Supply and Demand Assessment (SDA) – Russian River

• No announcements at this time.

The SDA Unit has continued to work on the models and tools developed for the Russian River Watershed during the State Water Board's 2021-2022 Regional Drought Response. These tools provided the necessary information for the Division of Water Rights (Division) to assess water availability and issue water right curtailments to ensure adequate, minimal water supplies for critical purposes under the emergency regulation.

The Russian River watershed is divided into the Upper Russian River (URR) and the Lower Russian River (LRR) at the confluence of Dry Creek and the mainstem Russian River. To allow a finer spatial resolution for assessing water supply, the watershed was further delineated into 28 subbasins. The URR consists of subbasins 1-13 and the LRR consists of subbasins 14-28, as depicted in the Russian River Subbasin Map. The SDA Unit then used the Precipitation Runoff Modeling System (PRMS) and the Santa Rosa Plains (SRP) GS Flow hydrological models to simulate supply conditions throughout the Russian River watershed. These models rely on meteorological datasets from sources such as the National Oceanic and Atmospheric Association (NOAA), Western Regional Climate Center (WRCC), and California Irrigation Management Information System (CIMIS). Most of the pre- and post-processing steps have been automated with R scripts.

To capture the water demand in the Russian River watershed, water right demand estimates were incorporated based on information from annual reports of water diversion and use submitted to the Division. The SDA Unit continued to develop the Division’s demand dataset methodology and converted it into a series of R scripts and manual review spreadsheets that apply data quality correction flags. For example, the scripts identified and corrected unit conversion errors, duplicate reporting, and misplotted points of diversion. The SDA Unit then used a Russian River specific water allocation tool adopted from the UC Davis Drought Water Rights Allocation Tool (DWRAT) to allocate available supply amongst water right holders based on their respective water right priority and water demands. This version of DWRAT allocates water at the subbasin level, accounts for imported flows, and runs independently for the URR and LRR.

The SDA Unit’s demand methodology, along with the supply scripts and the two Russian River specific versions of DWRAT, will be made available on the California Water Board Data Center GitHub page as separate repositories.

• Russian River Drought Webpage
• North Coast Regional Water Quality Control Board Russian River Webpage
• Russian River Voluntary Sharing Program
• Curtailment Status Map

Supply and Demand Assessment Information

Project Watersheds:

• Russian River
• Butte Creek
• Napa River
• Navarro River