to migrate between the two nations.
rootwad	The mass of roots associated with a tree adjacent or in a stream that provides refuge and nutrients for fish and other aquatic life.
reuse	The additional use of previously used water.
hazardous waste	Waste that poses a risk to human health or the environment and requires special disposal techniques to make it harmless or less dangerous.
remnant vegetation	Native vegetation that remains after surrounding land has been cleared.
rocketsonde	A 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.
petroleum ether	(also called Petrolether or ligroin) is a mixture of different hydrocarbons
endocrine function	The endocrine system in an animal regulates hormone activity
cut off	A channel cut across the neck of a bend.
yolk sac	a small sac attached to the larvae that provides nutrients needed to survive and grow
landscape	A heterogenous land area with interacting ecosystems that are repeated in similar form throughout.
cbod	Carbonaceous Biochemical Oxygen Demand. A BOD test in which a nitrification inhibitor is added, so that only the carbonaceous oxygen demanding compounds are measured.
troposphere	The lowest layer of the atmosphere located between the earth's surface to approximately 11 miles (17 kilometers) into the atmosphere
revetment	A facing of stone, bags, blocks, pavement, etc., used to protect a bank against erosion.
flashiness	Term that describes the degree to which a watershed is able to attenuate the intensity of stormflows through infiltration, retention, detention, … A "flashy" watershed has a high degree of impervious surface resulting in fast, intense flood peaks.
imhoff cone	a clear, cone-shaped container used to measure the volume of settleable solids in a specific volume of water.
percolation	The movement of water downward through the subsurface to the zone of saturation.
bioassay	a test to determine the relative strength of a substance by comparing its effect on a test organism with that of a standard preparation.
latitude	Latitude is the angular distance north or south from the equator to a particular location
bed layer	Flow layer, several grain diameters thick (usually two) immediately above the bed.
dam	A barrier built, usually across a watercourse, for holding back water or diverting the flow of water.
centrifugal force	The apparent force in a rotating system that deflects masses radially outward from the axis of rotation
contaminant	Any physical, chemical, biological, or radiological substance or matter that has an adverse affect on air, water, or soil.
estuary	thin 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).
flow rights	Access to a particular volume of water in time and space.
biosphere	the earth and all its ecosystems.
photosynthesis	The manufacture by plants of carbohydrates and oxygen from carbon dioxide and water in the presence of chlorophyll, using sunlight as an energy source.
crest line or width	The distance from one stream bank to the other along the crest of a waterfall.
drainage basin	an area of land where all water drains into a central water body
absorption	The process in which incident radiant energy is retained by a substance
icing	Masses or sheets of ice formed on the frozen surface of a river or floodplain
mesolow	A small scale low pressure center, ranging from the size of an individual thunderstorm to many tens of miles.
oxbow lake	a U shaped remnant of a part of a meander which forms a lake
fill period	The spring period of lessening runoff, when reservoirs are filled at a rate designed to maintain flood storage and reach targeted summer pool elevations
biodiversity	the variety of plant, animal, and microorganism species present in the ecosystem and the community structures the form.
acid rain	Rainfall with a pH of less than 7.0
biota	Collectively, the plants, microorganisms, and animals of a certain area or region.
evaporation	The process by which atoms or molecules in a liquid state gain sufficient energy to enter the gaseous state (usually with a heat catalyst).
lagoon	a shallow pond where sunlight, bacterial action, and oxygen work to purify wastewater
environment	The sum of all external influences and conditions affecting the life and development of an organism or ecological community; the total social and cultural conditions.
distribution coefficent	also called partition coefficient
stormwater	Stormwater is the surface water runoff that occurs after rain
slickensides	a smooth striated polished surface produced on rock by movement along a fault.
return flow	The portion of withdrawn water not consumed by evapotranspiration or system losses that returns to its source or to another body of water.
bankfull width	The width of a river or stream channel between the highest banks on either side of a stream.
limestone	rock that consists mainly of calcium carbonate and is chiefly formed by accumulation of organic remains.
cyanobacterial	Predominantly photosynthetic prokaryotic organisms containing a blue pigment in addition to chlorophyll; occur singly or in colonies in diverse habitats; important as phytoplankton.
metallorganic	a compound that possesses carbon but no direct M-C bond i.e
chute	A very steep cascade that is confined to a narrow channel.
mineralization	The process whereby concentrations of minerals, such as salts, increase in water, often a natural process resulting from water dissolving minerals found in rocks and soils through which it flows.
ec units	Electrical conductivity is a measure of the physical ability of a sample to carry an electric current
storm tracks	The path or tracks generally followed by a cyclonic disturbance.
surface water	water that flows in streams and rivers and in natural lakes, in wetlands, and in reservoirs constructed by humans.
infiltration	The movement of water through the soil surface into the soil.
plan position indicator	Also known as a PPI Scope, it is a radar indicator scope displaying range and azimuth of targets in polar coordinates.
digital terrain model	A data model that attempts to provide a three dimensional representation of a continuous surface
river miles	Generally, 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.
boulder	Rock fragment whose diameter is greater than 250 mm.
waterlogging	saturation of soil with irrigation water so the water table rises close to the surface.
snow squall	A heavy snow shower accompanied by sudden strong winds, or a squall.
apiarists	Those involved in the production of honey.
assimilation	The incorporation (or conversion) of nutrients and contaminants into the ecosystem.
gaining stream	A stream or reach of stream whose flow is being increased due to an inflow of ground water.
moraine	the leftover matter - usually rock and debris from a glacier
bank	The rising ground bordering a lake or river, or forming the edge of a cut or hollow.
transpiration	An essential physiological process in which plant tissues give off water vapor to the atmosphere.
retrogression	In meteorology, it is the movement of a weather system in a direction opposite to the direction of the basic flow in which it is embedded
landscape features	The land, water, vegetation, and structures that compose the characteristic landscape.
bank-full discharge	The stream discharge corresponding to the water stage that first overtops the natural banks
bed	Bottom of a channel bounded by banks.
annular space	the space between two concentric cylindrical objects, one of which surrounds the other, such as the space between the walls of a drilled hole and a casing.
absorption	the uptake of water, other fluids, or dissolved chemicals by a cell or an organism (as tree roots absorb dissolved nutrients in soil).
creel census survey	The collection of data concerning the number of fish caught by sport fishers on a particular stream or in a particular area.
operable unit	a term used by the Superfund program to describe a discrete action that comprises an incremental step toward comprehensively addressing site problems
water right	A legally protected right to take possession of water occurring in a natural waterway and to divert that water for beneficial use.
extraction	Water taken from rivers for off-stream use or consumption.
sewage	The waste and wastewater produced by residential and commercial sources and discharged into sewers.
macroinvertebrates	Invertebrates with a body greater than 1 mm that is, that can be seen with the naked eye.
base line or width	The distance from one stream bank to the other along the base of a waterfall.
hydrology	The study of the properties, movement and behavior of water on the land surface and under ground.
dock	A place for vessels to load and unload cargo or to be repaired.
index fishing program	program of annual netting used to estimate fish population size
sucker mouth	tube-like mouth which sucks prey into their jaw
average year water demand	Demand for water under average hydrologic conditions for a defined level of development.
rain rejection	Occurs when water ordered from a dam by an irrigator is not then taken from the river, or is returned to the river because of rain in the meantime.
forb	A non-grass herbaceous plant.
purge	to force a gas through a water sample to liberate volatile chemicals or other gases from the water so their level can be measured.
tropopause	The boundary zone or transition layer between the troposphere and the stratosphere
overdraft	pumping 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.
biofilm	A gelatinous sheath of algae and micro-organisms, including benthic algae and bacteria, formed on surfaces such as gravel, sediment and plants (ARMCANZ & ANZECC 2000).
upwelling	The process by which water rises from a lower to a higher depth, usually as a result of divergence and offshore currents
ionosphere	A complex atmospheric zone of ionized gases that extends between 50 and 400 miles (80 to 640 kilometers) above the earth's surface
cobble	Substrate particles that are smaller than boulders and are generally 64-256 mm in diameter
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
natural resource	any form of matter or energy obtained from the environment that meets human needs.
threatened species	Under the Federal Endangered Species Act, animal populations may be determined to be either threatened or endangered
condensation	sublimation, vapourization, transpiration, evapotranspiration, volatilization).
runout	The horizontal distance from the crest to the base of a waterfall.
deposition	Accumulation of sediment on the channel bed or banks.
conductivity	A measure of the amount of salts dissolved in water.
solubility	the amount of mass of a compound that will dissolve in a unit volume of solution.
propagules	Any part of an organism, produced sexually or asexually, that is capable of giving rise to a new individual.
height	The vertical distance from the base to the crest of a waterfall.
lunette	A wind-formed, half-moon shaped crescent, usually of sand or fine sediment.
analytical watershed	For planning purposes, a drainage basin subdivision used for analyzing cumulative impacts on resources.
biological integrity	the ability to support and maintain balanced, integrated functionality in the natural habitat of a given region
rehabilitation	To restore to a former state or capacity
spring	an issue of water from the earth; a natural fountain; a source of a body or reservoir of water.
channel pattern	Aspect of a stream channel in plan view, with particular reference to the degree of sinuosity, braiding, and anabranching.
mouth	The mought is the end of a river, where it empties into a large body of water.
urban runoff	Storm water from city streets and gutters that usually contains a great deal of litter and organic and bacterial wastes into the sewer systems and receiving waters.
fall velocity	Velocity at which a sediment particle falls through a column of still water.
eddy	A circular current of water, usually resulting from an obstruction.
confluence	The meeting or junction of two or more streams.
detergent	synthetic washing agent that helps remove dirt and oil
greenhouse effect	The overall warming of the earth's lower atmosphere primarily due to carbon dioxide and water vapor which permit the sun's rays to heat the earth, but then restrict some heat-energy from escaping back into space.
nmr spectroscopy	is a spectroscopic technique to identify functional groups and structure of a compound
bed slope	Inclination of the channel bottom.
leap	A single vertical, or very near vertical, fall of water.
population	The number of people living in a certain area.
fecal coliform	the portion of the coliform bacteria group which is present in the intestinal tracts and feces of warm-blooded animals
lag time	the time from the center of a unit storm to the peak discharge or center of volume of the corresponding unit hydrograph.
perfected water right	a water right which indicates that the uses anticipated by an applicant, and made under permit, were made for beneficial use
capacity building program	A holistic approach to knowledge building and transfer, which fosters skill development, competency, innovation and confidence
habitat	The type of environmental in which a given plant or animal lives and grows, including physical and biological conditions.
snag	Any standing dead, partially dead, or defective (cull) tree at least 10 inches in diameter at breast height and at least 6 feet tall.
capillary zone	soil area above the water table where water can rise up slightly through the cohesive force of capillary action
homogeneous	is a system that consists of only one phase i.e
apogee	The point farthest from the earth on the moon's orbit
fry	recently emerged fish, after the yolk sac has been absorbed
bridge owner	Any Federal, State, Local agency, or other entity responsible for a structure defined as a highway bridge by the National Bridge Inspection Standards (NBIS).
