Glossary

A
acre-foot(af) - The volume of water necessary to cover one acre to a depth of one foot. Equal to 43,560 cubic feet or 325,851 gallons or 1,233 cubic meters.
appropriation - The right to use water for a beneficial use or the acquisition of such a right gained through the process of diverting surface water and putting it to a beneficial use. See also prior appropriation, junior appropriator, senior appropriator
aquifer - One or more geologic formations containing sufficient saturated porous and permeable material to transmit water at a rate sufficient to feed a spring or for economic extraction by a well. Combination of two Latin words, aqua or water, and ferre, to bring; literally, something that brings water.
aquatic integrity - The overall condition of a waterbody including chemical, physical and biological components. The integrity condition is generally based on a comparison to a reference which is a relatively undisturbed system and represents the best quality to be expected for the ecoregion.
artificial recharge - The deliberate act of adding water to a groundwater aquifer by means of a recharge project; also, the water so added. Artificial recharge can be accomplished via injection wells, spreading basins, or in-stream projects. See also incidental recharge, natural recharge, recharge.

B
BOD - biochemical oxygen demand - the oxygen required for the biochemical degradation of organic material (carbonaceous) and the oxygen used to oxidize inorganic material such as sulfides and ferrous iron. In other words, a measure that indicates the degree to which dissolved oxygen levels would change in a stream based on the contributions of organic matter.
base flow - Streamflow derived from groundwater seepage into the stream.
basin - a large watershed, often associated with major rivers (for example, the Chattahoochee River basin).
benthic macroinvertebrate - an animal lacking a backbone or internal skeleton which lives on or near the bottom of a body of water (for example, crayfish, mayflies, and nymphs. Because they spend their entire lifecycle in water, they are good indicators of the health of that waterbody.
beneficial use - A use of water, such as domestic, municipal, agricultural, mining, stock watering, recreation, wildlife, or power generation, that provides a benefit. Water rights not put to beneficial use are subject to forfeiture. Historically, very few uses of water have been declared non-beneficial by courts
biological integrity - The condition of the biological components (usually benthic macroinvertebrates and/or fish) of a waterbody. The integrity condition is generally based on a comparison to a reference which is a relatively undisturbed system and represents the best quality to be expected for the ecoregion.
biota - all the flora and fauna of a given area.
biotic - pertaining to life or living organisms.
BMP - (Best Management Practices) activities, prohibitions of practices, maintenance procedures and other management practices to prevent or reduce the pollution of waters of the United States.
buffers - land adjoining and immediately adjacent to a stream that provides protection from or filters unwanted constituents.

C
Clean Water Act - a law enacted by the U.S. Congress in 1972 and enforced by the federal Environmental Protection Agency nationally and the Georgia Environmental Protection Division locally. The Clean Water Act established three main goals: "zero discharge" or the elimination of polluting discharges to the nation's waters by 1985; "fishable and swimable waters" or the restoration and protection of water quality and wildlife habitat; and "no toxics in toxic amounts" or the prohibition of the discharge of toxic pollutants in amounts that are toxic to the environment or life.
condensation - the cooling of water vapor so that it becomes liquid.
conservation - the management of water resources so as to eliminate waste or maximize efficiency of use.
consumptive use - A use that makes water unavailable for other uses, usually by permanently removing it from local surface or groundwater storage as the result of evaporation and/or transpiration. Does not include evaporative losses from bodies of water.

D
discharge - The volume of water (and suspended sediment if surface water) that passes a given location within a given period of time.
diversion - Physical removal of surface water from a channel
drainage basin - A hydrologic unit consisting of a part of the surface of the earth covered by a drainage system consisting of a surface stream or body of impounded surface water plus all tributaries. The runoff in a drainage basin is distinct from that of adjacent areas.

