Chapter 17.64
WOODLANDS AND WATERSHED (WW) DISTRICT
Sections:
17.64.010 Purpose.
17.64.020 Permitted uses.
17.64.030 Conditional uses.
17.64.040 Design review required.
17.64.050 Development standards.
17.64.060 Alternate development standards.
17.64.070 Miscellaneous provisions.
17.64.010 Purpose.
This district is intended to:
A. Implement the policies applicable to areas designated woodlands and watershed in the general plan;
B. Minimize the potential for erosion and land movement in steeply sloping areas;
C. Minimize long-term cost for constructing and maintaining roads, water systems and sewer systems;
D. Minimize the downstream effects of siltation and sedimentation in water courses;
E. Maintain or enhance the natural ability of watershed areas to absorb and retain rainfall, both for replenishment of groundwater and moderation of downstream flooding;
F. Minimize the public and private cost of providing adequate fire protection services in high fire hazard areas;
G. Minimize the long-term risk to, or loss of, life and property resulting from wildfire in high fire hazard areas;
H. Minimize the long-term cost to the community for providing services (water, sewer, fire, police, schools) in remote areas;
I. Minimize future demands on the city’s water supply system;
J. Minimize the city’s long-term liability for public protection in remote/hazardous areas;
K. Preserve community open space, especially for public protection in remote/hazardous areas and protection of views and ridgelines;
L. Preserve wildlife habitat;
M. Encourage land planning which carefully considers the community-wide implications of natural conditions noted above;
N. Allow development which is sensitive to the intrinsic suitability of the land and its varying capability for residential development. (Prior code § 27.110)
17.64.020 Permitted uses.
A. Uses that were legally established prior to the effective date hereof;
B. The following uses, subject to design review and the standards of Section 17.64.060:
1. One single-family dwelling,
2. One accessory building or structure without plumbing,
3. Noncommercial horticulture and gardening;
C. One second unit, consistent with the provisions of Section 17.116.030 and the following design and development criteria:
1. The building must be located within the building envelope approved for the main residence.
2. The building may not be located on a slope greater than ten percent (10%);
3. No trees may be removed. The applicant must submit a tree survey map with the building permit application;
4. The building may not be located within fifty (50) feet of a class III stream, within seventy-five (75) feet of a class II stream, or within one hundred (100) feet of a class I stream. The applicant must submit a stream classification study, completed by a qualified professional, with the building permit application;
5. The applicant must submit a biological survey, completed by a qualified professional, to insure that no rare or endangered plant or animal species are present in or adjacent to the proposed building footprint. This survey must be submitted with the building permit application;
6. The applicant must submit a grading and drainage plan, completed by a qualified professional, to insure that the location of the building will not create a significant adverse impact on the drainage patterns on the property, as determined by the director of public works. This plan must be submitted with the building permit application;
7. The applicant must submit documentation to insure that there are adequate septic/sewer facilities and water to serve the accessory unit;
D. Tree/shrub/scrub trimming/clearing within fifty (50) feet of buildings, as needed to comply with fire safety standards adopted by the city council;
E. Provided there are no significant impacts on erosion, wildlife habitat and visual character, earth movement activities and trimming or clearing of trees, shrubs or scrub are permitted as approved in advance by the city planner, city engineer or planning commission;
F. Animal husbandry, except horses and cattle provided:
1. The noise created by the animals does not raise the ambient sound level at the property boundary by five dBA,
2. The animals’ care and keeping does not create any “nuisance” or “health hazard,” as defined by the Napa County department of environmental health. (Ord. 03-4 § 18: prior code § 27.111)
17.64.030 Conditional uses.
A. An accessory building or structure with toilet plumbing and/or cooking facilities, pursuant to the provisions of Section 17.64.020(C);
B. A second unit that is located on a slope greater than ten percent (10%), but less than thirty percent (30%), and/or which requires the removal of trees, and/or is in an area which has been cleared of trees without previous review, but is otherwise in compliance with the provisions of Section 17.64.020(C);
C. Agriculture or commercial agriculture;
D. “Home occupations” as defined in Section 17.116.040;
E. “Wineries” (without tours and tastings) defined as follows: Wineries which shall include a laboratory for the testing of grapes and wine; facilities for the crushing of grapes; the processing and fermenting of grape juice to make wine; the aging of wine; the bottling of wine; and the warehousing and shipping of wine. A winery includes offices; equipment maintenance shops; employees’ eating facilities; cooperage repair shops; wine storage tanks; scales; employee parking; and winery waste treatment and/or disposal facilities. A winery shall not include the retail sales on the premises of wine or any other products; public visitor facilities or activities to include tours and tasting; public assembly events; eating and drinking places or catering; picnic facilities, farm labor or other employee housing,
F. Flag lot development subject to the provisions of Chapter 17.112. (Ord. 03-4 § 19: prior code § 27.112)
17.64.040 Design review required.
Pursuant to Chapter 17.164 all subdivisions, signs, grading, removal of vegetation and new structures and buildings (except for one second unit which complies with the provisions set forth in Section 17.64.020(C)) for both permitted and conditional uses shall require design review. (Ord. 03-4 § 20: prior code § 27.113)
17.64.050 Development standards.
A. Lot area: five to forty (40) acres; depending on physical features, the city’s ability to provide public services and community impacts of subdivision design considerations.
