WSPC12491 ‎(2)‎

• File Number: 8220.101.10
• Description: Colorado River Water Projects - Glen Canyon Dam-Lake Powell - Adaptive Management
• State: CO
• Basin: Colorado Mainstem
• Date: 10/13/1998
• Author: AZ-CO-NV-NM-UT-WY
• Title: Proposal for Interim Lake Mead Reservoir Operation Guidelines Related to Surplus-Normal-and Shortage Year Declarations - Six State Proposal - Straw Man Drafts - 10-13-98 and 11-04-98
• Water Supply Pro - Doc Type: Report/Study

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Six State Proposal ~ ~~ \. 0- v ~,
Straw Man Draft ~ '^ rf u.. " 9Ji7'
Includes Fassett and Mutz comments to ~~ ~ ~ J {
11/4/98 4. v h f) (}.J .

affect that Iestrltc.d incauses an

performed if the shortage criteria are

The Bureau of Reclamation has been studying options for shortage criteria for a number of V 6;:}i)

years. The framework for most of these strategies is to declare limited cutbacks well in advance ~ ~

of the point where those levels are criti~ The lowest priority 10 ~cr basinLower Divisiou water "f/~;~':
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user, the Central Arizona Project, bears the burden of most of the delivery reduction. The timing ~\1 ~ VW"

of the reduction is based on the use of computer models to simulate reservoir operations. The ~ ~
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model study focuses on the statistical probability of reservoir levels dropping below a critical ~~

"protect" leveL The Six States endorse this framework and propose to adopt the protect level in~;

Lake Mead of elevation 1050 which is the elevation of the intake structure for the Southern 1'~

Nevada Water Project. The Bureau of Reclamation has nicknamcdnamed this shortage strategy

"80P1050." In accordance with the Bureau's studies, this level would not be guaranteed but the

risk of drawing down to below that level would be limited to 20%. When the model studies

indicate that the reservoir level is in jeopardy, a first tier shortage would be declared which would

reduce Arizona's consumptive use by the CAP and other similar priority users to no more than

1,000,000 acre feet (about a 500,000 afreduction). Nevada would also share in shortages, but to

a much more limited extent. If reservoir conditions continue to deteriorate, additional cuts in use

by CAP will be required.

VI. Overrun Accountin2

The Draft California 4.4 Plan includes a provision that allows individual entitlement

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