E
EPA - (U.S. Environmental Protection Agency) the federal regulatory agency responsible for oversight of the Clean Water Act and other environmental programs.
EPD - (Georgia Environmental Protection Division of the Department of Natural Resources) the state regulatory agency responsible for water allocation and wastewater permitting; designated by the EPA to enforce the Clean Water Act.
EPT - a group of three orders of insects (Ephemeropter {mayflies}, Plecoptera {stoneflies} and Trichoptera {caddisflies}) generally considered as sensitive to pollution and are used in some cases as primary indicators of stream aquatic integrity.
effluent - Treated wastewater discharged from sewage treatment plants. See tertiary treatment.
ephemeral flow - When water flows in a channel only after precipitation. See also intermittent flow, interrupted flow, perrenial flow
eutrophication - over-enrichment of a water body with nutrients resulting in excessive growth of organisms and depletion of oxygen concentration.
evaporation - the transformation of liquid water to a gas or vapor. This process is accelerated by heat or wind (see hydrologic cycle).
evapotranspiration - the loss of water by evaporation from soil or vegetation.

F
fecal coliform - bacteria that forms in the colon of humans or animals and is transmitted through fecal material. The presence of fecal coliform bacteria in water, while not threatening to human health, is often used to indicate the presence of other harmful pathogens. Sources of fecal coliform bacteria include waste from all warm blooded animals including deer, geese, raccoons, dogs, cattle, chickens, horses, and humans. Nonpoint sources of fecal coliform include wildlife, pasture areas, confined animal production areas and septic systems. Point sources include sewage treatment plant discharges and sewer overflows. and Fecal coliform easily attaches to soil particles, is easily delivered to streams via sediment, becomes re-suspended with sediment during storm events, and can even thrive and proliferate in stream sediments for an unknown period of time. Concentrations of fecal coliform can vary widely in undeveloped and developed watersheds. The screening level for fecal coliform used for the Alcovy study was 4,000 colonies/mL, based on the state standard for Georgia.
Flow rate - rate of water movement. Usually expressed as cfs or m3/s.
free groundwater - Unconfined groundwater whose upper surface is a free water table.

G
gaging station - A site on a stream, lake, reservoir or other body of water where direct systematic observations of hydrologic data are obtained.
gaining stream - A stream reach in which the water table adjacent to the stream is higher than the water surface in the stream, causing groundwater to seep into the stream, increasing its flow. See also losing stream
gpcd - Gallons per capita per day
Grab sample - a water quality sample taken from one particular location in the stream/river at a praticular date and time.
groundwater - water that is stored or flows underground through areas of soil and rock.

H
habitat integrity - the condition of the physical habitat (banks, sediment) of a water body, particularly with respect to its suitability for aquatic life. The integrity condition is generally based on a comparison to a reference which is a relatively undisturbed system and represents the best quality to be expected for the ecoregion.
Hydrograph - graphical or tabular representation of the flow rate of a stream/river with respect to time
hydrologic cycle - the process in which water evaporated from rivers, lakes, and oceans rises and condenses into clouds, and then falls back to earth as rain, hail, sleet or snow.
hydrology - The study of the characteristics and occurence of water, and of the hydrologic cycle

I
impervious surface - a surface which does not allow water or other liquids to pass through. Examples include asphalt, roof-tops and concrete. Impervious surfaces greatly increase the volume and velocity of runoff and, therefore, the amount of pollution and sediment that enters streams or lakes.
incidential recharge - Water incidentally added to a groundwater aquifer due to human activities, such as excess irrigation water applied to fields or water discharged as waste after a use. See also recharge, artificial recharge, natural recharge.
infiltration - the draining or seeping of water into the earth and other entities such as storm water pipes.
intermittent - a stream that flows only periodically throughout the year.
intermittent flow - Surface water flowing only during periods of seasonal runoff. See also ephemeral flow, interrupted flow, perrenial flow.
interrupted flow - Water flowing alternately on the channel surface in some stream stretches and disappearing underground in others. See also ephemeral flow, intermittent flow, perrenial flow

J
junior appropriators - The holder of a surface water right which was acquired subsequent to other water rights on the same stream. See also appropriation, senior appropriator

K

L
laser level - A procedure for levelling an agricultural field to a high degree of precision so as to more uniformly spread water and increase irrigation efficiency
losing stream - A stream reach in which the water table adjacent to the stream is lower than the water surface in the stream, causing infiltration from the stream channel, recharging the groundwater aquifer and decreasing the stream flow. See also gaining stream.

