[Added 6-28-1999 by Ord. No. 2-1999]
The primary purpose of the Open Space Conservation District (OSC) is to preserve open land, sensitive natural, scenic and historic areas and rural community character that would be lost under conventional development. In addition, it is the intent of this district to permit a reasonable amount of residential development in the form of small, compact neighborhoods of single-family detached homes in an open space setting, located and designed to reduce the perceived intensity of development, preserve natural resources and scenic vistas and provide privacy and neighborhood identity. Specific objectives are as follows:
A. 
To provide an effective means of responding to site conditions for the preservation of steep slopes, woodlands, stream valleys, floodplains and wetlands.
B. 
To preserve scenic vistas and elements of the Township's rural character by minimizing views of new development from existing roads.
C. 
To provide for the creation, retention and protection of open space in the Township.
D. 
To encourage innovation and promote design flexibility, efficiency and ingenuity in the siting of singe-family detached homes and their accompanying infrastructure.
E. 
To require less impervious surface than necessary with conventional development, reduce erosion and sedimentation associated with earth disturbance, reduce pollutants from surface water runoff and maintain high levels of groundwater recharge.
F. 
To provide an opportunity to attain the objectives of the Township's Comprehensive Plan and Open Space, Recreation and Environmental Resources Plan with regard to open space preservation, orderly growth and enhancement of environmental resources.
G. 
To provide for the enhancement of woodlands through natural succession and reforestation, where appropriate, and to encourage the preservation of habitat for various forms of wildlife.
H. 
To protect and preserve prime agricultural land, natural and historic resources, the continued viability of agricultural security areas and the continuity of development and viability of agricultural operations.
[Added 6-25-2001 by Ord. No. 4-2001]
A. 
The Open Space Conservation District is defined and established to include and be an overlay upon all parcels 15 acres or larger within any Residential District designated on the Willistown Township Zoning Map as of the date of adoption of this article.
B. 
Multiple contiguous undeveloped parcels may be developed under this district, provided that they are developed according to a single plan with common authority and common responsibility. Willistown Township may require evidence of an agreement among all owners of included parcels demonstrating binding commitment to common development of the parcels.
C. 
All property within the District used or intended to be developed for residential purposes shall comply with the provisions of this article.
D. 
In the case of a conflict between the provisions or requirements of the Open Space Conservation District and those of the underlying district, the provisions of the Open Space Conservation District shall apply, as determined by the Board of Supervisors.
A building may be erected or used and a lot may be used or occupied within the OSC Open Space Conservation District only for a purpose permitted by right in the RU Residential District and for the following uses:
A. 
Uses by right.
(1) 
Singe-family detached dwelling.
(2) 
Common open space areas. A development in this District shall provide for common open space.
B. 
Conditional use standards for conventional development.
(1) 
Authorization to develop a tract pursuant to the requirements of the underlying residential district (conventional development), rather than the Open Space Conservation District, may be granted by the Board of Supervisors as a conditional use pursuant to § 139-118.1, provided that the applicant follows the procedures and submits the information required below, proves conformance with the standards and criteria set forth in § 139-118.1 and, in addition thereto, establishes the following:
(a) 
That conventional development will preserve natural and scenic features, historic sites and historic resources to a degree equal to or greater than development under the Open Space Conservation District. The applicant must submit sketch plans for both development under the Open Space Development option and the conventional development option in order to demonstrate compliance with this requirement. The applicant may be required to protect such features, sites and resources from further development with appropriate conservation easements running with the land. Where development of less than the entire parcel is intended or where the parcel is intended to be developed at less density than conventional development would permit, the applicant may be required to file a development plan for the entire parcel pursuant to § 123-17 of the Subdivision and Land Development Code or may be required to restrict further subdivision and/or development on the remainder of the tract by recorded conservation easement.
(b) 
That the applicant has achieved the Open Space Conservation goals set forth in § 139-150 by conveyance of a perpetual conservation easement to a recognized nonprofit corporation established for that purpose or by any other means of facility ownership set forth in § 139-156.
