TO: Napa County Planning Commission
FROM: Brian D. Bordona, Director Planning, Building and Environmental Services
REPORT BY: Hannah Spencer, Planner III
SUBJECT: Promise Winery Variance (P25-00283-VAR), Use Permit (P22-00384-UP), and Exception to the Road and Street Standards
RECOMMENDATION
title
STEVE MCPHERSON / PROMISE WINERY / VARIANCE P25-00283, USE PERMIT P22-00384-UP, AND EXCEPTION TO THE NAPA COUNTY ROAD AND STREET STANDARDS
CEQA Status: Consideration and possible adoption of a Mitigated Negative Declaration. According to the proposed Mitigated Negative Declaration (State Clearing House No. 2025120435), the proposed project would not have any potentially significant environmental impacts after implementation of mitigation measures. Mitigation measures are proposed for the following areas: Biological and Tribal Cultural Resources. The project site is not included on a list of hazardous materials sites compiled pursuant to Government Code Section 65962.5.
Request: Approval of a Variance to the 300-foot winery setback from a private road and the 600-foot winery setback from Sage Canyon Rd/Hwy 128 to allow winery buildings in the setbacks; a Use Permit to establish a new phased 30,000 gallons per year winery, including the conversion and expansion of an existing barn to a winery, construction of a wine cave and covered crush pad/bottling area for wine production, conversion of an existing accessory dwelling unit to a tasting room, construction of an unenclosed covered parking structure, associated tours and tastings by appointment only, and establishment of a marketing program; and an exception to the Napa County Road and Street Standards (RSS) for project driveway improvements that serve the same overall practical effect of the Napa County Road and Street Standards.
The project is located on an approximately 62.56-acre site within the Agricultural Watershed (AW) zoning district with a General Plan land use designation of Agriculture, Watershed, and Open Space (AWOS) at 2004 Sage Canyon Rd, St. Helena, CA 94574; APN: 032-520-009.
Staff Recommendation: Adopt the Initial Study/Mitigated Negative Declaration and Mitigation Monitoring and Reporting Program prepared for the project and approve the Variance No. P25-00283, Exception to the Road and Street Standards, and Use Permit No. P22-00384, as conditioned.
Staff Contact: Hannah Spencer, Planner III; Hannah.spencer@countyofnapa.org, (707) 253-4018
Applicant Contact: Steve McPherson, 2004 Sage Canyon Rd, Saint Helena, CA 94574
Applicant Representative Contact: Josh Devore, DP&F Law, 1500 First Street, Suite 200, Napa, CA 94559; jdevore@dpf-law.com, (707) 261-7000.
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EXECUTIVE SUMMARY
Proposed Actions:
That the Planning Commission:
1. Adopt the Initial Study/Mitigated Negative Declaration and Mitigation Monitoring and Reporting Program (MMRP) based on recommended Findings 1-7 in Attachment C;
2. Approve the Variance request (P25-00283-VAR) based on recommended Findings 8-12 in Attachment A, and subject to the recommended Conditions of Approval in Attachment B;
3. Approve the Exception to the Road and Street Standards based on recommended Findings 13-15 in Attachment A, and subject to the recommended Conditions of Approval in Attachment B;
4. Approve the Use Permit (P22-00384) based on recommended Findings 16-19 in Attachment A, and subject to the recommended Conditions of Approval in Attachment B.
Discussion:
The Use Permit request (P22-00384) proposes to convert and expand an existing barn to a winery, convert an accessory dwelling unit (ADU) to a tasting room, construct a 5,000 square foot production cave and an adjacent covered crush pad/bottling space, and to construct a small unenclosed covered parking structure with an ADA restroom. A total of 1,229 square feet of indoor winery accessory use and 9,192 square feet of winery production use is proposed, resulting in a 13.4% accessory to production use ratio. The request includes a Variance application (P25-00283) to allow the winery to use existing buildings and construct new buildings within the 300-foot and 600-foot winery road setbacks, approximately 279 feet from the road centerline of a private road and 344 feet to 555 feet from the road centerline of Sage Canyon Rd/Hwy 128. Parking improvements include seven standard and two accessible spaces. Driveway improvements include widening and installation of intervisible turnouts along sub-standard segments of the road in areas outside of stream setbacks, as well as signage and management of vegetation to maintain line of sight. Two outdoor patios will be used for outdoor seating and onsite consumption of wine (Business & Professions Code §23358, 23390 and 23396.5). The winery would be constructed in two phases: Phase I includes the tasting room, winery barn, three employees, and production of 5,000 gallons per year; Phase II increases production to 30,000 gallons per year and adds two employees, after completion of cave and crush pad construction visitation, tours and tasting, retail wine sales, and a marketing program would be established as set forth in the recommended Conditions of Approval in Attachment B.
Staff has reviewed the proposed project and supports granting approval, subject to the attached recommended Findings and recommended Conditions of Approval included in Attachments A and B, respectively. Wineries are conditionally permitted uses within the Agricultural Watershed (AW) zoning district. The project is located within one (1) mile of six (6) existing wineries and is surrounded by mountainous terrain with oak and riparian woodland, shrubland, and grassland interspersed with rural residences, vineyards, and wineries. Most of the project footprint utilizes an existing building complex and surrounding areas disturbed by graveled parking and agricultural uses. Construction activities will result in 7,000+/- cubic yards of earthwork, removal of five oak trees from the building complex, and conversion of 1,500+/- square feet of chaparral habitat. Proposed construction activities avoid impacts to all sensitive biotic communities found on the property, including riparian habitat, oak woodland, serpentine shrubland, and serpentine grassland. Mitigation measures require pre-construction surveys and tribal monitoring to ensure potential impacts to protected plants, wildlife species and tribal cultural resources are significantly reduced. Additionally, the project proposes an overall decrease in water demand (-0.2862+/- acre-feet per year) by converting the ADU and using recycled winery process wastewater for vineyard irrigation. The Water Availability Analysis, prepared by CMP Civil Engineering & Land Surveying Inc., details that the proposed 2.74 acre-feet per year (AFY) water usage is within the parcel’s estimated yearly groundwater recharge total of 50.05 AFY. Sanitary wastewater would be disposed of onsite in an existing conventional septic system that currently serves the existing accessory dwelling unit. Winery process wastewater disposal would be accommodated through a new pretreatment water recycling unit and used for irrigation, as detailed in the Water Feasibility Report, prepared by CMP Civil Engineering & Land Surveying Inc.