coag	Council of Australian Governments-the peak intergovernmental forum in Australia, comprising the Prime Minister, state premiers, territory chief ministers and the President of the Australian Local Government Association.
falls	The sudden descent of a stream primarily over a vertical or extremely steep section of its stream bed
diversion	The transfer of water from a stream, lake, aquifer, or other conduit to another watercourse or to the land, as in the case of an irrigation system.
stream reach	An individual segment of stream that has beginning and ending points defined by identifiable features such as where a tributary confluence changes the channel character or order.
windfall	Trees or parts of trees felled by high winds.
core area	The area of habitat essential in the breeding, nesting, and rearing of young, up to the point of dispersal of the young.
meander loop	Individual loop of a meandering or sinuous stream lying between inflection points with adjoining loops.
herbicide	a chemical used to kill nuisance plants
freezing rain	Rain that falls as liquid and freezes upon impact to form a coating of glaze on the colder ground or other exposed surfaces
anaerobic	also refers to metabolic activities, glycolysis, in the absence of oxygen which occurs in some microorganisms.
biomass	The total dry weight of all organisms in a particular sample, population, or area.
irrigation	The supply of water to farmland so that crops can grow in areas wherewater supplies are scarce or unreliable
hydrologic balance	An accounting of all water inflow to, water outflow from, and changes in water storage within a hydrologic unit over a specified period of time.
lachrymator	a compound that makes the eyes fill with tears but does not damage them (“teargas”)
armour layer	An impermeable surface built up over a period of time by weathering.
anomalous propagation	This refers to the non-standard propagation of a beam of energy, radio or radar, under certain atmospheric conditions, appearing as false (non-precipitation) echoes
eutrophication	The natural process by which lakes and ponds become enriched with dissolved nutrients, resulting in increased growth of algae and other microscopic plants.
headcutting	The process by which the stream is actively eroding the streambed downward (degrading, incising, downcutting) to a new base level
dependable supply	The annual average quantity of water that can be delivered during a drought period.
sedimentation	(1) The combined processes of soil erosion, entrainment, transport, deposition, and consolidation
fish ladder	a stepped fishway with water flowing over it
drawdown	the 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.
biological diversity	The variety of and variability among living organisms and the ecological systems of which they are part, including diversity among species, the variation within species, and the variety of ecosystem functions they provide.
suspended solids	the small solid particles in water that cause turbidity
canopy	A layer of foliage in a forest stand
flow	The amount of water passing a particular point in a stream or river, usually expressed in cubic feet per second (cfs).
overbank flow	Water flow over the top of the bankfull channel onto the floodplain.
water quality-based toxics control	an integrated strategy used in NPDES permitting to assess and control the discharge of toxic pollutants to surface waters
grade control structure	A weir, dam, sill, drop structure, or other structure used to control erosion in stream channels with steep grades or where the slope has been destabilized.
stability	The ability of an instrument or sensor to maintain a consistent output when a constant input is applied over time
littoral zone	The part of the shoreline that is submerged at high tide and exposed at low tide.
effective precipitation	the part of precipitation which produces runoff; a weighted average of current and antecedent precipitation "effective" in correlating with runoff
downstream	The direction that the river flows, towards the mouth of the river.
confluence	The point at which the two streams merge
assimilative capacity	the 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.
hydrology	The science of waters of the earth; water's properties, circulation, principles, and distribution.
urban runoff	storm water from city streets and adjacent domestic or commercial properties that carries pollutants of various kinds into the sewer systems and receiving waters.
channel	A depression created by constant erosion that carries the stream's flow.
dewater	remove or separate a portion of the water in a sludge or slurry to dry the sludge so it can be handled and disposed; remove or drain the water from a tank, trench, or aquifer.
environmental assessment	A 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.
water velocity	the speed at which the river or stream is flowing
freshet	A rapid temporary increase in stream flow due to heavy rains or snow melt.
prevailing wind	A wind that blows from one direction more frequently than any other during a given period, such as a day, month, season, or year.
radarsonde observation	An upper air observation used to determine winds and other meteorological data, by tracking the range, elevation, and azimuth of a radar target carried aloft
watercourses	A river, stream or creek in which water flows in a natural channel, whether permanently or intermittently.
hydraulic action	The force of the water wears away the river bank from underneath
erosion	The wearing away of rock or soil by the action of water, wind, ice or other mechanical or biological forces.
water cycle	natural 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
refractive index	is a physical property that quantifies the refraction of light by a solid or liquid
phenolphthalein alkalinity	the alkalinity in a water sample measured by the amount of standard acid needed to lower the pH to a level of 8.3 as indicated by the change of color of the phenolphthalein from pink to clear.
ultraviolet	Electromagnetic radiation that has a wavelength shorter than visible light and longer than x-rays
anoxic	Without oxygen.
turbulence	The irregular and instantaneous motions of air which is made up of a number of small of eddies that travel in the general air current
physiographic province	an area with similar characteristics based on geology, soil type, and topography.
metals	These are elements such as iron, manganese, copper, lead and zinc
low-flow specialists	Flora and/or fauna that recruit and thrive in low flow conditions.
recurrence interval	average amount of time between events of a given magnitude
overcast	The amount of sky cover for a cloud layer that is 8/8ths, based on the summation layer amount for that layer.
discharge	the amount of water flowing past a given point on a stream; measured in cubic feet or cubic metres per second
biological	Relating to any living organism either plant, animal, fungus or virus.
geomorphology	The study of present day landforms.
sedimentation	Deposition of sediments in lakes or other areas of relatively still water
drought	although there is no universally accepted definition of drought, it is generally the term applied to periods of less than average precipitation over a certain period of time
silt	Substrate particles smaller than sand and larger than clay (3 to 60 um).
ecosystem	A system formed by the interaction of a group of organisms and their environment.
oligomer	is a polymer or polymer intermediate containing relatively few structural units (more than two units) i.e
riparian area	the border of the stream above its banks; wet soil areas influenced by the water of a stream, lake, or wetland
cut bank	The outside bank of a bend, often eroding opposite a point bar.
scour	process of water eroding material through high velocities in conjunction with moving sediment.
terrestrial vegetation	Plants growing on land beyond the flood zone of a river or stream.
erosion control matting	Fibrous matting (e.g., jute, paper, etc.) placed or sprayed on a streambank for the purpose of resisting erosion or providing temporary stabilization until vegetation is established.
algicide	substance or chemical used specifically to kill or control algae.
clarification	the clearing action that occurs during wastewater treatment when solids settle out
sea surface temperature	The temperature of the water's surface
sludge	solid 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.
irrigation efficiency	The efficiency of water application and use
gum-leaf skeletoniser	A native Australian moth (Uraba lugens) that primarily feeds on gum leaves.
siltation	Siltation is the deposit or accumulation of very tiny soil particles (silt).
conjunctive use	The operation of a groundwater basin in combination with a surface water storage and conveyance system
quenching	a reaction is terminating by deactivating reactive intermediates
general scour	General scour is a lowering of the streambed across the stream or waterway at the bridge
ravine	Another name for a narrow gorge.
public water system	a 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.
extraction	is a process to isolate a compound from a mixture by either temporary chemical modification or distribution within two layers.
compensation	An addition of specific materials or devices to counteract a known error.
tceq	Texas Commission on Environmental Quality.
calibration bath	A uniform temperature enclosure using carefully stirred fluid to provide excellent thermal contact and uniformity for temperature calibration.
sample	bacterial 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.
pool	A segment where the water is deeper and slower moving.
reservoir level	The elevation of the water in a reservoir at a given time, measured in feet above sea level.
chromatography	is a technique to separate compounds from each other
foot	See Base.
resilience	the ability of an ecosystem to maintain or restore biodiversity, biotic integrity, and ecological structure and processes following disturbance.
large woody debris	Pieces of wood larger than 10 feet long and 6 inches in diameter, in a stream channel.
moorings	The place where a ship or boat is docked (or tied up)
contraction	Effect of channel or bridge constriction on flow streamlines.
coarse woody debris	Portion of a tree that has fallen or been cut and left in the woods
heterogeneous	is a system that consists of at least two phases (solid-liquid)
top of gates	The maximum controlled elevation at a project, typically the top of a spillway gate in a closed position or crest elevation of an uncontrolled outlet structure.
wave energy	The energy generated by coastal surface waves.
combined sewer overflow	the discharge of a mixture of storm water and domestic waste when the flow capacity of a sewer system is exceeded during rainstorms.
fema	Federal Emergency Management Agency; The federal agency responsible for dealing with emergency flood conditions and flood insurance.
spot ratio	See Distance to Target Ratio.
midreaches	streams carrying the water from several tributaries
headgate	the gate that controls water flow into irrigation canals and ditches
brine	highly salty and heavily mineralized water containing heavy metal and organic contaminants.
detritus	Decaying organic matter found on the bottom of a stream or lake, or in the top soil layer.
runoff	A general term for water that flows across the landscape after a significant rainfall event
evaporation	the changing of water to water vapor
cystophora	Type of robust brown algae found on reefs in South Australia.
hydrologic cycle	Often called the water cycle, it is the vertical and horizontal transport of water in all its states between the earth, the atmosphere, and the seas.
instantaneous flows	The velocity of a volume of water.
dia.	Diameter
runoff	Water that has from something
hydraulic model	a computer model of a segment of river used to evaluate hydraulic conditions
riparian	Referring to or relating to areas adjacent to water or influenced by water associated with streams or rivers on geological surfaces.
cross section	Section normal to the trend of a channel or flow.
convection	The transfer of heat by the circulation of fluid or gas.
sustained overdraft	long term withdrawal from the aquifer of more water than is being recharged.
katafront	A front where the warm air descends the frontal surface, except in the low layers of the atmosphere.
return flow	surface water that returns to the natural environment after diversion for beneficial uses, such as for irrigation.
bed forms	three-dimensional configurations of bed material, which are formed in streambeds by the action of flowing water.
dominant discharge	(A) Discharge of water which is of sufficient magnitude and frequency to have a dominating effect in determining the characteristics and size of the stream course, channel, and bed; (B) discharge which determines the principal dimensions and characteristics of a natural channel
petroleum derivatives	chemicals formed when gasoline breaks down in contact with water.
designated use	Classification designated in water quality standards for each water body or segment that defines the optimal purpose for that water body.
tragedy of the commons	the idea that no one takes responsibility for things that everybody owns.
funnel cloud	A violent, rotating column of air visibly extending from the base of a towering cumulus or cumulonimbus toward the ground, but not in contact with it
kcfs-month	One kcfs-month is a flow of 1,000 cubic feet per second for one month or 0.0595 million acre-feet.
toe	The break in slope at the foot of a stream bank where the bank meets the bed.
monomictic	lakes 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).
hydraulic jump	Abrubt, turbulent, noisy transition from super-critical flow to sub-critical flow
max/min	A common thermometer feature allowing you to quickly display the maximum and/or minimum values measured during a specified period of time.
subcritical flow	flow characterized by low velocity and a Froude number less than 1
stream	A general term for a body of flowing water; natural water course containing water at least part of the year
bank stability	The properties of a stream bank that counteract erosion, for example, soil type, and vegetation cover.