(2) 
The applicant shall comply with the procedures governing conditional use applications outlined under § 139-118.1 of this chapter.
(3) 
The sketch plans to be submitted by the applicant as part of a conditional use application shall include the following items, at a minimum:
(a) 
Tract data. A survey plan which identifies total acreage of the tract, tract boundaries showing bearings and distances and the ownership of the tract and all adjacent properties. The legal limits of rights-of-way shall be shown, along with the limits of an ultimate right-of-way.
(b) 
Environmental data. A plan which identifies the limits of designated floodplain areas, seasonal wet and alluvial soil conditions, woodland areas and steeply sloped land in excess of a slope of 15%.
(c) 
Development data. Sketch plans which indicate the proposed subdivision of the tract with sufficient data to prove that the proposed layout will comply with all requirements of this article and the Zoning, Subdivision and Land Development and Environmental Protection Ordinances.
(d) 
Means of access. A plan which identifies all existing access-point/curb cuts, including but not limited to public roads, along the frontage of the tract and for a distance of at least 500 feet east and west of the tract, and such other existing access-point/curb cuts at a greater distance from the tract if such existing access-point/curb cuts will in any way impact upon the traffic entering into and/or exiting from the proposed development. The plan shall also show all other public roads within 500 feet of the tract proposed for development and all new access points or connections into the existing public highway system proposed as part of the development plan.
(4) 
In addition, the applicant shall submit the following studies:
(a) 
Traffic impact study. The applicant shall be responsible for the preparation and cost of a traffic impact study. Such study shall be prepared by a traffic consultant hired by the applicant with the approval of the Township. The study shall enable the Township to access the impact of a proposed development on the highway network, to identify traffic problems associated with the proposed development, to identify solutions and to present improvements to be incorporated into the project design.
(b) 
Community impact study. The applicant shall submit a study which will sufficiently assess the impact the development will have on the community and its level of public services and manner in which negative impacts thereon shall be resolved by the applicant, to enable the Board of Supervisors to ascertain if the proposed development is capable of being serviced by the public services as proposed and, further, to determine if the applicant has made reasonable effort to minimize the negative impact of the development on such services. The study shall include, at a minimum, a study of at least the following services and facilities:
[1] 
Fire protection. The impact the proposed development will have on fire protection capability, including, but not limited to, municipal water supply, pumping capacity and specialized equipment, should be analyzed. The applicant must adequately demonstrate what effect the proposed development will have on these factors and its ability to meet any specialized needs so that the development will not have any adverse impact on the public safety by adversely affecting the fire protection capability available to the community including the proposed development.
[2] 
Solid waste. A study to determine what amount of solid waste will be generated as a result of the development should be analyzed. The study should identify what method will be used to dispose of solid waste and what effort will be directed toward recycling solid waste.
[3] 
Historical. A study shall be made that determines the location of historic properties and structures both on and within 500 feet of the site and the effect said development will have on these properties and structures, and what effort the developer will make to preserve such historic properties and structures. Determination of historical significance and the treatment of all negative impacts will be considered by the Township Historical Commission, with the final decision on treatment resting with the Board of Supervisors.
[4] 
Water. A study of the amount of water needed for domestic and fire use shall be provided. The study shall indicate the location of the source and anticipated pressure of the proposed source. The applicant shall indicate willingness to pay for the cost of improvements to a public water system if it is determined that connection to said system is necessary.
[5] 
Sewer. A study providing information on the alternative methods of sewage disposal shall be provided. The developer shall provide information on the estimated gallons per day of sewage that will be treated by the proposed use(s).
(c) 
Environmental impact study. A study shall be prepared which surveys environmental information and which addresses how these sensitive areas will be conserved and protected. This information shall serve as a basis for designing the development which is responsive to environmental conditions as provided in this article and the Environmental Protection Ordinance.[1]
[1]
Editor's Note: See Ch. 73, Environmental Protection.
