Chapter 18.10


18.10.010    Use and bulk regulations.

18.10.020    Purpose.

18.10.030    Permitted uses.

18.10.040    Prohibited uses.

18.10.050    Use variances.

18.10.060    Property development standards.

18.10.070    Design standards.

18.10.010 Use and bulk regulations.

Use and bulk regulations applying specifically to open space uses are set forth in this chapter. Also applying to open space districts are additional regulations set forth in other chapters and sections as follows:

(A) HMC 18.05.040, Zoning districts – Establishment and application.

(B) HMC 18.05.050, Rules of interpretation of district boundaries.

(C) HMC 18.05.060, Interpretation and application – Supplementary district regulation.

(D) Article II of Chapter 18.05 HMC, Definitions.

(E) Chapter 18.70 HMC, Planned Unit Development Districts.

(F) Chapter 18.75 HMC, Landscape Regulations.

(G) Chapter 18.80 HMC, Off-Street Parking and Loading.

(H) Chapter 18.85 HMC, Signs.

(I) Chapter 18.90 HMC, Nonconforming Uses and Nonconforming Buildings.

(J) Chapter 18.110 HMC, Administration.

(K) HMC 18.115.050, Use variances. [Ord. 1659 § 1, 2017].

18.10.020 Purpose.

The purpose of this title is to preserve and enhance significant natural, recreational viewsheds and public space areas by protecting their inherent character, and by accommodating developments that are compatible with these natural and recreational amenities. [Ord. 1659 § 1, 2017].

18.10.030 Permitted uses.

The following listed uses and no others are permitted uses in open space districts:

(A) All uses commonly referred to as agriculture, horticulture, crop and tree farming, orchards, gardening, nursery operations, together with the operation of any farm machinery or vehicles incidental to the above uses; provided, that:

(1) No building in which livestock or fowl may be housed shall be permitted.

(2) No farm building shall be constructed closer to the front lot line than the rear-most face of the primary building.

(B) Single-family detached dwelling and dwellings for tenants who own or are primarily employed on the agricultural use on the lot.

(C) Golf courses and golf clubs, both private and public, but not including miniature golf courses and driving ranges which are commercially operated.

(D) Parks, forest preserves, and recreational areas, when publicly owned and operated.

(E) Parks and recreation areas for nonintensive uses, including hiking, bicycling or bridle trails, picnic areas, playing fields, and similar uses.

(F) Open land uses, primarily passive in nature, including wildlife sanctuary, forest preserve, nature center, and similar uses.

(G) Storm water detention basins, provided such areas do not occupy more than 30 percent of the total lot area and are naturally designed. Underground storm water management systems shall be exempt from this requirement; provided, that:

(1) All required and appropriate studies are completed to justify their use.

(2) No negative impact results from the use of underground systems.

(3) The underground systems complies with all applicable codes and regulations.

(H) Signs, as permitted in Chapter 18.85 HMC.

(I) Temporary buildings for construction purposes for a period of time not to exceed such construction.

(J) Temporary roadside stands for the sale of open space products grown on the premises.

(K) Accessory buildings and uses customarily incidental to any of the above uses. [Ord. 1659 § 1, 2017].

    Penalty, see HMC 18.120.030.

18.10.040 Prohibited uses.

The following uses or activities are prohibited in this district:

(A) Use of motor vehicles, except within approved driveways and parking areas.

(B) Mobile home dwelling units.

(C) Removal of healthy trees, except in compliance with the subdivision for the tract in question, if any, conforming to customary standards of forestry, erosion control and engineering.

(D) Regrading, altering, diverting, or modifying water courses or bodies, except in compliance with the subdivision for the tract in question, if any, conforming to customary standards of forestry, erosion control and engineering.

(E) Any permanent development on land designated for park or open space in the most recent highland parks and recreation master plan. [Ord. 1659 § 1, 2017].

18.10.050 Use variances.

In an OS district, use variances may be allowed in accordance with the limiting conditions and procedures as set forth in HMC 18.115.050. [Ord. 1659 § 1, 2017].

18.10.060 Property development standards.

(A) Minimum Lot Size. Every lot in this district shall have a minimum lot area of three acres. All lots in this district shall have at least one lot line fronting a public street with a minimum of 150 feet frontage, except when an easement is provided as the sole means of access. In such case, the access easement shall be no less than 30 feet in width.

(B) Minimum Floor Area in an OS District. In an OS district, the following building coverage standards shall apply:

(1) Residential Buildings. No dwelling may be established, erected, or changed so that its floor area, exclusive of basements, terraces, unenclosed porches, and garages in square feet is less than 1,200 square feet.

(2) Nonresidential Buildings. No building, except for greenhouses, farm buildings, and related buildings, shall have a ground floor area of more than one percent of the total lot area.

Exhibit 1 – Open Space District
Development Example

(C) Maximum Floor Area Ratio. In an OS district, the floor area ratio of all buildings and structures on a zoning lot shall not exceed 0.5.

(D) Maximum Lot Coverage. In an OS district, the following lot coverage standards shall apply:

(1) Not more than 20 percent of the area of a lot may be covered by the combination of buildings, drives, sidewalks and parking area.

