AQUIFER STORAGE AND RECOVERY FOR THE CITY OF ROSEVILLE: A CONJUNCTIVE USE PILOT PROJECT

The City of Roseville (the City) is located in the Central Valley of California near the State Capital of Sacramento. The City is studying the feasibility of Aquifer Storage and Recovery (ASR) using dual purpose (injection/extraction) wells to sustain water supply reliability in one of the fastest growing regions of the state.Sacramento and the surrounding areas are going at an alarming rate. Sustaining a reliable water supply is a challenge because existing supplies are fully allocated and taking more surface water from the American River would have a detrimental impact on downstream the environments. Conjunctive Use is the coordinated management of surface water and groundwater supplies to increase the yield of both. This process can be enhanced by storing excess water supplies underground during wet years for use during the dry years – a form of drought proofing.The City's ASR program is a potential element of a comprehensive, regional conjunctive use program being implemented in southern Placer County and northern Sacramento County. The ASR program will provide 1) reliability for local water purveyors and 2) opportunities to increase flows to the Bay-Delta system during dry periods through groundwater banking and surface water exchange.The principal purpose of the Roseville ASR Feasibility Study / Demonstration Project is to evaluate opportunities to store treated surface water from Folsom Lake in the groundwater basin underlying Placer County by direct injection during “wet” years for extraction to supplement the City's surface water supply during “dry” years. The key areas being investigated include 1) Hydrogeologic and water quality issues 2) Water rights and contract entitlements, and 3) Regulatory and institutional issues.Testing performed to date has shown ASR to very successful in this location and the City is planning to expand the program to include 8 wells installed over the next 3–5 years.