SGMA 101

Groundwater is a critical resource for California’s ecosystems, communities, and economies. Over the last century, California has experienced groundwater overdraft that has resulted in declining of groundwater. In response to decades of overuse and a prolonged drought, the California legislature adopted the Sustainable Groundwater Management Act of 2014 (SGMA, pronounced sigma).

In a nutshell, what is the Sustainable Groundwater Management Act?

The objective of sustainable management is to balance the resource needs of communities, economies, and the environment. The Sustainable Groundwater Management Act (SGMA) is groundwater legislation that requires that groundwater resources remain a reliable and healthy source of water for all those who depend on it. SGMA requires that we consider and protect all uses of groundwater. This includes farms, cities, businesses, tribes, and households that depend on local groundwater, in addition to the creeks, rivers, marshes and wetlands that also rely on groundwater resources. Fundamentally, SGMA is built on the premise that local knowledge and the best available science will create the most effective plan for understanding and managing local groundwater resources. 

The Sustainable Groundwater Management Act corrects our current course to ensure the long-term reliability of our connected surface water and groundwater resources.

SGMA Snapshot

The SGMA Timeline

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Groundwater Subbasins in California

The Department of Water Resources (DWR) divides groundwater basins across California into localized Subbasins. Subbasin boundaries are a combination of political (county lines, city lines) and hydrogeologic boundaries (aquifers, faults, streams). California leaders recognize that the best way to achieve groundwater sustainability throughout the state is to allow local groups who understand their community best, to create these plans at the local level.

There are a total of subbasins in California. Of those, have been rated “critically overdrafted” or “high” priority.

Groundwater Sustainability Agencies (GSAs)

Recognizing that management of groundwater is best accomplished at the local level, the Sustainable Groundwater Management Act empowers existing local water agencies such as municipal water agencies, reclamation districts, counties or irrigation districts to form Groundwater Sustainability Agencies (GSAs). These agencies are responsible for working with their local communities to develop a Groundwater Sustainability Plan (GSP), which includes:

  1. Assessing current groundwater conditions and characterizing water use
  2. Working with the beneficial users and uses in their subbasin to develop and implement sustainability goals to address current and future challenges
  3. Identifying projects, programs, and actions to meet sustainability goals
  4. Developing monitoring networks to track the achievement of the sustainability goals

GSAs are required to, encourage the active involvement of diverse social, cultural, and economic elements of the population within the groundwater basin prior to and during the development . . . of the groundwater sustainability plan.” (Wat. Code § 10727.8, subd. (a)

If a GSA does not develop a GSP to set a path towards sustainability or if the subbasin does not meet its sustainability goals, the State will take over the management of the local basin.

Groundwater Sustainability Plans (GSPs)

GSAs are currently developing Groundwater Sustainability Plans for dozens of groundwater basins across the State. The plans will address the following questions:

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Why should you get involved?

Over the next two years, you will have opportunities to provide input to your local GSAs. You can help guide the development of the local GSP by providing local information about your groundwater use (e.g. well construction) and by representing your interests as a local groundwater user.

This plan will guide groundwater management in your community for generations to come.

Participation Toolkit

Find more resources & learn more!


Find your Groundwater Sustainability Agency


Subscribe to the Solano Collaborative for e-newsletters


Provide information about your water interests and needs


Provide comments on draft sections of the Groundwater Sustainability Plan


Attend a local meeting in your community