Based on the reasons stated above, staff recommends approval of the project, subject to the recommended Conditions of Approval.
ENVIRONMENTAL IMPACT
ENVIRONMENTAL DETERMINATION: Consideration and possible adoption of a Mitigated Negative Declaration. According to the proposed Mitigated Negative Declaration (State Clearing House No. 2025120435), the proposed project would not have any potentially significant environmental impacts after implementation of mitigation measures. Mitigation measures are proposed for the following areas: Biological and Tribal Cultural Resources. The project site is not included on a list of hazardous materials sites compiled pursuant to Government Code Section 65962.5.
BACKGROUND AND DISCUSSION
Owner/Applicant: Steve McPherson, 2004 Sage Canyon Rd, Saint Helena, CA 94574
Representative: Josh Devore, DP&F Law, 1500 First Street, Suite 200, Napa, CA 94559; jdevore@dpf-law.com, (707) 261-7000.
Zoning: Agricultural Watershed (AW)
General Plan Designation: Agriculture, Watershed and Open Space (AWOS)
Parcel Size: 62.56-acres
Application Filed: November 10, 2022
Resubmittals Received: December 18, 2023, June 3, 2024, October 28, 2024, May 14, 2025, October 1, 2025, and October 31, 2025
Application Deemed Complete: November 6, 2025
Courtesy Notice Sent: December 9, 2022; updated January 3, 2024
State Clearinghouse Number: 2025120435
Existing Development: The project is located on a moderately to steeply sloped parcel in the Pritchard Hill area, on the north facing slopes above Sage Creek and Sage Canyon Road/State Highway 128 (SR 128). The project driveway is on the south side of SR 128, located approximately 0.8 mile east of its intersection with Chiles Pope Valley Road. A 40-foot-wide right-of-way easement through a City of Napa-owned parcel (APN 032-520-006) provides access from SR 128 to the project parcel and a neighboring parcel. Portions of the existing shared private driveway are in the Sage Creek stream setback, which flows along SR 128 and borders the northern project parcel’s boundary. According to Napa County GIS Environmental Maps (Vegetation layer) and a 2018 Biological Resources Assessment prepared by FirstCarbon Solutions, for Vineyard Erosion Control Plan #P17-00348, the property contains disturbed oak woodland (understory used for pasture), oak woodland, riparian woodland and ephemeral streams, nonnative grassland, serpentine shrubland, serpentine grassland, and native mixed chaparral.
The project proposes to use an existing building complex located on a topographic bench between 430 to 460 feet above mean sea level (above msl). The building complex contains an accessory dwelling unit (ADU), a barn, paved and graveled parking areas, domestic septic system and groundwater well, a 20,000-gallon water tank, landscaping and agricultural uses. Other uses on the property include a main residence and associated domestic septic system and groundwater well, a swimming pool and pool house (to be demolished per #P17-00348), garage, shed, a 4.46-acre vineyard, livestock corrals, and water tanks.
The applicant, Promise Wine, LLC, owns the adjacent parcel to the west (APN 032-520-008) which is developed with a residence, accessory structures and accessed via the western segment of the shared private driveway (through APN 032-520-003). The applicant manages both parcels as a single farming operation. The nearest (non-project related) off-site residence is located to the north, across SR 128, approximately 600 feet from the proposed winery building.
Adjacent General Plan Designation / Zoning / Land Use: The surrounding area consists of mountainous terrain with oak woodland, riparian woodland, shrubland, and grassland interspersed with rural residences, vineyards, and wineries.
Table 1. Surrounding Land Uses
|
Direction |
Land Uses |
|
North |
Land zoned AW with AWOS General Plan Designation. City of Napa easement parcel, Sage Creek, rural residential land use, grassland, oak woodland. |
|
East |
Land zoned AW with AWOS General Plan Designation. Rural residential land use, Sage Creek, oak woodland. |
|
South |
Land zoned AW with AWOS General Plan Designation. Wineries, serpentine shrubland, oak woodland, vineyard. |
|
West |
Land zoned AW with AWOS General Plan Designation; Applicant’s residence, serpentine shrubland, oak woodland. |
Nearby Wineries located within one (1) mile of the project: Neyers Vineyards Winery, Bryant Family Winery, Villa Del Lago, Chappellet Winery, Kuleto Villa Vineyards, and Gandon Winery.
Request: Promise Wine, LLC requests a Phased Use Permit to allow a new 30,000 gallon per year winery, an exception to the Napa County Roads and Street Standards, and a Variance to winery setbacks established under Sec. 18.104.230(A) of the Zoning Code.
Phase I consists of the following:
• Conversion and expansion of an existing 1,300 square foot barn to a 2,794 square foot winery building (production use only) for barrel fermentation and aging of up to 5,000 gallons of wine per year with all other production steps occurring at an offsite custom crush facility; and an existing 1,268 square foot accessory dwelling unit to a tasting room (no change in size) with 845 square feet of accessory use and 423 square feet of production use.
• Construction of a new 2,465+/- outdoor patio next to the winery and a new 900 square foot unenclosed covered parking structure with a 62 square foot accessible restroom (accessory use) and 62 square feet of storage space (production use).
• Visitation, tours and tasting, retail wine sales for up to eight visitors per day, or 56 per week, and two marketing events per year with up to 25 people per event between the hours of 6 p.m. to 10 p.m., with cleanup by 11 p.m. Events would be held at the tasting room, winery patio and surrounding areas.
• On-premises consumption of wine at the tasting room and winery outdoor patios (Business & Professions Code §23358, 23390 and 23396.5).
• Hours of operation are seven days a week from 8:00 a.m. to 5:00 p.m., except during harvest for production, and seven days a week from 9:00 a.m. to 6:00 p.m. for visitation.
• Two (2) full-time employees and one part-time employee (two employees are owner-operators who live onsite).
• Seven (7) on-site parking spaces consisting of: two existing standard spaces, three new standard spaces, and two new accessible spaces. Three of the seven spaces (two standard, one accessible) will be housed in the unenclosed covered parking structure.
