The Napa County Board of Supervisors has approved work plans for implementing the county’s groundwater sustainability plan.
The work plans — prepared by water consultants Luhdorff & Scalmanini Consulting Engineers, ERA Economics and Stillwater Sciences — aim to help the county meet its goal to reduce pumping from the subbasin by 10 percent.
They offer guidance on conserving water at vineyards, wineries and other places where water is used throughout the county; reducing groundwater pumping, and protecting and supporting terrestrial and aquatic groundwater dependent ecosystems.
The work plans are designed to help roll out the Napa Valley Subbasin Groundwater Sustainability Plan, a 20-year roadmap to ensure that groundwater is managed sustainably within a groundwater basin. The GSP was first submitted on Jan. 31, 2022, and approved on Jan. 26, 2023, by the California Department of Water Resources. But behind-the-scenes work on addressing water conservation has been years in the making.
“We’ve been at it for 10 years now on this very important piece of legislation, the Sustainable Groundwater Management Act that was signed by Gov. Jerry Brown, a feature of which was the idea that groundwater should be managed locally,” said Jamison Crosby, natural resources conservation manager of Napa County’s Natural Resources Division. “And I personally think that we’ve demonstrated that, as local government in Napa County, we are up to the task of managing our natural resources.”
Grape growers voice their approval
During the meeting where the work plans were approved, local viticulturists and representatives from Napa Valley Grapegrowers, a nonprofit representing more than 600 Napa grape growers, expressed support of the GSP’s rollout while offering additional feedback.
Molly Moran Williams, NVG industry and community relations director, pointed out that de minimis — or household — water users are not included in the work plans although they represent a disproportionately high-intensity use.
In Water Year 2023, a time period from Oct. 1, 2022, through Sept. 30, 2023, agricultural use made up 74 percent of groundwater pumping, while municipal and small public water systems together used 9 percent and domestic users consumed 17 percent, according to the county’s Water Year 2023 report.
She further pointed to an NVG survey issued to the organization’s members that found 89 percent of growers were interested in water conservation education, and 88 percent said they already monitor their water consumption.
“Meanwhile, the majority of survey respondents also noted that costs and uncertainty of efficacy were among the greatest barriers for furthering conservation,” she continued.
Williams encouraged the county to work on incentive programs for farmers who allow the county to obtain monitoring data from their facilities.
The supervisors agreed, and Crosby reported that her team is piloting a program that aims to enlist growers who are utilizing effective conservation practices and who would be willing to share with the county pumping and groundwater level data.
Water Year 2023 report heads to the DWR
The board’s unanimous vote also authorized staff to submit the Napa County Groundwater Sustainability annual report to the California Department of Water Resources for Water Year 2023.
The weather whiplash from long-term drought in previous years to a deluge in 2023 resulted in reduced total pumping and a “wet year” designation. However, Vicki Krestinger Grabert, senior hydrologist with Luhdorff & Scalmanini Consulting Engineers, noted that climate conditions will require ongoing adaptation and conservation practices.
“We have an uncertain climate and extreme events occurring,” Krestinger Grabert explained. “The basin is very responsive to these events, both when they’re drier and wetter conditions, and there’s a need to look at other opportunities to try and buffer those effects.”
Due to severe drought conditions in water years 2021 and 2022, subbasin pumping exceeded recommended levels, according to the report.
“The community is very proactive about stewardship and conservation practices,” Krestinger Grabert said. “In discussions with all of the different sectors, we see opportunities for expanding those measures voluntarily.”