Groundwater management in California: progress in wine regions

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In a previous entry, we discussed the Sustainable Groundwater Management Act and how it affects vineyard owners and grape growers. As we approach the June 30, 2017 deadline for high and medium priority basins to establish their groundwater sustainability agencies (GSA), how are different wine regions getting ready for SGMA compliance? This article reviews the progress in notable California wine growing regions.


The county has elected to submit to the California Department of Water Resources (DWR) an alternative to the required groundwater sustainability plan (GSP). This option is available to communities with a comparable groundwater management plan. The deadline for submission is January 1, 2017. Napa County seems well prepared for the impending SGMA compliance with a draft basin analysis report available for public comment. A public workshop will be held to present the report on November 3, 2016.

The Napa Valley Sub-basin is designated as a medium priority basin. The county is already implementing its own Groundwater Monitoring Program with encouraging results. Recent studies have demonstrated stable water levels in most wells with some stress in others. There are some recent concerns, however, about the construction of new winery and resort projects and their impact on water resources. 


The Sonoma County Water Agency proposed in its initial plan that farming interests play an advisory role in the implementation of the groundwater sustainability plan. However, the wine industry is reportedly seeking a more active voting role in the GSP’s formation and implementation. A list of upcoming public meetings is provided here for those interested.

The Santa Rosa Plain, Petaluma Valley and Sonoma Valley basins are designated as medium priority basins. The Santa Rosa Plan and Sonoma Valley basins already have existing groundwater management plans while the Petaluma Valley basin is still in the exploring stage. Per the existing plan, each of the three basins will have its own GSA and GSP while maintaining coordination with the other basins on the development and implementation of the GSPs.

Paso Robles

The situation is much more complicated for the Paso Robles basin. The most recent effort to elect a management district to meet the GSA formation requirement failed to get voter attention and acceptance. The vast majority of voters voted against forming district, as well as a parcel tax to finance the sustainability plan. This means the Paso Robles basin may be subject to state DWR management as opposed to local management if the community fails to establish a GSA by June 2017.

The Paso Robles basin is a high priority basin subject to critical overdraft. Water basins in this category are required to be managed by a GSP by 2020.


The Salinas Valley Basin consists of both 2 high and 6 medium priority sub-basins in the Central Coast. The Monterey/Salinas wine region largely falls under high priority sub-basins. Discussion on the structure of a GSA and its activities is still ongoing.

The Content Building Institute (CBI) has built an assessment of stakeholder views on the development of the GSA. According to the CBI, most stakeholders believe that agriculture should play a large role in the GSA’s governance activities. With agriculture accounting for 90% of water use in the county’s water use, the right balance between agricultural and other interests will be one of the key challenges for the Salinas Valley Basin. The next stakeholder forum will be held on November 14, 2016.

The SGMA continues to create different levels of uncertainties related to water management for California grape growers. It’s critical for growers to monitor the development of the regulation and identify best water management practices for their vineyards. Our product Sap Flow helps you monitor your water use, identify significant water savings opportunities and enhance the quality of the fruit.

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