B. Lot width: twenty (20) to two hundred (200) feet; depending on necessary clearing and earthmoving, and the effect on safety and privacy considerations.
C. Setbacks: twenty (20) to fifty (50) feet or ten (10) percent of the width (sideyards) and ten percent (10%) of the depth (front and rear yards); depending on the effect on safety and privacy considerations.
D. Maximum building and structural coverage: the lesser of ten percent (10%) of the lot area, or twenty thousand (20,000) square feet.
E. Building height limit: no part of a building or structure may be more than thirty-five (35) feet above the natural grade, except that the planning commission may grant a variance to this height limitation subject to adoption of findings in Section 17.172.050, plus the finding that the design at hand and existing screening vegetation reduces potential negative visual impact on the community to levels of insignificance.
F. Variations to the development standards in this district may be allowed as part of design review approval upon application by the property owner or initiated by the city to provide for clustering of building sites to minimize grading, vegetation removal and view impacts. Clustering of building sites shall not result in more than one primary unit on each parcel or a reduction in minimum parcel area. (Prior code § 27.114)
17.64.060 Alternate development standards.
The minimum lot size, setbacks and use restrictions shall be determined as specified in Sections 17.64.020, 17.64.030 and 17.64.050, provided the following have been documented to the city’s satisfaction:
A. All clearing and earthmoving shall be conducted in compliance with an erosion control plan as prepared by a registered civil engineer and approved by the city engineer.
B. There will be no disturbance of definite or suspected landslides or soil creep areas, as identified on maps produced by United States Geological Survey (USGS) or on any other more detailed study prepared by properly credentialed professionals and reviewed by the city’s geotechnical consultant.
C. There will be no disturbance of riparian areas within one hundred (100) feet of intermittent or perennial streams noted on USGS maps.
D. There will be no earth movement on slopes in excess of thirty percent (30%). Exceptions to this rule may be granted by the city engineer for minor trenching and backfilling for the installation of utilities and for temporary, nongraded access for construction purposes where no trees or substantial vegetation will be removed and where the surface will be recontoured to previous condition and revegetated according to the erosion control plan. Applications for an exception to the rule shall include submittal of a construction plan for the equipment to be installed, a plan for the maintenance of that equipment, a soils and slope stability analysis prepared by a geotechnical engineer, an erosion control plan pursuant to subsection A of this section, and a revegetation plan, utilizing native plant species, for the area that will be disturbed by the earth movement. Prior to granting an exception, the city engineer must find that the project does not have potential for creating significant erosion problems. A performance bond shall be required and held by the city for one year after completion of the project to insure that the recontouring and revegetation were properly installed.
E. There will be no buildings (other than water tanks, which shall be screened) constructed within one hundred (100) feet of the primary ridgeline on any parcel. The intent of this section is to reduce the visual impact of buildings that would obscure public views of the most prominent ridgeline on each property, without precluding the opportunity of the property owner to site a building that could attain a view. In implementing this section, the commission shall adopt a finding that the approved plan balances the owner’s interest in attaining a view against the city’s interest in preventing the obstruction of scenic views.
F. The natural ability of the site to retain rainwater and allow its percolation into underground reserves shall not be diminished by more than ten percent (10%).
G. Water and sewer systems will be constructed and maintained, at the applicants expense, to meet such standard as may be adopted by ordinance of the city council, or in the absence of such to the satisfaction of the city engineer. If individual and/or private water and/or sewage systems are proposed, prior approval must be obtained from the Napa County department of environmental management.
H. The proposed subdivision shall have a gravity-flow emergency water supply system sufficient to provide (simultaneously per possible dwelling site in the application at hand) two thousand five hundred (2,500) gallons (within twenty (20) minutes), or such greater quantity as may be required by ordinance adopted by the city council.
I. The fuel loading within fifty (50) feet of the building or building envelope shall be maintained at a level not to exceed such standard as may be adopted by ordinance of the city council.
J. New roads/common drives/driveways shall be maintained so as to guarantee all of the following:
1. Safe two-way year-round passage of emergency vehicles, as defined in St. Helena Access Road Standards, as adopted by ordinance of the city council.
2. Erosion from road cuts/fills shall not exceed such standard as specified in an erosion control plan approved by Napa County resource conservation district, pursuant to ordinance adopted by the city council, or in the absence of such, to the satisfaction of the city engineer.
3. Dust creation shall be minimized and shall not exceed such standard as may be adopted by ordinance of the city council.
4. Earth movement shall not obstruct or obliterate circulation improvements.
5. Grading shall occur between April 1st and October 15th unless approved otherwise by the city engineer.
K. Emergency vehicle access shall be constructed and maintained, at the applicants expense, to allow interconnection with nearby roads. (Ord. 01-13 § 3; prior code § 27.115)
17.64.070 Miscellaneous provisions.
A. Automobile Parking. Off-street parking shall be provided in compliance with Chapter 17.124.
B. Fire-Resistive Construction. Roofing materials shall be noncombustible. All residences shall have interior and exterior sprinklers. All other structures shall have exterior sprinklers. All parcels shall have two thousand five hundred (2,500) gallons of water storage situated adjacent to or at a higher elevation than the main structure on the parcel. (Prior code § 27.116)