Consistent with the declaration of legislative intent and statement of community development objectives found in §§ 310-2 and 310-3 of Article I of this chapter, it is the intent of this article to benefit the public health, safety and welfare by conserving and protecting areas of steep slopes from the harmful consequences of excessive clearing of vegetation, excessive grading and/or inappropriate development. In so doing, the Township shall be guided by the goals of the Township Comprehensive Plan, 1994, Open Space and Environmental Resource Protection Plan, and the following objectives:
A. 
Guard against property damage and personal injury and minimize the potential for erosion, soil failure, stream siltation, and contamination of surface waters caused by the misuse of steep slope areas.
B. 
Conserve existing woodlands for air and water quality benefits, to provide habitat for wildlife, and to maintain the ecological balance among the natural systems on steep slope areas.
C. 
Permit land uses by right that are compatible with protection of steep slope areas and encourage the use of steep slope areas for open space and conservation uses.
D. 
Prohibit development in steep slope areas wherever possible, and require all land use, clearing, grading and construction to satisfy performance standards that guard against potential harmful consequences.
E. 
Regulate the expansion of any land use or development that existed on steep slope areas prior to enactment of these requirements.
F. 
Protect adjoining properties from harmful consequences of development permitted under relief from the provisions of these requirements.
The Steep Slope Conservation Overlay District is established as all those areas of the Township with a slope of 25% or more, referred to as "steep slopes" or "steep slope areas." This district may be referred to as the "Steep Slope District."
A. 
Steep slope map:
(1) 
Areas of steep slopes shall be plotted on a map known as the "Steep Slope Conservation Overlay District Map of Perkiomen Township (Steep Slope Map)," as determined from United States Geological Survey (USGS) maps to indicate the approximate boundaries of the Steep Slope District.
(2) 
The boundaries shown on the Steep Slope Map may be supplemented or modified by boundaries determined by examination of one or both of the following sources whenever a subdivision or land development plan is submitted for review by the Township:
(a) 
Contour maps prepared from aerial photography.
(b) 
On-site survey prepared by a registered professional engineer or surveyor.
(3) 
Changes in the boundaries of the Steep Slope District may be plotted as amendments to the Steep Slope Map when feasible.
B. 
Boundary delineation and interpretation:
(1) 
Applicants shall show the boundaries of the Steep Slope District on all subdivision and land development plans, based on one or more of the sources listed in § 310-188A herein.
(2) 
The Township Engineer shall decide whether or not the Steep Slope District has been shown with sufficient accuracy on the applicant's plans. Based on the Township Engineer's advice, the Township Zoning Officer may require applicants to revise the boundaries shown on the plans.
(3) 
The burden of proving the correct boundary shall be on the appellant, supported by engineering and/or surveying data or mapping, testimony of a soil scientist, or other acceptable evidence.
The Steep Slope District shall be an overlay on all zoning districts and shall function in accordance with the following:
A. 
For any lot or portion thereof lying within the Steep Slope District, the regulations of the overlay district shall take precedence over the regulations of the underlying district.
B. 
Should the underlying zoning of any lot or any part thereof which is located in the Steep Slope District be changed through any legislative or judicial action, such change shall have no effect on the overlying Steep Slope District unless such change was included as part of the original application.
C. 
Should the overlying Steep Slope District be declared inappropriate to any lot through any legislative or judicial actions, such change shall have no effect on the underlying zoning district.
D. 
All uses, activities and development occurring within any Steep Slope District shall be undertaken only in strict compliance with the provisions of this article, with all federal and state laws, and with all other applicable Township codes and ordinances.
The following open space and conservation uses are permitted by right, provided that they shall not include any structures, roads, driveways, parking areas, construction or other development or grading or clearing of vegetation:
A. 
Wildlife sanctuary, woodland preserve, arboretum and passive park and recreation areas.
B. 
Game farm or hunting preserve.
C. 
Forestry and reforestation in accordance with recognized natural resource and soil conservation practices.
D. 
Pasture and grazing land in accordance with recognized natural resource and soil conservation practices.
E. 
Outdoor plant nursery or orchard in accordance with recognized natural resource and soil conservation practices.
F. 
Cultivation and harvesting of crops in accordance with recognized natural resource and soil conservation practices.
G. 
Front, side or rear yards and required lot area for any district, subject to the requirements of § 310-193, Development regulations, and provided such yards shall not be used for any use prohibited under § 310-192 herein.
H. 
Nonstructural accessory uses necessary to the operation and maintenance of the above-permitted uses.
The following uses shall be permitted on steep slopes of 25% or more when authorized by the Board of Supervisors as conditional uses in accordance with § 310-53 of Article VIII and with the conditional use standards and criteria in § 310-194 herein:
A. 
Structures, roads, driveways, parking areas and underground utilities, except that under no circumstances shall more than 50% of the driveway traverse regulated steep slopes.
B. 
Clearing of vegetation or grading, including the addition of fill composed of earth, rock or inorganic construction debris.
C. 
Sealed public water supply wells with approval of the Pennsylvania Department of Environmental Protection.
D. 
Storm sewers and stormwater detention basins with the approval of the Township Engineer and the Pennsylvania Department of Environmental Protection (if applicable).
E. 
On-site sewage disposal systems, when approved by the Pennsylvania Department of Environmental Protection and/or the Montgomery County Department of Health (if applicable).
F. 
Utility transmission lines and aboveground utility line structures.
G. 
Extractive uses and borrow pits in accordance with recognized conservation practices and regulations of the Pennsylvania Department of Environmental Protection.
H. 
Public sanitary sewers with the approvals of the Township Engineer, Authority Engineer and Pennsylvania Department of Environmental Protection (if applicable).
