Forecast-Informed Reservoir Operations (FIRO) Colloquium
| What: | Training provided for students and early-career scientists at the first Forecast-Informed Reservoir Operations (FIRO) Colloquium |
| When: | 11–28 July 2022 |
| Where: | La Jolla, California |
In July 2022, the first Forecast-Informed Reservoir Operations (FIRO) Colloquium took place at Scripps Institution of Oceanography (SIO). FIRO is a reservoir-operations strategy that better informs decisions to retain or release water by integrating additional flexibility in operational policies and rules with enhanced monitoring and improved weather and water forecasts, resulting in better-managed water resources. For FIRO to achieve its fullest realization and benefits for society, new kinds of scientists and engineers with comprehensive multidisciplinary exposure and understanding are required. Not only will FIRO require people who understand how precipitation, forecasts, and reservoirs work, but they will also need to understand the many competing and compounding costs and benefits that accrue and must be balanced.
This colloquium provided basic training that we envision will be needed by students and early-career people across the country in the next decade or so. The colloquium was attended by 28 students and early-career professionals and consisted of two weeks of lectures at the SIO, a local field trip to the southern California FIRO site at Prado Dam, a tour of Scripps Pier, and a 4-day tour of FIRO operations in Northern California. Exposure of attendees from all disciplines to the workings of storm and flood forecasts, reservoir operations, and assorted environmental and community requirements from well operated reservoirs provided a broad background on FIRO and was supplemented by many interactions with each other and with lecturers and other professionals in the field.
What is FIRO?
FIRO is a reservoir-operations strategy that better informs decisions to retain or release water by integrating additional flexibility in operational policies and rules with enhanced monitoring and improved weather and water forecasts (American Meteorological Society 2023; Delaney et al. 2020; Jasperse et al. 2020). Most reservoirs have operational requirements set by regulators or the reservoir owners and operators for combinations of flood protection, water supply, dam safety, the environment, power generation, and recreation. Many of these operational standards used to meet these requirements were developed decades ago and limit the use of modern advancements in weather and streamflow forecasting.
FIRO strives to incorporate advanced weather and runoff forecasts into reservoir operations decisions through updates of the operational guidelines and requirements, such as allowing safe storage of water in reservoirs within the “flood pool” as long as there is no forecasted precipitation that would render that extra water a flood risk. FIRO is already in practice at Lake Mendocino in the Russian River watershed of Northern California, where landfalling atmospheric rivers (ARs) provide 30%–50% of annual precipitation and almost all precipitation extremes and floods (e.g., Ralph et al. 2013). Delaney et al. (2020) demonstrate that implementing FIRO at Lake Mendocino can increase median storage by >30% over conventional reservoir operations, expanding available water supplies, mitigating flood risk, and providing healthy ecosystems.
FIRO is currently being explored around the western United States as a collaborative multiagency effort, engaging experts and stakeholders in civil engineering, hydrology, meteorology, biology, economics, and climate from several federal, state, tribal, and local groups and others. Besides the operations at the Russian River, FIRO viability assessments are underway in the Yuba–Feather River Watersheds at the Lake Oroville and New Bullards Bar Reservoirs (Northern California) and in the Santa Ana River Watershed at Prado Reservoir (Southern California). Figure 1 highlights multiple factors that need to be considered when applying FIRO at the Prado Reservoir, illustrating the variety of expertise and multidisciplinary approach required.
Cross-sectional diagram of Prado Reservoir depicting the primary operational constraints and FIRO management objectives (provided by the Orange County Water District).
Citation: Bulletin of the American Meteorological Society 104, 8; 10.1175/BAMS-D-23-0004.1
Colloquium overview and goals
Evaluating and implementing FIRO to simultaneously increase water supply reliability and mitigate flood risk is of increasing interest at reservoirs throughout the western United States. The complexity of FIRO demands interdisciplinary collaborations between policymakers, hydrologists, engineers, meteorologists, and ecologists, among others. For FIRO to achieve its fullest realization, evaluated and implemented on the large scale, new kinds of scientists and engineers with detailed understanding of how reservoirs and modern forecasts work and how all of the many competing and compounding benefits accrue and must be balanced are going to be needed. The FIRO Colloquium provided a new generation of students and early-career professionals with an in-depth look at the state-of-the-art methodologies needed to better manage water resources in the western United States amidst climate change, population growth, and other infrastructure and resource stressors.