noctilucent clouds	Rarely seen clouds of tiny ice particles that form approximately 75 to 90 kilometers above the earth's surface
detention time	the 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.
rain	Precipitation in the form of liquid water droplets greater than 0.5 mm
lake	Any inland body of standing water, usually fresh water, larger than a pool or pond; a body of water filling a depression in the earth's surface.
aeration	the mixing or turbulent exposure of water to air and oxygen to dissipate volatile contaminants and other pollutants into the air.
rock face	The vertical to very steep section of a stream bed that a waterfall descends
macrophyte	macroscopic plants in the aquatic environment
ephemeral stream	Stream or reach of stream that does not flow for parts of the year
mean velocity	The average cross-sectional velocity of water in a stream channel
bank	Sides of a channel between which the flow is normally confined.
headwater elevation	The water elevation immediately upstream of a dam.
remediation	methods used to remove or contain a toxic spill or hazardous materials from a Superfund site; a generic term used to describe cleanup activities.
ephemeral	An ephemeral waterbody is a stream, lake or other type of wetland that only contains water for a short period following rainfall, typically for only a few weeks to several months.
snowflakes	An ice crystal or an aggregate of ice crystals which fall from clouds.
pathogens	Any virus, bacteria, or fungi that cause disease.
sedge	A plant from the family Cyperaceae
water column	an imaginary column extending through a water body from its floor to its surface
fault block	A plane of fracture in a rock along which displacement has occurred.
relative humidity	The ratio of the actual amount of water vapor (absolute humidity) present in the air to the saturation point at the same temperature, usually expressed as a percentage.
horizon	One of several lines or planes used as reference for observation and measurement relative to a given location on the surface of the earth
severe weather	Generally, any destructive weather event, but usually applies to localized storms, such as blizzards, intense thunderstorms, or tornadoes.
dropsonde	A radiosonde dropped with a parachute from an aircraft rather than lifted by a balloon to measure the atmosphere below.
stratopause	The boundary zone or transition layer between the stratosphere and the mesosphere
aquatic life use	a beneficial use designation in which the water body provides suitable habitat for survival and reproduction of desirable fish, shellfish, and other aquatic organisms.
down log	Portion of a tree that has fallen or been cut and left in the woods.
gradient	The rate of change in (vertical) elevation per unit of horizontal distance.
ecosystem	an interdependent biological system involving interaction between living organisms and their immediate physical, chemical and biological environment.
daylight	In the restoration field, a verb that denotes the excavation and restoration of a stream channel from an underground culvert, covering, or pipe.
centripetal force	The force required to keep an object moving in a curved or circular path
retardation factor	is the ratio of how far the center of a spot traveled compared to the solvent front (=Rf-value)
conservation	The process or means of achieving recovery of variable populations.
weather vane	Originally used as a wind vane, it is an instrument that indicates the wind direction
bioaccumulation	uptake and retention of substances by an organism from its surrounding medium (usually water) and from food.
buys ballot's law	Describes the relationship of the horizontal wind direction to the pressure distribution
cut bank	The outside, often eroding, bank on a channel bend
ozone	A nearly colorless gas and a form of oxygen (O2)
ambient background concentration	a representative concentration of the water quality in a receiving water body, determined from monitoring
water table aquifer	an aquifer confined only by atmospheric pressure (water levels will not rise in the well above the confining bed).
fluvial	Migrating between main rivers and tributaries
mammatocumulus	An obsolete term for cumulonimbus mammatus, it is a portion of a cumulonimbus cloud that appears as a pouch or udder on the under surface of the cloud
anadromous fish	fish that migrate from salt water to fresh water for spawning
sinking	controlling 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.
baetid	A type of insect called a mayfly from the family Baetidae.
habitat conservation plan	An agreement between the Secretary of the Interior and either a private entity or a state that specifies conservation measures that will be implemented in exchange for a permit that would allow taking of a threatened or endangered species.
twilight	Often called dusk, it is the evening period of waning light from the time of sunset to dark
stream morphology	The form (dimension, pattern and profile) and structure of the stream channel.
monitor	track a characteristic over time, using uniform methods to evaluate change non-point source pollution: pollutants that enter waterways from broad land areas as a result of the way the land is used (e.g
hydric	Wet.
interbasin transfer	The diversion of water from one drainage basin to one or more other drainage basins.
deepening	Used 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
diurnal	Pertaining to actions or events that occur during a twenty-four hour cycle or recurs every twenty-four hours
melting point	is the temperature at which a solid becomes a liquid, usually reported as a range
stream power	Directly related to the sediment transport rates of a stream and measured as the loss of potential energy per unit length of stream channel
heterocercal tail	shark-like asymmetrical tail
blackwater	Water that contains waste of humans, animals or food.
irrigation return flow	applied water that is not transpired, evaporated, or deep-percolated into a groundwater basin but returns to a surface water supply.
sand	Loose particles of hard, broken rock or minerals
corona	A pastel halo around the moon or sun created by the diffraction of water droplets
pyrophoric	means that a compound catches on fire when it comes in contact with air
meander bend	a windings or sinuous section of a stream channel
katabatic wind	A wind that is created by air flowing downhill
braided stream	A complex tangle of converging and diverging stream channels (Anabranches) separated by sand bars or islands
orogeny	period of mountain-building.
clarifier	a tank in which solids settle to the bottom and are subsequently removed as sludge.
stream power	a measure of energy available to move sediment, or any other particle in a stream channel
pressure altitude	The altitude in standard atmosphere at which a given pressure will be observed
turbidity	"The term ""turbid"" is applied to waters containing suspended matter that interferes with the passage of light through the water or in which visual depth is restricted."
ground water reservoir	primarily 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).
water vapor	Water in gaseous form
ph	measure of acidity
off-channel area	Any relatively calm portion of a stream outside of the main flow.
permanent wetlands	Wetlands that are permanently inundated, as opposed to semi-permanent wetlands, which are inundated periodically and may have long periods of no water inundation.
theodolite	An optical instrument used to track the motion of a pilot balloon, or pibal, by measuring the elevation and azimuth angles.
run	Shallow stream section with moderate currents.
pathogenic bacteria	cysts 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.
altimeter	An instrument used to determine the altitude of an object with respect to a fixed level
organelles	in eukaryotic cells that carry out photosynthesis, where the chlorophyll pigments and related enzymes are located, specialized structures that carry out photosynthesis in plants and algae.
underflow	movement of water through subsurface material.
acequia	irrigation channels constructed during the period of Spanish Colonial Mission settlement
depth of flow	The height of the water surface above the streambed.
stream profile	A view of a stream's course from its headwaters to its mouth, showing the steepness of the descent.
dredging	Removing material (usually sediments) from wetlands or waterways, usually to make them deeper and wider.
surface water	Water flowing or held in waterways or wetlands on the surface of the landscape.
watch	A forecast issued well in advance of a severe weather event to alert the public of the possibility of a particular hazard, such as tornadoes, severe thunderstorms, flash and river floods, winter storms, or heavy snows.
overlook	A viewing area for a waterfall or a scenic area.
isinglass	a sticky substance that is made from swim bladders of fish
seal	the 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.
usace	U.S
demand	The numerical expression of the desire for goods and services associated with an economic standard for acquiring them.
allogenic recharge	recharge that occurs in a sinking stream, entering an aquifer through sinkholes or fault planes
salts	nutrients, pesticide chemicals or contaminants, are washed into a lower layer of soil or are dissolved and carried away by water.
flora	The plants of a particular region.
hypersaline	Characteristic of an aquatic environment where the water is much saltier than normal sea water.
meander	curves in the stream channel where the stream dissipates energy.
nonthreshold pollutant	substance or condition harmful to a particular organism at any level or concentration.
transmissivity	refers to the rate at which limestone allows the transmission of water
groundwater	water 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.
senesced	Includes vegetation whose leaves have lost most of their nutrients and are dropping from the trees.
short wave	A progressive wave of smaller amplitude, wave length, and duration than a long wave
articulated concrete mattress	Rigid concrete slabs which can move without separating as scour occurs; usually hinged together with corrosion-resistant cable fasteners; primarily placed for lower bank protection.
invertebrate	an animal without a back bone
bioengineering	The use of living plants to stabilize soil
point source	source of pollution that involves discharge of wastes from an identifiable point, such as a smokestack or sewage treatment plant
eutrophic	Rich in mineral and organic nutrients that promote a proliferation of plant life, especially algae.
losing stream	A stream or reach of stream from which some water flows from the stream bed into the ground.
oligotrophic	having a low supply of plant nutrients
biological diversity	The variety of different species, the genetic variability of each species, and the variety of different ecosystems that they form.
daily mean	The average temperature for a day computed by averaging either the hourly readings or, more commonly, the maximum and minimum temperatures.
debris flow	A rapidly moving mass of rock fragments, soil, and mud, with more than half of the particles being larger than sand size.
per capita water use	The water produced by or introduced into the system of a water supplier divided by the total residential population; normally expressed in gallons per capita per day (gpcd).
towering cumulus	Another name for cumulus congestus, it is a rapidly growing cumulus or an individual dome-shaped clouds whose height exceeds its width
kelvin temperature scale	A temperature scale with the freezing point of +273°K (Kelvin) and the boiling point of +373° K
tagged	external identification, such as a wire or flag which indicates previously captured strugeon
milligrams per liter	the weight in milligrams of any substance dissolved in one liter of liquid; nearly the same as parts per million by weight.
dew point	The air temperature at which, under current barometric pressure, the water vapor currently in the air would condense into water or dew (or reach 100% humidity)
filter	a device used to remove solids from a mixture or to separate materials
supersaturated	is a solution that contains more than the maximum amount of solute at a given temperature
groundwater basin	A groundwater reservoir, defined by an overlying land surface and the underlying aquifers that contain water stored in the reservoir
meander belt	The area between lines drawn tangential to the extreme limits of fully developed meanders
calcium carbonate	CACO3 - a white precipitate that forms in water lines, water heaters and boilers in hard water areas; also known as scale.
consumptive use	the quantity of water not available for reuse
geomorphology/morphology	That science that deals with the form of the Earth, the general configuration of its surface, and the changes that take place due to erosion and deposition.
meander	Something that meanders follows a winding path.
flow duration curve	a measure of the range and variability of a stream's flow
channel-forming discharge	See dominant discharge.
bathochromic shift	is a shift to higher wavelength in the UV-Vis spectrum
runoff	That portion of rainfall or snowmelt that moves across the land surface into streams and lakes.
oxbow lake	A small arc-shaped lake formed when a meander is sealed off by deposition
cooling tower	large 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.
monitoring and evaluation program	Development of monitoring and evaluation activities to determine the success or otherwise of measures put in place as part of stormwater management projects.
specific heat	the amount of heat required to raise the temperature of a kilogram of a substance (water) by 1 degree Celsius.
moisture content	the amount of water lost from soil upon drying to a constant weight, expressed as the weight per unit of dry soil or as the volume of water per unit bulk volume of the soil.
