WSPC12493 ‎(2)‎

• File Number: 8220.101.10
• Description: Colorado River Water Projects - Glen Canyon Dam-Lake Powell - Adaptive Management
• State: CO
• Basin: Colorado Mainstem
• Date: 4/1/1996
• Author: DOI-BOR
• Title: CRSSez - Annual Colorado River System Simulation Model - Overview-Users Manual - Update of 04-01-96 - With Revisions of 09-01-96 - 04-01-96
• Water Supply Pro - Doc Type: Report/Study

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demands based on upstream inflow and downstream gains and
diversion returns. Operations at most of these reservoirs are
interdependent on runoff forecasts, projected uses, and relative
contents of Lake Powell while meeting the Law of the River.
Monthly input and output are coordinated through 4 separate
programs and can provide an overwhelming amount of information on
each inflow, diversion, reservoir, and powerplant point. After
making any changes to the hydrology, demands, and output control,
a run for up to 15 traces can be made. An 85 trace run requires
6 job submittals that along with control verification will take
about 2 days to perform. Modification of the CRSS computer code
requires extensive expertise and changes are governed by
procedural rules to assure changes produce valid results.
BecaQse of the discontinued use of Reclamation's CYBER mainframe
computer, the full CRSS fortran code has been adapted by Ray
Bennett of the Colorado Division of Water Resources to run on the
IBM-PC, and will allow continued cross checking of results of
both models.

CRSSez Description:

For planning studies that compare differences in annual values, a
less rigorous analysis may be acceptable, especially if
information is only required for major diversions and reservoirs.
Figure 1 shows the schematic of the Colorado River Basin
developed for the CRSSez model that has provided acceptable
results for analyzing banking operation effects on Mead and
Powell contents and releases. Changes to the EZ computer code
can be made by anyone familiar with BASIC, although most
suggestions for incorporating new operating procedures can be
requested through Reclamation.

The biggest difference between the EZ configuration and CRSS is
that the 12 reservoirs have been reduced to 3. The storage
capacity of the reservoirs above Powell have been combined and
operated as 1 reservoir. The end of year 'storage target for this
upper reservoir is dependant on storage in Powell and is governed
by a combined set of rules that apply to the separate reservoirs.
Lakes Mohave and Havasu have been discarded since on an annual
basis they have no scheduled change in storage. Their assumed
constant annual evaporation is included in system uses below
Hoover Dam.

Uses in the Upper Basin have been combined into 1 use. Uses in
the Lower Basin have been combined into each states largest
municipal user and each states remaining other users. System
uses not counted against the states apportionments are combined
into two, above and below Hoover Dam.

Gains and losses in the Upper Basin have been combined into one
as gains above Glen Canyon Dam. Gains and losses in the Lower
Basin have been combined into two, above and below Hoover Dam.

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