M
maf - million acre feet
monitoring well - A non-pumping well used for drawing water quality samples. See also observation well.

N
natural recharge - Naturally occurring water added to an aquifer. Natural recharge generally comes from snowmelt and storm runoff. See also recharge, artificial recharge, and incidental recharge
nitrogen - Sources of nitrogen include fertilizer, human & concentrated animal waste, and decomposing plant material. Nonpoint sources of nitrogen include fertilized lawn and crop areas, septic systems, concentrated animal waste areas, and grass clippings and other yard wastes that get dumped into backyard ditches and streams. Point sources include sewage treatment plant discharges and sewer overflows. Concentrations of nitrogen in streams typically increase as urban and agricultural areas increase. Nitrogen is highly soluble and reaches stream in a dissolved state through surface runoff and subsurface flow. The screening level for nitrogen used for the Alcovy study was 1.5 mg/L TN, based on recommended literature values.
non-consumptive use - A use that leaves the water available for other uses. Examples are power generation and recreational uses. See consumptive use
non-point source - A source of water pollution that originates from a broad area, such as agricultural chemicals applied to fields or acid rain. See point source
nonpoint-source pollution - water pollution that originates from various or diffuse sources; examples include stormwater runoff and streambank erosion (see point-source pollution).
NPDES - National Pollutant Discharge Elimination System. - a provision of the Clean Water Act which prohibits discharge of pollutants into waters of the United States unless a special permit is issued by EPA, a State, or (where delegated) a tribal government on an Indian reservation.
NTU -

O
observation well - A non-pumping well used for observing the elevation of the water table or the piezometric pressure. See also monitoring well.

P
pathogen - a disease-producing agent; usually refers to a living organism, such as bacteria.
perrenial - Year-round flow. See also ephemeral flow, intermittent flow, interrupted flow.
phosphorous - key nutrient in controlling aquatic plant growth. Sources of phosphorus include fertilizer, animal & human waste. Concentrations of phosphorus in streams typically increase as urban and agricultural areas increase. In Piedmont streams phosphorus is typically found chemically attached to soil particles and is easily transported with sediment Phosphorus enters streams from runoff and erosion from nonpoint sources, such as fertilized areas, and from point sources, such as sewage treatment plant discharges or sewer overflows. Excess concentrations can cause eutrophication (algae blooms) in streams and particularly in lakes and reservoirs. The screening level for phosphorus used for the Alcovy study was 0.1 mg/L TP, based on recommended literature values
point source - A source of water pollution that originates from a single point, such as an outflow pipe from a factory. See non-point source.
point source pollution - pollution that originates at one location, usually a pipe, tank or ditch; examples include discharges from industrial facilities, water reclamation facilities and collected storm water runoff that is directed through a pipe.
potable water - Water of a quality suitable for drinking.
precipitation - the formation of a liquid or solid from a gas, as in the formation of rain, hail, sleet or snow from gaseous moisture in clouds; in the hydrologic cycle, precipitation describes the formation of rain or snow and their subsequent falling to earth.

Q

R
RBP - Rapid Bioassessment Protocols - procedures for conducting biological (periphyton, benthic macroinvertebrates, fish) and habitat investigations for determining the aquatic integrity (relative condition) of streams and rivers.
recharge - To add water to an aquifer; also, the water added to an aquifer. See also artifical recharge, incidental recharge, natural recharge.
regulated flow - A surface flow downstream from a dam or other flow control structure.
reserved rights - Water rights held by the U.S. government created by withdrawal of public lands from entry. The right to divert as much water as is necessary to serve the purposes for which the land was withdrawn. These proprietary rights are superimposed over any state system of riparian and/or appropriative rights. Priority date is the date the lands were set aside (generally, the date of statehood in western states). State-created rights in existence before this date, if any, are superior; others are subordinate. Reserved rights do not depend upon the diversion of water and putting it to beneficial use; nor are they quantified at the time of creation. On Indian reservations, the basis for quantification generally is practicably irrigable acreage, or PIA. See also appropriative rights, riparian rights, Winter's Doctrine.
reservoir capacity - The amount of water a surface reservoir is capable of storing
reservoir storage - Water stored in a surface reservoir.
riffle pool - a section of stream that has shallow, fast-flowing water followed by deep, slow-flowing water.
riparian - Of, or pertaining to, rivers and their banks.
riparian area - the land immediately adjacent to lakes, rivers, and streams.
riparian rights - Surface water rights assigned on the basis land ownership along a stream reach. Common in the eastern United States. See also appropriative rights, reserved rights
rip-rap -large boulders or rocks placed along a stream bank to prevent erosion.
runoff - rain or melted hail, sleet, or snow that finds its way to a lake or stream by flowing over land.