convection	Motions in a fluid that transport and mix the properties of the fluid
refugia	Places of shelter from danger or pursuit
average annual runoff	For a specified area, it is the average value of annual runoff amounts calculated for a whole hydrologic cycle of record that represents average hydrologic conditions.
imbricated	Reference to stream bed sediment particles, having an overlapping or shingled pattern.
reproducibility	See repeatability.
dispersion	the movement and spreading of contaminants out and down in an aquifer.
launching	Release of undercut material (stone riprap, rubble, slag, etc.) downslope or into a scoured area.
channel capacity	Volume at which a channel spills its bank (see bankfull).
ecosystem	(1) Recognizable, relatively homogeneous units, including the organisms they contain, their environment, and all the interactions among them
spring flood	A flood that occurs in spring months, in the southern hemisphere corresponding to the months of September, October and November.
saroc	San Antonio River Oversight Committee; a twenty-two member citizen committee appointed in 1998 to guide the planning and implementation of the San Antonio River Improvements Project.
dry wash	A streambed that carries water only during and immediately following rainstorms.
infiltration	paving, 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.
hatch box	A device used to incubate relatively small numbers of eggs
riffle	A reach of stream that is characterized by shallow, fast-moving water broken by the presence of rocks and boulders.
barrage	a construction across the mouth of a river that prevents the entry of seawater; behind a barrage' the water is fresh.
resource	A person, thing, or action needed for living or to improve the quality of life.
tributary	a stream that contributes its water to another stream or body of water.
catalyst	is a compound that increases the rate of the reaction by lowering the activation energy for a chemical reaction, but does not change the yiel
paving	Covering of stones on a channel bed or bank (used with reference to natural covering).
bed material	Material found in and on the bed of a stream (May be transported as bed load or in suspension).
tilt block	A formation where two geological features tilt or dip around each other to form a depression.
right of capture	the 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
turbidity	A measure of water clarity
cone of depression	natural depression in the water table around a well during pumping.
auto-off	The ability of a device to turn itself off to conserve power after a specified period of time without any user inputs
interbasin transfer	The transfer of water out of one river basin for the benefit of a public water system in another river basin
tributary	A stream or river that feeds into a larger watercourse.
biodiversity	The variability among living organisms from all sources (including terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part) and the diversity within and between species and of ecosystems (ARMCANZ & ANZECC 2000).
preservative	a chemical added to a water sample to keep it stable and prevent compounds in it from changing to other forms or to prevent microorganism densities from changing prior to analysis.
drizzle	Slowly falling precipitation in the form of tiny water droplets with diameters less than 0.02 inches or 0.5 millimeters
ditch	A long narrow trench or furrow dug in the ground, as for irrigation, drainage, or a boundary line.
collectors	aquatic invertebrates that feed on fine material
decomposer	Any of various organisms (as many bacteria and fungi) that feed on and break down organic substances (such as dead plants and animals).
particle size distribution	See Substrate Analysis.
swales	Small depressions, natural or artificial, that carry water only after a rainfall.
lake	separated by the fairly thin thermocline zone, from the lower, colder, denser zone of water, the hypolimnion.
micro-fauna	Any fauna not visible to the naked eye.
steady-state mass balance	the 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.
lotic-adapted species	species for which all or part of their life history is dependent on flowing water.
deionized water	water free of inorganic chemicals.
deposition	the laying down of material by erosion or transport by water or air.
groundwater runoff	the 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.
contaminate	To make impure or unclean by contact or mixture.
buffer strip	A barrier of permanent vegetation, either forest or other vegetation, between waterways and land uses such as agriculture or urban development, designed to interrupt and filter out pollution before it reaches the surface water resource.
electrofishing	a biological collection method that uses electric current to facilitate capturing fishes.
vertical wind profile	A series of wind direction and wind speed measurements taken at various levels in the atmosphere that show the wind structure of the atmosphere over a specific location
subpolar	The region bordering the polar region, between 50° and 70° North and South latitude
mouth	the point at which a river empties into another body of water
conduction	The trasnfer of electrical energy or heat through or by means of a conductor.
stone	Rock or rock fragments used for construction.
perihelion	The point of the earth's orbit that is nearest to the sun
glacier	A 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.
current velocity	the velocity of water flow in a stream, measured in units of length per unit of time, such as feet per second (fps).
in-situ stripping	treatment system that removes or strips volatile organic compounds from contaminated groundwater or surface water by forcing an air stream through the water and causing the compounds to evaporate.
secchi disc	A circular plate, generally about 10-12 in (25.4-30.5 cm) in diameter, used to measure the transparency or clarity of water by noting the greatest depth at which it can be visually detected
point bar	An accumulation of alluvium - usually sand or gravel - caused by a decrease in sediment transport capacity on the inside of a meander bend.
irrigation efficiency	the percentage of water applied, and which can be accounted for, in the soil moisture increase for consumptive use.
pressure altimeter	An aneroid barometer calibrated to indicate altitude in feet instead of units of pressure
prognostic chart	A chart of forecast predictions that may include pressure, fronts
first flush	Describes situations when contaminants (e.g
meander scrolls	Low, concentric ridges and swales on a floodplain, marking the successive positions of former meander loops.
in-channel benches	Bench-like formation of sediment formed in the river as a result of flow movement of sediment
isopleth	A line connecting equal points of value
risk	The chances of something happening that will have an impact on objectives
barrage	any artificial obstruction placed in water to increase water level or divert it
median diameter	Particle diameter of the 50th percentile point on a size distribution curve such that half of the particles (by weight, number, or volume) are larger and half are smaller (D50).
endangered species	one having so few individual survivors that the species could soon become extinct in all or part of its region.
silt	Substrate particles smaller than sand and larger than clay.
morphology	the form, shape, or structure of a stream or organism.
climatic year	a period used in meteorological measurements
bioremediation	a process that uses living organisms to remove pollutants.
halo	The ring of light that seems to encircle the sun or moon when veiled by cirrus clouds
constructed wetland	A vegetated detention area designed and built to remove contaminants from stormwater runoff, but which can also provide secondary benefits of habitat enhancement/creation and active and passive recreational and educational opportunities.
average yearly supply	The average annual supply of a water development system over a whole hydrologic system.
bipolar	The ability of a panel meter to display both positive and negative readings.
hydrolysis	the decomposition of organic compounds by interaction with water.
autogenic recharge	recharge that occurs by falling directly on an aquifer's outcrop at the surface
split-mode	refers to the fact that only a small amount of the sample is actually introduced to the GC column
clay	Substrate particles that are smaller than silt and generally less than 0.004 mm in diameter.
melting	the changing of a solid into a liquid.
degradation	General and progressive (long-term) lowering of the channel bed due to erosion, over a relatively long channel length.
shear	Force parallel to a surface as opposed to directly on the surface
undertow	the current beneath the surface that sets seaward or along the beach when waves are breaking on the shore.
afterbay	A reservoir that regulates fluctuating discharges from a hydroelectric power plant or a pumping plant.
spillway	A channel or passageway around or over a dam through which water is released, or “spilled,” past the dam without going through the turbines
potentiometric surface	the surface to which water in an aquifer can rise by hydrostatic pressure
stream	a general term for a body of flowing water.
aerobic	life or processes that require, or are not destroyed by, the presence of oxygen.
high clouds	A term used to signify cirriform clouds that are composed of ice crystals and generally have bases above 20,000 feet
boulder wind	A local name referring to an extremely strong downslope wind in the Front Range of the Rocky Mountains near Boulder, Colorado.
cercla	Comprehensive Environment Response, Compensation and Liability Act
water quality criteria	scientifically derived ambient limits developed and updated by EPA, under section 304(a)(1) of the Clean Water Act, for specific pollutants of concern
hydraulic modelling	Numerical modelling to simulate the hydraulics of a river and predict water surface profiles based on cross-sections, a long profile and a roughness coefficient (simple model) or simulating three dimensional-flow complexities.
irrigation	The controlled application of water to cropland, hayland, and/or pasture to supplement that supplied through nature.
runoff	water that runs off the soil surface
cyclone	An area of closed pressure circulation with rotating and converging winds, the center of which is a relative pressure minimum
floodplain bench	A small level area that forms at the effective discharge stage within an over-wide, entrenched channel.
litre	The basic unit of measurement for volume in the metric system; equal to 61.025 cubic inches or 1.0567 liquid quarts.
nematodes	Also called round worms, they are thin, long worm-like animals with tapering ends that lack segments and appendages.
siltation	the process of becoming clogged by fine sediments
stable/stability	Occurs when a rising air parcel becomes denser than the surrounding air
fascine	Matrix of willow or other natural material woven in bundles and used as a filter
hyporheic	A region of saturated sediments beneath and beside the active channel that contains some proportion of surface water.
bifurcate	Division or a fork, often represented by two branches splitting from one.
macroalgae	Large aquatic photosynthetic plants that can been seen without the aid of a microscope.
thalweg	(1) The lowest thread along the axial part of a valley or stream channel
subtropical	The region between the tropical and temperate regions, an area between 35° and 40° North and South latitude
hydraulic	Refers to river surface profiles, including cross section, length and depth.
nutrient	as a pollutant, any element or compound, such as phosphorous or nitrogen, that fuels abnormally high organic growth in aquatic ecosystems
geologic control	A local rock formation or clay layer that limits the vertical or lateral movement of a stream at a particular point.
discharge	In the simplest form, discharge means outflow of water
clay	Particle whose diameter is in the range of 0.00024 to 0.004 mm.
flow hazard	Flow characteristics (discharge, stage, velocity, or duration) that are associated with a hydraulic problem or that can reasonably be considered of sufficient magnitude to cause a hydraulic problem or to test the effectiveness of a countermeasure.
completion	sealing off access of undesireable water to the well bore by proper casing and/or cementing procedures.
wave length	The least distance between particles moving in the same phase of oscillation of a wave
confluence	where two or more bodies of water meet
sky	The vault-like apparent surface against which all aerial objects are seen from the earth.
reach	in general, a length of stream with relatively homogenous characteristics.
tundra	A tundra is a cold, treeless area; it is the coldest biome.
caving	Collapse of a bank caused by undermining due to the action of flowing water.
ecology	The study of interrelationships of living organisms to one another and to their surroundings.
gaging station	A particular site in a stream, lake, reservoir, etc., where hydrologic data are obtained.
snow crust	The crisp, almost icy, surface on fallen snow, usually formed by the slight melting and refreezing of the surface snow.
dew point	The temperature to which air must be cooled at a constant pressure to become saturated.
irrigation water	water which is applied to assist crops in areas or during times where rainfall is inadequate.
variable ceiling	Occurs when the height of a ceiling layer increases and decreases rapidly, The ascribed height is the average of all the varying values.
adsorption	the adhesion of a substance to the surface of a solid or liquid
pentachorophenol	toxic substance usually used as a wood preservative.
heavy water	water in which all the hydrogen atoms have been replaced by deuterium.
annual flood	Maximum flow in 1 year (may be daily or instantaneous).
toxicity	The quantity or degree to which a substance is poisonous or harmful to plant, animal or human health.
