(InEDC) Cris Alacon, EL DORADO COUNTY – Drought and Fire Risk Reinforces the Need for High-Elevation Storage in the Sierra Nevada
Alder Creek Reservoir, located in El Dorado County between the Sierra Nevada ridge and Placerville, has been identified as an important multi-beneficial storage project. High elevation storage in El Dorado County is a prudent climate adaptation strategy to address the unique vulnerabilities faced by foothill communities that have no meaningful groundwater resources. This project is designed to address California’s diminishing snowpack in the Sierra Nevada and the threat of continuous droughts. State and federal support is needed to expedite the required feasibility study already that has already been authorized by Congress.
El Dorado County Faces Water Supply Problems From Lack of Meaningful Groundwater in the Foothills
Unlike the Central Valley and other regions with groundwater basins, El Dorado County’s west slope is dominated by rock geologic formations that produce negligible groundwater supplies. El Dorado County’s reliance on surface water limits its ability to meet the needs of its growing population and agricultural sector as well as respond to prolonged droughts and intense fire-fighting needs. The existing American River reservoir system has limited capacity because Folsom Reservoir is too small to handle increased runoff caused by earlier snowpack melt, creating serious flood control challenges for the region. While investments in Valley surface storage and groundwater banking provide relief to the balance of the state, they do not serve communities or environmental resources located upstream of the Valley floor, including those in El Dorado County.
The source of water that sustains California’s Central Valley and the Delta is from the headwaters of the Sierra Nevadas, which produces abundant runoff from rain and snowmelt. High elevation storage is critical to meeting current and future water needs for the state.
“Two-thirds of California’s surface water supply comes from headwaters of the Sierra Nevada”
El Dorado Water Agency (EDWA) has completed the American River Basin Study (ARBS) in collaboration with the Department of the Interior, Bureau of Reclamation, and other water managers in the American River Basin. The ARBS identifies water supply-demand imbalances created by climate change and develops adaptation portfolios to address basin-specific water supply vulnerabilities. This study supports the need for additional storage as a climate adaptation measure. Located in higher elevations of the South Fork American River Basin away from sensitive habitat 168,000 acre-feet water storage project would increase the total Upper American River watershed storage to 2 million acre-feet 18% of the total storage capacity of Folsom Lake, which is 977,000 acre-feet 110 MW of new, carbon-free hydropower generation would increase downstream hydropower generation Progress Needed to Make Alder Creek Reservoir A Reality.
In addition, Congress has already authorized $3 million in federal funding for Reclamation to conduct a feasibility study to evaluate Alder Creek Reservoir. El Dorado Water Agency is requesting the California Natural Resources Agency support the development of feasibility study and address the water resilience challenges unique to the Sierra Nevada headwaters and foothill communities.
Located in the upper reaches of the American River watershed, above a natural fish barrier, Alder Creek is uniquely positioned to capture snowmelt and create storage from the upper South Fork of the American River.
Project Highlights
- 168,000 acre-feet water storage project would increase the total Upper American River watershed storage to 2 million acre-feet
- 18% of the total storage capacity of Folsom Lake, which is 977,000 acre-feet
- 110 MW of new, carbon-free hydropower generation would increase downstream hydropower generation
- Located in higher elevations of the South Fork American River Basin away from sensitive habitat