• Use of an existing domestic septic system to serve the tasting room and winery. No winery process wastewater to be generated from the Phase I winery facility; cleaning of equipment will occur offsite.
• Use of an existing groundwater well (Well #1) and an existing 20,000-gallon water storage tank for winery domestic uses.
• Upgrades to the project entrance to meet Caltrans’ sight distance requirements and road improvements, including an exception to the Napa County Roads and Street Standards (NCRSS) to achieve the same overall practical effect of the NCRSS for commercial roads.
• Connection to a 110,499-gallon fire protection/vineyard irrigation water tank (permitted under BR25-00800) and construction of a new fire pump house.
• Limited catered and pre-prepared food pairings (no commercial food facility proposed).
• Removal of five native oak trees from the building complex, consisting of four Blue Oaks ranging from 9-inch to 24-inch DBH and one 22-inch DBH White Oak.
• An overall 27.7% accessory/production use ratio consisting of 907 square feet of indoor accessory use and 3,279 square feet of production use.
Phase II consists of the following:
• Construction of a 5,000 square foot Type I wine cave for winery operations and storage (production use only), a 1,235 square foot covered crush pad and an adjacent 1,040 square foot mechanical enclosure to allow full wine production of up to 30,000 gallons per year.
• Conversion of a portion of the winery building interior to allow accessory uses including an employee restroom, break room, and office.
• Increasing visitation to 15 visitors per day, or 105 per week, and increasing marketing events to seven events per year with six 25-person events and one 100-person event. Portable restrooms will be used for the large event.
• No changes to Phase I on-premises consumption of wine.
• No changes to Phase I hours of operation.
• Increase employee count by adding two (2) part-time employees, for a total of five (5) employees.
• Construction of two (2) additional standard parking spaces for a total of nine (9) on-site parking spaces.
• Installation of a water recycling, biological processed waste system package unit and associated tanks to recycle winery process water and reuse for vineyard irrigation.
• Excavation of approximately 7,000 cubic yards of spoils and final placement of spoils spread uniformly throughout vineyard blocks B and C.
• No changes to Phase I limited catered and pre-prepared food pairings.
• An overall 13.4% accessory/production use ratio consisting of 1,229 square feet of indoor accessory use and 9,192 square feet of production use.
Zoning Setbacks: Excepting the 300-foot and 600-foot winery setbacks required under Sec. 18.104.230(A), all existing (E) and proposed (P) project structures meet required road and yard setbacks listed under Sec. 18.112 and 18.104.010.
Table 2. Zoning Setbacks
|
Zoning Setback Type |
Required Setback Distance |
(E) ADU |
(E) Barn |
(P) Covered Parking Structure |
(P) Covered Crush Pad |
(P) Cave Portal |
|
Road Setback |
70 feet from centerline of SR 128 |
488+/- feet |
344+/- feet |
555+/- feet |
421+/- feet |
450+/- feet |
|
Winery Setback - Highways |
600 feet from centerline of SR 128 |
488+/- feet |
344+/- feet |
555+/- feet |
421+/- feet |
450+/- feet* |
|
Winery Setback -Other Public or Private Roads |
300 feet from centerline of shared private driveway |
360+/- feet |
279+/- feet |
382+/- feet |
379+/- feet |
400+/- feet |
|
Front Yard |
20 feet from front property line |
> 250 feet |
> 200 feet |
> 250 feet |
> 250 feet |
> 300 feet |
|
Side Yard |
20 feet from side property lines |
> 400 feet |
> 700 feet |
> 400 feet |
> 700 feet |
> 700 feet |
|
Rear Yard |
20 feet from rear property line |
> 1,500 feet |
> 1,500 feet |
> 1,500 feet |
> 1,500 feet |
> 1,500 feet |
*Per Sec. 18.104.230(A), Cave portals that are not visible from the road are exempt from the winery setbacks. All proposed winery structures, including cave portals, are screened from view from both the shared private road and Highway 128 by the surrounding topography and vegetation.
Parcel History: The project is located on Parcel “B” of a 1989 subdivision approved by Tentative Map No. 2489-PM. Although the original property was subdivided, subdivision Parcels “A” and “B” have been under the same ownership and continue to be managed together as a single farming operation. As noted previously, the applicant currently owns the adjacent parcel to the west (a.k.a. Parcel A). In 2016, Lot Line Adjustment #W16-00020 expanded the project parcel from 50.19-acres to 62.56 acres in size and subsequently changed the assigned APN from 032-520-007 to 032-520-009. The original single-family dwelling was built in 1965 and converted to a guest house in the late 1980’s to allow construction of the property’s main residence and barn, which commenced in 1990. In 2016, the landowner replaced the guest house with an ADU and completed related driveway improvements to meet Napa County Road and Street Standards for residential driveways.
Since 1994, the property has been subject to a Williamson Act Type “H” Contract which initially focused on alpaca breeding. Over time, agricultural uses of the property changed and in 2018, the County approved Erosion Control Plan #P17-00348-ECPA to establish a 4.46-acre vineyard (net 3.56 acres). Approximately 0.65 acres have been planted in Vineyard Block A and initial grading/site preparation has occurred in Vineyard Blocks B and C. To satisfy conditions of approval of #P17-00348, the landowner recorded a deed restriction protecting 3.12 acres of Oak Woodlands in the northeast portion of the property, under Document No. 2018-0022516.
Code Compliance History: There are no open or pending code violations on the subject property, however there are four expired building and grading permits related to the main residence and private residential wine cave. Additionally, there is an expired building permit for the existing electric gate at the project driveway entrance (B16-01286) which is within the access easement on the City of Napa’s easement parcel (APN 032-520-006).
Discussion Points:
Setting
The project site totals approximately 62.56-acres and is located at 2004 Sage Canyon Road/State Highway 128 (SR 128), approximately 0.5-mile east of Lake Hennessey. The property is in the Pritchard Hill area, on the north facing slopes above Sage Creek and SR 128. The existing building complex (project site) is located on a topographic bench in the northern-center portion of the parcel, approximately 344+/- to 488+/- feet from the highway. This area contains a barn, accessory dwelling unit (ADU), landscaping, parking areas and associated improvements. A portion of the existing barn is also within the 300-foot setback from the shared private road that serves the project parcel and the adjacent parcel to the west (APN 032-520-008). Other uses in vicinity include vineyard blocks A and B (approximately 2 acres), livestock pastures within disturbed oak woodland areas, a pool house, and a fenced garden. The residential driveway continues up a steep hill to the main residence and vineyard block C. Most of the property is either in the 600-foot setback from the highway, contains slopes exceeding 15 percent, or is vegetated with sensitive biotic communities including oak woodland, serpentine grassland, serpentine shrubland, and riparian habitat.
