With this year being the 11th driest snowpack on record since 1950 according to the state, and with the State Water Project announcing it will deliver only 20% of requested water supplies in 2020, projects like the Piru Stormwater Capture for Groundwater Recharge Project have been a critical piece to Ventura County’s important water supplies. This project provides a sustainable source for recharge of the Piru Groundwater Basin and the improvement of the water quality in Piru Creek.
The project began capturing stormwater in December 2019 and has treated all stormwater runoff as well as other nuisance flows from 36 urban acres located in the Piru community. During an average wet year, available runoff for capture was estimated at 17 acre-feet per year (AFY). The water is then saved from the existing storm drain system and transported to the existing United Water Conservation District (UWCD) Piru Spreading Grounds which spread for infiltration and recharge of the Piru Groundwater Basin. Debris, trash and other pollutants are removed by a pre-treatment device, a 10-ft diameter Continuous Deflective Separation (CDS) unit, before entering the spreading grounds.
“The Piru Stormwater Capture for Groundwater Recharge Project has multiple benefits to the Piru community including better water quality to meet compliance with Bacteria Total Maximum Daily Load, groundwater recharge, and water supply enhancement,” explains Ewelina Mutkowska, Ventura County Public Works Agency’s Watershed Protection (VCPWA WP), Senior Stormwater Manager. “This will massively help improve the water quality of Piru Creek and add recharge to the Piru Groundwater Basin. Capture of stormwater runoff is a sustainable source for groundwater recharge, and we need to look for more similar opportunities to enhance our water supply sources countywide”.
The State has determined that Santa Clara River (SCR) downstream of Piru Creek does not meet water quality objectives for bacteria as required by the federal Clean Water Act. Wet and dry discharges from urban areas were found to be major source of bacteria pollution. This project was developed by VCPWA WP in collaboration with UWCD and funded by the State Proposition 1 Stormwater Grant Program, to capture urban runoff, improve water quality and recharge our precious groundwater.