Sustainable groundwater plan launched
By Jay Gamel
After decades of research and planning, a plan to reverse Sonoma Valley’s continuing groundwater losses has been unanimously approved by an independent agency formed for that purpose. That plan will be submitted to the state water agency for approval in January.
The Sonoma Valley Groundwater Sustainability Agency (SVGWA) unanimously adopted a state-mandated Groundwater Sustainability Plan (GWP) for the Sonoma Valley subbasin on Dec. 6. Similar plans are currently being adopted for the Santa Rosa and Petaluma groundwater basins using the same process.
“The Sonoma Valley Groundwater Sustainability Plan represents a multiyear effort by the local community to lead management of their groundwater basin to ensure sustainable conditions using the best available science and data, while incorporating the input of a variety of stakeholder and groundwater user interests,” said Jay Jasperse, chief engineer and director of groundwater management for Sonoma Water.
Covering 166 square miles, Sonoma Valley’s groundwater basin contains approximately 2,000 domestic, agricultural, and public supply wells. In 2012, it was estimated that 5.83 billion gallons of water was used in Sonoma Valley. Nearly 60% of the valley’s water supply comes from groundwater. The remainder comes from the Russian River, other local surface water, and recycled water, according to the agency’s website.
Since local groundwater losses were first documented in 2007, extensive studies have been made and in-depth planning to stem those losses was set in motion. Those studies led to all three Sonoma County basins being designated as critical by the California Department of Water Resources (DWR), which was given the authority to require remedial management plans for groundwater throughout the state with the passage of the Sustainable Groundwater Management Act (SGMA) in 2014. The DWR has regulatory oversight over the plans, as well as the authority to impose plans in the event local governments fail to act or come up with unacceptable plans.
SGMA (think “sigma”) also authorizes fees to be imposed for groundwater use to underwrite the cost of planning and implementing groundwater recovery systems, with the goal of achieving groundwater sustainability by 2042 and maintaining it through 2070.
Groundwater historically has been free of any government regulation in the western United States, though it has been the source of many conflicts since the 19th-century European migrations to the region. Diminishing rainfall and rising temperatures have made everyone more aware of California’s dwindling water supply, already strained to the max by population and agriculture demands. Conservation measures have been imposed in most years for nearly a decade. The new groundwater plan predicts weather impacts on groundwater supplies may get much worse over the next 20 years.
While initial start-up costs were well funded by state and local water agencies, future plan expenses may be borne by users, both commercial and agricultural. At this point, wells pulling less than two acre feet of water a year are exempt. An acre foot is defined as one acre of surface area covered in one foot of water; it takes 325,851 gallons of water to cover one acre one foot deep, which effectively rules out residential users.
Developing a comprehensive picture of Sonoma County’s groundwater basins was the first step in a process started in 2018. Next came figuring out how to define “sustainability,” and then what it would take to achieve defined goals. Five public workshops were convened throughout the process of developing the Sonoma Valley plan and projects.
The DWR has two years to decide if the Sonoma Valley plan is acceptable after it is submitted in January, but implementation will begin right away, according to Jasperse.
The extensive plan itself describes the subbasin, its water sources, and existing land use and well regulations, with exhaustive coverage of the basin’s geology. It includes a water model and a water budget, including future projections. Sustainable management criteria are included, along with how those criteria will be met. There is a monitoring plan, along with five-year progress reviews that provide an opportunity to update and alter any necessary parts of the plan. The submitted plan also contains indexes of all reference materials and appendices of comments, responses, budgets, monitoring protocols, and projections of future land use and growth.
The first five years of the planning cycle will focus on administration, communication, and engagement development; monitoring and data gathering; determining data gaps; and determining potential projects and management directions. Coordination with state and federal resource agencies will occur, along with “development and implementation of a funding strategy.”
The possible imposition of fees to support groundwater sustainability efforts has concerned water users since the SGMA was passed. While a voluntary approach is favored by all county and private stakeholders, the SGMA provides the legal authority to impose mandatory fees. How that would be done is not specified. Will meters on wells be required? Property taxes or regulatory fees? These and other questions were addressed by a rate and fee study by Oakland-based Raftelis Financial Consultants, Inc., commissioned in 2017. The consultants provided a progress report in December 2018 that is available online (search “sonoma valley groundwater fee study”).
The SVGWA board will discuss fee options at its scheduled meetings on Feb. 28, 2022, and March 28, 2022, and will have a draft fee study available for review by its April 25, 2022, meeting.