Winery Proposal and Design
The Use Permit request (P22-00384) proposes to convert and expand an existing barn to a winery, convert an ADU to a tasting room, construct a 5,000 square foot production cave and an adjacent covered crush pad/bottling space, and construct a small, covered parking structure with an ADA restroom. A total of 1,229 square feet of indoor winery accessory use and 9,192 square feet of winery production use is proposed, resulting in a 13.4% accessory to production use ratio. The request includes a Variance application (P25-00283) to allow the winery to use existing buildings and construct new buildings within the 300-foot and 600-foot winery road setbacks, approximately 279 feet from the centerline of the private road and 344 feet to 555 feet from the road centerline of SR 128. Parking improvements include seven standard and two accessible spaces. Driveway improvements include widening and installation of intervisible turnouts along sub-standard segments of the road in areas outside of stream setbacks, as well as signage and management of vegetation to maintain line of sight. Two outdoor patios will be used for outdoor seating and onsite consumption of wine (Business & Professions Code §23358, 23390 and 23396.5). The winery would be constructed in two phases: Phase I includes the tasting room, winery barn, three (3) total employees, and production of 5,000 gallons per year; Phase II increases production to 30,000 gallons per year and adds two (2) employees after the cave and crush pad are constructed. Visitation, tours and tasting, retail wine sales, and a marketing program would be established as set forth in the recommended Conditions of Approval in Attachment B.
Overall, the project proposes grading/excavation of a net 7,000+/- cubic yards and adding 20,930 square feet of impervious surface area on the project parcel, plus 925 square feet of new impervious surface area on the City of Napa’s access easement parcel. Excess soil cut from the project site and cave spoils will be spread uniformly in the onsite vineyards to achieve an onsite balance, resulting in an approximate one-foot-deep layer of spoils added to Vineyard Blocks B and C (not yet planted).
Visitation and Marketing
Consistent with the definition of “marketing of wine” (County Code Section 18.08.370), the applicant proposes a visitation and marketing program to include tours and tastings for up to 15 guests per day with a maximum of 105 guests per week (limited to 8 people per day/56 per week during Phase I). Visitation would be by appointment only and would occur between the hours of 9:00 a.m. and 6:00 p.m., Monday-Sunday. The applicant also proposes a total of six (6) marketing events per year allowing a maximum of 25 guests, and one (1) marketing event per year allowing a maximum of 100 guests (limited to 2 events per year with 25 people during Phase I). Conditions of Approval for the project require that shuttling is provided for all marketing events to accommodate the parking demand. Portable restroom facilities will be used for the largest event to avoid excessive loading on the domestic wastewater system. Marketing events will take place between 6:00 p.m. and 10:00 p.m. with quiet clean-up completing by 11:00 p.m.
Traffic / VMT Analysis
The parcel is accessed via a private shared driveway off SR 128. The project includes upgrades to the driveway entrance including trimming vegetation, re-striping the project driveway apron, installing new traffic safety signage and LED blinking warning signs along SR 128, and relocating existing mailboxes further back into the shoulder in coordination with Caltrans and Public Works. See below for further details on driveway improvements.
The County maintains a set of Transportation Impact Study Guidelines (TIS Guidelines) that define situations and project characteristics that trigger the need to prepare a TIS. Per the County’s current TIS Guidelines, a project is required to prepare a TIS if it generates 110 or more net new daily vehicle trips and is presumed to have a less than significant impact for Vehicle Miles Travelled (VMT). Based on the County’s winery trip generation assumptions, the proposed project would generate an average of 24 daily new trips on weekdays (27 during harvest) and 24 daily new trips on weekends (26 during harvest). Due to the relatively low number of new daily trips, the project would not conflict or be inconsistent with CEQA Guidelines section 15064.3, subdivision (b). Impacts would be less than significant.
Parking
The winery project was analyzed to determine whether the proposed parking supply would be sufficient for the anticipated daily demand during harvest conditions. The project site, as proposed, would have a total of nine (9) parking spaces (with two designated for ADA drivers). Visitors to the Winery will be by appointment only. On a busy day, the 15 visitors (eight daily vehicles based on 2.6 people per vehicle) will arrive in a staggered arrangement so that there should never be more than three to four guest vehicles at the site at any time. Occasionally, visitors will arrive in a higher-occupancy vehicle such as an SUV, minivan or smaller shuttle bus. Two existing parking spaces located at the main residence, uphill from the project site, would be used to accommodate the two full-time employees who live onsite (owners). The other three part-time employees would then occupy the remaining spaces. Although the project would accommodate parking for daily operations, marketing events are estimated to require additional parking- 10 guest parking spaces for 25-person events and 39 spaces for 100-person events. Recommended Conditions of Approval require the winery to provide shuttle services for all marketing events. As such, the proposed project would not be in conflict with General Plan Policy CIR-14.
Project Entrance Improvements
To improve vehicle sight distance at the project entrance, the applicant proposes to trim vegetation along SR 128, re-stripe the project driveway apron, install new traffic safety signage and LED blinking warning signs along SR 128, and relocate existing mailboxes further back into the shoulder in coordination with California Department of Transportation and Napa County Department of Public Works, and as specified in the recommended Conditions of Approval.
Exception to NCRSS
Due to the access easement location, stream setbacks, and avoidance of mature oak trees and steep hillsides, the project requests an exception to the Napa County Roads and Street Standards (NCRSS). To achieve the same overall practical effect of the NCRSS for commercial roads, the project proposes driveway widening and installation of intervisible turnouts along sub-standard segments of the road, as well as signage and management of vegetation to maintain line of sight. Vegetation management consists of vegetation trimming along the driveway and removal of one Blue Oak tree from the upper portion of the driveway, below the proposed winery building’s parking area. The paved driveway would be extended to the winery building to improve access and provide paved parking spaces and paved fire truck hammerhead turnaround areas. On May 20, 2025 (updated January 6, 2026), the Napa County Engineering Services Division and Fire Marshal’s office determined these measures would achieve the same overall practical effect of the NCRSS.