(5) 
Conditional use approval shall not be required for a conventional development where the Board of Supervisors determines all of the following criteria are met:
[Added 11-10-2008 by Ord. No. 4-2008]
(a) 
The property within the proposed subdivision is subject to a perpetual conservation easement subject to the requirements of the Conservation and Preservation Easements Act, 32 P.S. § 5051 et seq., held by a qualified conservation organization.
(b) 
The conservation easement provides for open space that satisfies the minimum common open space requirements of the Open Space Conservation District, except that the area subject to the conservation easement need not be held in a tract or tracts separate from the development area.
(c) 
The property is being subdivided consistent with and subject to the provisions of the conservation easement.
(d) 
The subdivision and conservation easement limitations are consistent with the overall goals and conservation objectives of the Open Space Conservation District.
(e) 
A supporting recommendation by the Planning Commission is obtained.
(f) 
The subdivision complies with all other ordinances of the Township.
The following standards shall apply to development in this district:
A. 
Parcel yield (number of lots or density). The maximum number of lots and/or dwelling units shall be determined by applying the standards in § 73-11.1 of the Willistown Township Environmental Protection Ordinance to the underlying zoning district. Density shall be no greater than that which the underlying zoning subdivision and environmental protection regulations would permit.
B. 
Common open space. Not less than 75% of the total tract area shall be designated on the plan as common open space and held in a tract or tracts separate from the development area.
C. 
Development area. The area(s) of the tract not designated as part of the common open space shall be designated on the plan as development area(s). Development areas are all areas not designated as common open space and include, but are not limited to, building areas, yards, driveways, sewage-related mechanical facilities and roads.
D. 
Perimeter setback. Structures shall be situated so as to maintain a minimum setback from any tract property line of 100 feet. Where existing natural features of the site, including but not limited to woodland areas, changes in topography, hedgerows or other site characteristics results in the dwelling unit being completely visually screened from the adjacent property and guaranties are provided through the planning process that such features will remain undisturbed, this setback may be reduced to 75 feet.
E. 
Area and height regulations.
(1) 
Minimum lot size: 15,000 square feet.
(2) 
Maximum lot size: one acre.
(3) 
Maximum building coverage: 20%.
(4) 
Minimum lot width: 75 feet.
(5) 
Minimum front yard: 25 feet.
(6) 
Minimum side yard: 10/25 feet aggregate.
(7) 
Minimum rear yard: 25 feet.
(8) 
Height. No building other than a farm building shall exceed 35 feet in height.
(9) 
Maximum impervious coverage:
[Added 5-14-2001 by Ord. No. 1-2001; amended 6-4-2004 by Ord. No. 5-2004; 11-10-2008 by Ord. No. 4-2008]]
Lot Size
Percent
Impervious
Less than 1/2 acre
30%
1/2 acre to less than 1 acre
25%
1 acre
20%
F. 
Access to common open space. All dwelling units shall have access to common open space without the obstruction of intervening lots, structures, fences or other impediments to pedestrians.
G. 
Historic sites and structures listed on the Township's Historic Resource Inventory. Historic sites and structures, including their cultural landscapes, may be included as part of the required common open space, subject to compliance with the requirements of this article. In addition, historic structures that are restored as single-family dwellings are not subject to inclusion in the parcel yield calculation determined pursuant to § 139-153A above. Reconstruction, alteration or restoration of historic structures shall conform to the current requirements of the United States Secretary of the Interior's Standards for Rehabilitation.
H. 
Cultural landscape delineation and protection. Cultural landscapes required to preserve an historic site's integrity shall be maintained. The Planning Commission shall delineate what areas are to be included in the required cultural landscape.
I. 
Viewsheds, scenic vistas, scenic roads and significant visual landscapes. Dwellings and accessory buildings shall be configured so as to be located outside of broad, open vistas visible from roads or other public vantage points. In addition, such structures shall be located outside the immediate boundaries of scenic roads. See § 139-155 below for relevant design standards. Viewsheds, scenic vistas, scenic roads and significant visual landscapes are defined and inventoried in the Township's Open Space, Recreation and Environmental Resources Plan.
