TO: NAPA COUNTY ZONING ADMINISTRATOR
FROM: Joseph Dotta for Brian D. Bordona - Planning, Building, Environmental Services Director
REPORT BY: Joseph Dotta, Planner I
SUBJECT: Harvest STOMP 2026 at Opus One Winery
RECOMMENDATION
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Harvest STOMP 2026 at Opus One Winery Temporary Event Category 4 Application #P26-00169
CEQA Status: Ministerially Exempt from the provisions of the California Environmental Quality Act (CEQA). The project site is not included in the list of hazardous materials sites pursuant to Government Code Section 65962.5.
Request: Approval of an application for Temporary Event License filed by Arwen Gallenkamp on behalf of the Napa Valley Grapegrowers to hold Harvest STOMP 2026 at Opus One Winery. This new Category 4 event is an annual fundraising gala to raise funds for Napa Valley Grapegrowers and Napa Valley Farmworkers Foundation. Festivities will include a reception with food and wine, auction and live band performance. The event will be for a maximum of 550 attendees from 6:00 pm to 11:00 p.m. on Saturday, August 22, 2026. This event is proposed to be held on one parcel located at 7900 St Helena Hwy, Napa, CA, Assessor’s Parcel # 031-020-007-000. The parcel located at 7848 St Helena Hwy, Napa, CA, Assessor’s Parcel # 031-020-009-000, will not feature event activities and its driveway will be used for site access.
Staff Recommendation: Find that the project is Ministerially Exempt from CEQA and approve the Temporary Event Application.
Staff Contact: Joseph Dotta, Planner I, (707) 299-1361 or Joseph.dotta@countyofnapa.org.
Applicant Contact: Caleb Mosley, Executive Director, Napa Valley Grapegrowers, cmosley@napagrowers.org. Arwen Gallenkamp, Event Productions, arwen.gallenkamp@gmail.com.
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EXECUTIVE SUMMARY
That the Zoning Administrator:
1. Find that the project is Ministerially Exempt from the CEQA; and
2. Approve the Temporary Event Category 4 License P26-00169.
Discussion: On June 22, 2026, Arwen Gallenkamp, on behalf of Napa Valley Grapegrowers, applied for a permit for a Category 4 Temporary event to be held at Opus One Winery on Assessor’s Parcel # 031-020-007-000 (and Assessor Parcel # 031-00020-009 for access only) on Saturday, August 22, 2026, for a maximum of 550 people from 6:00pm-11:00pm. The event is the Napa Valley Grapegrower’s annual fundraising gala to raise funds and to benefit the Napa Valley Farmworkers Foundation. Festivities will include a reception with food and wine, auction and live band performance. This event is open to the public via ticketed admission, with attendance managed through ticket sales. Parking for this event will be accommodated on-site for all vendors, staff, and guests. Guests will utilize a walking path to access the main event area with golf carts acting as shuttles for those with accessibility needs. Vendor trucks will access the site via the Northern access road off of Highway 29. Staff, guests, and rideshare will use the main entrance off of Highway 29 and exit south to Oakville Cross Road.
Unlike conditional use permits or other discretionary permits, temporary event permits are ministerial and shall be approved and issued if the minimum standards contained in the “Minimum Standards Table” of the Temporary Events Manual (the Minimum Standards) are met. Since the permit is ministerial, the purpose of the hearing is for the Zoning Administrator to evaluate and consider evidence regarding whether the applicant has demonstrated that the minimum standards have been met or are likely to have been met prior to the event. The Zoning Administrator cannot impose standards, conditions, or restrictions on the permit beyond what is provided in the Minimum Standards. As such, the public comment should be limited to whether the Minimum Standards have or have not been met or will likely be met before the event permit. Any permits, approvals or authorizations required from other agencies, departments, or divisions must be satisfied prior to the event.
A temporary event license is a ministerial permit and therefore, such action is final and not subject to the appeal provisions under Napa County Code 2.88.