Noise
The project would result in a temporary increase in noise levels during grading and construction activities and the intermittent increase of ambient noise resulting from wine making and visitation. The nearest non-project related residence is located to the north, across SR 128, approximately 600 feet from the proposed winery. Due to the distance, existing vegetation, and ambient noise levels from the highway, the potential for the creation of significant noise from the winery is significantly reduced. All production activities would occur inside the winery, within the covered crush pad located behind the winery, and in the cave. Noise resulting from winery truck traffic for a 30,000-gallon winery is expected to be negligible, as the facility would generate an average of one truck trip per day and three truck trips per day during harvest. Standard project conditions of approval further reduce noise impacts to neighbors by prohibiting outdoor amplified music and requiring marketing events to finish by 10:00 p.m., with quiet cleanup ending by 11:00 p.m.
Biological Resources
The property contains developed and disturbed areas including agricultural and residential structures, ranch roads, vineyards, and disturbed oak woodland with understory used for pasture. The project proposes to use buildings and adjacent areas within an existing building complex that is mapped as ‘Urban or Built-up’ according to the Napa County GIS Environmental Maps (Vegetation layer). All sensitive biotic communities found on the property will be avoided. These include riparian habitat, oak woodland, serpentine shrubland, and serpentine grassland. Additionally, all trees proposed for removal are outside of habitats classified as oak woodland, riparian oak woodland, or coniferous forest and therefore, the vegetation canopy cover retention and removal mitigation requirements under Conservation Regulations do not apply.
Based on inspection of the site, County GIS layers, and review of FirstCarbon Solutions’ 2018 Biological Resource Assessment, staff concluded that a portion of the proposed cave and crush pad area (approximately 1,500 square feet) contains chaparral habitat that is within range of documented occurrences of two rare plants: green jewelflower (Streptanthus hesperidis) and Greene’s narrow-leaved daisy (Erigeron greenei). To ensure impacts to protected plant species are avoided and/or reduced significantly, mitigation measures recommended for the project include pre-construction botanical surveys in conformance with California Department of Fish and Wildlife protocols. Since the project also proposes removing five oak trees from the building complex, pre-construction bat habitat assessments and nesting bird and raptor surveys are recommended to mitigate any potential impacts to bats and nesting birds and raptors. By incorporating the recommended mitigation measures in addition to standard Conditions of Approval for stream protection, impacts to biological resources would be less than significant.
Cultural Resources
A Cultural Resources Assessment of the property was completed as part of the vineyard erosion control project #P17-00348, prepared by FirstCarbon Solutions dated May 5, 2017 (on file with County records, Confidential). The 2017 study included a check of the information on file with the County and the Northwest Information Center to identify any cultural resource survey reports and/or archaeological site records relevant to the project property. According to the 2017 study, no cultural resources have previously been recorded within 0.5 miles of the project parcel. FirstCarbon Solutions conducted a pedestrian survey of the property’s vineyard blocks and surrounding areas and recommended standard measures for accidental discovery of archeological artifacts or human remains during construction, consistent with the County’s standard Conditions of Approval.
On May 30, 2025, County Staff sent invitations to consult on the proposed project to Native American tribes who had a cultural interest in the area and who as of that date had requested to be invited to consult on projects, in accordance with the requirements of Public Resources Code section 21080.3.1. No request for consultation was received during the 30-day consultation invitation; however, in October 2025, the County received new information and concerns raised by the Middletown Rancheria of Pomo Indians of California (“Middletown Rancheria”). Representatives of Middletown Rancheria concluded the project is within Middletown Rancheria’s Area of Concern due to its proximity to Lake Hennessy and known tribal cultural resources. The project was determined to have the possibility of unearthing tribal cultural resources which include, but are not limited to, Native American human remains, funerary objects, items or artifacts, sites, features, places, landscapes or objects with cultural values to the Middletown Rancheria during ground disturbance activities.
Due to the possibility of unearthing tribal cultural resources during ground disturbance activities, tribal monitoring mitigation measures have been incorporated into the project for preservation or mitigation of significant impacts to tribal cultural resources. As such, the proposed project would avoid and reduce potential impacts to unknown resources and would result in less-than-significant impacts to tribal cultural resources, including those that may be eligible for the California Historical Resources Information System or local register, or cultural resources as defined in Public Resources Code Section 5024.1(c).
Water Availability Analysis
A Water Availability Analysis was prepared by CMP Civil Engineering & Land Surveying Inc., originally prepared on December 6, 2023, and most recently updated on October 6, 2025 (WAA). As directed by the County’s WAA Guidance Document dated May 2015 and the Interim Standards, the report includes Tier 1 calculations for the existing and proposed water uses and a groundwater recharge analysis and a Tier 2 well interference analysis. Although the existing project well is located within 1,500 feet of Sage Creek, a designated Significant Stream, the WAA concludes that a Tier 3 surface water interference analysis is not required because the project proposes a reduction in overall groundwater use through the removal of an existing residential use and the recycling of winery process wastewater for supplemental vineyard irrigation. Through these changes in operation, the project will reduce overall well pumping time and will therefore reduce any assumed harm relative to current conditions.
There are two existing wells on-site:
• Well #1 is the project well which currently serves the accessory dwelling unit and vineyard. Well #1 was completed in 1988 to a depth of 290 feet. At the time of completion, Well #1 produced 20 gallons per minute (gpm) during a four-hour well yield test (on file with county records; no permit number).
• Well #2 is a non-project well that currently serves the main residence. Well #2 was constructed in 2014 and yields 1 gpm (Permit No. E14-00169).
Tier 1: The Tier 1 analysis considered existing uses onsite to include the main residence, accessory dwelling unit (with landscaping), and vineyard. The existing total groundwater usage is estimated at 3.03 acre-feet per year (AFY). Of the project parcel’s 3.03 AFY of existing groundwater use, 1.25 AFY is used for residential use and up to 1.78 AFY is used/permitted for agriculture (vineyard). Of the project parcel’s existing groundwater use, 75% (or 2.28 AFY) is sourced from the project well, Well #1.