finite element	a method of solving the governing equations of a numerical model by dividing the spatial domain into elements in each of which the solution of the governing equations is approximated by a continuous function.
fresh water	water containing less than 1,000 parts per million (ppm) of dissolved solids of any type
wet bulb thermometer	A thermometer used to measure the lowest temperature in the ambient atmosphere in its natural state by evaporating water from a wet muslin-covered bulb of a thermometer
phreatophytes	plants that send their roots into or below the capillary zone to use ground water.
pile dike	Type of permeable structure for the protection of banks against caving; consists of a cluster of piles driven into the stream, braced and lashed together.
confined aquifer	A water-bearing subsurface stratum that is bounded above and below by formations of impermeable soil or rock.
sampling	Sampling creeks and lakes to assess ecological condition involves visiting a site to count and identify macroinvertebrate species, observe the presence and extent of all major plant types, measure water clarity, assess sediment condition, and collect water samples for water quality assessment in a laboratory.
flood routing	The process of determining progressively the flood elevation (or flood "wave") at successive points along a stream.
leaf area index	A measure of the total area of leaves, twigs, stems, etc
flood plain	the area often affected by a flood
humus	decayed organic matter in or on the soil
lifts	Layers of loose soil
pretreatment	processes used to reduce, eliminate, or alter the nature of wastewater pollutants from non-domestic sources before they are discharged into publicly owned treatment works (POTWs).
effluent	any substance, particularly a liquid, that enters the environment from a point source
endemism	the characteristic of being confined to or indigenous in, a certain area or region.
coagulation	in water treatment, the use of chemicals to make suspended solids gather or group together into small flocs.
whole-effluent toxicity	the aggregate toxic effect of an effluent measured directly by a toxicity test.
heat stroke	Introduced to the body by overexposure to high temperatures, particularly when accompanied by high humidity
alluvium	sediments deposited by erosional processes, usually by streams.
deflation	A process whereby finer silts and clays are removed by the action of wind over geological time.
water pollution	Generally, the presence in water of enough harmful or objectionable material to damage the water quality.
phytoplankton	Plant plankton.
routing parameters	coefficients 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.
tropics/tropical	The 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
plateau	A plateau is a large, flat area of land that is higher than the surrounding land.
disproportionation	refers to the transformation of a substance into two or more dissimilar substances usually by simultaneous oxidation and reduction i.e
hard water	Water high in multivalent cations, such as calcium and magnesium
acidic	the condition of water or soil that contains a sufficient amount of acid substances to lower the pH below 7.0.
concentration	amount of a chemical or pollutant in a particular volume or weight of air, water, soil, or other medium.
planned environmental water	Planned environmental water to encompass ‘rules based' environmental water, that is, planned environmental water may be delivered through flow rules which specify flows that must be released from storages for environmental purposes. It may also be delivered or retained through restrictions upon the taking of water. Planned environmental water may replicate natural flow patterns taking into account the timing, frequency and variability of flows. Planned environmental water may seek to achieve specific environmental outcomes such as maintaining the success of bird breeding events in specific wetlands, or may be aimed at maintaining general river health through passing flows or end-of-system flow targets.
objectives	Specific statements about what a project intends to achieve.
gabion	Basket or compartmented rectangular container made of wire mesh
gabions	Rock-filled wire baskets (generally square) that are stacked together to reinforce an eroding stream bank.
ice	The solid form of water
backwater curve	Longitudinal profile of the water surface in a stream where the water surface is raised above its normal level by a natural or artificial obstruction.
pool	A deep, usually wide, section of stream with slow currents at low flow
secchi disc	A circular plate, generally about 10-12 inches (25.4-30.5 cm) in diameter, used to measure the transparency or clarity of water by noting the greatest depth at which it can be visually detected
carrying capacity	number of organisms a habitat can support throughout a year without damaging organisms or habitat
cascade	A short, steep drop in streambed elevation often marked by boulders and agitated white water.
aquaduct	A pipe or conduit made for bringing water from a source.
jack field	Rows of jacks tied together with cables, some rows generally parallel with the banks and some perpendicular thereto or at an angle
suspended load	specific sediment particles maintained in the water column by turbulence and carried with the flow of water.
aspirator	is a device that produces vacuum by means of the Venturi effect
autochthonoous material	Organic material produced in the stream usually through primary production.
riverine habitat	The aquatic habitat within streams and rivers.
barrier net	A net system that is placed across a river, stream or channel to block the passage of fish from dam turbine intakes or other hazards without blocking the water flow.
irrigation diversion	Generally, a ditch or channel that deflects water from a stream channel for irrigation purposes.
algae	simple plants, mostly microscopic without roots and leaves.
sediment	The organic material that is transported and deposited by wind and water.
deposition	A river lays down or drops the sediment or material that it is carrying such as sand, mud, and small stones or sticks
altitude	How high a place is above sea level.
filter blanket	Layer of graded sand and gravel laid between fine‑grained material and riprap to serve as a filter.
catchment	Another term for Watershed commonly used in Canada and Europe.
microhabitat	zones of similar physical characteristics within a mesohabitat unit, differentiated by aspects such as substrate type, water velocity, and water depth.
bathymetric	related to the measurement of water depth within a water body.
water availability model	a numerical surface water flow model used to determine the availability of surface water for water right permitting.
biota	the plant (flora) and animal life (fauna) of a region or ecosystem.
humboldt current	Also known as the Peru Current, this ocean current flows northward along the western side of South America, offshore Chile and Peru
downgradient	the direction that groundwater flows; similar to "downstream" for surface water.
organism abundance and condition	that portion of an Index of Biotic Integrity that is a metric measuring species abundance and condition, including proportion of individuals as hybrids and proportion of individuals with disease, tumors, physical damage, or physical anomalies.
bellot winds	Refers 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.
bright band	A narrow, intense radar echo due to water-covered ice particles at the melting level where reflectivity is at its greatest.
erosion	The wearing down or washing away of the soil and land surface by the action of water, wind, or ice.
acre-foot	A quantity or volume of water covering 1 acre to a depth of 1 ft; equal to 43,560 ft3 or 325, 851 gal.
acid rain	rainwater carrying acidic atmospheric pollutants (nitrous or sulfuric oxides)
scattered	The amount of sky cover for a cloud layer between 3/8ths and 4/8ths, based on the summation layer amount for that layer.
repeatability	The ability of an instrument to reproduce the same output reading when the same input value is applied to it consecutively (measuring the same temperature)
fork	the place where two rivers meet
acre-foot	The volume of water that will cover one acre to a depth of 1 foot.
pile	Elongated member, usually made of timber, concrete, or steel, that serves as a structural component of a river‑training structure.
constriction	Natural or artificial control section, such as a bridge crossing, channel reach or dam, with limited flow capacity in which the upstream water surface elevation is related to discharge.
groundwater reservoir	an aquifer or aquifer system in which ground water is stored
flashy stream	Stream characterized by rapidly rising and falling stages, as indicated by a sharply peaked hydrograph
dissolved organic compounds	Carbon substances dissolved in water.
permafrost	Perennially frozen layer in the soil, found in alpine, arctic, and antarctic regions.
peak flow	the maximum volume of water that is carried in the river over a certain period of time, expressed in cubic feet per second (cfs)
monitoring	The collection of data by various methods for the purpose of understanding natural systems and features, evaluating the impacts of development proposals on such systems, and assessing the performance of mitigation measures.
interfacial tension	the strength of the film separating two immiscible fluids (e.g., oil and water) measured in dynes per, or millidynes per, centimeter.
functional feeding groups	classification of aquatic invertebrates by their feeding method
hydroelectric plant	electric power plant in which the energy of falling water is used to spin a turbine generator to produce electricity.
seeding	is a technique to initiate crystallization from saturated or super-saturated solutions
flow regime	the pattern of flow in a river which can be described in terms of the quantity and variability of water flows.
oxbow lake	An oxbow lake is a stagnant lake that is formed alongside a winding river when the river changes path because of soil erosion, leaving an abandoned stream channel, cut off from the rest of the river.
acid	donate an unshared pair of electrons to an acid or react with an acid to form a salt, a substance that has fewer free hydrogen ions, H+, than hydroxyl ions, OH-, (see alkaline).
enrichment	the addition of nutrients such as nitrogen and phosphorous from wastewater effluent or agricultural runoff to surface water
filtration	the mechanical process which removes particulate matter by separating water from solid material, usually by passing it through sand.
sediment load	the amount of sediment carried by a stream
mixed liquor	a mixture of activated sludge and water containing organic matter undergoing treatment in an aeration tank.
abatement	Reducing the degree or intensity of, or eliminating, pollution.
riffle	Moderately swift water with ripples and small rolling waves caused by the slight increase in the steepness of, or an obstruction in, a stream bed.
climate	generalized weather at a given place on earth over a fairly long period; a long term average of weather
lindane	a pesticide that causes adverse health effects when present in domestic water supplies and is toxic to freshwater fish and aquatic life.
thermometer	An instrument used for measuring temperature
greenway	A strip of undeveloped land near an urban area, set aside for recreational use or environmental protection.
solar eclipse	An 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
diablo winds	Dry winds in the Diablo mountain range in central California that can exceed 60 miles per hour
siltation	the deposition of soil particles moved by the river caused by an obstruction to the river's flow or lower flow velocity.
gray water	Wastewater from a household or small commercial establishment that specifically excludes water from a toilet, kitchen sink, dishwater, or water used for washing diapers.
impaired water body	a 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.
trajectory	The curve that a body, such as a celestial object, describes in space
choking	Excessive constriction of flow which may cause severe backwater effect.
cold wave	A rapid fall in temperature within twenty-four hours to temperatures requiring substantially increased protection to agriculture, industry, commerce, and social activities
recharge	The process by which rain, snowmelt or surface water infiltrates and replenishes ground water reserves.
flood forecasting	Prediction 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.
saturated zone	the area below the water table where all open spaces are filled with water under pressure equal to or greater than that of the atmosphere.
cut-off low	A closed cold core low completely removed from the primary westerly flow
thermocouple	The sensor of a thermoelectric thermometer, consisting of electrically conducting circuit elements of two different thermoelectric characteristics joined at a junction.
hydrologic balance	an accounting of all water inflow to, water outflow from, and changes in water storage within a hydrologic unit over a specified period of time.
alkaline	substance with pH greater than 7.0; alkalinity is caused by high concentrations of hydroxyl ions; basic
jack	Device for flow control and protection of banks against lateral erosion consisting of three mutually perpendicular arms rigidly fixed at the center
ice fog	Fog that is composed of minute ice particles
drop	A single vertical, or very near vertical, fall of water
in-situ flushing	introduction of large volumes of water, at times supplemented with cleaning compounds, into soil, waste, or groundwater to flush hazardous contaminants from a site.
evapotranspiration	The combination of water that is evaporated and transpired by plants as a part of their metabolic processes.
leave strips	Generally narrow bands of forest trees that are left along streams and rivers to buffer aquatic habitats from upslope forest management activities.
angler-day	The time spent fishing for any part of a day by one person.
