WSPC01844

• File Number: 8283.200
• Description: Colorado River Basin-Colorado River Computer Models-Colorado River Decision Support System-Ray
• State: CO
• Water Division: 5
• Date: 7/13/1994
• Title: Consumptive Use Modeling-Task 1.14b-Consumptive Use Prototype Development-Phase Iia
• Water Supply Pro - Doc Type: Report/Study

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Task 1.14(b) - Consumptive Use Prototype Development

where cu = consumptive use (L3)

c = volumetric water use of an industry site (L3)

The above equation is repeatedly used for each site of each type of industry to obtain
the total consumptive use.

2.9 CD Methods for Exports

2.9.1 Develop Methodology

Consumptive use included in the export category are all water diversions out of the
area being considered. The net export amount is calculated by also accounting for water
diversions into the given area. Nearly all the transbasin diversions both out of and into
the Colorado River System are measured and reported by the Geological Survey, or local
water commissioners and users. This allows the computation of consumptive use and
losses due to export to be quite accurate.

2.9.2 Develop and Implement Subroutine

210 The methodology for estimating consumptive use from export is implemented

in a FORTRAN subroutine. The subroutine can be called by a main program to
compute for the consumptive use for any number of export sites in a given area for any
period of time (daily, biweekly, monthly, yearly, etc.).

The equation that is used:

cu = c --- for all export sites

where cu = consumptive use (L3)

c = net water diversion (L3)

The above equation is repeatedly used for each export site to obtain the total
consumptive use.

211 CD Methods for Evaporation from Reservoirs

2.11.1 Develop Methodology

Reservoir consumptive use is an estimate of water loss from reservoirs through
evaporation. It is estimated based mainly on free water surface (FWS) evaporation and
the surface area of the reservoir. Precipitation or salvage value_will be accounted to
obtain the net water loss from the stock ponds. The ~g~val!teis assumed equal to
reservoir losses. Reservoirs are classified as measured and unmeasured. The measured
reservoirs which are operated by n Reclamation and other entities have their
consumptive use already calculated.

2.11.2Develop and Implement Subroutine

The methodology for estimating consumptive use of reservoirs is implemented in a
FORTRAN subroutine. The subroutine can be called by a main program to compute for
the consumptive use for any number of reservoirs in a given area for any period of time
(daily, biweekly, monthly, yearly, etc.).

The equation that is used is:

7/13/94 - Draft of Task Memorandum

13

IDS Group, CSU