The Evolving Landscape of Groundwater Management in California

California passed the Sustainable Groundwater Management Act in 2014. The SGMA requires that (1) new Groundwater Sustainability Agencies form by June 2016 in all SGMA high and medium priority basins, (2) new groundwater sustainability plans (GSP) by January 2020 (critically overdrafted basins) or 2022 (other basins), and (3) have sustainable groundwater management within 20 years of GSP adoption. Th4e GSPs are required to include description of the basin hydrogeologic conceptual model, water budget and groundwater conditions, development of minimum thresholds, measureable objectives, and interim milestones to achieve sustainability, description of projects and management actions, and a funding plan. The SGMA defines six sustainability indicators for the development of sustainable management criteria: (1) chronic lowering of groundwater levels (2) reduction of groundwater storage, (3) seawater intrusion, (4) water quality degradation, (5) land subsidence from groundwater extraction, and (6) depletion of interconnected surface water from groundwater pumping. Some of the challenges to complying with SGMA and achieving sustainability include that many GSAs were formed within basins, making it more difficult to assure collaboration, cooperation and consistency in data used and assumptions. Additionally, assessing surface water depletion from groundwater extraction is technically difficult, especially considering the lack of adequate monitoring networks for stream flow and shallow groundwater, and understanding where streams are losing and gaining. Addressing the water quality sustainability indicator will also be particularly challenging because SGMA is silent on what is required, there is no state guidance, and there are many regulations related to contamination. A brief description of the California hydrogeologic and policy setting will be presented along with statewide groundwater depletion conditions, a brief review of the requirements of SGMA, new regulations, progress to date, and identification of key challenges and opportunities as California works to meet SGMA mandates.