Staff recommend approval of the request permit subject to compliance with County Code Chapter 5.36 and all applicable Minimum Standards in the Temporary Events Manual prior to the event.
ENVIRONMENTAL IMPACT
ENVIRONMENTAL DETERMINATION: Pursuant to Napa County’s Local Procedures for Implementing the California Environmental Quality Act (CEQA) and Sections 15022 and 15268 of the State CEQA Guidelines issuance/approval of a temporary event license shall be conclusively presumed to be ministerially exempt from the requirements of CEQA and thus preparation of an environmental document is not required. The project site is not included on a list of hazardous materials sites complied pursuant to Government Code Section 65962.5.
BACKGROUND AND DISCUSSION
Property Owner: Opus One Winery
Applicant/Representative: Caleb Mosley, Executive Director, Napa Valley Grapegrowers, cmosley@napagrowers.org. Arwen Gallenkamp, Event Productions, arwen.gallenkamp@gmail.com.
General Plan Designation: Agricultural Resource (AR)
Zoning: Agricultural Preserve (AP)
Project Site Area: 49.17 (APN: 031-020-007 - Event Parcel) and 49.34 acres (APN: 031-020-009 - Parcel used for Site Access only)
Application Submittal Date: June 22, 2026
Code Compliance History: There are no new violations on record with this proposed activity.
Discussion: On June 22, 2026, Arwen Gllenkamp, on behalf of the Napa Valley Grapegrowers, requested a license to hold Harvest STOMP 2026 on Saturday, August 22, 2026, with the event taking place on Assessor’s Parcel # 031-020-007-000. The event is the Napa Valley Grapegrower’s annual fundraising gala to raise funds and to benefit the Napa Valley Farmworkers Foundation. Festivities will include a reception with food and wine, auction and live band performance. Parking for this event will be accommodated on-site. A maximum of 550 people will be in attendance, which will be controlled through public ticket sales. Hours of the event are 6:00pm-11:00pm. Per the venue site plans, ADA restrooms will be available for the public as required by the Minimum Standards.
Noise: Since the temporary event permits are ministerial, applicants are not required to submit a noise study for County review. Furthermore, County Code Section 5.36.010 exempts temporary events from the County’s noise standards, provided such events are conducted pursuant to a license issued pursuant to Chapter 5.36, respectively, of the code and then only as specifically required by such chapter of any manual of standards adopted by resolution of the Board of Supervisors for the purpose of implementing such chapter.
Permit/License Process: Since the event will have a maximum of 550 attendees, under County Code Section 5.35.015.G, it is considered a Category 4 event. This will be the first Category 4 event to occur on this parcel this year.
Event Authorization: County Code Sections 5.36.050.B requires a public hearing before the Zoning Administrator prior to issuance of a Category 4 license/permit. This Category 4 event meets the definition of a “temporary event” under County Code section 5.36.010, which means “…any festival, fair, show, house or garden design tour, concert, dance, rally, parade, demonstration of competition of creative athletic form, or any other gathering or assemblage of individuals for the purpose of observing or engaging in expressive activities within the ambit of the First Amendment of the United States Constitution and Sections 2, 3, and 4 of Article 1 of the California Constitution, including, but not limited to music, dance, theater, speech, athletics, or any other visual, audio, or tactile arts, or combination thereof.”
Per County Code Section 5.36.050B, within thirty days following receipt of a completed application, a public hearing shall be scheduled before the Zoning Administrator on the Department’s recommendation. At least ten days prior to the hearing, notice shall be given to property owners within 1,000 feet, interested persons, and mailed to the property owners and emailed to interested parties. The Notice was published in the Napa Valley Register on July 16, 2026.
The application is complete per the County’s application checklist and the required Certificate of Insurance was provided. Other agencies and departments were notified of the application and have determined the application meets or will likely meet the Minimum Standards that are within those agencies and departments’ jurisdictional authority.
Public Comments: As of the date this report was released, we have received no public comments.
SUPPORTING DOCUMENTS
1. Attachment A - Application
2. Attachment B - Site Plan