The purpose of the Open-Space (O-S) zoning district is to conserve natural resources, preserve ecological systems, protect scenic and cultural landscapes, and provide opportunities for passive recreation and public access where appropriate. This designation is intended to identify lands not suited for development or to land most valuable in an undeveloped state. Factors limiting the development of land would include such constraints as unstable soils, high fire hazard, remote location, poor access, or susceptibility to flooding. Valuable natural areas could include rare and endangered species and habitat, wildlife corridors, riparian vegetation zones, areas with creeks or water features, or designated scenic resources.

The O-S District is consistent with the Open-Space, Public, Agriculture, and Recreational Land Use Designations in the General Plan. The regulations contained in this Article shall apply in all Open-Space (O-S) Districts except for the Airport Industrial Park Planned Development – Open Space designation. (Ord. 1262, §2, adopted 2025)

For purposes of this Article, the words and phrases set out herein shall have the following meanings within the Open-Space Zoning District:

BOARDWALKS AND ELEVATED WALKWAYS: Structures that allow passage over sensitive areas such as wetlands or riparian zones, reducing ground disturbance and preserving natural hydrology and vegetation.

CAMPGROUND – OPEN-SPACE: Areas designated for overnight camping, including tent sites, fire rings, picnic tables, and restrooms, with minimal permanent infrastructure, intended for recreational use compatible with natural open space settings.

CULTURAL, HISTORICAL, OR ARCHAEOLOGICAL INTERPRETIVE FACILITIES: Facilities or installations that convey the cultural, historical, or archaeological significance of a site through signage, exhibits, or programming. Such uses shall be low-impact and compatible with preservation of the surrounding environment.

ENVIRONMENTAL EDUCATION CENTERS: Small-scale facilities dedicated to outdoor learning, interpretation, and stewardship. May include classrooms, demonstration gardens, or displays focused on ecology, conservation, and sustainable practices, provided they maintain the character of the surrounding open space.

FIREBREAK: A linear or perimeter strip of land or area where combustible vegetation and materials are removed or reduced to a noncombustible condition to slow or stop wildfire spread and support firefighting operations. Width, location, and maintenance shall comply with the applicable fire code or an approved Fuels Management, Vegetation Management/Wildfire Mitigation Plan.

GRAZING: The controlled feeding of livestock on open land for the purpose of vegetation management, fuel reduction, or habitat restoration, consistent with an approved conservation, fuel management, or habitat restoration plan.

HABITAT BANKING OR MITIGATION SITES: Lands preserved, enhanced, or restored to offset environmental impacts elsewhere, typically under a conservation easement or regulatory agreement. These areas support long-term ecological functions and comply with state or federal mitigation requirements.

INTERPRETIVE SIGNAGE AND EDUCATIONAL KIOSKS: Signs or display stations designed to inform visitors about the natural, cultural, or historical features of a place. They often include text, images, maps, or interactive elements.

NATIVE PLANT PROPAGATION; NURSERY AREAS: Designated spaces used to grow and reproduce local, native plant species, usually from seeds or cuttings to support restoration, conservation, or landscaping projects that aim to preserve the local ecosystem.

NON-OBTRUSIVE TOWER: A structure intended for wildfire detection, environmental monitoring, emergency communication, or similar public safety functions, and is designed to have minimal visual and environmental impact. These towers are typically slender, uninhabited, and constructed using neutral colors or materials that help them blend with the surrounding landscape. They avoid prominent placement on ridgelines or scenic vistas whenever possible and do not include large equipment shelters or features that would significantly alter the natural character of the site. Lighting is not permitted unless required by state or federal safety regulations.

OUTDOOR EDUCATION: Organized programs that provide structured instruction and hands-on learning in outdoor or natural settings, including field studies, environmental science, ecology, outdoor skills, and natural interpretation.

PARKING LOTS (TRAILHEADS OR OPEN-SPACE ACCESS): Surface parking areas intended solely to support public access to trails, parks, or open space areas. These lots shall be minimally sized, use permeable materials where feasible, and be sited to reduce visual and environmental impacts.

PUBLIC PARKS AND RECREATION AREAS WITH LIMITED FACILITIES: Open space areas accessible to the public for passive or low-impact recreation, such as walking, wildlife viewing, or picnicking. May include benches, restrooms, or shade structures, but do not permit large-scale or intensive recreational infrastructure.

REWILDING: The restoration or protection of land and ecosystems to support native species, natural processes, and ecological functions, with minimal ongoing human management.

SLOPE STABILIZATION: Engineering, vegetative, and bioengineering measures to prevent or correct slope failure and erosion, including grading/terracing, soil reinforcement, rockery/riprap, retaining systems, slope drains, and temporary/permanent erosion control BMPs (e.g., silt fence, fiber rolls, hydro-mulch, check dams, sediment basins).

SPECIAL EVENTS OR TEMPORARY USES CONSISTENT WITH OPEN-SPACE VALUES: Short-term activities such as nature walks, educational workshops, cultural gatherings, or community celebrations that promote awareness, stewardship, or enjoyment of open space resources without significant alteration of the site.

