Relief Dam

Image:Relief_Reservoir_Emigrant_Wilderness.jpg

Relief Dam is a rockfill dam on Summit Creek, a tributary of the Middle Fork Stanislaus River, in Tuolumne County, California. The dam is part of the Spring Gap-Stanislaus Hydroelectric Project, and is owned and operated by Pacific Gas and Electric (PG&E).{{Cite web|url=http://www.waterboards.ca.gov/waterrights/water_issues/programs/water_quality_cert/springgap_ferc2130.shtml|title = Water Quality Certification | California State Water Resources Control Board}}{{Cite web| title=Middle and South Forks of the Stanislaus River and Tributaries | url=http://www.waterboards.ca.gov/waterrights/water_issues/programs/water_quality_cert/docs/springgap_stanislaus_ferc2130/401cert.pdf | archive-url=https://web.archive.org/web/20090614050137/http://www.waterboards.ca.gov/waterrights/water_issues/programs/water_quality_cert/docs/springgap_stanislaus_ferc2130/401cert.pdf | archive-date=2009-06-14}}

Completed in 1910, the dam stands {{convert|145|ft|m}} above the riverbed and is {{convert|505|ft|m}} long at the crest. Altogether it contains {{convert|136984|yd3|m3}} of fill.{{Cite web|url=http://cdec.water.ca.gov/cgi-progs/profile?s=RLF&type=dam|title=California Data Exchange Center}} The dam forms Relief Reservoir, which has a storage capacity of {{convert|15122|acre feet|m3}} of water and a full surface area of {{convert|189|acre|ha}}. The drainage basin behind the dam totals {{convert|24.51|mi2|km2}}.

The reservoir is primarily drawn down in the late summer and fall to supplement flows to the hydroelectric powerhouses at Donnells Dam and Beardsley Dam (part of the separate PG&E Tri-Dam Project) and others on the Stanislaus River.