The FIRO Colloquium was held from 11 to 28 July 2022 at the University of California, San Diego (UCSD), Scripps Institution of Oceanography (SIO) in La Jolla, California, and was hosted by the Center for Western Weather and Water Extremes (CW3E). The first two weeks of the colloquium consisted of expert-led classroom-style lectures and hands-on practical sessions, and a third week consisted of site visits to several reservoirs in Northern California. The colloquium was organized by an interdisciplinary team of meteorologists, hydrologists, and engineers who welcomed 28 participants over the 3-week period. Of these participants, 18 were students and 10 were early-career professionals primarily spanning the atmospheric science, hydrology, and engineering disciplines (Fig. 2).
The career stage and primary field of interest of the participants, 28 in total.
Citation: Bulletin of the American Meteorological Society 104, 8; 10.1175/BAMS-D-23-0004.1
Colloquium activities
Speakers and structure.
The colloquium featured 14 speakers from CW3E and 22 speakers from academia, state, and federal agencies, including the National Centers for Environmental Prediction (NCEP), National Weather Service (NWS), European Centre for Medium-Range Weather Forecasts (ECMWF), the University at Albany, and the U.S. Army Corps of Engineers (USACE). The full instructor list is presented in the appendix.
Invited speakers provided classroom-style lectures in seven different sessions (see section “Lecture sessions”) during weeks 1 and 2 of the colloquium. The lectures were complemented by seven hands-on practical sessions, a tour of the Ellen Browning Scripps Memorial Pier, and visits to several FIRO and water resource sites within California (Table 1).
Schedule of lectures, practical sessions, and tours across the three weeks of the FIRO Colloquium. IVT= integrate vapor transport.
Lecture sessions.
Lectures targeted different aspects of FIRO, including watershed hydrology, extreme precipitation, atmospheric forecasting, hydrology and forecasting, observations and monitoring, reservoir operations, environmental considerations, and design of FIRO viability assessments (Table 1). Figure 3 illustrates the flow of the lecture series through these topics.
Flow of the lecture series topics. First topic is watershed background and last topic is environment and FIRO viability assessment.
Citation: Bulletin of the American Meteorological Society 104, 8; 10.1175/BAMS-D-23-0004.1
The lectures and practical sessions were organized to bring the diverse (with experience in various disciplines relevant to water resources and management) group of students and early-career professionals together to learn from and interact with a group of scientists and practitioners working actively on FIRO projects and FIRO viability assessments. Each lecture had an objective that started with “After this lesson the students will be able to …” and concluded with aims such as “describe the techniques and challenges of detecting and predicting atmospheric rivers in the western US” or “discuss the operations of dams to provide irrigation water supply, hydroelectric power, ecological habitats and recreational areas to adjacent communities.”
The lectures on the first full day of the colloquium delivered background information on watersheds, managed river systems, reservoir operations, and the FIRO screening process. The screening process is a vital first step to assess whether FIRO might be feasible at a particular reservoir based on fundamental water management criteria and is a primary consideration throughout this colloquium. Atmospheric rivers, which provide much of the annual precipitation on the U.S. West Coast (e.g., Ralph and Dettinger 2012; Ralph et al. 2013), were a focus in the extreme precipitation session. Thus far, FIRO is being evaluated primarily in U.S. West Coast watersheds where ARs are key to the hydrometeorological climate. Specific high-impact ARs, including the 14 February 2019 AR that caused devastating flooding and $100 million in damages in Riverside County (Riverside County 2019), were described and discussed.
In the atmospheric forecasting session, ensemble forecasting was introduced, which led to the important concepts of forecast uncertainty and forecast skill, communications, stakeholders, and decision-making. The session on field observations described operational multi-agency and multi-institute monitoring campaigns run out of CW3E, AR Reconnaissance (AR Recon; Cobb et al. 2023; Ralph et al. 2020), to improve in situ observations needed to improve forecasts most relevant to FIRO.
Near the end of week 2, reservoir-operation methods and limitations were introduced, including how FIRO differs from traditional reservoir operations, methods for evaluating hydrologic forecasts, models to simulate and evaluate FIRO strategies, and metrics of FIRO viability. The lecture series concluded with a day on environmental considerations and design of a FIRO viability assessment. Fisheries concerns and opportunities, climate variability and change, benefit and policy, development of a steering committee, and elements of a research and operations partnership (RAOP) were all addressed.
