Forecast Informed Reservoir Operations: Seven Oaks Dam
FIRO is a reservoir-operations strategy that better informs decisions to retain or release water by integrating additional flexibility in operation policies and rules with enhanced monitoring and improved weather and water forecasts (American Meteorological Society; 2020). Since 2014, CW3E and federal, state, and local partners have developed, tested, and implemented FIRO at reservoirs across the Western United States. FIRO is now being assessed nationwide.
OVERVIEW
Seven Oaks Dam is located on the Santa Ana River in San Bernardino County, approximately 35 miles upstream of Prado Dam. The 2,450-square-mile Santa Ana River watershed serves communities across Orange, Riverside, and San Bernardino Counties. The dam is operated jointly by the Orange County Flood Control District, San Bernardino County Flood Control District, and Riverside County Flood Control and Water Conservation District.
Built in 2000 primarily for flood risk management, water released from the dam is primarily recharged into the San Bernardino Basin Area, supplying water to roughly one million people across San Bernardino and Riverside Counties. San Bernardino Valley Municipal Water District and Western Municipal Water District are working to add water conservation as a secondary authorized purpose of the dam, which would unlock significant additional recharge and water supply, up to 200,000 acre-feet in wet years under future estimated water supply conditions.
The motivation for implementing FIRO at Seven Oaks Dam is to better manage the compounding flood risk and water conservation challenges posed by sequences of strong atmospheric rivers impacting the Santa Ana River Basin. The Preliminary Viability Assessment completed in July 2026 found FIRO to be viable, with the Santa Ana watershed ranking in the top 10% nationally for forecast skill for extreme precipitation. Simulations showed that modest increases in winter storage can improve groundwater recharge without compromising flood risk management.
FIRO PROGRESS
Forecast Informed Reservoir Operations implementation progress at Seven Oaks Dam. Green circles with checkmarks indicate completed milestones, blue and gold circles without checkmarks indicate upcoming milestones.
KEY FEATURES
3000 ac-ft
additional groundwater per year potentially enabled by FIRO (preliminary estimate)
~1 Million
People across San Bernardino and Riverside Counties benefit from the San Bernardino Basin Area water supply
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Steering Committee member organizations working collaboratively to advance FIRO at Seven Oaks Dam
Federally Listed Endangered Species
Environmental considerations related to protected species and their habitat is an important consideration of the Seven Oaks Dam FIRO project, as the reservoir is primarily within the San Bernardino National Forest. More than a dozen threatened and endangered species are present in the watershed downstream of the dam, including the Least Bell’s Vireo, Southwestern willow flycatcher, Santa Ana River woolly-star, and San Bernardino kangaroo rat. CW3E and project partners are developing environmental metrics to evaluate how changes in reservoir operations may affect species’ habitats.
STEERING COMMITTEE
Co-Chairs
Heather Dyer, San Bernardino Valley Municipal Water District
F. Martin Ralph, Center for Western Weather and Water Extremes, Scripps Institution of Oceanography, UC San Diego
Cary Talbot, US Army Corps of Engineers, Engineer Research and Development Center
Members
Van Crisostomo, US Army Corps of Engineers, Los Angeles District
Jayme Laber, NOAA National Weather Service
Michael Anderson, California State Climate Office, California Department of Water Resources
Rebecca Christensen, US Fish and Wildlife Services
Lisa Haney, Orange County Water District
Joseph Forbis, US Army Corps of Engineers, Engineer Research and Development Center
James Tyler, Orange County Public Works
Michael Fam, San Bernardino County Public Works
Betsy Miller, San Bernardino Water Conservation District
Mallory O’Conner, Western Municipal Water District
Joshua Fuller, National Marine Fisheries Service, NOAA
Mimi Abel, Physical Sciences Laboratory, NOAA
Support Staff
Greg Woodside, San Bernardino Valley Municipal Water District
Arleen O’Donnell, Eastern Research Group
Rob Hartman, RKH Consulting Services
Kyla Semmendinger-Raney, Center for Western Weather and Water Extremes, Scripps Institution of Oceanography, UC San Diego
Kyla Van Maanen, Center for Western Weather and Water Extremes, Scripps Institution of Oceanography, UC San Diego
RESOURCES
Preliminary Viability Assessment
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Contact Kyla Van Maanen at kvm@ucsd.edu for more information
Last updated: June 30, 2026