Santa Clara Valley Water fisheries and aquatic habitat collaborative effort

SEI’s Water Evaluation And Planning (WEAP) system has been applied since 2015 to model the operations and aquatic habitat of the Santa Clara Valley Water District. The WEAP model results were used to design the set of reservoir re-operations which better protect local Chinook and steelhead habitat downstream under the Fisheries and Aquatic Habitat Collaborative Effort (FAHCE). These re-designed operations were certified under the final environmental impact report in 2023.

The Valley Water WEAP model has also been applied to support the Anderson Dam Seismic Retrofit Project (ADSRP). The model is used to submit monthly temperature monitoring reports downstream of Anderson dam, informing a local fish rescue effort in June 2021 as well as the 2025 biological opinion from the National Marine Fisheries Service for the ADSRP construction.

To support this project, SEI developed the Aquatic Habitat Assessment (AHA) plugin for WEAP to evaluate the habitat suitability of native aquatic species. Information on stream hydraulics, utility operations, local demands and biological needs of species are all integrated in the WEAP model. The AHA plugin was used to compare the habitat suitability of local Chinook salmon and steelhead trout in the Three Creeks watershed of Santa Clara County under alternative reservoir reoperation scenarios. A Tableau dashboard was used to visualize the model results of both human water supply and aquatic habitat under alternative reservoir reoperation scenarios.

The results were ultimately used to unite a range of conflicting parties to refine and ultimately reach consensus on a common solution for a set of reservoir reoperations which best optimize and balance limited water supplies for human use and aquatic habitat, helping the district to meet California Environmental Quality Act requirements.