hydrologic cycle	The constant circulation of water from the sea to the atmosphere, to the land and back to the sea by surface, underground and atmospheric pathways.
clarity	The observed clearness of the water.
macroinvertebrate	Invertebrates visible to the naked eye, such as insect larvae and crayfish.
debris flow	A rapid moving mass of rock fragments, soil, and mud, with more that half of the particles being larger that sand size.
drought refuges	Drought refuges are places that sustain life during the dry seasons, particularly in ephemeral streams.
continent	A large land mass rising abruptly from the deep ocean floor, including marginal regions that are shallowly submerged
dry well	A portable calibration furnace that uses narrow metal enclosures rather than liquid to generate uniformity at thermal contact for pre-set temperatures.
overflow rate	one of the guidelines for design of the settling tanks and clarifiers in a treatment plant.
blowing dust	Dust that is raised by the wind to heights of six feet or greater
sloughing	Movement of a mass of soil down a bank into the channel (also called slumping)
bed load	Sediment that is transported in a stream by rolling, sliding, or skipping along the bed or very close to it; considered to be within the bed layer (contact load).
reference site/reach	A minimally impaired site that is representative of the expected or desired ecological conditions and integrity of other sites in the region.
bed form	Recognizable relief feature on the bed of a channel, such as a ripple, dune, plane bed, antidune, or bar
macroinvertebrates	Stream-dwelling arthropods (insects, crustaceans) without a backbone that can be viewed without magnification
coliform bacteria	A group of bacteria used as an indicator of sanitary quality in water
spring	The point at which a stream emerges from an underground course through unconsolidated sediments or through caves
overbank	Water flow over the top of bank.
interstate water	according 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.
attenuation	the process whereby the magnitude of a flood event is reduced by slowing, modifying, or diverting the flow of water.
shredders	aquatic invertebrates that feed on leaves or twigs that fall into a stream
sea breeze	A diurnal coastal breeze that blows onshore, from the sea to the land
colonially nesting	Colonial birds nest in the same place at the same time, and coloniality has been a successful evolutionary strategy for many bird species.
micro-organism	any organism not visible to the naked eye, for example, bacteria.
stationary phase	is a term used in chromatography
flow	the rate of water discharged from a source expressed in volume with respect to time.
habitat diversity	The number of different types of habitat within a given area.
hi/low alarm	A feature common to thermometers that will alert you via visual and/or audible cues (or, in some cases, email or texts) when a measurement is outside user-specified limits for safety or desirability
benthic invertebrates	Aquatic animals without backbones that dwell on or in the bottom sediments of fresh or salt water
supercritical flow	flow characterized by high velocity and a Froude number greater than 1
stream	river 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.
bog	a type of wetland that accumulates appreciable peat deposits
watershed restoration	Improving current conditions of watersheds to restore degraded habitat and provide long-term protection to aquatic and riparian resources.
bar screen	in wastewater treatment, a device used to remove large solids from the incoming wastewater stream.
swale	Small depressions, natural or artificial, that carry water only after a rainfall.
pascal's law	When an external pressure is applied to any confined fluid at rest, the pressure is increased at every point in the fluid by the amount of external pressure applied
conduit	a natural or artificial channel through which fluids may be conveyed.
ceilometer	An instrument that is used to measure the angular elevation of a projected light on the base of a cloud
discharge	Volume of water flowing past a given point in a stream per unit time, typically reported in cubic feet per second.
time zone	An area using the same standard of time.
condensation point	is the temperature at which the conversion of a substance from the vapor state to a denser liquid or solid state takes place usually initiated by a reduction in temperature of the vapor
jetteau	a jet of water.
environmental impact statement	A formal document to be filed with the Environmental Protection Agency that considers significant environmental impacts expected from implementation of a major federal action.
sedimentation	a large scale water treatment process where heavy solids settle out to the bottom of the treatment tank after flocculation.
bank-full channel width	The top surface width of a stream channel when flowing at a bank-full discharge.
heat wave	A period of abnormally and uncomfortably hot weather
river	a natural stream of water of considerable volume.
manning's "n"	Manning's n-value is a coefficient used to describe boundary roughness of a channel or pipe
ocean	such as a bay, mouth of a river, salt marsh or lagoon, deepwater tidal habitat and tidal wetland, they are usually partially enclosed by land but have free access to the ocean and are at least occasionally diluted by fresh water runoff from the land.
topography	Surface height, in this case refers to land surface height or relief.
snow	Frozen precipitation in the form of white or translucent ice crystals in complex branched hexagonal form
pressures	Aquatic ecosystem condition reports include the pressures (ie issues that cause potential decline in ecosystem condition)
river continuum	a conceptual model explaining changes in composition of aquatic invertebrate communities in streams and rivers
indian summer	A period of abnormally warm weather in mid to late autumn with clear skies and cool nights
ecklonia radiata	Is commonly known as kelp and is an example of robust brown algae.
point bar	The convex side of a meander bend that is built up due to sediment deposition.
break	A horizontal interruption in the drop of a waterfall.
saturated solution	is a solution that contains the maximum amount of solute at a given temperature.
conservation	The continuing protection and management of natural resources in accordance with principles that assure their optimum long-term economic and social benefits.
control point	The temperature at which a system is to be maintained.
evapotranspiration	The total amount of water that is transferred from the earth's surface to the atmosphere
aquifer	an underground layer of soil, rock or gravel able to hold and transmit water.
hygroscopic	is a compound that absorbs water from the air or a solution, nature of drying agents
spawning	laying and fertilizing eggs spawning habitat: parts of a stream or lake that provide suitable areas for fish to spawn; usually gravel beds
washing	is a process to remove small amounts of byproducts or a catalyst from a reaction mixture.
lake	An inland body of standing water deeper than a pond, an expanded part of a river, a reservoir behind a dam.
gully reclamation	use of small dams of manure and straw; earth, stone,or concrete to collect silt and gradually fill in channels of eroded soil.
resilience	Resilience is defined as "the capacity of an ecosystem to tolerate disturbance without collapsing into a different state that is controlled by a different set of processes
ecosystem	An interdependent biological system involving interaction between living organisms and their immediate physical, chemical and biological environment.
vernal equinox	Taking place in the Northern Hemispheric spring, it is the point at which the ecliptic intersects the celestial equator
environmental indicator	a measurement, statistic or value that provides evidence of the effects of environmental management programs or of the state or condition of the environment.
groundwater prime supply	Long-term average annual percolation into major groundwater basins from percolation into major groundwater basins from precipitation falling on the land and from flows in rivers and streams.
dew	Condensation 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.
thermometer	An instrument used to measure temperature.
biomonitoring	a test used to evaluate the relative potency of a chemical by comparing its effect on a living organism with the effect of a standard population on the same type of organism.
centigrade	A temperature scale based on 100 degrees of difference between the freezing and boiling points of water
foodweb	a model structure used to represent the links between organisms within an environment, based upon the order in which various organisms consume one another.
mud	A soft, saturated mixture mainly of silt and clay.
profundal zone	a lake's deep-water region that is not penetrated by sunlight.
solute	any substance derived from the atmosphere, vegetation, soil, or rock that is dissolved in water.
wetted perimeter	The line on which the stream's surface meets the channel walls.
rain gage	any instrument used for recording and measuring time, distribution, and the amount of rainfall.
rain	water drops which fall to the earth from the air.
bonn convention	The Bonn Convention was established to protect those species of wild animals that migrate across or outside national boundaries
secondary treatment	second 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
river channels	Large natural or artificial open streams that continuously or periodically contain moving water, or which form a connection between two bodies of water.
bridge scour	Excessive erosion of the stream banks and bottom below a bridge as a result of the concentration and direction of streamflow.
stable channel	A stream channel with the right balance of slope, planform, and cross section to transport both the water and sediment load without net long-term bed or bank sediment deposition or erosion throughout the stream segment.
aggradation	General and progressive buildup of the longitudinal profile of a channel bed due to sediment deposition.
temperature	Measure of how hot or cold it is in an area.
ptc	=Phase Transfer Catalysis, utilizes a catalyst which is able to transport an ion from one phase (usually aqueous) into the other phase (organic).
jetter	one (as a geyser) that sends out a jet.
wedge	Primarily refers to an elongated area of shallow high pressure at the earth's surface
temperate climate	Climates with distinct winter and summer seasons, typical of regions found between the Tropics of Cancer and Capricorn and the Arctic and Antarctic Circles
reynold's number	Dimensionless ratio of inertial force to viscous force used to describe the characteristics of fluid flow in a channel or pipe
grout	Fluid mixture of cement and water or of cement, sand, and water used to fill joints and voids.
evaporation	The process by which a liquid changes to a vapour.
sea level pressure	The atmospheric pressure at mean sea level, usually determined from the observed station pressure.
free ground water	water in interconnected pore spaces in the zone of saturation down to the first impervious barrier, moving under the control of the water table slope.
hydrologic unit	A distinct watershed or river basin defined by an 8-digit code.
undercast	In aviation, it is an opaque cloud layer viewed from an observation point above the layer
channel diversion	Removal of flows by natural or artificial means from a natural length of channel.
carbon exchange	The process by which carbon is exchanged between the biosphere, geo-sphere, hydrosphere and atmosphere of some habitable body.
methylene chloride	=dichloromethane
slope	The ratio of the change in elevation over distance.
riparian habitat	The aquatic and terrestrial habitat adjacent to streams, lakes, estuaries, or other waterways.
gallon	A unit of volume
cascade	A short, steep drop in stream bed elevation often marked by boulders and agitated white water.
flow augmentation	Increased flow from release of water from storage dams.
blizzard	A severe weather condition characterized by low temperatures, winds 35 mph or greater, and sufficient falling and/or blowing snow in the air to frequently reduce visibility to 1/4 mile or less for a duration of at least 3 hours
cross-contamination	a 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
hydrograph	The graph of stage or discharge against time.
water demand schedule	A time distribution of the demand for prescribed quantities of water for specified purposes
cold vapor	method to test water for the presence of mercury.
hail	Precipitation that originates in convective clouds, such as cumulonimbus, in the form of balls or irregular pieces of ice, which comes in different shapes and sizes
flood	The temporary inundation of normally dry land areas resulting from the overflowing of the natural or artificial confines of the stream channel.
isohyet	line that connects points of equal rainfall.
easterlies	Usually applied to the broad patterns of persistent winds with an easterly component, such as the easterly trade winds.
murray-darling basin commission	The executive arm of the Murray-Darling Basin Ministerial Council
phytoplankton	Minute 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.
hydraulic radius	The cross-sectional area of a stream divided by the wetted perimeter.
waterfall	a sudden, nearly vertical drop in a stream, as it flows over rock.
dense fog advisory	Advisory issued when fog reduces visibility to 1/8 mile or less, creating possible hazardous conditions.
euphotic zone	surface layer of an ocean, lake, or other body of water through which light can penetrate
table	water beneath the surface of the ground, consisting largely of surface water that has seeped down, water beneath the earth's surface, occurring in aquifers at one or more depth levels, (see surface water).
