SUSTAINABLE GROUND WATER SUSTAINABILITY ACT
In 2014, the Governor Brown signed 3 bills that collectively became known as The Sustainable Groundwater Management Act (SGMA) which created a new structure for managing the State’s groundwater resources. SGMA requires formation of Groundwater Sustainability Agencies (GSA) for all basins designated as high or medium priority by CA Department of Water Resources (DWR). The newly formed GSAs are then responsible for the development of Groundwater Sustainability Plans (GSP), that when implemented will avoid “undesirable results” in groundwater elevations, storage levels, water quality degradation, land subsidence, seawater intrusion and downstream interconnected water impacts. Currently DWR has calculated that 127 groundwater basins in California must comply with SGMA requirements, including the Borrego Valley Basin. The County of San Diego and Borrego Water District (BWD) are the two agencies comprising the GSA for the Borrego Basin. Borrego is not alone, the County of San Diego has also filed with DWR to be part of 3 other local GSA for the San Diego River, San Luis Rey River and San Pasqual Basins. Each of these basins will go through a similar process with stakeholders from those areas.
Under SGMA, depending upon the severity of the overdraft, the GSAs have prescribed amounts of time to complete their respective GSP. In the case of the Borrego Valley Basin, the severity of the 70% overdraft places the Basin in the CRITICALLY OVERDRAFTED classification, which means the GSP must be completed at the fastest pace possible. In this case, SGMA allows 2 years (January 2020) for completion of the Plan but the County and BWD have committed to complete the Borrego GSP by July 2019. SGMA prescribes that implementation of the GSP shall take place within the next 20 years (2040).
After decades of excessive pumping, the Borrego Groundwater Basin is critically over drafted and dramatic reductions in water consumption by current and future water users are needed to bring the Basin into sustainability. The latest estimate, based on a 2015 study conducted by the United States Geological Service (USGS), calculates the over draft of the Borrego Basin to be approximately 13,000 acre feet or 4.2 billion gallons per year. This amount of water is equal to approximately 70% of the current total municipal, recreational/irrigation and agricultural water demands of 19,100 acre feet per year. The 2015 USGS study also concluded that on average 5,700 acre feet of inflow comes into the Borrego Basin annually, therefore an estimated reduction in yearly water usage from 19,100 acre feet down to 5,700 is needed for sustainability (-70%). The County of San Diego and Borrego Water District, in cooperation with stakeholder groups in the Valley are now embarking upon the development of the Borrego Basin Groundwater Sustainability Plan (GSP) .