London Grove Township
City Zoning Code
City Zoning Code
PART 16
STEEP SLOPE DISTRICT
§ 27-1601 Purpose and Specific Intent.
1.
To promote the public health, safety and welfare by protection of steep slope areas.
2.
To permit only those uses of steep slope areas which are compatible with the conservation of natural conditions and which maintain stable soil conditions by minimizing disturbances to vegetative ground covers and restricting the regarding of steep slope areas.
3.
To limit soil erosion and the resultant destruction of the land, siltation of streams and damage to the property of individuals.
4.
To protect low-lying areas from flooding by limiting the increase in stormwater runoff caused by grading of slope areas, changes of ground cover, or the erection of structures.
5.
To maintain the ecological integrity and habitat value of steeply sloped areas, i.e., indigenous vegetation and wildlife, which could be adversely affected by otherwise permitted disturbances.
6.
To allow the continuing replenishment of ground water resources and the maintenance of springs.
§ 27-1602 General Provisions.
1.
No area within the Steep Slope District shall hereafter be used without full compliance with the terms of this part and other applicable regulations. The Steep Slope District shall be deemed to be an overlay on any zoning district(s) now or hereafter enacted to regulate the use of land in the township.
2.
The Steep Slope District shall have no effect on the permitted uses in the underlying zoning district, except where said uses are intended to be located within the boundaries of the Steep Slope District, as defined herein, and said uses are in conflict with the permitted uses set forth in this part.
3.
In those areas of the township where the Steep Slope District applies, the requirements of the Steep Slope District, to the extent they are more restrictive, shall supersede the requirements of the underlying zoning district.
4.
Each application for construction or land disturbance within the Steep Slope District shall be submitted in accordance with section 27-1606. Any area of the Steep Slope District that falls within the subject lot or lots shall be interpolated and shown on the site plan required under section 27-1606 through shading of such area or areas.
5.
Should the Steep Slope District boundaries be revised, to exclude previously included lands, as a result of legislative or administrative actions or judicial decision, the zoning requirements applicable to the area in question shall revert to the requirements of the underlying zoning district(s) without consideration of this part.
6.
For any parcel or any part thereof on which the Steep Slope District is an overlay, should the underlying zoning classification(s) be changed as a result of legislative or administrative actions or judicial decision, such changes(s) in classification shall have no effect on the boundaries of the Steep Slope District, unless an amendment to said boundaries was included as part of the proceedings from which the subsequent change(s) originated.
7.
It is not intended by this part to repeal, abrogate, or impair any existing easements covenants, or deed restrictions. However, where this part imposes greater restrictions, the provisions of this part shall prevail.
8.
The granting of a zoning permit or approval of a subdivision or land development plan within or near the Steep Slope District shall not constitute a representation, guarantee, or warranty of any kind by the township, or by any official or employee thereof, of the practicability or safety of the proposed use and shall create no liability upon the township, its officials or employees. This chapter does not imply that areas outside the Steep Slope District boundaries or land uses permitted within said Steep Slope District will always be totally free from the adverse effects of erosion.
§ 27-1603 Designation and Interpretation of District Boundaries.
1.
The Steep Slope District consists of two types which are delineated and defined as follows:
A.
Prohibitive Slope. Prohibitive slopes are those of 25% or greater slope (e.g. sloping 25 feet or more vertical over a distance of 100 feet horizontal). Slopes shall be deemed prohibitive when there are four adjacent contour intervals of two feet each such that, in aggregate, they delineate a slope of at least 25%.
B.
Precautionary Slope. Precautionary slopes are those of 15 to 25% slope (e.g. sloping 15 to 25 feet vertical over a distance of 100 feet horizontal). Slopes shall be deemed precautionary when there are five adjacent contour intervals of two feet each such that, in aggregate, they delineate a slope between 15% and 25%.
2.
Steep slopes shall be determined by either aerial photogrammetric methods or by field survey. The contour intervals shall be set forth at no more than two feet per interval on slopes less than 25%, and may be set forth at five feet per interval on slopes over 25%. On properties containing no slopes greater than 10%, USGS 7.5 minute quadrangles may be used as the source of slope information, subject to the approval of the zoning officer upon the recommendation of the township engineer.
3.
Where an interpretation is needed as to the exact location of the boundaries of the district in relation to a given parcel, an initial determination shall be made by the township engineer. Any party seeking such a determination may submit a topographic survey of the property and any other pertinent documentation for consideration. The township engineer shall make a written report of the results of his initial determination, a copy of which shall be provided to the board of supervisors.
4.
Any party aggrieved by any such determination of the township engineer or other decision or determination under this part may appeal to the zoning hearing board. The party contesting the location of the district boundary shall have the burden of proof in case of any such appeal.
§ 27-1604 Uses Permitted by Right.
1.
In any part of the Steep Slope District, all grading shall be minimized, and no grading shall be undertaken within any area of the Steep Slope District except where approved in conjunction with a use permitted under the terms of this part.
2.
The following are the only uses permitted as of right in areas of prohibitive slope. Such uses also shall be in compliance with the base zoning district, and shall not involve the erection of buildings, construction of streets, installation of sewage disposal systems, or permanent removal of top soil unless replaced by approved engineered structures or vegetation.
