Seawater intrusion in the southern Oxnard Plain has long been a problem due to agricultural, industrial, and residential land uses that rely on groundwater. When pumping exceeds recharge, water levels in the groundwater basin can fall below sea level, drawing seawater into the aquifers and impacting water quality.
Unlike coastal Los Angeles and Orange County, Ventura County has no seawater intrusion barrier in place, and the sea impairment renders the groundwater useless for agricultural or municipal uses.
To protect groundwater supplies, United Water is planning a project in collaboration with the United States Navy that will provide a barrier to seawater using extraction wells for hydraulic control and reverse osmosis to treat the brackish groundwater. The project will create as much as 20,000 acre-feet per year of advanced treated “new” water.
The project will reduce groundwater pumping, prevent seawater intrusion into groundwater basins, create an additional irrigation and emergency supply, and is estimated to conserve enough drinking water to supply about 40,000 families for a year.