Practical sessions.
Hands-on group exercises were an important part of the colloquium, giving the participants opportunities to apply what had been learned in the lectures and to interact with the instructors and each other. A practical associated with extreme precipitation provided participants with opportunities to analyze relationships between landfalling ARs, watershed precipitation, and reservoir inflow in Northern California using 20 years of data and a spreadsheet modeling framework. Another practical, building on this extreme precipitation exercise, focused on forecast risk communication and case studies of high-impact events, so that participants gained better appreciation for the importance of extreme precipitation within the western U.S. hydroclimate, the need for skillful weather forecast models in reservoir operations, and the importance of effective forecast communications.
Following lectures on observational techniques, a practical session tasked participants with drawing flight tracks using the same software and techniques used operationally during AR Recon campaigns (Cobb et al. 2023; Ralph et al. 2020). The participants worked in groups and there was careful consideration of which atmospheric features were most important to sample to improve forecasts, based on the atmospheric forecast that had been provided. There was lively discussion when the final tracks were compared so that participants could explain their choices and perspectives (Fig. 4).
An operational AR Recon flight track (black) and tracks drawn by the participants (A: pink; B: green; C: blue). Integrated vapor transport magnitude is shaded in units of kg m−1 s−1 and direction is indicated by vectors; mean sea level pressure is contoured in hPa.
Citation: Bulletin of the American Meteorological Society 104, 8; 10.1175/BAMS-D-23-0004.1
The final practical session incorporated all the knowledge gained through the week to demonstrate how weather forecast information is used during historical flood events to support FIRO decision-making for an actual reservoir. This exercise demonstrated how multiple lines of information are used to make timely and well-supported reservoir release decisions.
Field tours.
Field tours were an important part of the colloquium, providing the participants with up-close and personal exposure to the settings, conditions, and infrastructures that FIRO is embedded within. The location of this colloquium was well suited to conduct several field tours over the course of the three weeks, with direct access to a research pier on SIO campus, Prado Dam a few hours away, and several key sites of interest a short flight away in Northern California.
Prado Dam day trip.
At the end of the first week, USACE and the Orange County Water District (OCWD) hosted tours of Prado Dam and downstream groundwater recharge facilities, 160 km north of SIO. This visit allowed participants to meet water managers to discuss the challenges and constraints at the facility and to discuss how FIRO is currently being evaluated at Prado Dam to help meet flood-control and water-supply objectives. Participants visited the dam to learn from the reservoir operators about real-time operations, the OCWD field station to discuss the successful management to maintain critical endangered bird habitat, and finally the downstream OCWD groundwater recharge facilities to discuss how water is diverted from the Santa Ana River into groundwater recharge basins to support water supply.
Scripps Pier tour.
At the end of the second week, participants took a tour of the Ellen Browning Scripps Memorial Pier, part of UCSD’s SIO campus. This pier is a research facility that houses numerous environmental monitoring stations and enables small boat and scientific diving operations. Participants saw various pieces of observational equipment that had previously been discussed in the lectures. A highlight for many was launching a radiosonde balloon and watching the transmitted data arrive in real time, prompting discussions about the state of the atmosphere and applying lessons already learned regarding observations and their importance in weather forecasts.
FIRO Northern California tour.
The week 3 tour was a key component of the colloquium, providing participants with tours of four reservoirs at various stages of FIRO implementation. The participants built on classroom experiences during these visits to hear directly from the water manager managers about FIRO. The first day of the tours visited the Russian River, where FIRO has been implemented at Sonoma Water’s Lake Mendocino, providing a 20% improvement in water supply during drought year 2020 (Jasperse et al. 2020). The tour included stops at Lake Sonoma, the Mirabel inflatable dam and fish passage facility, and groundwater recharge ponds. Discussions included environmental justice and water supply to disadvantaged communities, environmental work performed downstream of Lake Sonoma for fisheries benefit, and water supply challenges including a regulatory change that reduced inflow into Lake Mendocino.
The second day was a trip to the U.S. Bureau of Reclamation’s (USBR) 977,000 acre-foot (1 acre-foot ≈ 1233.5 m3) Folsom Lake reservoir on the mainstem of the American River, which provides water supply, flood protection, and environmental water for the California Central Valley. The Sacramento Area Flood Control Agency (SAFCA) spoke about its partnership with USBR, USACE, and the Central Valley Flood Protection Board to provide improved flood protection for one of the most at-risk regions in the nation while maintaining water supply.
