The district defined seven management strategies, which the research team evaluated against climate, land use and regulatory uncertainties using a water resources model. First, we worked with district stakeholders to outline the parts of the plan and set measureable objectives for sustainability. We tested a participatory process with the Yolo County Flood Control and Water Conservation District, a water-limited irrigation district in the Central Valley. Successful GSPs will require an effective participatory decision-making process.

Three years after California passed the Sustainable Groundwater Management Act (SMGA), groundwater sustainability agencies (GSAs) are now preparing to develop their groundwater sustainability plans (GSPs), the blueprints that will outline each basin's road to sustainability. Whether and how SGMA achieves its goals hinges on open questions about its implementation. The nature of the revolution, however, is not yet clear. OCTOBER–DECEMBER 2016 165 Leigh Bernacchi C alifornia is grappling with the implications of the Sustainable Groundwater Management Act (SGMA), a visionary and potentially revolutionary law that could profoundly change the way water is managed in the state.GSAs must be formed by 2017 and GSPs completed by 2020 or 2022. A GSP provides the template for achieving sustainable groundwater manage- ment in a GSA’s jurisdiction within 20 years.

New local entities called groundwa- ter sustainability agencies (GSAs) will do the bulk of the work of implementing SGMA by developing, implementing and updating groundwater sustain- ability plans (GSPs).

To accomplish these objectives, SGMA relies primarily on local control, with an enforcement backstop provided by the State Water Resources Control Board. In concept, this forward-thinking framing aligns the requirements of the law with the im- pacts of unsustainable groundwater use and the actions needed to address those impacts. These are “significant and unreasonable” (1) lowering of groundwater levels, (2) reduction in groundwater storage, (3) seawater intrusion, (4) water quality degradation, (5) land subsidence and (6) impacts on beneficial uses of interconnected surface waters. To address the problem of chronic groundwa- ter overdraft, SGMA, adopted in 2014, declares a state policy of managing groundwater sustainably, with sustainability defined as avoiding six specific undesirable results. Falling water tables are driving a well-drilling race that threatens farms, communi- ties and ecosystems. In some areas, declining groundwater levels have caused the land surface to subside at a rate of more than one inch per month, damaging roads, canals and pipelines. In part because of California’s historical lack of groundwater use regulation, this crucial resource is threatened. Groundwater accounts for between one-third and two-thirds of California’s water use in a given year and serves as a lifeline when surface water runs low during drought. In the foreground is a pressure relief structure for subsurface water pipes. Outlook Unanswered questions for implementation of the Sustainable Groundwater Management Act Michael Kiparsky, Director, Wheeler Water Institute, Center for Law, Energy & the Environment, UC Berkeley School of Law A rig drills a new well in Merced County.

Outlook unreplied