Glossary

• Title: Glossary of CDSS Terms
• Description: Glossary of terms used throughout the CDSS documentation.
• Decision Support - Doc Type: Report
• Date: 7/5/2005
• DSS: All
• Basin: Statewide
• Prepared By: CWCB

C
A computer programming language that is newer than FORTRAN and which provides more facilities
for object-oriented programming and I/O.
C++
An extension to the C programming language. C++ was developed to ease object-oriented
programming while using many of the features of the C programming language.
Calendar Year
A one year period starting January 1 and ending December 31. See also water year and irrigation
year.
Calibration
The iterative process whereby repeated executions of a simulation model are made with different
controlling parameters, the goal being to adjust parameters until the simulated results match historical
results within an acceptable tolerance.
Call
The placing of a call by a senior priority to the water commissioner to shut down junior priorities so that
the senior is able to divert its full entitlement. In such cases, junior priorities are curtailed or called out.
(Rice (1991))
Class A Pan Evaporation
Class A pan is a U.S. Weather Bureau evaporation pan. The pan is a cylindrical container fabricated of
iron or metal with a depth often inches and a diameter of 48 inches. The pan is placed on an open
wooden platform with the top of the pan 16 inches above the ground surface. The pan is filled to an
eight inch depth and refilled when it reaches seven inches. The depth of water that evaporates is
measured and coefficients can be applied to estimate evaporation amounts from water bodies. A
typical coefficient for lakes is 0.7.
Compact
A contract between states of the union, entered into with the consent of the national government, and
in water, defining the relative rights of two or more states on an interstate stream to use the waters of
that stream. (Rice (1991))
Conditional Water Right
A right to perfect a water right with a certain priority upon the completion with reasonable diligence of
the appropriation upon which such water right is to be based. (Rice (1991)) See also absolute water
right.
Condition of Continuity
The requirement that water volumes must be strictly accounted for. (Rice (1991))
Conveyance Loss
The loss of water from a conduit due to leakage, seepage, evaporation, or evapotranspiration. (Rice
(1991))
Consumptive Use (CU)
Consumptive Use (CU) is the estimated amount of water leaving a managed water system in a
specified area due to human activity. There are a few assumptions that are acknowledged along with
this definition:
Water in the upper-basin diverted outside of Colorado's Western Slope water system is
assumed not to returned to the system in any way.
Some portion of what might be considered water use will not be consumptive use. In
other words, some portion of the water delivered to a municipal area or irrigated field
will return to the system in the form of treatment center discharges, sewer run off,
ground-water recharges and/or precipitation. Where possible these amounts will be
included in CU estimates for the CDSS CU model.
The selection of a small area for the calculation of consumptive use may not be able to
account for all the interactions of water injection and withdraw from the area's water
system.
CRDSS
Colorado River Decision Support System