The third day was a trip to the 966,000 acre-foot New Bullards Bar reservoir on the North Yuba River, where the best option for additional flood protection has been to begin construction of a new spillway lower in the dam to facilitate earlier flood releases guided by FIRO. The tour included an overview of the planned spillway called the Atmospheric River Spillway.
The final day was a trip to the California Department of Water Resources (DWR) Oroville Dam that stores up to 3.5 million acre-feet of water on the mainstem of the Feather River. Here the participants learned about the California State Water Project (which delivers water from Northern California to the Central Valley and urban areas of Southern California), the 2017 spillway failures and subsequent repairs, and a myriad of water supply, flood protection, and related challenges. DWR summarized water issues facing the state and actions being taken to better understand and accommodate climate change, improve measurements of water conditions, and the necessity of more flood protection and water supply through actions like FIRO.
At the end of the trip the students reported that the Northern California tours were the best part of the colloquium because it built on the two weeks of lectures and provided the real-life experience of water managers addressing tough water issues using FIRO. They were able to see facilities, hear in-depth explanations of the water issues by the professionals managing the projects, and ask questions to enhance their understanding.
Outcomes and future plans
The FIRO colloquium provided members of the next generation of scientists, engineers, resource managers, and policymakers with an in-depth look at a state-of-the-art methodology to better manage water resources in the western United States. This training is key to ensure FIRO will achieve its fullest realization and benefits for society.
“The colloquium was a fantastic experience and I came away with a huge appreciation for the tremendous effort being undertaken at CW3E, USACE, and participating agencies in advancing forecasts, modeling, and operations.”
Acknowledgments.
The FIRO Colloquium Organizing Committee acknowledges the University of California, San Diego’s Scripps Institution of Oceanography’s Center for Western Weather and Water Extremes for support. This publication and work were supported by the California Department of Water Resources AR research program (Award 4600013361) and the U.S. Army Corps of Engineers Engineer Research and Development Center (Award 609 W912HZ-15-2-0019).
Appendix: Instructor List
Table A1 contains a list of instructors and their institutions.
Instructors and their institutions.
References
American Meteorological Society, 2023: Forecast-informed reservoir operations. Glossary of Meteorology, https://glossary.ametsoc.org/wiki/Forecast-informed_reservoir_operations.
Cobb, A., and Coauthors, 2023: Atmospheric river reconnaissance 2021: A review. Wea. Forecasting, https://doi.org/10.1175/WAF-D-21-0164.1, in press.
Delaney, C. J., and Coauthors, 2020: Forecast Informed Reservoir Operations using ensemble streamflow predictions for a multipurpose reservoir in Northern California. Water Resour. Res., 56, e2019WR026604, https://doi.org/10.1029/2019WR026604.
Jasperse, J., and Coauthors, 2020: Lake Mendocino Forecast Informed Reservoir Operations final viability assessment. UC San Diego, 141 pp., https://escholarship.org/uc/item/3b63q04n.
Ralph, F. M., and M. D. Dettinger, 2012: Historical and national perspectives on extreme West Coast precipitation associated with atmospheric rivers during December 2010. Bull. Amer. Meteor. Soc., 93, 783–790, https://doi.org/10.1175/BAMS-D-11-00188.1.
Ralph, F. M., T. Coleman, P. J. Neiman, R. J. Zamora, and M. D. Dettinger, 2013: Observed impacts of duration and seasonality of atmospheric-river landfalls on soil moisture and runoff in coastal Northern California. J. Hydrometeor., 14, 443–459, https://doi.org/10.1175/JHM-D-12-076.1.
Ralph, F. M., and Coauthors, 2020: West Coast forecast challenges and development of atmospheric river reconnaissance. Bull. Amer. Meteor. Soc., 101, E1357–E1377, https://doi.org/10.1175/BAMS-D-19-0183.1.
Riverside County, 2019: Zone 4 report to the zone commissioners. Tech. Rep., 13 pp., https://rcflood.org/Portals/0/Downloads/Zone%204%20with%20Emergency%20Intro%20Final.pdf?ver=2020-01-13-131755-163.