J. 
Natural resources. The applicant shall establish that development, including site improvement, lot design and open space configuration, preserves natural resources and environmentally sensitive areas in accordance with Chapter 73, the Willistown Township Environmental Protection Ordinance.
K. 
Landscaping buffering and screening. Natural areas or buffers shall be required for all proposed development in accordance with the requirements for the underlying zoning district pursuant to Article X of the Willistown Township Environmental Protection Ordinance.
L. 
Detention, retention and sewage disposal areas. Traditional stormwater management basins (detention basins) and sewage-related mechanical facilities (grinder pumps, sand filters, etc.) are not permitted in the common open space. Stormwater management facilities or portions thereof that can be integrated into the natural environment or which incorporate natural site features, such as swales. natural retention ponds, filter strips, riparian buffers, etc., are permitted to be located in the required common open space. Subsurface disposal areas, spray irrigation disposal areas and sewage holding and settling ponds with associated monitoring wells and equipment are permitted to be located in the required common open space. Utility easements may be included as part of the common open space. Easements satisfactory to the Planning Commission shall be established to enable maintenance of such facilities by the appropriate parties.
A. 
A minimum of 75% of the total tract area shall be held as common open space in a tract or tracts separate from the development area.
B. 
Land designated as common open space shall be configured so as to:
(1) 
Minimize negative impacts of development on the tract;
(2) 
Maximize conservation of site features identified as having particular conservation value, historical significance or scenic or recreational values, as inventoried in the Willistown Open Space, Recreation and Environmental Resources Plan, including mature trees, woodlands, riparian stream valleys, hedgerows, fence lines, historic sites or structures and their cultural landscapes, historic or scenic roads, significant visual landscapes or scenic vistas, pedestrian and equestrian trails and other noted landscape features;
(3) 
Serve as buffer areas between grouped dwellings of varying types and between grouped dwellings and adjacent tracts; and
(4) 
Be part of and contiguous to a larger integrated open space system, including protected areas on adjoining lands.
C. 
No more than 80% of the common open space shall be comprised of land within the one-hundred-year floodplain, wetlands or slopes in excess of 25%.
D. 
Any area designated as common open space shall not be less than one acre in area. No single area or portion of an area designated as common open space shall be counted toward the minimum required open space wherever such area or portion of area is less than 100 feet in width or has a ratio of the longest to shortest dimension exceeding four to one, except in the case of a public pedestrian or equestrian trail system, viewshed, scenic corridor or other linkage between two larger, noncontiguous open space areas. Equestrian or pedestrian trail linkages identified by the Township shall not be disturbed unless the property cannot otherwise be developed and then only when relocation of the trails is approved by the Planning Commission. There shall be no more than three noncontiguous areas of common open space.
E. 
No structures or impervious surfaces shall be counted towards the common open space requirements, except as permitted in § 139-153, Development standards.
F. 
The following uses are permitted in the common open space:
(1) 
Woodland, meadow, wetland, watercourse, wildlife sanctuary or similar conservation-oriented or natural area.
(2) 
Passive recreation area, including parkland, pedestrian or equestrian trails, community gardens and other recreation uses approved by the Planning Commission but excluding structures and use of motorized or nonmotorized vehicles.
(3) 
Pasture land, open field or lawn.
(4) 
Subsurface disposal areas, spray irrigation disposal areas and sewage holding and settling ponds with associated monitoring wells and equipment, excluding stormwater management basins (detention and retention basins) and sewage-related mechanical facilities (grinder pumps, sand filters, etc.).
(5) 
Easements for drainage, access, sewer or water lines, or other public purposes.
(6) 
Agriculture, pursuant to the requirements of the underlying district.
[Amended 3-13-2023 by Ord. No. 2-2023]
The location of common open space, dwellings and site improvements shall be in response to the inventory of site features and environmentally constrained areas required under Article III, Conservation Plan Requirements, of the Environmental Protection Ordinance,[1] and as otherwise regulated therein. The following standards shall apply during the siting process:
A. 