Applications for conditional uses shall comply with the procedures in § 310-53 of Article VIII of this chapter and provide the following information and documentation:
A. 
A plan by a registered professional engineer or surveyor which accurately locates the proposed use with respect to the Steep Slope District boundaries and existing development within 200 feet of the proposed use, together with all pertinent information describing the proposal and a topographical survey with contour elevations at no greater than five-foot intervals.
B. 
A plan of proposed development or use of the site conforming to the preliminary plan requirements of Chapter 264, Subdivision and Land Development, with contours shown at two-foot intervals, throughout the steep slope areas proposed for development or use. Contours shall be accurately drawn from on-site survey or aerial photographic sources.
C. 
Proposed modifications to the existing topography and vegetative cover as well as the means of accommodating stormwater runoff.
D. 
Documentation of any additional engineering and/or conservation techniques designed to alleviate environmental problems created by the proposed activities, in compliance with the Township's sedimentation and erosion control regulations.
E. 
A table shall be provided on the plan, containing the amount of total regulated steep slope area in acres and/or square feet and a total of proposed disturbed area of steep slopes in acres and/or square feet. This table shall be shown on the plan presented for the conditional use and on the approved development plans. The maximum amount of steep slope disturbance shall not exceed 5% of the total lot area.
F. 
The following, as deemed necessary by the Board of Supervisors:
(1) 
Typical tract cross sections at a vertical and horizontal scale deemed appropriate by the Township Engineer.
(2) 
Specifications of building materials and construction, including filling, grading, materials storage, water supply, and sewage disposal facilities.
A. 
All structures, roads, driveways, parking areas, grading, and clearing of vegetation shall be set back a minimum of 10 feet from the boundary of the Steep Slope District, unless otherwise approved as part of a conditional use application.
B. 
Areas of open space or a conservation easement shall be provided as recommended by the Planning Commission and required by the Board of Supervisors for those areas of steep slopes that should not be clear cut or disturbed.
C. 
Finished slopes of all cuts and fills shall not exceed 33% (3:1) unless the applicant can demonstrate to the satisfaction of the Township Engineer that steeper slopes can be stabilized and maintained adequately.
In considering a conditional use application, the Board of Supervisors shall consider the following:
A. 
Relationship of the proposed use to the objectives set forth in § 310-187.
B. 
Adverse effects on abutting properties.
C. 
The need for a woodland management plan on wooded steep slopes areas. This plan shall utilize the plant materials listed in Chapter 264, Subdivision and Land Development. Substitutions to this list must be approved by the Township.
D. 
Evidence that:
(1) 
Proposed buildings or structures are of sound engineering design and that footings are designed to extend to stable soil and/or bedrock and that the proposal will be sound from architectural, engineering and environmental perspectives and will have no adverse impacts on the health, safety and welfare of the community.
(2) 
Proposed roads, drives and parking areas are designed so that land clearing and/or grading will not cause accelerated erosion. Both vertical and horizontal alignment for such facilities shall be so designed that hazardous conditions are not created.
(3) 
Alternative placements on non-steep-slope areas were carefully evaluated for structures, including buildings, retaining walls, swimming pools, roads, access driveways, parking facilities and other development, and can be shown to be inappropriate or infeasible to the satisfaction of the Board of Supervisors.
(4) 
Proposed on-lot sewage disposal facilities are properly designed in conformity with applicable regulations.
(5) 
Proposed nonagricultural displacement of soil is for purposes consistent with the intent of this chapter and will be executed in a manner that will not cause erosion or other unstable conditions. The applicant shall provide an erosion and sediment control plan and supporting evidence.
(6) 
Surface runoff of water will not create unstable conditions, including erosion, and that appropriate stormwater management facilities will be constructed as necessary.
A. 
Areas of steep slopes that meet one or more of the following criteria as determined by the Township Zoning Officer shall be exempt from the conditional use process.
(1) 
Areas that are natural or man-made and that are less than 200 square feet in area shown in plan view. In order to be considered for an exemption, the areas must be truly isolated such that there are no other areas of steep slopes within 50 feet in any direction.
(2) 
Man-made steep slope areas that are greater than 200 square feet but are not environmentally sensitive.
(3) 
Maintenance and/or repair of an existing underground utility facility on any steep slope area.
B. 
It shall be the burden of the applicant to prove to the satisfaction of the Township Zoning Officer that the slopes meet an exemption criterion and to demonstrate that the proposed alteration, regrading, clearing or construction upon such slopes can and will be accomplished without causing damage to the site or to adjacent property and, further, that there will be no erosion, soil failure, stream siltation, contamination of surface waters, increase in total runoff into any watercourse or increase in the point discharge levels or velocities at any given point of collection or discharge, and will not otherwise be injurious to the health, safety and welfare of the Township.
C. 
If an applicant wishes to obtain an exemption from the steep slope requirements of Article XXIV as provided for above, the applicant shall make a request to the Township Zoning Officer prior to the filing of a subdivision or land development plan or a permit application.
At the conclusion of work done pursuant to an approval obtained under this article, an as-built plan prepared by a surveyor or engineer registered in the Commonwealth of Pennsylvania shall be submitted to the Township. The plan shall be subject to review and approval by the Township Zoning Officer and/or the Township Engineer. No certificate of completion or certificate of occupancy shall be issued until the as-built plan has been approved.
The granting of a certificate of occupancy, certificate of completion, or the approval of a subdivision or land development plan on or near the Steep Slope District shall not constitute a representation, guarantee or warranty of any kind by the Township or any official or employee thereof regarding the practicability or safety of the proposed use and shall create no liability upon the Township, its officials or its employees. Protections provided by this article are reasonable for regulatory purposes and are based on engineering and scientific studies. The article does not imply that areas outside the Steep Slope District are free from the adverse effects of erosion and sedimentation.