TRAIL, BICYCLE (SHARED-USE PATH): A Public Trail or path primarily designed for bicycle travel, typically with a stabilized surface for bicycle traffic. Equestrian and pedestrian use is not allowed unless expressly posted and designed.

TRAIL, EQUESTRIAN: A Public Trail primarily designed, constructed, and maintained for horseback riding. May run parallel to, or be separated from, a Multi-Use Trail. Includes equestrian- specific features such as hitching rails, mounting blocks, manure bins, and trail width/clearance suitable for horses.

TRAIL, MULTI-USE: A Public Trail designed and signed for concurrent use by multiple non- motorized users, typically including hikers, bicyclists, and may include equestrian use where specifically posted and designed. Surfaces may be stabilized.

TRAIL, NATURE/FOOTPATH: A Public Trail intended for pedestrian travel only (hiking, walking, running), typically with a natural surface and minimal improvements to protect sensitive resources. Bicycles and equestrian use are not allowed unless expressly posted and designed.

TRAIL, PUBLIC: A publicly accessible route for travel and recreation located in parks, open space, or easements, designed for pedestrian use and, where signed or improved, may include other permitted non-motorized users.

TRAIL SPUR (ACCESS SPUR): A short Public Trail segment that provides connection from a trailhead, street, school, park, or neighborhood to a Multi-Use, Bicycle, Equestrian, or Nature/Footpath.

TRAILHEAD: A designated access point to one or more trails that may include parking, restrooms, potable water, signage/maps, staging areas (including equestrian staging), and maintenance access while safeguarding open-space from prohibited access or usage.

WATER DETENTION AND RECHARGE FACILITIES: Infrastructure designed to temporarily capture, hold, and infiltrate stormwater to reduce runoff, prevent erosion, and recharge groundwater. Includes bioswales, retention basins, and percolation ponds designed to integrate with natural systems.

WILDFIRE PUBLIC SAFETY INFRASTRUCTURE: Equipment intended to support wildfire preparedness, detection, and emergency response. This includes, but is not limited to, dedicated firefighting assets (e.g., water storage tanks, staging areas) and emergency communication infrastructure (e.g., public alert systems, emergency sirens, and related systems) necessary to ensure operational readiness during wildfire events. (Ord. 1262, §2, adopted 2025)

The following uses are allowed by right in the Open-Space (O-S) District:

Conservation and Habitat Restoration Activities, consistent with approved conservation, fuel management, or habitat restoration plans;

Grazing, consistent with approved conservation, fuel management, or habitat restoration plans;

Fuel Break, consistent with approved conservation, fuel management, or habitat restoration plans;

Habitat Corridors and Linkages, consistent with approved conservation, fuel management, or habitat restoration plans;

Interpretive signage and Educational Kiosks;

Native Plant Propagation Areas;

Native Tree Nurseries;

Outdoor Education;

Rewilding, consistent with approved conservation, fuel management, or habitat restoration plans;

Row & Field Crops and Animal Raising – General Agriculture, excluding permanent structures;

Slope Stabilization And Erosion Control, consistent with approved conservation, fuel management, or habitat restoration plans;

Wildfire Public Safety Infrastructure. (Ord. 1262, §2, adopted 2025)

The following uses require approval of an appropriate Use Permit pursuant to the provisions contained in Article 20 of this Chapter.

Campground (Open-Space);

Cultural, historical, or archaeological interpretive facilities;

Environmental education centers;

Habitat banking or mitigation sites;

Park and recreation services;

Parking lot(s) serving trailheads or open-space recreation areas;

Special events or temporary uses consistent with open space purpose and intent;

Trail, Bicycle (Shared-Use);

Trail, Equestrian;

Trail, Multi-Use;

Trail, Nature/Footpath, consistent with approved conservation, fuel management, or habitat restoration plans;

Trail, Public;

Trail-Spur;

Trailhead;

Water detention and recharge facilities. (Ord. 1262, §2, adopted 2025)

A.    Primary structures: Maximum height of 25 feet.

B.    Accessory structures: Maximum height of 15 feet or height of main building, whichever is less.

C.    Improvements:

1. Non-obtrusive towers and equipment used exclusively for wildfire detection, emergency communications, or similar public safety purposes may exceed 25 feet. Any such increase would be subject to discretionary review, and must be the minimum necessary for operational effectiveness and designed to reduce visual and environmental impact.

2. Fences or walls: Maximum height of 7 feet, unless consistent with an approved conservation, fuel management or habitat restoration plan, or approved by Use Permit. (Ord. 1262, §2, adopted 2025)

There is no minimum site area for uses in the O-S District; however, development intensity must conform to open space purpose and intent. (Ord. 1262, §2, adopted 2025)

Yard setbacks apply to all new structures, additions, grading, and site improvements, including fences, walls, pavement, and other hardscape features, as conveyed below.

A.    Environmental. A minimum 100-foot setback is required from the edge of sensitive environmental resources, including creeks and rivers (measured from the top of bank), wetlands (from the delineated wetland boundary), and mapped sensitive habitat areas.

