Forecast Informed Reservoir Operations

FIRO is a proposed management strategy that uses data from watershed monitoring and modern weather and water forecasting to help water managers selectively retain or release water from reservoirs in a manner that reflects current and forecasted conditions.

FIRO is being developed and tested as a collaborative effort focused on Lake Mendocino that engages experts in civil engineering, hydrology, meteorology, biology, economics and climate from several federal, state and local agencies, universities and others.


Executive Summary
Preliminary Viability Assessment
Watershed Characteristics and Challenges
Interagency Cooperation

Jay Jasperse

(Sonoma Water)

F. Martin Ralph

(Center for Western Weather and Water Extremes at Scripps Institution of Oceanography)

Michael Anderson

(California State Climate Office, Department of Water Resources)

Levi Brekke

(Bureau of Reclamation)

Michael Dettinger

(United States Geologic Survey)

Nick Malasavage

(US Army Corps of Engineers)

Alan Haynes

(Caifornia Nevada River Forecast Center, NWS)

Joseph Forbis

(US Army Corps of Engineers)

Natalie Manning

(NOAA Restoration Center)

Cary Talbot

(US Army Corps of Engineers)

Robert Webb

(NOAA’s Earth System Research Laboratory)

Arleen O’Donnell

(Eastern Research Group)

Ann Dubay

(Sonoma Water)

David Ford

(David Ford Consulting)

Rob Hartman

(RKH Consulting Services)

The Lake Mendocino Forecast Informed Reservoir Operations (FIRO) Preliminary Viability Assessment Work Plan describes an approach for using modeling, forecasting tools and improved information to determine whether the Lake Mendocino Water Control Manual can be adjusted to improve flood-control and water supply operations. This proof-of-concept FIRO viability assessment uses Lake Mendocino as a model that could have applicability to other reservoirs.

The 1959 Lake Mendocino Water Control Manual (with minor updates in 1986), specifies reservoir elevations to control flooding and establishes the volume of storage that may be used for water supply. The Manual was developed using the best information available at the time, but it has not been adjusted to reflect changing climate conditions and reduced inflows over the past 30 years.

The FIRO Steering Committee has developed a work plan for assessing the viability of FIRO that takes advantage of current science and technology. FIRO envisions modern observation and prediction technology that could provide water managers more lead time to selectively retain or release water from reservoirs based on longer-term forecasts. Optimizing reservoir operations potentially benefits water supply and environmental flows without diminishing flood control or dam safety.

This Work Plan presents an approach for considering a proof-of-concept FIRO viability assessment using Lake Mendocino as a model. Specifically, it outlines a process for evaluating whether FIRO can support adjustments to the Manual. The work plan describes current technical and scientific capabilities, and outlines technical/scientific analyses and future efforts to demonstrate the potentioal of FIRO to improve reservoir management.

The assessment will present a suite of actions ranging from practical, short-term steps to longer-term research needs. If deemed viable, FIRO will likely be implemented incrementally, as science evolves and implementation criteria are met. FIRO follows adaptive management principles for continual improvement of reservoir operations. In the case of Lake Mendocino, and much of the west coast, this hinges on opportunistically applying advances in monitoring and predicting atmospheric rivers, their associated precipitation and runoff.

While aimed at benefitting Lake Mendocino, the project has transferability potential, thus the Work Plan will document a process that can be replicated in other watersheds. It consists of the following steps:

  • Develop evaluation criteria and methodology
  • Develop evaluation scenarios
  • Identify science needs and carry out necessary research projects
  • Evaluate model results
  • Evaluate FIRO viability (preliminary) and assess benefits
  • Develop implementation strategies

The AR Colloquium Kicks-Off

In late December 2013 an Atmospheric River storm greatly increased the amount of water in Lake Mendocino (thick blue line shows reservoir storage; green dashed line shows cumulative rainfall). The “rule curve” (dashed orange line) led to the release of this water. The lack of later rains (to February 2014) led to drought conditions and extremely low lake levels. Figure courtesy of F. M. Ralph (UC San Diego/ Scripps /CW3E; and J. Jasperse (Sonoma Water) – FIRO Steering Committee Co-Chairs. (Click above for full size image)

(Click above for full size image)

The flow chart shows how the assessment decisions will be made. (Click above for full size image)

Atmospheric river type storms are the cause of most floods on the Russian River, and across much of the west coast. Figure is from Ralph and Dettinger 2012, EOS. (Click above for full size image)

FIRO Task Groups and Leads

Preliminary Viability Assessment:

David Ford (David Ford Consulting Engineers)

Jay Jasperse (Sonoma Water)

Procedural Matters:

Mike Dillabough (U.S. Army Corps of Engineers)


Marty Ralph (CW3E; Scripps Institution of Oceanography)

Cary Talbot (U.S. Army Corps of Engineers)