prt	An acronym for Platinum Resistance Thermometer
food chain	A sequence of organisms, each of which uses the next, lower member of the sequence as a food source.
tributary	A river or stream flowing into a larger stream
tropical depression	A tropical cyclone in which the maximum sustained surface winds are 38 miles per hour (33 knots) or less
greenhouse effect	The 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.
absolute zero	Considered to be the point at which theoretically no molecular activity exists or the temperature at which the volume of a perfect gas vanishes
flow regime	The spatial and temporal patterns of flow in a river.
nutrients	nitrates and phosphates, usually resulting in an increase in biomass and productivity, (see oligotrophic).
delta	A delta is a low, watery land formed at the mouth of a river
stratigraphy	The arrangement of strata or geologic layers
hardwood bottomland	hardwood forested lowlands adjacent to some rivers, especially valuable for wildlife breeding, nesting, and habitat.
isobar	The line drawn on a weather map connecting points of equal barometric pressure.
flush	to open a cold-water tap to clear out all the water which may have been sitting for a long time in the pipes; to force large amounts of water through a system to clean out piping or tubing and storage or process tanks.
index of biotic integrity	a multi-metric measure of biological condition developed from collection of data for fish or other organisms
activated carbon adsorption	the process of pollutants moving out of water and attaching on to activated carbon.
fingerling	small fish under one year of age
vadose zone	the zone between land surface and the water table where the moisture content is less than saturation (except in the capillary fringe) and pressure is less than atmospheric
substrate	inorganic material that forms the streambed
baroclinity	The state of stratification in a fluid in which surfaces of constant pressure intersect surfaces of constant density
delta	an alluvial deposit made of rock particles (sediment, and debris) dropped by a stream as it enters a body of water.
bed slope	The inclination of the channel bottom, measured as the elevation drop per unit length of channel.
external cost	cost of production or consumption that must be borne by society; not by the producer.
conservation recommendations	Suggestions by conservation agencies regarding discretionary measures to minimize or avoid adverse effects on a proposed action of federally listed threatened or endangered species or designated critical habitat.
multicell storm	A thunderstorm made up of two or more single-cell storms.
plankton	microscopic floating plant and animal organisms of lakes, rivers, and oceans.
graded stream	Geomorphic term used for streams that have apparently achieved a state of equilibrium between the rate of sediment transport and the rate of sediment supply throughout long reaches.
watershed	Area that drains to a common outlet
salinity intrusion	The movement of saltwater into a body of freshwater
plankton	microscopic plants and animals suspended in the water
pascal	The unit of pressure produced when one newton acts on about one square meter.
river channels	The trenches in which rivers flow for most of the year.
seed bank	Ground or soil where multiple seeds from plant species are stored until germination.
anistropic aquifer	an aquifer in which permeability varies with direction of flow
snow garland	Snow appearing as a beautiful long thick rope draped on trees, fences and other objects
condensation	the change of state from a gas to a liquid
surface supply	Water supply from streams, lakes, and reservoirs.
littoral zone	area on or near the shore of a body of water.
earthlight	The 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.
biosphere	The transition zone between the earth and the atmosphere within which most terrestrial life forms are found
permeability	the ability of a water bearing material to transmit water
quicksilver water	a solution of mercury nitrate used in gilding.
wetted perimeter	The boundary of wetted contact between a stream of flowing water and its containing channel at a given discharge, measured in a direction perpendicular to the flow.
phreatic zone	the area in an aquifer in which relatively all pores and fractures are saturated with water
longitudinal profile	A graphic presentation of elevation vs
absolute humidity	A type of humidity that considers the mass of water vapor present per unit volume of space
lateral erosion	Erosion in which the removal of material is extended horizontally as contrasted with degradation and scour in a vertical direction.
erosion	The wearing away, in this case by water and rocks constantly rubbing
cut-off high	A warm high which has become displaced and is on the polarward side of the jet stream
tributary	a river of creek that flows into a larger river.
nutrient enrichment	A term that describes the addition of too much nutrient (nitrogen, phosphorus and carbon), to waterbodies from human actions and the resulting responses that typically leads to changes in plant and animal communities and degradation of water and sediment quality.
mesoscale	The scale of meteorological phenomena that range in size from several kilometers to around 100 kilometers
atropisomer	is a stereoisomer that results from hindered rotation about a single bond where the steric strain barrier to rotate is high enough to isolate the different conformers.
brackish	Beackish water is water that is saltier than river water but less salty than sea water.
frontolysis	The destruction or dying of a front where the transition zone is losing its contrasting properties
hail	a form of precipitation which forms into balls or lumps of ice over 0.2 inch in diameter
detention	Water management practice or system that delays the downstream progress of stormwater by the use of temporary storage or metered outlets.
hydraulic radius	Corss-sectional area divided by the wetted perimeter.
controller	A device that regulates the power supply to a heater or bath to bring it up to a specified temperature.
organometallic	the compound has at least one metal-carbon bond i.e
unconfined aquifer	an aquifer containing water that is not under pressure; the water level in a well is the same as the water table outside the well
mesic	Moderately wet.
cover	vegetation or other features that provide shelter for wildlife
organic carbon	Refers to carbon that is bound to organic compounds, usually described as the amount of decaying natural organic matter in a water sample.
sanitary sewers	underground pipes that carry off only domestic or industrial waste, not storm water.
ip rating	A measure of an instrument's protection against the ingress of dust, water and other substances into the equipment
recruitment	survival of young plants and animals from birth to a life stage less vulnerable to environmental change.
thermodynamics	Study 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.
tributary	small, permanent stream emptying into the main stem of the river.
glacier	a huge mass of land ice that consists of recrystallized snow and moves slowly downslope or outward.
constant pressure surface	A surface along which the atmospheric pressure is equal everywhere.
marsh	an area periodically inundated and treeless and often characterized by grasses, cattails, and other monocotyledons
hydrogeology	the geology of groundwater, with particular emphasis on the chemistry and movement of water.
significant ecological asset	Relating to the six significant ecological assets: Barmah-Millewa Forest, Gunbower and Koondrook-Perricoota forests, Hattah Lakes, Chowilla Floodplain, Murray Mouth and Corrong and Lower Lakes and the River Murray Channel.
barrier	A physical block or impediment to the movement or migration of fish, such as a waterfall (natural barrier) or a dam (man-made barrier).
pool/riffle ratio	The 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
pavement	Streambank surface covering, usually impermeable, designed to serve as protection against erosion
national estuary program	a 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.
prehistoric	before people were around to keep records of history
infrared spectroscopy	is a spectroscopic technique to identify functional groups, looks at vibrational modes of the molecule
landscape impoundment	body of reclaimed water which is used for aesthetic enjoyment or which otherwise serves a function not intended to include contact recreation.
imperiled species	declining, rare, or uncommon species; species federally listed as threatened or endangered, or candidates for such; and species with limited distributions.
urban runoff	Storm water from city streets and gutters that usually carries a great deal of litter and organic and bacterial wastes into the sewer systems and receiving waters.
siltation	The deposition or accumulation of fine soil particles.
channel	An area that contains continuously or periodically flowing water that is confined by banks and a stream bed.
biodiversity	biological diversity or the variety of life forms, comprising genetic diversity (within species), species diversity and ecosystems diversity.
mobile phase	is a term used in chromatography
meander	Bend or curve in a stream channel.
coliform bacteria	that are not in themselves harmful but whose presence is indicative of possible pollution or the presence of other more harmful microorganisms which, through its population size or condition, mirrors environmental conditions within an ecosystem.
environmental impact	the positive or negative effect of any action upon a given area or source.
flood-frequency curve	Graph indicating the probability that the annual flood discharge will exceed a given magnitude, or the recurrence interval corresponding to a given magnitude.
solute	chemical or pollutant in a specified volume or weight of solvent, air, water, soil or other medium, accumulating a level of some material over and above the level found in the ambient environment, generally applied to an organism.
helical flow	Three‑dimensional movement of water particles along a spiral path in the general direction of flow
effective porosity	the portion of pore space in saturated permeable material where the movement of water takes place.
coromell	The 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.
aquifer	A body of rock that is sufficiently permeable to conduct groundwater and to yield economically significant quantities of water to wells and springs.
water yield	The quantity of water derived from a unit area of watershed.
interceptor sewer	very large sewer lines that collect the flow from main and trunk lines and carry them to treatment plants.
peninsula	A peninsula is a body of land that is surrounded by water on three sides.
wellfield	area containing one or more wells that produce usable amounts of water or oil.
nutrient depletion	Detrimental changes on a site in the total amount of nutrients and/or their rates of input, uptake, release, movement, transformation, or export.
safe yield	the 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."
depth	How deep the water is.
grass/forb	Herbaceous vegetation.
daily discharge	Discharge averaged over 1 day (24 hours).
community water system	In Texas, a public water system which has a potential to serve at least 15 residential service connections on a year-round basis or serves at least 25 residents on a year-round basis.
predator	an animal that hunts and kills other animals for food
tropical storm	A tropical cyclone in which the maximum sustained surface winds are from 39 miles per hour (34 knots) to 73 miles per hour (63 knots)
bank	The ground at the side of a river
reserves	amount of a particular resource in known locations that can be extracted at a profit with present technology and prices.
big water	To avoid reducing channel capacity, the San Antonio River Improvements Project plan calls for these wider stretches of water to be excavated just upstream of a grade control structure where the overall main channel can be widened
geohydrology	a term which denotes the branch of hydrology relating to subsurface or subterranean waters; that is, to all waters below the surface.
bed load	Sediment that moves near the streambed.
cfu	colony forming units. Concentrations of water quality indicator organisms such as fecal coliform bacteria are measured in cfu/100 ml.
kilowatt hour	One kilowatt of power applied for one hour.
stream power	Measure of energy available to move sediment, or any other particle in a stream channel
coliform	A group of bacteria found in the intestines of warm-blooded animals (including humans), also in plants, soil, air, and water
turbid	thick or opaque with matter in suspension
sand filters	devices that remove suspended solids from a wastewater treatment plant effluent or water treatment plant product.
channel	a natural or artificial watercourse that continuously or intermittently contains water, with definite bed and banks that confine all but overbanking streamflows.
jet streak	A region of accelerated wind speed along the axis of a jet stream.
meander	the twisting and turning of a river's flow
dissolved oxygen	oxygen dissolved in water; the amount depends on water temperature, plant photosynthesis, plant and animal respiration, and physical aeration
regulated	a river or creek where water is released from storage to meet diversions requirements downstream, or to reduce flooding.
meander or full meander	Meander in a river consists of two consecutive loops, one flowing clockwise and the other counter‑clockwise.
recreational rivers	Rivers 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.
upstream	Opposite to the currents flow - towards the source of the river
cyclogenesis	The process that creates a new low pressure system or cyclone, or intensifies a pre-existing one
channel forming flow	See Dominant Discharge
flashiness	a measure of a river or stream's tendency to carry a high percentage of its flow volume in large, infrequent events rather than more moderate flows that occur frequently.
water cycle	the process of water moving from a lake or ocean to the clouds and back to the earth again
hydraulic roughness	an estimate of the resistance to flow due to energy loss caused by friction between the channel and the water
reach	A section of stream between two defined points.