(2) Not more than 15 percent of the area of a lot may be used by any combination of detention, retention facilities, or utility easements.

(E) Minimum Front Yard. In an OS district, no portion of any principal building hereafter erected or enlarged shall be located closer than 25 feet, but in no case more than 35 feet, to the front property line.

(F) Minimum Side Yard. In an OS district, no portion of any building hereafter erected or enlarged shall be located closer than 30 feet on either side of the building to the side property line. The total aggregate of provided side yard shall not be less than 30 percent of the lot width. Accessory buildings shall be exempt from this requirement.

(G) Minimum Rear Yard. In an OS district, no portion of any building hereafter erected or enlarged shall be located closer to the rear property line than 25 percent of the lot depth. Accessory buildings shall be exempt from this requirement.

(H) Sensitive Areas. Where a designated wetland, waterway, or other environmentally sensitive area is located within a lot, the following additional setbacks shall be provided:

(1) Streams, natural channels, ponds, and other natural, permanent water bodies. Minimum 200 feet from water’s edge at the mean water level.

(2) Wetlands and other environmentally sensitive areas. Minimum 50 feet from the boundary of the area.

(3) Accessory buildings shall be exempt from these requirements.

(I) Additional Yard Requirements. All lots that are undeveloped or unimproved at the time of the passing of the ordinance codified in this title, and are adjacent to an active railroad right-of-way on at least one side, shall have a minimum 50-foot easement on all yards abutting the active railroad.

(J) Building Height. No building or structure may be changed or erected in this district so as to have a height greater than 35 feet.

(K) Parking for farm machinery, implements, and equipments shall be provided behind the rear-most face of the primary building. [Ord. 1659 § 1, 2017].

18.10.070 Design standards.

(A) Public Amenities. All parks that are open to the public shall provide the following amenities:

(1) Uniform site identification signage.

(2) Appropriate site furnishings (picnic tables, benches, bike racks, drinking fountains, trash receptacles, etc.) for the intended scale and use of the park.

(3) Street trees in accordance with Chapter 18.75 HMC for parks and recreational facilities.

(B) To the extent practical, place parks and recreation facilities to reduce impact on adjacent development, including impacts of noise, traffic and lights. Further, place active amenities, such as basketball courts and sports fields, away from neighboring homes to the extent practical.

(C) Place permanent restrooms in highly visible areas that receive the most visitation and near public streets, if possible, to reduce vandalism risks and increase safety.

(D) Accessibility. All active parks and recreational facilities shall provide the following:

(1) Access and connection to surrounding neighborhoods by sidewalks, bicycle lanes, or off-street trails to insure visitability and multiple ways of accessing parks. Where practical, primary access to the park should be provided via a local street with sidewalks, not an arterial street.

(2) Incorporate universal access principles to facilitate access and movement within parks for people of all ages and abilities.

(E) Safety. Incorporate public safety and security design guidelines in the design and operations of parks, green space, and facilities. Permitted publicly supported guidelines, subject to the regulations of this title, may include:

(1) Use of lights to deter crime.

(2) Landscaping to allow unobstructed views of surrounding areas.

(3) Locating play equipment and other recreation facilities in areas that are visible from the street.

(F) Protection of Natural Areas. Natural features in any open space district shall generally be maintained in their natural condition, but may be modified to improve their appearance, function, or overall condition, as recommended by a qualified expert in the particular area being modified. Permitted modifications may include:

(1) Reforestation.

(2) Woodland management.

(3) Meadow management.

(4) Buffer area landscaping.

(5) Streambank protection.

(6) Wetlands management.

(G) Encourage environmentally sustainable landscape designs and best practices that minimize surface water runoff and other infrastructure impacts.

(H) Incorporate native plants into each landscape where practical, for their educational and habitat value and to maintain a sense of place.

(I) Evaluate the use of turf versus other landscape types when designing new parks or renovating existing ones to efficiently use maintenance resources.

(J) Dedication of Open Space.

(1) There shall be no open space requirements for those developments that comply with the “base zoned densities” identified in the underlying district. For those developments wishing to dedicate land for parks, open space, or public space, such open space shall meet the general requirements of the underlying district.

(2) For residential developments, developers may provide open space, but such dedication shall be subject to the provisions of Chapter 18.70 HMC. Developers may receive density credits for any open space dedication, but such credits may not exceed the total allowable density for the lot without such dedication.

(3) For commercial development, developers are encouraged to dedicate open space for public purposes. In such cases, where required, superior landscape may be offered to support public space provisions.

(K) Method of Owning/Maintaining Open Space.

(1) Within all developments that comply with the base zone densities, open space shall become a function of the underlying zoning and setback requirements. In these instances, ownership and maintenance responsibilities shall remain with the owner.

(2) The landowner/developer for all other development shall determine how the open space will be held for ownership purposes. Open space can be held passively, owned by the landowner, held as active open space, open for public use, and owned by the landowner, the town, or third party, or preserved through a conservation easement. In certain instances, the town may elect not to accept ownership of open space that is not compatible with the town comprehensive plan or most current parks and recreation master plan. [Ord. 1659 § 1, 2017].