A Multi-Agency Cooperative Program and Pilot Study to Evaluate Forecast-Informed Reservoir Operations (FIRO)

Forecast Informed Reservoir Operations (FIRO) is a proposed strategy of incorporating hydrometeorological forecasts into reservoir operations. Available storage for many existing multi-purpose reservoirs is allocated according to static storage guide curves (also called 'rule curves'), which balance the needs for water supply and flood protection. Guide curves were developed using seasonal runoff patterns and basin hydrologic characteristics from data available at the time of reservoir construction and are often overly conservative for flood protection at the expense of water supply storage. FIRO is a novel approach to reservoir management that could improve water supply reliability while also improving downstream flood protection for many multi-purpose reservoirs. Lake Mendocino was selected for a pilot study to evaluate FIRO as a management strategy. Lake Mendocino is a dual use reservoir located in the Russian River basin in northern California and is owned and operated for flood control by the U.S. Army Corps of Engineers (USACE) and is operated by the Sonoma County Water Agency for water supply. The USACE operates Lake Mendocino in accordance to operational rules to meet all of the reservoirs congressionally mandated purposes. To explore potential implementation of FIRO, the Lake Mendocino FIRO Steering Committee, a collaborative partnership that consists of water managers and scientists from several federal, state, and local agencies, and universities, has submitted a deviation request. This plan is closely coordinated with the USACE to follow the policies defined by their management and include: (1) completing studies that are consistent with USACE procedures and protocols, (2) pursuing interim deviations to the Water Control Manual (WCM) to test and evaluate FIRO strategies before the WCM changes are proposed.