B.    Visual. To minimize visual impacts, development within or near setback areas shall be sited and designed to maintain natural sightlines and reduce visual prominence through building placement, height and massing control, material selection, and landscape screening, with particular attention to ridgelines.

C.    Slope. For sloped terrain, additional setbacks from the top of slope and toe of slope are required to avoid excessive grading. Slope percentage shall be measured as average grade over a horizontal distance of at least 25 feet, based on existing (pre-project) topography.

1. On slopes 15% to less than 30%, principal structures and foundations shall be set back a minimum of 10 feet from the top of ridge and 10 feet from the toe of slope.

2. On slopes 30% or greater, new structures and grading to create building pads are prohibited unless the review authority finds that no practicable alternative exists and that a geotechnical report demonstrates stability without increasing erosion risk; where allowed, the minimum top- and toe-of-slope setbacks shall be 30 feet.

D.    Yard Setbacks: Any adjacent lot that shares a side or rear lot line with land zoned O-S shall provide a transition yard measured from that line as follows for the following uses:

1. Single Family Residential: Rear 25 feet, side 12 feet;

2. Multifamily: Rear 30 feet, side 15 feet;

3. Non-Residential: Rear 35 feet, side 15 feet.

E.    Exception. As part of the applicable Use Permit process, the Zoning Administrator or the Planning Commission may allow encroachments into required setbacks when no practicable alternative exists and the proposed design minimizes both physical and visual disturbance. Findings shall be supported by site-specific analysis, including (as applicable) a geotechnical report, erosion and sediment control plan, and visual analysis. (Ord. 1262, §2, adopted 2025)

A.    For all trailheads and recreation areas the parking requirements shall be one space per ten (10) average daily visitors. The required number of parking spaces may be adjusted by the Community Development Director through a Determination of Appropriate Use, based on anticipated patterns of use, including but not limited to similar regional facilities; bicycle or pedestrian access requirements; equestrian facilities; educational or group programming; seasonal or event-based usage; proximity to public transit or urbanized areas.

B.    Parking surfaces shall be permeable and screened with vegetation, where feasible.

C.    No overnight public parking is allowed unless allowed by an issued Special Event or Use Permit.

D.    Other Uses: All other uses are subject to the provisions contained in Article 17 of this Chapter. (Ord. 1262, §2, adopted 2025)

A.    Resource Protection: Grading or vegetation removal shall only be permitted with approval from the Community Development Director or Public Works Director on an emergency basis when not part of an approved conservation, fuel management or habitat restoration plan.

B.    Lighting: Artificial lighting in the Open-Space District is generally discouraged. Any lighting must be minimal and dark-sky compliant according to International Dark-Sky Association’s (IDA) guidelines for outdoor lighting to minimize light pollution.

C.    Fencing: For Allowed uses, the use of fencing in the Open-Space Zoning District is generally discouraged. Any fencing installed must be wildlife-friendly or implemented to maintain public safety. Fences are prohibited if they would impede wildlife movement within a designated wildlife or habitat corridor, as determined by the City based on substantial evidence.

D.    Parking Lot and Recreation Area Landscaping: Landscape plantings in the Open-Space District must be native and drought-tolerant species. Parking and recreation surfacing shall be permeable except where infeasible for compliance with the Americans with Disabilities Act or to serve emergency access.

E.    Requirements for Special Events: Events in the Open-Space District must be consistent with the purpose of the zoning district set forth in this Article and shall not significantly degrade natural resources or impair public enjoyment of the area. All events require prior approval through a Use Permit. (Ord. 1262, §2, adopted 2025)

Whenever a use is not listed in this Article as a use allowed by right or a use subject to a Use Permit in the O-S Zoning District, the Community Development Director shall determine whether the use is appropriate for the Zoning District, either as of right or subject to a Use Permit. In making this determination, the Planning Director shall find as follows:

A.    That the use would not be incompatible with other existing or allowed uses in the O-S Zoning District.

B.    That the use would not be detrimental to the continuing preservation of resources or access to the area in which the use would be located.

C.    That the use involves a similar scale and impact to uses that are designated allowed uses in this Article.

D.    That the use is consistent with the purpose and intent of the Open-Space Zoning District, including the protection of natural resources, scenic values, and the long-term preservation of open space for public or ecological benefit.

E.    In the case of determining that a use not listed in this Article as an allowed or permitted use could be established with the securing of a Use Permit, the Community Development Director shall find that the proposed use is similar in nature and intensity to the uses listed as permitted uses. All determinations of the Community Development Director regarding whether a use can be allowed or permitted in the Open-Space Zoning District shall be final unless a written appeal to the City Council, stating the reasons for the appeal, and the appeal fee, if any, established from time to time by City Council resolution, is filed with the City Clerk within ten (10) days of the date the decision was made. Appeals may be filed by an applicant or any interested party. The City Council shall conduct a duly noticed public hearing on the appeal in accordance with the applicable procedures as set forth in this Chapter. At the close of the public hearing, the City Council may affirm, reverse, revise or modify the appealed decision of the Community Development Director. All City Council decisions on appeals of the Director’s actions are final for the City. (Ord. 1262, §2, adopted 2025)