There are no changes proposed to the existing main residence nor the permitted vineyard. The accessory dwelling unit is proposed to be converted to a tasting room and as a result, the overall water use attributed to residential use will decrease from 1.25 AFY to 0.75 AFY. CMP Civil Engineering & Land Surveying Inc. estimates the project to require a total of 0.76 AFY from the following uses: 0.55 AFY for winery processing; 0.11 AFY for employees and visitors; and 0.10 acre‐feet for winery landscaping. Phase II of the project includes the beneficial reuse of treated process wastewater (0.55 AFY) to be used for vineyard irrigation. Thus, the parcel’s total annual proposed water use (for Phase I and Phase II) is estimated to reduce from 3.03 AFY to 2.74 AFY. The project would result in an overall net reduction of approximately 0.2862+/- AFY of groundwater use.
Winery Domestic Water Usage:
Phase I domestic water usage is estimated to require 22,880 gallons per year, or 0.07 AFY:
• 2 full-time employees at 15 gallons per shift per employee and 1 part-time employee at 8 gallons per shift = 13,870 gallons per year
• 8 visitors per day at 3 gallons per person = 8,760 gallons per year
• 2 marketing events per year 25 guests per event, at 5 gallons per person = 250 gallons per year
Phase II domestic water usage is estimated to require 37,340 gallons per year, or 0.11 AFY:
• 2 full-time employees at 15 gallons per shift and 3 part-time employees at 8 gallons per shift per employee = 19,710 gallons per year
• 15 visitors per day at 3 gallons per person = 16,380 gallons per year
• 6 marketing events per year 25 guests per event and 1 event with 100 people, at 5 gallons per person = 1, 250 gallons per year
Winery Process Water Usage:
Winery process water is water used throughout the winery in winemaking tasks, including in the washing of grapes, cleaning of hoses, tanks, pumps, equipment, and building floors, and the preparation and washing of barrels, along with various other activities such as bottling. As discussed in the WAA, winery process water use is generally expressed as a ratio of water used to wine produced. During Phase I, the project proposes barrel storage and aging of up to 5,000 gallons of wine per year with all production steps occurring at an offsite custom crush facility, including barrel washing. As such, the project does not propose to use winery process water in Phase I. In Phase II, the project proposes full wine production for up to 30,000 gallons of wine per year. Per the WAA, 30,000 gallons of wine is estimated to require 180,000 gallons of water per year or 0.55 AFY, based on an assumed winery process water ratio of 6:1 (6 gallons of water for every 1 gallon of wine produced).
See Tables 1 and 2 below for estimated water usage broken down by project phasing.
Table 1. Phase I: Proposed Groundwater Usage (entire parcel)
|
Source of Demand |
Well No. |
Existing (AFY) |
Proposed (AFY) |
Difference (AFY) |
|
Main Residence |
2 |
0.75 |
0.75 |
No change |
|
Accessory Dwelling Unit (ADU) |
1 |
0.40 |
0 (converted to tasting room) |
-0.40 |
|
Landscaping |
1 |
0.10 |
0.10 |
No change |
|
Vineyard |
1 |
1.78 (permitted under P17-00348) |
1.78 |
No change |
|
Employees (winery and tasting room employees) |
1 |
0 |
0.04 |
+0.04 |
|
Tasting Room Visitation |
1 |
0 |
0.026 |
+0.026 |
|
Marketing Events |
1 |
0 |
250 gallons |
+250 gallons |
|
Total |
-- |
3.03 |
2.696 |
-0.334 |
Table 2. Phase II: Proposed Groundwater Usage (entire parcel)
|
Source of Demand |
Well No. |
Existing (AFY) |
Proposed (AFY) |
Difference (AFY) |
|
Main Residence |
2 |
0.75 |
0.75 |
No change |
|
Accessory Dwelling Unit |
1 |
0.40 |
0 (converted to tasting room) |
-0.40 |
|
Landscaping |
1 |
0.10 |
0.10 |
No change |
|
Vineyard |
1 |
1.78 (permitted under P17-00348) |
1.23 (recycled process wastewater to supplement vineyard irrigation) |
-0.55 |
|
Winery Production (process wastewater) |
1 |
0 |
0.55 |
+0.55 |
|
Employees (winery and tasting room employees) |
|
0 |
0.06 |
+0.06 |
|
Tasting Room Visitation |
1 |
0 |
0.05 |
+0.05 |
|
Marketing Events |
1 |
0 |
0.0038 (1,250 gallons) |
+0.0038 (1,250 gallons) |
|
Total |
-- |
3.03 |
2.7438 |
-0.2862 |
Due to the parcel location outside of the GSA boundary, a parcel specific recharge calculation was prepared. In calculating the recharge for the 62.56-acre parcel, the project WAA quantifies the amount of average annual rainfall infiltrating to the underlying aquifer based on the average rainfall data collected from 2013 to 2023 provided by the Oregon State University PRISM Climate Group (30.72 inches), estimated losses to runoff, and estimated losses to evapotranspiration. CMP Civil Engineering & Land Surveying Inc. calculated groundwater recharge rate for this property is 0.80 acre‐feet of water per acre of land. The analysis estimates the total annual recharge rate for the property is 50.05 AFY. The project’s proposed reduction in water use of -0.2862+/- AFY would not impact groundwater availability. Comparing the proposed total groundwater use of 2.74 AFY to the calculated parcel groundwater recharge rate of 50.05 AFY, the WAA finds that the parcel has adequate water available to serve the proposed use and therefore passes the Tier 1 screening criteria.
Tier 2: The latest Interim Napa County Well Permit Standards and WAA Requirements require an interference analysis for any proposed increase in groundwater use occurring from project wells within 500 feet of any offsite well or 1,500 feet from any off‐site spring. A Tier 2 analysis is not required for discretionary projects that use an existing well provided there is no increase in groundwater use. As discussed above, the project proposes to utilize the existing well (Well #1) currently used to supply irrigation for the vineyard and domestic water for the accessory dwelling unit. The existing residential well (Well #2) will not supply water to the winery and will continue to serve the main residence at an estimated 0.75 AFY.
