Operating Plan for Colorado River System Reservoirs Approved

On Dec. 14, Secretary of the Interior Gale A. Norton approved the 2006 Annual Operating Plan (AOP) that governs the distribution of Colorado River water and the operation of Colorado River reservoirs. A letter transmitting the approved AOP has been sent to the governors of the seven Colorado River Basin states.

The AOP states that releases from Lake Powell to the lower Colorado River basin in water year 2006 (Oct. 1, 2005, to Sept. 30, 2006) will be made to meet the minimum objective release of 8.23 million acre-feet (maf). This is consistent with the requirements of the Criteria for Coordinated Long-Range Operation of Colorado River Reservoirs, according to Interior officials.

In the Lower Basin, consistent with the Interim Surplus Guidelines, the partial domestic surplus criterion will govern releases from Lake Mead in 2006. Under this criterion, surplus water would be available only to municipal water contractors in Arizona, California and Nevada. The total amount of surplus water that would be available is projected to be approximately 300,000 acre-feet; however, none of the water users has indicated they plan to take any of this surplus water.

The secretary may do a mid-year review of the 2006 AOP to determine if hydrologic conditions warrant an adjustment to the minimum objective 8.23 maf release amount from Lake Powell. Any revision to the AOP would consider the purposes and benefits of Lake Powell and Lake Mead and would occur through the consultation process as required by applicable Federal law.

The secretary will conduct a mid-year review in April if the March 2006 mid-month inflow forecast projects that the combined live storage in Lakes Powell and Mead will be less on Sept. 30, 2006, than the actual combined live storage of 23.106 maf that was in those reservoirs on Sept. 30, 2004. If the storage is higher than that level, there will not be a mid-year review.

The Colorado Basin River Forecast Center is expected to issue the mid-March forecast on or about March 15, 2006. The projected combined live storage of the two reservoirs will be determined by Reclamation's monthly operational model, which updates projected reservoir elevations in the Colorado River Basin at the beginning of each month.

The AOP was developed in consultation with representatives of the seven Colorado River Basin states, the Upper Colorado River Commission, tribes, appropriate federal agencies, representatives of the scientific community, environmental organizations, the recreation industry, water delivery contractors, contractors for the purchase of federal power and the general public, officials said.

The final AOP is available at http://www.usbr.gov/lc/region/g4000/AOP2006/AOP06_final.pdf.

This article originally appeared in the 12/01/2005 issue of Environmental Protection.

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