Glossary G – K

A - F | G - K | L - R | S - Z
GABION A wire basket or cage that is filled with gravel and generally used to stabilize stream banks and improve degraded aquatic habitat.
GAP ANALYSIS A method for determining spatial relationships between areas of high biological diversity and the boundaries of National Parks, National Wildlife Refuges (NWR), and other preserves.
GAS SUPERSATURATION The overabundance of gases in turbulent water, such as at the base of a dam spillway. Can cause fatal condition in fish similar to the bends.
GENERATION Act or process of producing electric energy from other forms of energy. Also refers to the amount of electric energy so produced.
GENERATOR A machine that changes water power, steam power, or other kinds of mechanical energy into electricity.
GEOGRAPHIC INFORMATION SYSTEM (GIS)A computer system capable of storing and manipulating spatial (i.e., mapped) data.
GEOTHERMALPower generated from heat energy derived from hot rock, hot water or steam in the Earth's surface.
GRAVITY DAM A dam constructed of concrete and/or masonry that relies on its weight for stability.
GRAVITY FEED SYSTEM A system that provides flow in a channel or conduit through the use of gravity.
GROUNDWATER Subsurface water and underground streams that can be collected with wells, or that flow naturally to the earth's surface though springs.
HABITAT The locality or external environment in which a plant or animal normally lives and grows. As used in this program, habitat includes the ecological functions of the habitat structure.
HABITAT CONSERVATION PLAN (HCP) 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.
HARVEST MANAGEMENT The process of setting regulations for the commercial, recreational and tribal fish harvest to achieve a specified goal within the fishery.
HATCHERY Refers to facilities that incubate eggs and rear the young for release into streams and rivers.
HATCHERY PRODUCTION The spawning, incubation, hatching, or rearing of fish in a hatchery or other artificial production facility.
HEAD The vertical height of water in a reservoir above the turbine. The more head, the more power that is exerted on the turbine by the force of gravity.
HEADGATE The gate that controls water flow into irrigation canals and ditches. A watermaster regulates the headgates during water distribution and posts headgate notices declaring official regulations.
HEADWATER Referring to the source of a stream or river
HEADWORKS A flow control structure on an irrigation canal.
HYDRAULIC HEAD The vertical distance between the surface of the reservoir and the surface of the river immediately downstream from the dam.
HYDROELECTRIC The production of electric power through use of the gravitational force of falling water.
HYDROLOGIC UNIT A distinct watershed or river basin defined by an 8-digit code.
HYDROLOGYThe science dealing with the continuous cycle of evaporation transpiration, precipitation, and runoff.
IMPACT A spatial or temporal change in the environment caused by human activity.
IMPOUNDMENT A body of water formed behind a dam.
INCIDENTAL HARVEST The take (or harvest) of species other than the target species in a fishery.
INCIDENTAL TAKE """Take"" of a threatened or endangered species that is incidental to, and not the purpose of, the carrying out of an otherwise lawful activity."
INDEPENDENT POWER PRODUCER (IPP)A company that builds power plants in order to sell electricity on the open market.
INDICATOR (ORGANISM) (Water Quality) An organism, species, or community that shows the presence of certain environmental conditions.
INDIGENOUS Existing naturally in a region, state, country, etc.
INFLOW Water that flows into a reservoir or forebay during a specified period.
INSTANTANEOUS FLOWS The velocity of a volume of water.
INSTREAM FLOWS The amount of water flowing in a stream. Regulators often consider factors like the natural hydrology of a stream and human developed diversions to determine the "instream flow" necessary to sustain fish habitat.
INTAKEThe entrance to a conduit through a dam or a water facility.
INTERRUPTIBLE POWERPower that, by contract, can be interrupted in the event of a power deficiency.
INTERTIEA transmission line or system of lines permitting a flow of electricity between major power systems.
INVESTOR-OWNED UTILITY (IOU)A utility that is organized under state law as a corporation to provide electric power service and earn a profit for its stockholders.
IMPOUNDMENT Body of water created by a dam.
IRRIGATION DIVERSIONGenerally, a ditch or channel that deflects water from a stream channel for irrigation purposes.
IRRIGATION SCREENS Screens using wire mesh placed at the point where water is diverted from a stream or river. The screens keep fish from entering the diversion channel or pipe.
JUVENILEThe early stage in the life cycle of anadromous fish when they migrate downstream to the ocean.
JUVENILE TRANSPORTATION Collecting migrating juvenile fish and transporting them around the dams using barges or trucks.
KILOWATT (kW)A unit of electrical power equal to one thousand watts.
KILOWATT-HOUR (kWh)A basic unit of electrical energy which equals one kilowatt of power used for one hour.
1) Snohomish County P.U.D.:
2) The Columbia River System: The Inside Story A 1991 publication from the U.S. Bureau of Reclamation, U.S. Army Corps of Engineers and Bonneville Power Administration
3) Public Power Fundamentals, a 1995 publication from the Public Power Council
4) Northwest Power Planning Council 2001 Columbia Basin Fish and Wildlife Program Description
5), 2001 Glossary of Terms
6) Bureau of Reclamation, Glossary of Hydropower Terms