The WAA documents Well #1 as completed to a depth of 290 feet in 1988 with a casing diameter of 6” and an annular seal depth of 32 feet. At the time of completion, the well yield test resulted in 20 gallons per minute for four hours. Due to the removal of a residential use and recycling of winery process wastewater for supplemental vineyard irrigation, the WAA estimates the project will result in a net decrease of 0.2862+/- AFY of groundwater pumped from the project well. Per the WAA Guidance Document, the Tier 2 requirements have been met due to the proposed reduction in groundwater use from the project well. No further analysis is required.
Tier 3: A Tier 3 review is the County’s adopted method for complying with its duties under the Public Trust Doctrine. As discussed herein, the existing project will comply with the WAA guidance document.
The latest Interim Napa County Well Permit Standards and WAA Requirements require an analysis of potential groundwater to surface water interaction for new, altered, or increased groundwater use occurring from project wells within 1,500 feet of any County‐identified Significant Stream inside the Napa River Watershed. Although the project well (Well #1) is approximately 416 feet from Sage Creek, the nearest Significant Stream, a stream interference analysis is not required because the project proposes a reduction in current groundwater use through the removal of a residential use and recycling of winery process wastewater for supplemental vineyard irrigation. The WAA estimates the modified uses of the site to result in a net decrease of approximately 0.2862 AFY of groundwater use. Through these changes in operation, the project will reduce overall well pumping time and will therefore reduce any assumed harm relative to current conditions.
Since the project well is within 1,500 feet of a designated significant stream, Napa County has conditioned the project to limit the existing volume of water (2.28 AFY) that may be pumped from the project well (Well #1), satisfying the County’s Public Trust duties. See Conditions of Approval 4.20(c) and 6.15(e).
Wastewater System
A Wastewater Feasibility Study, dated October 22, 2024, was prepared by CMP Civil Engineering & Land Surveying Inc. which concludes that the ADU’s existing engineered domestic wastewater treatment system and dispersal field has adequate capacity to serve the proposed domestic uses of the winery and tasting room (employees, visitation, marketing programs). Phase II of the winery project includes installation of a water recycling, biological processed waste system package unit with two 10,000 gallon holding tanks for treated wastewater to recycle winery process wastewater and reuse for vineyard irrigation. The Wastewater Feasibility Study demonstrates the site’s existing vineyard is larger than the area required for the compliant land-application of treated process wastewater (winery process wastewater reused for vineyard irrigation). Per Napa County guidelines, a Registered Civil Engineer, Registered Environmental Health Specialist, or Licensed Contractor will provide ongoing monitoring and evaluation of the system. The Division of Environmental Health reviewed this report and concurred with its findings, conditioning that the selected design and plans shall be designed by a licensed Civil Engineer or Registered Environmental Health Specialist and approved by the Division of Environmental Health. Impacts would be less than significant.
Water System
As discussed above, domestic water for the project will be provided via an existing onsite groundwater well. Because the project does not involve serving 25 or more people for 60 days or more per year, the project’s water supply system is not classified as a public water supply system and is exempt from State Water Board water supply permitting requirements. Prior to building permit issuance, the applicant will be required to meet County Environmental Health protection requirements for domestic water supply.
Green House Gas Emissions
On April 20, 2022, the Bay Area Air Quality Management District (BAAQMD) adopted new recommended thresholds for determining the significance of individual projects’ greenhouse gas impacts under CEQA. Under the new thresholds, proposed land use projects may be analyzed for consistency with a qualified greenhouse gas (GHG) reduction strategy in the event one has been adopted. To date, Napa County has not adopted a qualified GHG reduction strategy pursuant to CEQA Guidelines section 15183.5. Absent an adopted strategy, BAAQMD recommends that a land use project include specified minimum design elements to ensure that the project is contributing its “fair share” toward achieving the state’s key climate goal of carbon neutrality by 2045. Napa County has not adopted a qualified GHG reduction strategy or an air quality plan, therefore projects are evaluated per the BAAQMD recommended minimum design elements.
The project will be required, through Conditions of Approval, to meet relevant design standards identified by BAAQMD, including prohibiting the use of natural gas appliances or plumbing and compliance with the California Building Code Title 24 standards. Additionally, Conditions of Approval require implementation of the checked Voluntary Best Management Practices Measures submitted with the project application which include exceeding the minimum number required bike racks, reusing winery process wastewater for vineyard irrigation, adhering to Water Efficient Landscape Ordinance requirements, and using energy conserving lighting (LED) and water efficient fixtures for both existing and new structures.
The project’s proposed removal of five oak trees (approximately 0.12 acres of canopy) would result in a loss of carbon sequestration capacity for the site. To ensure consistency with County carbon sequestration policies under General Plan Policy CON-65(e), staff recommend incorporating Conditions of Approval that require the applicant to implement vegetation protection fencing during construction and a tree replacement plan for five or more native carbon sequestering trees on the site.
Grape Sourcing
The proposed winery will have a maximum production of 30,000 gallons of wine. The 3.56 acres of on-site vineyards and other local Napa County vineyards will provide a source for grapes for wine production. The applicant has signed the County’s 75 Percent Grape Source Agreement.
Variance Request
The proposal involves conversion of existing structures and construction of new structures for winery related uses within the 300-foot winery setback from a private road and the 600-foot winery setback from SR 128. This existing building complex is one of two accessible flatter areas of the property and is entirely within the 600-foot winery road setback. Additionally, a portion of the building complex (the existing barn) is within the 300-foot winery road setback from a private road that serves APN 032-520-008 and the project parcel. The other accessible level area of the property contains the main residence which meets the setback but is occupied by the landowner/winery operator and has a smaller footprint due to surrounding topography. Existing structures within the building complex include a barn/proposed winery which is 344+/- feet from the road centerline of SR 128 and 279+/- feet from the road centerline of the private road, and an ADU/proposed tasting room that is 488+/- feet from road centerline of SR 128. New winery structures proposed include an unenclosed covered parking structure with an ADA restroom and winery storage next to the proposed tasting room, located 555+/- feet from the road centerline of SR 128; and a covered crush pad with a mechanical enclosure located 421+/- from the road centerline of SR 128.
