FAQs

Read below for answers to several common questions about the Sustainable Groundwater Management Act (SGMA), Groundwater Sustainability Agencies (GSAs), and Groundwater Sustainability Plans (GSPs). For more information about a specific topic, read one of the FAQ pages below or check out the fact sheets in our resources library.

What is “sustainable” groundwater management?

SGMA defines sustainable management as managing and using groundwater in a way that can be sustained over a long period of time. Specifically, SGMA defines sustainable yield as the amount of groundwater that can be withdrawn annually without chronically lowering groundwater levels, causing seawater intrusion, degrading water quality, causing land subsidence or depleting interconnected surface water (for example, creeks, streams and rivers) in a manner that causes significant and unreasonable impacts. Local definitions of sustainable management will be defined in the GSPs created in each basin.

What areas of Sonoma County are affected?

While Sonoma County has 14 state-identified groundwater basins and sub-basins, only three – Santa Rosa Plain, Sonoma Valley and Petaluma Valley – are currently designated medium priority by the California Department of Water Resources. SGMA requires each of these three basins to have a locally-adopted GSP by 2022. A GSP is not required for Sonoma County’s 11 low- and very low-priority basins and subbasins, and SGMA does not apply outside of mapped groundwater basins. Basins are prioritized based on a number of factors, including population, amount of irrigated agriculture, and reliance on groundwater. The California Department of Water Resources may reprioritize basins in the future, which could result in medium-priority basins moving into the high-priority category and low- or very-low priority basins moving into the medium category.

Who will manage groundwater in Sonoma County?

The first requirement of SGMA was to form a Groundwater Sustainability Agency (GSA) by June 2017. The three GSAs formed in Sonoma County are regulatory bodies that can manage groundwater using a variety of tools, including setting fees, requiring water use reporting, regulating how much groundwater is pumped, and monitoring wells. This is the website for the Petaluma Valley GSA; click here for more information on the GSA for the Santa Rosa Plain GSA or the Sonoma Valley GSA.

When will the groundwater sustainability plan be in place?

SGMA provides specific timelines to implement the new requirements. Some key deadlines are below:

What will happen if state intervention becomes necessary?

SGMA states that if local GSAs fail to follow the established timeline, then the State Water Resources Control Board will step in and intervene in local groundwater management. More information on this process may be found here.

Will stakeholders and the general public be involved in implementing SGMA?

SGMA requires the GSA to involve groundwater users and the general public in the development of the GSP. Diverse stakeholders and the public at large will continue to be involved in implementing SGMA in Sonoma County, just as local agencies, agriculture, the environmental community, and private well owners had critical roles in the Basin Advisory Panels in Sonoma Valley and Santa Rosa Plain basins, though this process did not happen in the Petaluma Valley basin. Collaboration and stakeholder involvement will be key to the successful implementation of SGMA. Opportunities for stakeholder involvement include open public meetings of the GSA boards and advisory committees, advisory committee membership, and periodic community meetings.

Does SGMA affect my water rights?

Section 10720.5 of the SGMA specifies that the act and any groundwater management plans developed as a result of the act do not affect surface or groundwater rights. To learn more, visit the Resources library.

Who will pay for the implementation of SGMA and any programs/projects?

During the GSA- formation process, GSA-eligible entities applied for and received grants funded by Proposition 1 to cover costs of GSA formation. In addition, the Petaluma Valley GSA received a $1 million Proposition 1 grant for GSP development. For the first two years of GSA operation, costs not covered by grant funds are being covered by member agencies, in amounts specified in the JPA forming the GSA. The GSA will continue to aggressively pursue Proposition 1 and other grant opportunities to offset local costs. The law also allows for the GSA to collect fees to help pay for the costs of preparing and implementing the GSP. Read more on the Finances page.

How will the new law affect me?

SGMA gives GSAs broad authority to manage groundwater, including authority to increase groundwater supply (for example, projects to increase groundwater recharge or replenishment) and to manage groundwater demand through well monitoring and, if necessary, regulating groundwater extraction. However, SGMA does not authorize GSAs to meter domestic groundwater wells that use less than 2 acre-feet per year. An acre-foot is equivalent to 325,851 gallons, or the amount of water is takes to cover an acre with one foot of water. According to the Water Education Foundation, an average California household uses between one-half and one acre-foot of water per year for indoor and outdoor use. Local agencies also have authority to assess fees for groundwater management.

The GSA will decide which of these new authorities, if any, are needed to sustainably manage groundwater in each affected basin. Given that the groundwater sustainability process is only beginning, including numerous opportunities for public and well owner input, identifying specific impacts of the new law on well owners is speculative. Once the GSP is adopted, the impacts could vary depending on where your well is located to the amount of water you pump annually; the GSA will decide what is necessary to sustainably manage groundwater in the basin.

Will SGMA limit how much water I can use?

The GSP will include programs and projects needed for the basin to become sustainable within 20 years. Under SGMA, it is possible that a GSP could limit the water pumped by individual well owners who pump more than two-acre feet annually. An acre-foot is equivalent to 325,851 gallons or the amount of water is takes to cover an acre with one foot of water. According to the Water Education Foundation, an average California household uses between one-half and one acre-foot of water per year for indoor and outdoor use.