The Federal Energy Regulatory Commission on Oct. 26 put out for comment an environmental assessment on a planned rehabilitation project at the El Dorado hydroelectric facility in California.
FERC’s Office of Energy Projects has reviewed an application to amend the El Dorado Project license filed by the El Dorado Irrigation District (licensee). The licensee proposes constructing an earthen stability buttress, raising the crest of the dam, and upgrading appurtenant facilities.
This facility is located on the South Fork American River adjacent to the unincorporated community of Pollock Pines in El Dorado County, California. Any comments on the EA should be filed by Nov. 27.
In 2009, the commission’s Division of Dam Safety and Inspections determined that as a result of the Stability Evaluation and other supporting reports, interim risk reduction measures are required to ensure the safe long-term performance of the El Dorado dam. The licensee responded by agreeing with most of the requests but providing justification to retain its flashboards. The licensee subsequently prepared to make seismic improvements to the project. Because the proposed action involves a significant physical modification of an existing dam licensed by the Commission, an amendment of the project license is required.
In June 2014, the licensee filed its application for a non-capacity related amendment of license. The licensee proposes to construct an earthen stability buttress on the dry side (or downstream side) of the El Dorado forebay dam, raise the crest elevation of the forebay dam 10 vertical feet, and upgrade appurtenant facilities. Implementing the proposed action would increase dam stability, provide sufficient freeboard to relieve the current reservoir level operating restriction implemented in 2009, and meet current dam safety requirements. Implementing the proposed action would also recover reservoir capacity lost because of sediments accumulated over time in the El Dorado forebay. The proposed action would allow the licensee to regain full reservoir use and improve the reliability of an associated existing drinking water system.
The proposed action would not affect or increase the diversion capacity of the project, canal conveyance capacity, water rights, or hydropower generation capacity. The proposed modified forebay would continue to be used to meet drinking water and hydroelectric demands with a normal maximum operating storage capacity of approximately 554 acre-feet (af) after modification.