Viewsheds, scenic vistas and significant visual landscapes.
(1) 
Dwellings and accessory buildings shall be configured so as to be situated below ridgeline elevations to preserve existing scenic vistas. To achieve this objective, dwellings and accessory buildings should be sited entirely below the elevation of the nearest ridgeline whenever possible. Where the applicant claims that dwellings or accessory buildings cannot be situated below the ridgeline, it shall be the burden of the applicant to demonstrate why this is not possible and how the proposed design creates the minimum possible disturbance of views of the ridgeline. To the extent that any portion of a structure must be located above a ridgeline elevation, such siting shall be contingent upon the submission and approval by the Township Planning Commission of a plan for the mitigation of such ridgeline impacts. Such plans shall identify the locations and dimensions of the proposed structure(s), the architectural style proposed and shall demonstrate how the structure(s) shall be effectively screened from adjacent tracts and/or designed to minimize disruption of views of the ridgeline.
(2) 
In addition, dwellings and accessory buildings shall be configured so as to be located outside of broad, open vistas visible from roads or other public vantage points as inventoried in the Township's Comprehensive Plan.
[Amended 9-9-2024 by Ord. No. 6-2024]
B. 
Environmentally sensitive areas.
(1) 
Dwellings and accessory buildings shall be configured so as to be located outside environmentally sensitive areas, including natural drainage swales. Specific requirements pursuant to the Township's Environmental Protection Ordinance shall be considered.
(2) 
In addition, applicants shall minimize disturbance to valued woodlands and other vegetation consistent with the Township's Environmental Protection Ordinance. Hedgerows and other vegetation should be preserved and incorporated into the design of the site, either as part of the open space or as buffers between residential areas, roads and open space uses.
C. 
Scenic roads. Dwellings and accessory buildings shall be configured so as to be situated outside the immediate boundaries of scenic roads, as defined and inventoried in the Township's Comprehensive Plan. To achieve this objective, dwellings and accessory buildings should be sited outside the scenic road's visual corridor, whenever possible. Where the applicant claims that dwellings or accessory buildings cannot be situated outside the immediate boundaries of scenic roads, it shall be the burden of the applicant to demonstrate why this is not possible and how the proposed design creates the minimum possible disturbance of views along the scenic road. To the extent that any portion of a structure must be located within the scenic road's visual corridor, such siting shall be contingent upon the submission and approval by the Township Planning Commission of a plan for the mitigation of such impacts. Such plans shall identify the locations and dimensions of the proposed structure(s), the architectural style proposed and shall demonstrate how the structure(s) shall be effectively screened from the scenic road and/or designed to minimize disruption of views from the scenic road. At a minimum, views of dwellings and accessory buildings from scenic roads shall be minimized by the use of changes in topography, existing vegetation or additional landscaping.
[Amended 9-9-2024 by Ord. No. 6-2024]
D. 
Development area(s).
(1) 
Development areas shall consist of at least five, but no more than 25 lots, and be surrounded by open land. Modifications of this standard shall be permitted, provided that the applicant can demonstrate to the Planning Commission's satisfaction that alternatives are more appropriate for the tract in question and that such alternatives are not being proposed solely for economic reasons. All lots within development areas shall take access from interior roads, rather than from roads exterior to the site.
(2) 
Landscaping, buffering and screening of development areas pursuant to Article X of the Willistown Township Environmental Protection Ordinance should consider the form of development proposed. For example, applicants proposing hamlet or village development with minimum street setbacks should plant deciduous street trees at forty-foot intervals on both sides of each street so that the community has a traditional and stately appearance upon tree maturity. Common areas, community greens and cul-de-sac islands should also be planted with native species of shade trees and flowering shrubs.
E. 
