SEI staff have worked with the state’s water rights database, eWRIMS, to develop the eWRIMS Analyzer tool for rapidly assessing the legally defined water uses in a basin. The eWRIMS Analyzer can identify common data discrepancies, catalog beneficial uses, estimate the monthly legal maximum water use and estimate the monthly reported water use.

With the water use information developed using eWRIMS and other sources, SEI is building the Ventura Water Allocation Model (VWAM) using SEI’s WEAP software. WEAP is ideally suited to studying the impact of in-stream flow requirements on agriculture, cities and other beneficial uses in a watershed. In the development of the model, every water right is explicitly represented, allowing for a detailed assessment of the impact of in-stream flow requirements on water availability for all water users in a basin.

Working with partners at the Water Board, California Department of Fish and Wildlife, UC Davis, Utah State University and the California Environmental Flows Framework Technical Team , SEI is using the Functional Flows Calculator to develop the in-stream flow regimes within the model. The in-stream flow regimes will be tested in VWAM to determine impacts on other water users and quantify the trade-offs inherent in allocation of limited water supplies. VWAM will explore these tradeoffs under various conditions of changing climate, forest fire effects, and reservoir operations within the Ventura River watershed.