S
safe yield - Rate of surface water diversion or groundwater extraction from a basin for consumptive use over an indefinite period of time that can be maintained without producing negative effects
sedimentation - deposition of solids carried by storm water which accumulate in channel beds, flood plains and the bottoms of lakes and rivers.
sediment basin - a man-made basin or intentional ponding area designed to hold storm water for a period of time to allow sediment and other suspended material to settle. The water eventually flows out of the basin to downstream waterways, evaporates into the atmosphere or infiltrates the ground.
senior appropriator - The owner of a surface water right whose right was acquired prior to other rights holders on the same stream
service area - See diversion.
stakeholder - anyone who lives, play or works within in a watershed.
state waters -
storm flow - higher velocity flow which is cause by increased runoff reaching the stream channel due to precipiation.
streambank stabilization - a vegetative or mechanical method of preventing erosion or deterioration of the banks of waterways.
stream reach - A specific portion of the length of a stream.
suspended solids - measure of suspended material, particularly sediment, in the water column. Sources of TSS include erosion from surface runoff and re-suspension of in-stream sediments from the streambed and eroding stream banks. Nutrients, pesticides, metals and bacteria easily attach to sediments that are delivered to streams. Large increases in the amount of sediment delivered to streams can impair or eliminate aquatic habitats and can change the shape and flow of stream channels. The screening level for sediment used for the Alcovy study was 25 mg/L TSS, based on recommended literature values.
surface water - water that exists above ground, including lakes, rivers, streams, and oceans.
surface water diversion - See diversion

T
taxonomic category (taxon, taxa) - a classification or group of organisms (i.e., kingdom, phylum, class, order, family, genus, species).
TMDL - Total Maximum Daily Load - The maximum amount of point and nonpoint source pollutants a stream can take in during a single day and still support its designated uses.
tertiary treatment - Post-secondary treatment of water designed to improve the quality of the water to the point where it can be put to a particular beneficial use.
transpiration - The vaporization of water given off by plants. See also evaporation and evapotranspiration
turbidity - The reduction of transparency in water due to the presence of suspended particles.

U

V

W
water cycle - the process in which water evaporated from rivers, lakes, and oceans rises and condenses into clouds, and then falls back to earth as rain, hail, sleet, or snow.
water quality - The physical, chemical and biological characteristics of water and how they relate to its suitability for a particular use.
water reclamation (also wastewater treatment) - a process by which water used in houses and businesses goes down the drain and becomes wastewater, which is then cleaned using biological and chemical processes so the water can be returned to the environment.
water table - The upper boundary of a free groundwater body, at atmospheric pressure.
watershed - the area of land that slopes or drains toward or into a lake, river, stream, or wetland.
watershed project - a group of activities undertaken in a geographic area to restore and/or maintain beneficial uses of a waterbody already affected, degraded or threatened by point and nonpoint source pollution.
winter's doctrine - A legal doctrine arising from the case, Winters v. U.S., U.S. Supreme Court, 1908, 207 U.S. 564, that holds that , upon the creation of a federal reservation on the public domain, the reservation has appurtenant to it the right to divert as much water from streams within or bordering it as is necessary to serve the purposes for which the reservation was created. See reserved water right.

X

Y