Street widths, culs-de-sac, curbs, sidewalks and paths. Pursuant to Chapter 123, as amended (the Subdivision and Land Development Ordinance), applicants are permitted to modify select street widths and corresponding cul-de-sac dimensions and waive curb and sidewalk requirements where it can be shown that the objectives of this article will be advanced and better development design is achieved.
F. 
Agricultural lands. Disturbance to prime farmland soils and large tracts of contiguous land suitable for agricultural use should be minimized. Where agricultural activities are anticipated, setbacks or buffers should be utilized and the direction of prevailing winds and drainage should be considered in the development design.
G. 
Sanitary sewers.
(1) 
Land treatment technologies capable of recharging groundwater aquifers are strongly encouraged. Subsurface disposal areas, spray irrigation disposal areas and holding and settling ponds should be functional designed and used as amenities for the tract. For example, spray irrigation is particularly well suited to active recreation areas which require occasional lawn watering. Holding and settling ponds can be designed as natural lakes, adding aesthetic appeal and value to the site.
(2) 
Applicants proposing to develop lots of less than one acre utilizing community subsurface or spray irrigation systems may be eligible for a partial increase in density pursuant to Chapter 123, Article VI, § 123-40A(4).
H. 
Stormwater management.
(1) 
Stormwater management facilities (basins, wet ponds, swales, etc.) should be integrated into their surroundings to complement the natural character of the site. Well-designed facilities are most effective when they are barely recognizable. Properly designed, a stormwater facility may even be an asset to a site. In order to properly integrate stormwater facilities into a site, careful consideration must be given to their location, form and landscaping consistent with the Townships Environmental Protection Ordinance.[2] Applicants are strongly encouraged to consult the Pennsylvania Handbook of Best Management Practices for Developing Areas, Spring 1998, for specific information regarding planning, use and maintenance of BMP's.
[2]
Editor's Note: See Ch. 73, Environmental Protection.
(2) 
Location is critical to the site design. Facilities need not be hidden from view but should be integrated into the natural contours of the site and located based on geologic, topographic and soil conditions. Excessive grading, clearing of vegetation and alteration of watercourses and wetlands should be avoided. As with sewage holding ponds, stormwater facilities can serve multiple purposes, including wildlife habitat areas, irrigation areas and scenic amenities. The form of the facility should harmonize with the surrounding landscape. Curvilinear forms are more appropriate to natural settings. Landscaping consistent with the Township's Environmental Protection Ordinance, helps blend the facility into the natural landscape.
I. 
Other applicable standards. The design standards of the Township's Zoning and Subdivision and Land Development Ordinance[3] concerning circulation, off-street parking, signs, lighting, etc., shall apply to any development occurring under this article.
[3]
Editor's Note: See Ch. 123, Subdivision and Land Development.
[1]
Editor's Note: See Ch. 73, Environmental Protection.
A management plan for the disposition, use, maintenance and insurance of the common open space, including provisions for funding, shall be provided to and approved by the Township Planning Commission and Township Solicitor prior to plan approval. Management plans shall include, at a minimum, the following components:
A. 
Executive summary. A brief summary of the contents of the plan and a description of the open space to be managed. A description of the form of ownership and insurance for the common open space.
B. 
Description of existing conditions. A brief but detailed description of the site's resources and history, with emphasis on the common open space. All resources should be discussed, including the natural, scenic and historic resources of the site. Discussion of natural resources should list species found on the site and the overall condition and health of the natural system. Discussion of the cultural and historic resources should include the significance of the resource and its physical condition. Other resources should be similarly discussed, including their relative health, condition or significance.
C. 
Goals and objectives for the common open space. A list of the overall goals and measurable objectives for managing the common open space, including a description of the use(s) intended for the common open space.
D. 
Management measures. A description of the actions, budget and schedule for managing and restoring the common open space pursuant to the goals and objectives described in Subsection C above.
E. 
Maintenance and operation plan. A description of the annual maintenance and operation of the common open space, describing such things as mowing schedules, trail maintenance, invasive plant removal measures, structure upkeep and other relevant activities.