The barn and ADU were legally constructed in 1990 and 2016 under Building Permits #B46991 and #16-0470, respectively. Pursuant to County Code §18.104.230.C, conversion a of structure that legally existed prior to the adoption of the Winery Definition Ordinance (in 1990) is allowed without a variance provided that the structure is not expanded beyond the legally established footprint, and on a finding that the project is environmentally beneficial (to a structure that otherwise meets the setback). Although the barn was constructed in 1990, Section 18.104.230.C does not apply because the project proposes to expand the barn beyond its legally established footprint. Additionally, Section 18.104.230.C does not apply to the ADU as this building was replaced and expanded beyond its original footprint in 2016, which is after adoption of the WDO. For these reasons, both structures must meet the applicable winery road setbacks unless a variance is granted.
Furthermore, Resolution No. 2010-48 set the following policy regarding conversion of residences and barns for winery use that may request variances from winery setbacks: Exhibit A Section II - Conversion of Existing Structure states: To discourage property owners from constructing residences and barns with the express intent of converting them to wineries. The County does not generally support use permit proposals seeking to convert existing buildings to winery use if the buildings have been constructed or substantially modified within the last 5-7 years. As discussed above, it has been well over seven years since the ADU and the barn received occupancy.
The project includes a Cave Portal within the 600-foot winery setback however per Sec. 18.104.230(A)(1), cave portals that are not visible from the road are exempt from the winery setback. All proposed winery structures are screened from view from both the private road and SR 128 by the surrounding topography and vegetation, including the proposed cave portal. Therefore, the cave portal is not a part of this Variance request.
Staff supports the applicant's request for a variance. The barn and ADU are existing, located on a bench that is tucked into the hillside and screened from view from the private road and SR 128. The areas proposed for new structures are primarily disturbed and located adjacent to existing buildings. Most of the property is either in the 600-foot setback from the highway, contains slopes between 15 percent and greater than 30 percent, or is vegetated with sensitive biotic communities including oak woodland, serpentine grassland, serpentine shrubland, and riparian habitat. Developing other areas of the property with slopes less than 15% would elevate the geologic hazard and require substantial grading for access and new building pads, as well as permanent loss of vineyard or new stream crossings and conversion of sensitive biotic communities, depending on the location. Additionally, a portion of the existing barn/proposed winery building is within the 300-foot setback from the private road that serves the project parcel and the adjacent parcel to the west (APN 032-520-008).
As required by State and local statute, the granting of this variance would not confer a special privilege as the subject parcel contains a unique combination of existing development and regulatory constraints, namely slope and environmental constraints due to sensitive biotic habitat. There is nothing included in the variance proposal that would result in a measurable impact on the public health, safety, or welfare of the County of Napa. Conversion of the existing barn and ADU, as well as construction of the new structures would be subject to County Codes and regulations including but not limited to California building codes, fire department requirements, and water and wastewater requirements. The granting of the variance to the winery road setbacks will not adversely affect the health or safety of persons residing or working in the neighborhood of the property. The proposed winery structures would be located in an existing building complex that is screened from view from the private road and SR 128 due to surrounding topography and vegetation. Various County departments have reviewed the Project and commented regarding water, wastewater disposal, access, building permits, and fire protection. Conditions are recommended which will incorporate these comments into the project to assure protection of public health and safety.
Public Comments: On January 6, 2024, staff received a public comment regarding the requested exception to the NCRSS, the variance to winery setbacks, and cave excavation (see Attachment L). No other public comments have been received as of the date of this staff report.
Decision Making Options:
As noted in the Executive Summary Section above, staff recommends that the Planning Commission approve the project as proposed, subject to the Findings and Conditions of Approval in Attachment A and B, respectively. However, staff has provided the following options for consideration by the Planning Commission.
Option 1 - Approve Applicant's Proposal (Staff Recommendation)
Disposition - This action would approve the project as proposed, allowing construction and operation of a 30,000-gallon per year winery with related tours and tastings and marking program that would allow up to 15 guests per day, seven days per week. The requested Use Permit would decrease water demands, increase vehicle trips and miles, and wastewater generation at the property, in addition to establishing approximately 23,105 sq. ft. of winery development area. The Variance request meets the provision of Code Section 18.128.060 and new construction would be compliant with Napa County zoning code regulations for winery developments, including minimum setbacks from property lines, maximum lot coverage, and maximum building height. With implementation of mitigation measures pertaining to biological and tribal cultural resources, potential environmental impacts of the project would be less than significant, and additional Conditions of Approval would be enforced with the intention of preserving public health, safety, welfare and convenience.
Staff recommends this option as the request is consistent with the Zoning Ordinance and applicable General Plan policies.
Action Required - Follow the proposed action listed in Executive Summary. If conditions of approval are to be amended, specify conditions to be amended at the time the motion is made.
Option 2 - Modify the Applicant’s Proposal and Reduce Visitation
Disposition - Should the Planning Commission determine that the intensity of the visitation and marketing plan should be reduced, the Commission may take action to reduce the number of daily, weekly, or yearly visitors and/or reduce the number of proposed marketing events and/or reduce the hours of visitation.
Action Required - Follow proposed actions listed in the Executive Summary and amend scope and project specific conditions of approval to reduce the maximum daily visitation and/or number of marketing events. If significant revisions to the Conditions of Approval are required, the item may need to be continued to allow staff adequate time to prepare the revised conditions.
Option 3 - Deny Applicant's Proposal
Disposition - In the event the Commission determines that the project does not or cannot meet the required findings for the granting of a Use Permit and Variance, Commissioners should identify what aspect or aspects of the project are in conflict with the required findings. State Law requires the Commission to adopt findings, based on the General Plan and County Code, setting forth why the proposed Use Permit is not being approved.
Action Required - Commission would move to deny the project.
Option 4 - Continuance Option
The Commission may continue an item to a future hearing date at its own discretion.
Attachments:
A - Recommended Findings
B - Recommended Conditions of Approval and Final Agency Approval Memos
C - Promise Winery IS-MND
D - Use Permit and Variance Applications and Narratives
E - County Road and Street Standards Exception Request
F - Water Availability Analysis
G - Wastewater Analysis
H - Biological Study (prepared for Erosion Control Plan #P17-00348)
I - Vehicle Sight Distance & Mitigation Report
J - 30,000-gal Winery Comparison Table and Summary of Changes
K - Graphics (land use and zoning maps, existing conditions and slope exhibits, project plans, site inspection photos)
L - Public Comments