FERC Part 12D Safety Inspection and Review for Indian Valley Dam

Lake County, California

The Indian Valley Dam and Reservoir is a multi-purpose irrigation, water supply, and flood control facility owned and operated by the Yolo County Flood Control & Water Conservation District (District). Indian Valley Dam consists of a main dam, which is a zoned earthfill embankment with a compacted clay core approximately 224-feet high, and a saddle dam that is similar to the main dam in construction and is approximately 40-feet high. Indian Valley Reservoir provides summer irrigation needs within the District’s service area in Yolo County and flood storage to help mitigate damaging winter floods in Cache Creek downstream of the dam.

Slate provided independent consultant services for performing the eighth Federal Energy Regulatory Commission (FERC) Part 12D safety inspection and Potential Failure Modes Analysis (PFMA) for Indian Valley Dam. Slate reviewed supporting technical information, led the safety inspection, and developed conclusions and recommendations for the continued safe and reliable operation of the project. Slate facilitated the PFMA session with District staff. New potential failure modes were developed in the PFMA session including a series of spillway-focused PFMs to address potential concerns stemming from the Oroville spillway incident.