Vinita — A Grand River Dam Authority request to temporarily suspend the lowering of Grand Lake in August and September 2011 has been dismissed by the Federal Energy Regulatory Commission (FERC).

GRDA’s request, made in April, was for temporary relief from rule curve requirements included in GRDA’s license to operate Pensacola Dam and Grand Lake. In 1992, FERC, which is the federal agency with oversight of the nation’s hydroelectric facilities, issued that license to GRDA. In 1996, it was amended to include the Grand Lake rule curve. In the years since, that rule curve has required GRDA to lower the lake’s elevation in mid-August to facilitate a millet seeding project on exposed mudflat areas of the lake.

Late last year, GRDA initiated discussions on the possibility of a rule curve amendment. At the November 2010 meeting of the Grand Lake Technical Committee, GRDA Director of Ecosystems Dr. Darrell Townsend met with representatives from the United States Fish and Wildlife Service, Oklahoma Water Resources Board and the Oklahoma Department of Wildlife Conservation. Townsend polled committee members as to whether they would support an amendment that would grant GRDA operational discretion for Grand Lake within the power pool and eliminate the rule curve requirement.

The technical committee, which was also established under terms of the FERC license, did agree to support delaying the drawdown of Grand Lake until after the 2011 Labor Day weekend. However, the committee indicated it would not consider a license amendment to permanently change the rule curve until further modeling and studies could be completed by the United States Army Corps of Engineers.

Although the drawdown was originally implemented for wildlife habitat reasons, and not flooding concerns, FERC indicated a study, to research the upstream flooding potential, would need to be completed before it would consider the rule curve amendment, even on a temporary basis. According to GRDA, such a study would need to be completed by the United States Army Corps of Engineers. GRDA had requested that assistance from the Corps earlier in the year. However, in mid July, GRDA was informed by the Corps that its request for assistance was denied, due to the Corps’ current work load and lack of available staff.

Due to the FERC dismissal of the temporary relief request, GRDA will proceed with the drawdown in 2011, to meet requirements of the operating license.