The Secretary of the Interior - Washington - CO River Interim Guidelines for Lower Basin Shortages and the Coordinated Operations for Lake Powell and Lake Mead

• Year: 2007
• Title: The Secretary of the Interior - Washington - CO River Interim Guidelines for Lower Basin Shortages and the Coordinated Operations for Lake Powell and Lake Mead
• CWCB Section: Interstate & Federal
• Description: The Secretary of the Interior - Washington - CO River Interim Guidelines for Lower Basin Shortages and the Coordinated Operations for Lake Powell and Lake Mead
• Publications - Doc Type: Other

Interim Guidelines for the
Operation of Lake Powell
and Lake Mead
predictions for natural runoff. The CRBPA directed the Secretary to propose and adopt
criteria: "In order to comply with and cat~-y out the provisions of the Colorado River
Compact, the Upper Colorado River Basin Compact, and the Mexican Water Treaty, ...
for the coordinated long-range operation of the reservoir constructed and operated under
the authority of the Colorado River Storage Project Act, the Boulder Canyon Project
Act, and the Boulder Canyon Project Adjustment Act."
Pursuant to the CRBPA, the narrative provisions of LROC are utilized by the Secretary,
on an annual basis, to make determinations with respect to the projected plan of
operations of the storage reservoirs in the Basin. The AOP is prepared by Reclamation,
acting on behalf of the Secretary, in consultation with representatives of the Basin
States and other parties, as required by federal law. In the AOP, with respect to
operations of Hoover Dam, the Secretary is required to determine when Normal,
Surplus, or Shortage conditions occur in the lower Colorado River, based on various
factors including storage and hydrologic conditions in the Basin.
As described in the Final EIS:
• A "Normal Condition" exists when the Secretary determines that sufficient
mainstream water is available to satisfy 7.5 million acre-feet (maf) of annual
consumptive use in the Lower Division states (Arizona, California, and
Nevada). If a state will not use all of its apportioned water for the year, the
Secretary may allow other states of the Lower Division to use the unused
apportionment, provided that the use is authorized by a water delivery contract
with the Secretary.
• A "Surplus Condition" exists when the Secretary determines that sufficient
mainstream water is available for release to satisfy consumptive use in the
Lower Division states in excess of 7.5 maf annually. The water available for
excess consumptive use is surplus and is distributed for use in Arizona,
California, and Nevada pursuant to the terms and conditions provided in the
ISG. The current provisions of the ISG are scheduled to terminate in 2016. In
general terms, the ISG link the availability of surplus water to the elevation of
Lake Mead. When Lake Mead is full and Reclamation is making flood control
releases, surplus supplies are unlimited. As Lake Mead's elevation drops,
surplus water amounts are reduced, and ultimately eliminated. The ISG also
link surplus availability to continued progress by California in reducing its
agricultural use of water to benchmarks established in the ISG. If a state does
not use all of its apportioned water for the year, the Secretary may allow other
Lower Division states to use the unused apportionment, provided that the use is
authorized by a water delivery contract with the Secretary.
• A "Shortage Condition" exists when the Secretary determines that insufficient
mainstream water is available to satisfy 7.5 maf of annual consumptive use in
the Lower Division states. To date, the Secretary has never made such a
ROD -Colorado River Interim Guidelines for December 2007
Lower Basin Shortages and Coordinated 5
Operations for Lake Powell and Lake Mead