Supply and Demand Assessment (SDA) Information

Overview

From 2020 to 2023, in response to drought conditions, the State Water Board adopted emergency regulations and developed tools and information to further understand water availability in key watersheds. The Water Board's drought effort highlighted the need for specialized tools that can be used to evaluate water supply and demand and support broader water management. The Division of Water Rights, Supply and Demand Assessment Unit (SDA) was established in 2022 to develop water supply models and refine water demand data for select watersheds throughout California. The SDA Unit will focus on the following objectives:

Development of water supply (or hydrologic) models that assess surface water availability in select watersheds.
Refinement of water use data, including evaluation of the annual water use data reporting submitted by water right holders each year, that will be used to assess water demand in different water years.
Advancement of water allocation tools used to evaluate how various water use scenarios impact water supply in a given watershed.

All tools developed under this effort will be open-source and publicly available to support both local and Board efforts. This information can be used by interested parties to inform water management options and local solutions within a watershed. This work will provide the Board with additional resources to protect water availability in accordance with water right priority and public trust resources.

Announcements

August 27, 2024 - Additional Watersheds Selected for Water Supply & Demand Modeling
Six additional watersheds have been selected for development of water supply models and related demand information. The selection includes Gualala River, Mattole River, Salmon Creek, South Fork Trinity River, Tomales-Drake Bays, and Upper Putah Creek. More information to come.