Monitoring Well Installation
In 2022, with funding from the California Department of Water Resources Proposition 68 grant, three new multilevel groundwater monitoring wells (GMWs) were constructed by the GSA. These GMWs expand on the existing monitoring network, filling critical data gaps regarding groundwater levels, saltwater intrusion, and interconnected surface water, as the GSA works to track progress toward achieving the Groundwater Sustainability Plan goal of sustainable groundwater management by 2040.
Data collected will provide information from shallow and deep aquifer systems. The new wells range in depth from 103 feet to 505 feet below ground surface. The GMWs will help track seasonal fluctuations in groundwater levels and quantify annual changes in water budget components. The monitoring wells have been instrumented with dataloggers to remotely collect water-level and temperature data on an hourly basis.
Geophysical Investigations: WalkTEM, ERT, & AEM Surveys
In 2022, the GSA completed a geophysical investigation of portions of the basin to further characterize the basin and refine the basin hydrogeologic models for Groundwater Sustainability Plan implementation. Ground-based transient electromagnetic (WalkTEM) and Electrical Resistivity Tomography (ERT) geophysical surveys were performed and correlated with airborne electromagnetic (AEM) and borehole data from the DWR Statewide AEM Project. These surveys will be used to help fill data gaps related to saltwater intrusion and water quality in the southern portions of the basin. This project was completed with funding from the California Department of Water Resources Proposition 68 grant.
Read the full report below:
Outreach to Rural Well Owners Underway
Approximately 9,500 rural well owners in Sonoma County received surveys designed to elicit their concerns and ideas about local groundwater conditions. The purpose of the survey was to raise awareness about local groundwater management and to solicit feedback from well owners regarding any concerns they may have about groundwater in the basin. The survey results were used as the basis for focus groups to provide an opportunity for more in-depth discussions of issues and ideas for improving groundwater conditions.
This joint project of the county’s three Groundwater Sustainability Agencies (GSAs) was the first step in an engagement project designed to educate and receive feedback from well owners in the Petaluma Valley, Santa Rosa Plain and Sonoma Valley groundwater basins.
Practitioners Work Groups
The three Sonoma County GSAs received funding from California Department of Water Resources through the California Drought, Water, Parks, Climate, Coastal Protection, and Outdoor Access for All Act of 2018 (Proposition 68) to facilitate four work groups comprised of technical subject experts. The work groups were formed to help with the development of the Groundwater Sustainability Plans in four areas:
- Rural residential population projections;
- Agricultural water demand projections;
- Groundwater-dependent ecosystems; and
- Interconnected surface water depletion.
The work groups began meeting in summer 2020 and were facilitated by a neutral facilitator from the Consensus and Collaboration Program with CSU Sacramento. The work group products were shared with the Board and Advisory Committees of the GSAs, and used to develop the water budgets and Sustainable Management Criteria for Interconnected Surface Water.
Meeting materials are below:
Agricultural Water Demands:
- Ag Working Group Meeting slides (overview), Summer 2020
- Land-Use Surveys, Fall 2020
- Summary Report, 1-4-21
- Agricultural Expansion and Contraction Model, 1-20-21
Rural Residential Changes:
Interconnected Surface Water:
- Draft Meeting Summary, 10-7-2020
- Presentation, Meeting 1
- Draft Meeting Summary, 12-11-2020
- Presentation, Meeting 2
- Presentation, Meeting 3
- Surface Water Depletion Modeling presentation
- Santa Rosa Plain data, monitoring wells near streams
Groundwater Dependent Ecosystems:
Community Meeting: Defining Groundwater Sustainability in the Petaluma Valley Basin
May 26, 2021 Meeting topics included: overview of the basin and concerns, the groundwater budget (how much water is coming into the basin and how much water is going out — now and into the future), defining sustainability locally, and measuring sustainability.
Community Workshop: Sustainable Groundwater in Our Basin
This public workshop was held on July 15, 2020.
Part 1 includes: Opening Remarks , Welcome, The Petaluma Valley Groundwater Basin and Questions about the basin?
Part 2 includes: Defining Groundwater Sustainability and Questions about sustainability?
Presentations are available here:
Recharging Groundwater Basins: Facts, Myths, Projects and Possibilities
This public workshop held on December 11, focused on how groundwater can be recharged to help better manage and sustain local aquifers.
- Recharge: What is it? How does it work? What are the different types of recharge? | Marcus Trotta, Sonoma Water
- California’s Flood-MAR (Managed Aquifer Recharge) project: What is it? Where is it happening? How does it work? | Kamyar Guivetchi, California Department of Water Resources
- Local recharge efforts: What farmers are doing in Sonoma County to enhance recharge. | Dr. Phil Bachand, Bachand & Associates
Recharge Workshop Flyer
UCCE Groundwater Recharge Flyer
FloodMAR fact sheet
Implementation Factors FloodMAR
FloodMAR Research and Data Development
Increased Shallow Groundwater Levels from RAU-10 sb pamb
ALL Workshop Presentations
Recharge Workshop Notes
Climate Change Workshop
On May 22, the three Groundwater Sustainability Agencies held a public workshop “How a changing climate could affect our groundwater basins – and what we’re doing about it.” The focus of this public workshop was on how climate change must be addressed in the Groundwater Sustainability Plans.
How Models Can be Used to Determine the Impact of CLimate Change on Groundwater Presentation
Sonoma Water Regional Water Resource Climate Adapation Programs Presentation
The Sustainable Groundwater Management Act and Climate Change Presentation