The Sustainable Groundwater Management Act (SGMA), passed by the California Legislature in 2014, is an effort to regulate the use of groundwater in the state so that it
is sustainable into the long-term future. In a number of places in the state, notably the San Joaquin Valley, groundwater levels are down sharply over the past few decades, causing increased pumping costs, subsidence, and other undesirable consequences.

SGMA requires all medium and high priority basins (the San Gorgonio Pass Subbasin is a medium priority basin) to develop a Groundwater Sustainability Plan (GSP) by January 2022. The contents of this plan are prescriptive and well defined by SGMA. Major components of each plan are a water budget for the subbasin, a hydrogeological conceptual model of the subbasin, and a stakeholder outreach plan.

The plan then must be implemented by the local Groundwater Sustainability Agency or Agencies. SGMA requires local governmental agencies and stakeholders to work together to formulate the GSP. Local governmental agencies may include water districts, cities,
and counties. Stakeholders may include pumpers, taxpayers, developers, homeowners’ groups, environmental groups, and other organizations.