Buck Island Auxiliary is a crucial component of California's water resource infrastructure, serving as a hydroelectric facility with a primary purpose of generating electricity and providing recreational opportunities. Built in 1963 by Bechtel, this concrete gravity dam stands at 25 feet high and spans 244 feet in length, with a storage capacity of 1070 acre-feet. Located in El Dorado County, California, along Rockbound Creek in the city of Coloma, this dam is regulated by state agencies and overseen by the Federal Energy Regulatory Commission.

With a low hazard potential and a moderate risk assessment rating, Buck Island Auxiliary has a spillway width of 147 feet and a maximum discharge rate of 13,000 cubic feet per second. The dam is inspected regularly, with the last assessment conducted in August 2019. While the condition assessment is currently listed as not available, emergency action plans have been prepared and updated, ensuring that the dam is equipped to handle any potential risks or emergencies that may arise.

Overall, Buck Island Auxiliary plays a vital role in water resource management and climate resilience efforts in California. As a key contributor to the state's energy production and water supply, this dam exemplifies the intersection of infrastructure development, regulatory oversight, and emergency preparedness in ensuring the safety and sustainability of water resources in the region.