7409

• UCREFRP Catalog Number: 7409
• Author: U.S. Department of the Interior.
• Title: Quality of Water, Colorado River Basin.
• USFW Year: 1991.
• USFW - Doc Type: Progress Report No. 15,
• Copyright Material: NO

Definitions of Terms

Acre-foot is the quantity of water required to
cover 1 acre to a depth of 1 foot and is equivalent
to 43,560 cubic feet or about 326,000 gallons or
1,233 cubic meters.

Anoxic refers to the lack of oxygen.

Cablegation is irrigation from a piped ditch
were the rate of discharge to the furrow is
controlled by a cable attached to a plug in the
pipe.

Chemocline is a level in a lake or reservoir
where water quality shifts rapidly with elevation
from one zone of water quality to another.

Concentration is the flow-weighted average
concentration of total dissolved solids (salt)
measured in mg/L or tons/acre-foot.

Conductivity. See specific conductance.

Consumptive use is the total amount of water
taken up by vegetation for transpiration and
evaporation.

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Cubic feet per second (fts/s or cfs) is the rate
of discharge representing a volume of 1 cubic
foot passing a given point during 1 second and is
equivalent to approximately 7.48 gallons per
second or 448.8 gallons per minute.

Depletion in the context of this report is the
total man-caused loss of water from the river
system due to consumptive uses, evaporation,
evapotranspiration, and transmountain
diversion.

Discharge is the volume of water plus
suspended sediment that passes a given point
within a given period of time.

DisS-.llution is the process of dissolving.

Dissolved solids - see total dissolved solids.

Diversion is the total amount of water diverted.
Diverted water mayor may not return to the
river.

Eutrophication results from the enrichment of
a body of water with nutrients which stimulate
the growth of algae. Eutrophic lakes and
reservoirs overproduce algae causing loss of
dissolved oxygen and taste, odor, and esthetic
problems. (See trophic state.)

Gauging station is a particular site on a
stream, canal, lake, or reservoir where
systematic observations of hydrologic data are
obtained.

Historical flow is the flow actually experienced
at the gauging station or point of measurement.
It is the total runoff of a drainage area above the
point of measurement as influenced by nature
and the activities of man. It may be recorded or
estimated.

Natural flow. See definition of virgin flow.

Oxic refers to the presence of oxygen.

Return flow is the amount of water returned to
the river system after being diverted for use.

Salts are inorganic compounds of metals such as
sodium, calcium, magnesium, or potassium and
bases such as carbonates, sulfate, or chloride.
Soluble salts will dissolve into metallic and basic
ions when exposed to water.

Salt pickup is salts added to the system usually
by dissolution.

Sediment is a solid material that originates
mostly from disintegrated rocks and is
transported by, suspended in, or deposited from
water; it includes chemical and biochemical
precipitates and decomposed organic material
such as humus.

Specific conductance is a measure of the
ability of a water to conduct an electrical
current. It is expressed in micromhos per
centimeter at 25 .C. Specific conductance is
related to the type and concentration of ions in
water and can be used to estimate salinity or the
dissolved solids content of the water.