impairment	Impact that damages the biological integrity of a water body such that attainment of the designated use is prevented.
sedimentation	Deposition of sediment.
riparian	Related to the banks or floodplain area of a natural watercourse.
environmental flows	flows, or characteristics of the flow pattern, that are either protected or created to benefit the natural environment.
pollution	The alteration of the physical, chemical, or biological properties of water by the introduction of any substance into water that adversely affects any beneficial use of water.
gaging station	A particular point on a stream of known cross-section where systematic observations of water depth or discharge are obtained.
kcfs	A measurement of water flow equivalent to 1,000 cubic feet of water passing a given point for an entire second.
long wave trough	A wave in the prevailing westerly flow aloft which is characterized by a large length and amplitude
buoyancy	the tendency of a body to float or rise when immersed in a fluid; the power of a fluid to exert an upward force on a body placed in it.
commence to flow	Volume at which flow spills into a channel or wetland
validation	comparison of computer model results with a set of data that were not used for calibration.
eddy	A circular current or a current of water running contrary to the main current, usually resulting from an obstruction.
blowing spray	Salt spray that is raised by the wind to heights of six feet or greater
natural flow	the rate of water movement past a specified point on a natural stream
epiphyte	A non-parasitic plant that grows upon another plant.
bed material	The sediment mixture of which a streambed, lake, pond, reservoir, or estuary bottom is composed.
ripple	(1) A specific undulated bed form found in sand bed streams
odonates	Insect groups such as dragonflies and damselflies.
check dam	A structure placed bank-to-bank downhill from a headcut on a hillslope to help revegetate a gully.
data logger	An electronic device that records temperature data at a specific location at regular intervals over time with either a built-in sensor or through external sensors or probes
indicator tests	tests for a specific contaminant, group of contaminants, or constituent which signals the presence of something else (ex., coliforms indicate the presence of pathogenic bacteria).
ansi	An acronym for American National Standards Institute
texture	Refers to relative proportions of clay, silt, and sand in soil.
capillary action	movement of water through very small spaces due to molecular forces called capillary forces.
mouth	The end of the river
staphylococcus	A microscopic bacteria common to skin and mucous membranes
climate change	The slow variations of climatic characteristics over time at a given place.
supply	a schedule that shows the various quantities of things offered for sale at various prices at a point in time
derecho	A line of intense, widespread, and fast-moving thunderstorms that moves across a great distance
interstices	the void or empty portion of rock or soil occupied by air or water.
teleconnections	Information used by forecasters to determine what the weather might be elsewhere when compared with past weather conditions at the same degree of longitude.
biogeochemical cycling	the flow of chemical substances to and from the major environmental reservoirs (atmosphere, hydrosphere, lithosphere, and biosphere).
parts per million	The number of "parts" by weight of a substance per million parts of water
reclaimed water	domestic 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.
heat of vaporization	the amount of heat necessary to convert a liquid (water) into vapor.
indicator parameters	measurable 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.
assimilation	the ability of a water body to purify itself of pollutants.
longitude	Longitude is the angular distance east or west from the north-south line that passes through Greenwich, England, to a particular location
community	All the living organisms present in an ecosystem
infiltration	The downward movement of water through soil or porous rock.
drought	A continuous and lengthy period during which no significant precipitation is recorded.
impervious surface	Surfaces, such as roads, parking lots and roofs, whose properties prevent the infiltration of water and increase the amount of stormwater runoff in a watershed.
point source	Source of pollution from a single, well-defined outlet
stocking	release of fish into the wild
gallons per minute	A unit used to measure water flow.
spring	A place where water naturally seeps or gushes from the ground - often in marsh or bog areas
coniferous	cone-bearing trees with needles
geomorphology	The branch of geology that studies the nature and origin of land forms
ph	An expression of both acidity and alkalinity on a scale of 0 to 14, with 7 representing neutrality; numbers less than 7 indicate increasing acidity and numbers greater than 7 indicate increasing alkalinity.
waterfall	A waterfall is a sudden drop in a river as it flows over a rock cliff
plug flow	type 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.
habitat	the native environment or specific surroundings where a plant or animal naturally grows or lives
drawdown	The process of lowering the water level in a reservoir
pluvial	Of rain, formed by the action of rain, for example a body of water.
clay plug	Cutoff meander bend filled with fine grained cohesive sediments.
water cycle	evapotranspiration, 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
anaerobic sediments	Aquatic sediments that have a high organic matter content
mid-channel bar	Bar lacking permanent vegetal cover that divides the flow in a channel at normal stage.
subsurface drainage	Rainfall that is not evapotranspirated or does not become surface runoff.
native vegetation	Vegetation indigenous to an area and adapted to local conditions.
transpiration	the 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).
deadman	A log, block of concrete, rebar, or other object buried in a stream bank that is used to tie in revetment with cable or chain.
saltwater barrier	A physical facility or method of operation designed to prevent the intrusion of saltwater into a body of freshwater.
precision	See resolution.
extinction	complete disappearance of a species because of failure to adapt to environmental change.
evaporation	conversion of water from liquid to vapour
hazardous materials	Anything that poses a substantive present or potential hazard to human health or the environment when improperly treated, stored, transported, disposed of, or otherwise managed.
artesian zone	a 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.
climate	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.
banks	Banks are the sides of a river or stream between which the water normally flows.
supply augmentation	Alternative water management programs such as conjunctive use, water banking, or water project facility expansion that increase supply.
trituration	commonly refers to the grinding of powders in a pestle or mortar
ephemeral stream	A water course that is usually dry but sporadically contains stream flow, typically during significant rain or snowmelt events.
reach	Refers to a section of a main channel, usually defined between channel bends.
knickpoint	The point on a stream's profile where a sudden change in stream gradient occurs.
adaptive management	Adaptive management is a systematic process for continually improving management policies and practices by learning from the outcomes of operational programs by employing management programs that are designed to experimentally compare selected policies or practices, by evaluating alternative hypotheses about the system being managed.
polychlorinated biphenyls	toxic industrial chemical compound substances that were used in the manufacture of plastics and as insulating fluids in electrical transformers and capacitors
scour	the erosive action of running water in streams, which excavates and carries away material from the bed and banks
plug	cement, grout, or other material used to fill and seal a hole drilled for a water well.
impervious	Allowing little or no water to infiltrate; water tight
tornado alley	A geographic corridor in the United States which stretches north from Texas to Nebraska and Iowa
water-soluble substance	a substance that can readily disperse through the environment.
fresh:salt water interface	the region where fresh water and salt water meet
ecoregion	a geographic area over which the macroclimate is sufficiently uniform to permit development of similar ecosystems on sites with similar geophysical properties.
holocene	Geological time spanning the last 10 000 years.
calm	Atmospheric conditions devoid of wind or any other air motion
sedimentation	The physical process of settling of suspended particulates under the force of gravity (ARMCANZ & ANZECC 2000).
chocolatta north	A West Indian gale that blows from the northwest.
pathogen	microorganisms which can cause disease.
hydrology	The 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.
confluence	A rate at which wind flow comes together along an axis oriented normal to the flow in question
river	A large stream of water that flows along a certain path.
greenbelt	Strip of natural vegetation growing parallel to a stream that provides wildlife habitat and an erosion and flood buffer zone
discharge	The rate at which a volume of water passes through a cross section in a unit of time.
crown	the upper part of a tree or other woody plant that carries the main system of branches and the foliage.
tractive force	The drag on a streambed or bank caused by passing water, which tends to pull soil particles along with the streamflow.
skimming	using a machine to remove oil or scum from the surface of the water.
salt marsh	Saltwater wetlands that occur along many coasts.
secondary treatment	In sewage, the biological process of reducing suspended, colloidal, and dissolved organic matter in effluent from primary treatment systems
water-resistant	A non-technical term used to describe instruments that are protected from the ingress of liquids
operating guidelines	A set of guidelines that includes flood guides, minimum flow requirements, water release requirements, and other requirements to meet system operating objectives.
flood	an overflow or inundation that comes from a river or other body of water and causes or threatens damage
infiltration	the 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.
cfs	Cubic feet per second, typically used as a measure of flow in a stream
perigee	The point nearest the earth on the moon's orbit
siberian high	The semi-permanent high pressure area that forms over Siberia during the winter
segment	a water body or portion of a water body that is individually defined and classified
circulate	to move in a circle, circuit or orbit; to flow without obstruction; to follow a course that returns to the starting point.
hysteresis	A quality of a system such that the output is not only determined by the input but also by the internal state of the system, particularly as it is affected by previous measurements
thermal low	Also known as heat low, it is an area of low pressure due to the high temperatures caused by intensive heating at the surface
tertiary treatment	removal from wastewater of traces or organic chemicals and dissolved solids that remain after primary treatment and secondary treatment.
toxicant	a substance or a mixture of substances within a short period of time, usually 96 hours or less, after exposure
forebay	the water behind a dam.
rill erosion	Removal of soil particles from a bank slope by surface runoff moving through relatively small channels
salinisation	the accumulation of salts in the soil to a level that causes degradation of the soil.
hydrologic cycle	The hydrologic cycle is another name for the water cycle.
meander amplitude	The distance between points of maximum curvature of successive meanders of opposite phase in a direction normal to the general course of the meander belt, measured between centerlines of channels.
consumers	organisms that depend on other organisms for their food
boiling point	is the temperature when a liquid becomes a gas
fissile	Geologic term referring to rock (generally shale) that breaks along parallel planes as it weathers, resulting in thin, plate-like fragments.
gaseous	in a gas-like state; not solid, not liquid - like steam
squall	A 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
macrophytes	Aquatic plants that are large enough to be seen with the naked eye.
hydrologic region	A study area, consisting of one or more planning subareas, that has a common hydrologic character.
discharge	The amount of water flowing in a river per second.
osmosis	the 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.
hydrology	the science dealing with the properties, distribution, and circulation of water.
multi-disciplinary approach	An approach that utilizes the skills, knowledge and experience of professionals from several fields to develop a more holistic understanding and treatment of the components, issues, problems and variables of a project.
polychlorinated biphenyls	A group of chemicals found in industrial wastes.
residue	the dry solids remaining after the evaporation of a sample of water or sludge.
blowing sand	Sand that is raised by the wind to heights of six feet or greater
high flow pulses	the component of an instream flow regime that represents short-duration, in-channel, high flow events following storm events
rock	See cobble.
mountain breeze	A katabatic wind, it is formed at night by the radiational cooling along mountainsides
backwater pool	A pool that formed as a result of an obstruction like a large tree, weir, dam, or boulder.
pump	a device which moves, compresses, or alters the pressure of a fluid, such as water or air, being conveyed through a natural or artificial channel.
blowing snow	Snow that is raised by the wind to heights of six feet or greater
chemosphere	A vaguely defined region of the upper atmosphere in which photochemical reactions take place
tailwater	The part of a river downstream from a dam, where the flow and quality of the water are substantially affected by the dam discharge.
water year	A continuous 12-month period for which hydrologic records are compiled and summarized.