WSP00029

• File Number: 8271.300
• Description: Colorado River Basin Salinity Control Program - General Information and Publications-Reports
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 6/1/1976
• Title: Computer Simulation of Surface Water Hydrology and Salinity with and Application to Studies of Colorado River Management -- Part 2 of 2 -- Page 143 - end
• Water Supply Pro - Doc Type: Report/Study

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182

depletions given in Table 5.10, the average inflow to Lake Powell is

1= 8.4 MAF/yr (10.4 km3/yr). At a target discharge Dt = 8.25 MAF/yr
3
(10.2 km /yr) the time required to fill the 27 MAF reservoir can be

estimated as

(6.1)

S
I - Dt

27

8.4 - 8.25

=

180 years

=

Because reservoir discharge, evaporation, discharge TDS concentration,

and hydropower generating capacity all depend upon reservoir storage,

only reservoir storage was examined in determining a transient time

for model operations.

Using identical streamflow sequences and imposing the highest level

of stream depletions, two simulations of 200 years of observations

were made. In the first simulation the initial storages of both Lake

Powell and Lake Mead were set to their maximum values. In the second

simulation both reservoirs were given zero initial storage. The

transient time of the system was taken to be the number of years of

simulation required for the reservoir storages of the two runs to

coincide.

It was found that the time sequences of Lake Powell storage,coin-

cided after approximately 65 years. Roughly 125 years were required

for the sequences of Lake Mead storage to coincide.

A transient time of 150 years was used in all subsequent simu1a-

tions.

The long transient times observed are important in the context of

Colorado River Basin management. The result shows that substantial