overdraft of groundwater. The Santa Clara Irrigating Company was formed in 1870 and drew water from the Santa Clara River, using a ditch system to irrigate the grain crops. Early settlers began pumping soon afterwards to support farming activities with what at first was a more reliable source. In the modern era, much of the groundwater has been rendered useless for agricultural or potable uses by salt-water intrusion. Unlike coastal Los Angeles and Orange County, Ventura County has no barrier in place to prevent the ocean water from intruding into the inland aquifers. The Sustainable Groundwater Management Act signed into California law in 2014 created a framework for sustainable, local groundwater management for the first time in California history. In response, the Ventura County Board of Supervisors passed an emergency ordinance that halted well-drilling in the Oxnard Plain. Groundwater levels experienced a decrease during the drought which lasted from 2012 to 2015. Calleguas Municipal Water District Calleguas Municipal Water District, a water wholesaler, serves about 75 percent of Ventura County's population. Calleguas ships state water from the Delta to Oxnard, Port Hueneme, and Camarillo on the Oxnard Plain and Moorpark, Thousand Oaks, Simi Valley and unincorporated areas in the east county. These areas also use groundwater and surface water supplies but these sources have increased in salinity. The source of the salts is a combination of agricultural, industrial, and residential activities in conjunction with salts in the imported water. The United Water Conservation District funded a detailed feasibility study in 2014 and found that the impaired groundwater in the south Oxnard Plain is suitable for treatment by reverse osmosis at an acceptable recovery range of 72 to 80 percent. Many local agencies, particularly those in the Calleguas Creek Watershed, have built or are putting in desalters to treat salty groundwater. The treated water can be used for drinking supplies which will make the region less dependent on imported state water. The remaining salt concentrate will be sent out to sea through the Calleguas Regional Salinity Management Project. This $220 million pipeline project started in 2003 and stretches from the marine outfall into Simi Valley. That pipeline services desalters in Simi Valley, Moorpark and the Camrosa Water District in the Santa Rosa Valley. Camarillo and Santa Rosa Valley The city of Camarillo water system serves about two-thirds of its residents. It imports about 60 percent of its water from the state