Project Setting and Operations Sample Clauses

Project Setting and Operations. ‌ The Rocky Reach Project, the eighth dam upstream from the mouth of the Columbia River, is a run-of-river hydroelectric project with limited ability to modify river flows. The Project has an allowable forebay fluctuation of four feet, with minimum forebay elevation of 7033 and maximum of 707 feet for normal operation (710 under special flood control operation). However, in consideration of system reliability for the regional electric grid, the Project rarely allows the forebay elevation to drop below 704 feet. The forebay elevation is usually maintained between 706 and 707 feet. The forebay elevation has been above 706 feet over 73% of the time and within two feet of elevation 707 approximately 98% of the time, with average forebay elevation at 706.22 feet over a ten year period (1992-2001). The Project’s tailrace elevation averaged 617.59 over the same time period. The maximum tailwater elevation during this period was 635.2 feet (June 12, 1997) and minimum was 610.7 feet (April 21, 1998). Tailwater elevation is determined primarily by Project discharge, which is managed under the 1997 Agreement for the Hourly Coordination Agreement, as described later in this Section. On a daily basis, minimum and maximum discharge is related to the fluctuation in flows released from upstream federal dams, the Grand Coulee Project and Chief Xxxxxx Project. The Rocky Reach Reservoir (Reservoir) is 43 miles long, with an annual average flow of 113,200 cfs (1973-2001) since completion of Canadian storage reservoirs. The minimum daily average flow from 1973-2001 was 25,100 cfs (November 11, 1973) and the maximum daily average flow was 358,000 cfs (June 12, 1997). The surface area of the Reservoir is approximately 8,235 acres at a flow of 100,000 cfs and forebay elevation of 707 feet. The gross storage capacity of the Reservoir at 100,000 cfs is 387,500 acre-feet. The volume of water that the Reservoir can contain between the minimum and maximum forebay elevation is 36,400 acre- feet. This storage is useable for capturing or augmenting flow on an hourly basis. If inflow to the Project ceased, the Reservoir’s useable storage would be sufficient only to run the plant for about two hours. The inflow to the Project is primarily determined by operations of the FCRPS, which is composed of the federal dams and the accompanying electrical system on the Columbia and Snake Rivers in Oregon, Washington, and Idaho. The dams are operated by Reclamation and the U.S. Army Corps of Engineer...