Homepage for the Groundwater Resources Advisory Committee


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Groundwater Resources Advisory Committee

The Napa County Groundwater Resources Advisory Committee (GRAC) held its sixteenth and final meeting on February 27, 2014. A final report and presentation on the GRAC's recommendations will be provided to the County Board of Supervisors -tentatively scheduled for April 8, 2014. GRAC meeting agendas, minutes and related materials can be found below.

Meeting agendas and materials  


Nov. 5, 2014  Water Availability Analysis (WAA) Update Workshop
  Introduction Presentation provided by Patrick Lowe
  WAA Overview Presentation and Proposed Updates provided by Steve Lederer
        Board of Supervisors Meeting - April 8, 2014

 April 8, 2014

GRAC Final Report and Recommendations - see Item No. 9B for staff report, attachments and meeting video


     Agenda       Groundwater Workshop of March 10, 2014
March 10, 2014

Presentation: GRAC Update - Monitoring for Sustainability

Presentation: Understanding Groundwater in Napa County

Presentation: 2014 Drought Update


        Groundwater Reports and Monitoring Plan

Updated Hydrogeologic Conceptualization and Characterization of Groundwater Conditions (Full Report 32mb - Jan. 2013)

Napa County Groundwater Monitoring Plan (Jan. 2013)


     Agenda                      Handouts and Presentations
Feb. 27, 2014

Item 3b Handout: GRAC Work Plan

Item 5a Presentation: 2014 Drought Update

Action Minutes

Meeting Summary


Dec. 12, 2013

See agenda link - no additional handouts or presentation materials were provided


Oct. 24, 2013

See agenda link - no additional handouts or presentation materials were provided


July 25, 2013

Presentation: GRAC Outreach

Action Minutes  

June 27, 2013

Item 3d Handout: Response to GRAC Questions regarding Soil Root-Zone Water Balance Model

Item 3d Handout: Estimated Recharge in Napa Valley Area by Hydrogeologic Period

Action Minutes


April 25, 2013

Item 5b Handout: Follow-Up Question - MST Geology

Item 5b Handout: Updated Hydrogeologic Report and Groundwater Monitoring Plan Cliff Notes

Action Minutes

Feb. 28, 2013

2013 Updated Hydrogeologic Conceptualization and Characterization of Groundwater Conditions (Full Report 32mb)

2013 Napa County Groundwater Monitoring Plan

Action Minutes

Jan. 31, 2013

Item 5c Presentation: Updated Hydrogeologic Conceptualization Part 1: Report Overview and Recharge

Item 6a Handout: Draft Groundwater Data Management and Disclosure

Action Minutes

Oct. 25, 2012

Item 3c Handout: GRAC Work Plan Timeline

Item 5a Handout: Outline of Groundwater Data Mgmt. and Disclosure Guidance Document

Item 5a Handout: Publication of Data and Data Mgmt. and Disclosure Procedures

Item 5a Presentation: Groundwater Data Management and Disclosure

Item 5a Presentation: Landowners Perspective on Groundwater Monitoring

Item 5b Presentation: Draft Napa County Groundwater Monitoring Plan 

Action Minutes


Aug. 23, 2012

Item 5a Presentation: Draft Napa County Groundwater Monitoring Plan

Action Minutes  

July 26, 2012

Presentation: Update on WICC Board Activities

Presentation: Update on GRAC Activities

Handout: Draft GRAC Outreach Brochure

Action Minutes

June 28, 2012  

Item 5b Presentation: Draft Groundwater Monitoring Plan 2012

Item 5b Handout: Draft Groundwater Monitoring Plan 2012

Item 6b Handout: CASGEM and Napa County Programs Participant Letter

Item 6b Handout: GRAC General Outreach Brochure

Action Minutes

April 26, 2012  

Item 5a Presentation: Groundwater Conditions and Monitoring Recommendations

Item 5a Presentation: Conceptualization and Characterization of Hydrogeologic Conditions

Item 5a Handout: Updated Comments and Questions Regarding Groundwater Conditions

Item 5b Presentation: History and Update on the Milliken-Sarco-Tulocay (MST) Basin

Item 5c Presentation: Groundwater Monitoring Plan Annotated Outline
Action Minutes

