The marin municipal water district (district or mmwd) provides water to approximately 200,000 customers in the SAN francisco BAY area and serves a vital role in regional water supply and conveyance

The Marin Municipal Water District (MMWD) received a $301,256 Project Grant award from the U.S. Department of the Interior Bureau of Reclamation's Applied Science Grants program (CFDA 15.557) to improve water supply forecasting and operational decision-making. The project will incorporate software technology upgrades and algorithm-based strategies to enhance MMWD's water supply operations, which will benefit not only MMWD customers but also other regional water users. Specifically, the project aims to: (a) perform stochastic modeling to evaluate operational strategies under various hydrologic conditions, (b) implement technology software upgrades, and (c) enhance collaboration and communication with partners regarding water availability. Upon completion by September 30, 2026, the project will provide MMWD and its partners with a suite of improved forecasting tools to increase water supply resiliency and avoid potential loss of supply.

The district relies on local runoff as well as an imported water supply, both of which are under threat from climate change. In response, the district has identified the need to improve its operational forecasting in order to reduce drought risk and maintain environmental releases. This project will incorporate software technology upgrades deployed in concert with a matrix of algorithm-based strategies to influence near-term operational decisions for water managers at the district. Improvements to the district S water supply operations will benefit not only district customers but other users of the regional imported water supply, such as the cities of santa rosa and rohnert park, and the north marin water district (figure 1). Fulfilling this project is especially crucial considering the difficulties the district faced in 2021AND 2022 after two successive dry winters with significantly below average rainfall resulting in the district facing a serious risk of running dry altogether. This would have posed grave concerns not only for human health and safety, but also for sensitive aquatic environments to which the district routinely makes mandatory releases, the cessation of which would negatively impact federally- and state-listed threatened and endangered species, including coho salmon, steelhead trout, and california freshwater shrimp.additionally, in 2020, neighboring sonoma county was engulfed in the glass fire- responsible for billions in property damage and catastrophic environmental damage across 67,484 acres. The fire affected sonoma water S ability to convey water to its customers including marin water resulting in additional withdrawals of local water supplies in marin. The ability to combat wildfires like the glass fire depends on available district water resources. Watersmart applied science grant funds will be used to optimize water supply via these three tasks: (a) performing stochastic modeling to evaluate various operational strategies under a range of hydrologic conditions including climate-impacted conditions, (B) technology software upgrades, and (C) precise collaboration communication with partners regarding water availability. Upon completion of the project, the district and its partners will have a functional suite of forecasting tools providing simplified answers to regional operators. The purpose of this project is to ensure that the right information is available at the right time toincrease resiliency and avoid loss of supply.