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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uJJ2S9

17) Begin next year at step 1.

SPECIFIC MODELING PROCEDURES

The specific steps in each line above will be described (all
values are in 1000 acre-feet units):

Upper Basin Runoff, Use, and Shortage

Step 1. The natural runoff above Glen Canyon Dam is read from the
EZ file HYDRO.DAT, column 2 labeled NAT (or stochastic
HYDR058.DAT). The scheduled Upper Basin use is read from file
CONUSE.DAT, column 2, labeled U.BASIN.

Step 2. Compute the Upper Basin shortage using the formula
ubshort=(ushrt1+LOG(ubcu-ubcuO+1)^1.5*LOG(ushrt1+1)^1.5) where
ushrt1 is read from the HYDRO.DAT file, column 3, labeled
U.SHORT. ubcu is the scheduled use. ubcuO is a base scheduled
use and is held constant. LOG is the natural log function. The
idea of this is to use CRSS to compute a shortage for that
constant use for each of the hydrology runoffs and then let EZ
compute new shortages for any other use and runoff combination.
Optionally, the Upper Basin shortage can be read from file
USHORT.DAT that contains actual CRSS shortages for that use and
hydrology.

step 3. Deduct the shorted Upper Basin use from the natural
runoff.

Upper Reservoir Operations:

Step 4. The Upper Reservoir capacity is the sum of Taylor Park,
Blue Mesa, Morrow Point, Crystal, Fontenelle, Duchesne River,
Flaming Gorge, and Navajo reservoir capacities. The initial
Upper reservoir storage change is computed using the formula
duc=-1450+.1647*pin where pin is the depleted runoff computed
above. This storage change is then limited to a target storage
based on the elevation of Lake Powell. If Powell is above
turbine overload elevation 3690 then the maximum contents of the
Upper reservoir is set to the maximum and an additional 11 kaf is
added to raise Morrow Point and Crystal above their target
maximum to live capacity (live capacity is greater than maximum
target contents).

If Powell elevation is between turbine overload and rated power
head (3570 to 3690 ft) then Flaming Gorge capacity is broken out
and tested. The Flaming Gorge component of the Upper reservoir
is set to the greater of its own rated power head or a computed
percentage of its maximum contents. This percentage is the ratio
of current to live capacity of the total Upper Basin. The Blue
Mesa and Navajo component are set to live capacity minus target

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