Feb. 23, 2012  

Item 5a Presentation: Groundwater-Surface Water Interaction

Item 5b Presentation: Sonoma County Groundwater Monitoring Program

Item 5f Presentation: Well Location/Confidentiality

Item 5f Handout: State Water Code and Well Completion Report Form

Action Minutes

Dec. 12, 2011  

Item 3b Handout: Signed Resolution Amending Bylaws

Item 5a Presentation: Groundwater Study Results Part 2

Item 5a Handout: Comments and Questions Regarding Groundwater Conditions

Item 5a Handout: Requested Groundwater Study Area Maps w/Roads

Item 5b Presentation: CASGEM Program Update

Item 5b Handout: CASGEM Well Location Accuracy

Action Minutes

Oct. 27, 2011  

Item 6a Handout: County Groundwater Policies

Item 6b Presentation: Stakeholder Assessment

Item 6c Presentation: Groundwater Study Part 1

Action Minutes


Additional Background

On June 28, 2011 the Board of Supervisors approved creation of a Groundwater Resources Advisory Committee (GRAC). The GRAC will assist County staff and technical consultants with recommendations regarding groundwater, including data collection, monitoring, well pump test protocols, management objectives, and community support. A 15 member committee was appointed on September 20, 2011.

Feb. 14, 2011, Groundwater workshop

The Napa County Board of Supervisors held a Groundwater Workshop on Monday, Feb. 14, 2011. The workshop provided the Board with an update on groundwater resources throughout the county: what we know, what we don’t know, and how groundwater and County functions related to water resources are currently administered.

Workshop objective:

  • To bring everyone to the same level of understanding about groundwater in preparation to address the Board's strategic objective: "Presentation and action on a work plan for the development of a comprehensive county-wide policy and program for potable and recycled water." 

Workshop Elements

  •  Staff presentation on surface water supplies, General Plan implementation actions about water, and an overview of a stakeholder assessment study 
  •  Consultant presentation on county groundwater resources, review of County monitoring and data management systems, update on State regulatory requirements, and recommendations 
  •  Guest speaker, Paul Kelly, providing a perspective on Sonoma County's recent groundwater experience 
  •  Staff summary of County roles and responsibilities in water, and 
  •  Discussion with the Board on immediate next steps 

Workshop Presentations & Handouts - Feb. 14, 2011




Groundwater Reports and Data

The documents below were developed by Luhdorff & Scalmanini Consulting Engineers (LSCE) as part of a county-wide assessment of groundwater resources and data, and development of recommendations for implementing a comprehensive groundwater monitoring program in Napa County.

Executive Summary (Feb. 2011; an executive summary for the Napa County Comprehensive Groundwater Monitoring Program Study conducted by LSCE)

Data Management System (Nov. 2010; plan for gathering and storing data related to well construction, groundwater levels, pumping and more)

Data Collection Procedures (Nov. 2010; review, assessment and recommendations regarding accuracy, reliability and usability of data)

Conceptual Model Review (Nov. 2010; review of the 2005 Groundwater Model)

Precipitation and Streamflow Monitoring (Jan. 2010; guidance on the design of a countywide network of precipitation and streamflow monitoring stations)

Groundwater Conditions Report - Text Only (Feb. 2011; comprehensive report and recommendations on the status of groundwater in Napa County)

Groundwater Conditions Report - Figures (18mb) (Feb. 2011; figures that accompany the text-only document above)

Groundwater Conditions Report - Plate 1 (Feb. 2011; USGS map that accompanies the text-only document above)

Groundwater Conditions Report - Appendix (Feb. 2011; appendices, data to support the text-only document above)

Groundwater Planning and Review of Permitting and Ordinances - Text Only (Jan 2011; review of how groundwater planning and management fits in with the General Plan and current permitting policies and procedures)

Groundwater Planning and Review of Permitting and Ordinances - Appendix  (Jan. 2011; appendices to support the text-only document)

Other Related Links & Documents

Groundwater Stakeholder Assessment (Aug. 2010; an assessment of the feasibility of a collaborative groundwater data gathering effort in Napa County, prepared by the Center for Collaborative Policy, Sacramento CA)

California Statewide Groundwater Elevation Monitoring (CASGEM) Program  

Liquid Assets: Improving Management of the State's Groundwater Resources

2050 Napa Valley Water Resources Study

Senate Bill x7-7 2009 Urban and Agriculture Water Conservation