Bending the Multiverses for Watershed-Scale Forecast-Informed Reservoir Operations

Yung-Hsin Sun; Rebecca Guo; Gary Bardini

Forecast-Informed Reservoir Operations (FIRO) has been incorporated into the operational framework of Folsom Reservoir on the American River in California. As a key component of the federal Central Valley Project, Folsom Reservoir provides both water supply and critical flood risk reduction for the Sacramento metropolitan area. This presentation summarizes the strategies, governance, and technical analyses used to develop a watershed-scale FIRO program recently advanced by regional entities in collaboration with federal and state agencies to improve resilience to flood and drought.
The program is anchored by the Folsom Dam Raise Project and complementary facility modifications at two upstream reservoirs owned by local agencies and operated primarily for water supply and hydropower generation without designated flood control responsibility. These coordinated infrastructure investments enable multi-reservoir operations that deliver multi-benefit outcomes across the watershed and statewide.
In addition to structural improvements, the watershed-scale FIRO framework includes enhanced basin-specific hydroclimate data collection using emerging technologies; improved forecasting informed by the latest scientific understanding of atmospheric river processes and watershed characteristics; and nature-based solutions, including forest and watershed management, to sustain and extend the effectiveness of built infrastructure. Implementing this holistic approach requires navigating a complex landscape of jurisdictions, regulatory requirements, and diverse stakeholder interests. The presentation highlights key challenges and opportunities associated with multi-project, multi-agency collaboration and offers insights applicable to watershed-scale water management efforts nationwide.

Source Water Protection in the Context of Holistic Watershed Management: Advances in Research from The Water Research Foundation

Harry Zhang

Watershed management and source water protection are among top issues facing the water sector. Holistic watershed management follows the One Water paradigm shift, which promotes an integrated approach to managing all water flows as interconnected systems at a watershed level. Source water protection (SWP) is an integral component of holistic watershed management. The objectives of this presentation are to connect SWP with holistic watershed management from One Water perspective and illustrate the advances in research from The Water Research Foundation (WRF) over the past two decades.

Through a long-term collaboration with partner organizations such as AWWA and WEF, WRF has been advancing research in source water protection and holistic watershed management. Through examples, this presentation will demonstrate how to develop a roadmap and framework to evaluate SWP programs. In addition, SWP through effective use of the Total Maximum Daily Load (TMDL) process with successful strategies used by water utilities will be discussed. This presentation will cover quantifying the performance of SWP measures to improve utilities’ decision making by using nutrients and PFAS as example pollutants. Watershed-based PFAS management strategies have shown promise, as PFAS has become a challenge across water matrices and interconnected components such as soil media. Furthermore, the presentation will feature how to better connect SWP with holistic watershed management through the use of advanced watershed modeling tools. In summary, WRF has been applying a One Water approach to advance research in source water protection to further support holistic watershed management for utilities and municipalities.

A New View of Water: A Valuation of Water Supply from the Upper American River Watershed

Jared Soares; David Batker; Aaron Batker Pritzker; Rebecca Guo

Watersheds provide immense value, however estimating these values is challenging. Ecosystem goods and services valuation is a tool to evaluate the ecological benefits of watersheds and inform management decisions. In California, source watersheds are recognized as part of statewide water infrastructure, and the upper American River watershed contributes to regional and statewide water supply through a complex network of water systems and conveyances. Building on simulated statewide water allocations from California’s standard long-term water supply analytical tools, this water valuation provides an ensemble of values to water uses, ecosystems, and utilities based on at-source and at-site values that vary by regions in California. Using two separate but compatible hydrological models, this analysis estimates the value of water produced in the upper American River watershed as it flows through California’s water systems. Using simulated flows generated for each region, relevant values for municipal, agricultural, and ecological uses are applied to water flows to estimate the economic value of water produced from the upper American River watershed. We produce a range of value estimates, including at-source estimates between $1.1 and $1.5 billion annually, and at-site values between $1 and $11.1 billion annually. This water valuation provides essential references for water users and decision makers. The research demonstrates a practical way to estimate the economic value of water from source watersheds. The results can be applied to show how downstream water users are connected to source watersheds and inform management decisions for source watershed protection.