A coalition of environmental groups, including the Environmental Water Caucus, California Water Impact Network, California Sportfishing Alliance, Restore the Delta, Planning and Conservation League and Southern California Watershed Alliance sent an end of year letter to Senators Diane Feinstein and Kamala Harris, and Representative Jared Huffman, calling for funding of environmentally superior alternatives to new dams. Proposed alternatives included recycling, storm water capture, and groundwater treatment. The letter referred to the Environmental Water Caucus Report, A Sustainable Water Plan for California.
California Water Research joined the environmental groups in urging California’s two Senators and Representative Huffman to prioritize the San Luis (B.F. Sisk) Dam seismic remediation over federal funding for new California dams. The groups also called for delay of major multi-year spending commitments until costs for the seismic remediation of San Luis Dam are available. After the Oroville Spillway incident, California Water Research blogged about the long standing issue with geotechnical deficiencies in the San Luis Dam embankments. San Luis Dam is in a very seismically active area. Independently reviewed risk assessments for Reclamation have shown that a large earthquake could lead to crest settlement and overtopping of the dam, which would result in large uncontrolled releases and likely dam failure.
As covered by Ezra Romero for Valley Public Radio in April 2017, failure of San Luis Dam would create an enormous path of destruction, almost 10 miles wide and over 80 miles long, from Los Banos to Antioch in the western Delta. The inundation would immediately hit Santa Nella (population 1,400) and Los Banos (population 37,000). It would flow through western Merced and Stanislaus counties, impacting West Modesto (population 5,600.) In San Joaquin County, the inundation would impact the western part of Manteca (population 72,000), the western part of Stockton (population 298,000.) In Contra Costa County, the inundation would impact Discovery Bay (population 14,000), and Brentwood (population 55,000.) In 2003, the San Joaquin County Office of Emergency Services estimated that 165,000 people were in the inundation path in San Joaquin County alone. Failure of the dam would also cause major disruptions for years in the water supply for the Central Valley Project and State Water Project.
Although seismic remediation of San Luis Dam is scheduled to begin in 2020, no funding has been requested by Reclamation and release of the Environmental Impact Statement has been delayed until July 2019.