A.
Parks and outdoor recreational uses, consistent with the goals of watershed protection.
B.
Yard areas of a building within the Steep Slope Conservation District.
C.
Pastures and other agricultural activities such as tree farming that do not expose the soil to erosion on a regular periodic basis.
D.
Logging and woodcutting, where such activity is limited to highly selective removal of trees and does not involve clear-cutting. Maximum precautions shall be taken to avoid destruction of or injury to understory brush and trees.
E.
The minimum possible grading for a driveway accessing a building when it can be demonstrated that no other routing which avoids prohibitive slopes is feasible or economically reasonable.
F.
The minimum possible installation of public or private transmission lines such as power, phone, gas, water, sewer or storm sewer lines when it can be demonstrated that no other routing which avoids prohibitive slope is practicable or economically reasonable.
Within any lot, the maximum extent of areas classified as prohibitive slopes that may be permanently disturbed for the installation of site improvements shall be limited to 20% of the prohibitive slope area, or 10% of the lot area, whichever is the lesser, subject to the approval of the zoning officer on the recommendation of the township engineer. Any such disturbance in excess of either 20% of the prohibitive slope area or 10% of the lot area shall require the granting of a special exception by the zoning hearing board. On any lot, the total amount of impervious surface that may be installed within areas of prohibitive slope shall not exceed 20% of the total impervious area permitted according to the provisions of the underlying base zoning district.
3.
The following are the only uses permitted by right in areas of precautionary slope, provided they also are in compliance with the base zoning district and all other provisions of this chapter.
A.
All uses permitted in areas of prohibitive slopes.
B.
Tree farming, forestry, and other agricultural uses when conducted in conformity with conservation practices, including minimum tillage methods, approved by the Soil Conservation Service (SCS) or the Conservation District.
C.
Access roads.
D.
Accessory uses (except swimming pools), necessary for the operation and maintenance of the above permitted uses.
Within any lot, the maximum extent of areas classified as precautionary slopes that may be permanently disturbed for the installation of site improvements shall be limited to 40% of the precautionary slope area, or 20% of the lot area, whichever is the lesser, subject to the approval of the zoning officer on the recommendation of the township engineer. Any such disturbance in excess of either 40% of the precautionary slope area or 20% of the lot area shall require the granting of a special exception by the zoning hearing board. On any lot, the total amount of impervious surface that may be installed within areas of precautionary slope shall not exceed 40% of the total impervious area permitted according to the provisions of the underlying base zoning district.
§ 27-1605 Uses Permitted by Special Exception.
1.
Any of the following uses are permitted within the Steep Slope District when approved as a special exception by the zoning hearing board in accordance with section 27-1607 of this chapter.
A.
Any structure permitted by right, special exception or conditional use according to the terms of the underlying base zoning district.
B.
Any road necessary to provide primary access to a use permitted by this chapter, when no practical alternative exists in an area of lesser slope.
2.
In areas of prohibitive slopes these activities shall not be approved by the granting of a special exception unless the applicant demonstrates that there is no alternative which could avoid encroachment into the areas of prohibitive slope. In making its determination, the board shall give particular weight to the criteria and standards in section 27-1607 below.
§ 27-1606 Administration.
1.
Administration of this part is governed by part 27 of this chapter. In addition, the following specific requirements shall apply:
A.
Application Procedures. Before a permit is issued for any construction or land disturbance activity on land within or affecting the Steep Slope District, the following material, in full or in pertinent parts, shall be submitted for review by the zoning officer or the zoning hearing board. No zoning permit shall be issued by the zoning officer, and no special exception shall be granted by the zoning hearing board, without the township engineer's review of this material and his recommendation.
(1)
An earth-moving plan of the property at a scale of no more than 100 feet to the inch which indicates existing grades with contour lines at two-foot intervals and proposed grades within the area of any proposed activity, disturbance, or construction. All areas of prohibitive and/or precautionary slope shall be shaded accordingly.
(2)
A site plan indicating existing and proposed structures, other impervious surfaces, storm drainage facilities, and retaining walls. The site plan also shall locate and identify existing vegetation and ground cover within areas of prohibitive and precautionary slopes, as well as proposed landscaping material to be installed.
(3)
Architectural plans, elevations and sections, with such specifications as may be pertinent.
(4)
A statement, signed and sealed by a registered architect or engineer, explaining the building methods to be used in overcoming foundation and other structural problems created by slope conditions, preserving the natural watersheds and preventing soil erosion and excessive surface water runoff to neighboring properties and/or streets.
(5)
Plan, profile and typical cross-sections of any proposed street, emergency access, or driveway within areas of prohibitive and precautionary slopes, with the seal of a registered professional engineer thereon.
(6)
A sediment and erosion control plan, with construction narrative, setting forth the measures to control sediments generated on site by the proposed activity. The plan shall be prepared according to the standards and procedures established by the USDA Soil Conservation Service and the Pennsylvania Department of Environmental Protection.
(7)
A statement, signed by the owner or future occupant at the time of subdivision, land development, or building permit application, that there is a full understanding of any difficulties associated with access stemming from steep slopes.
§ 27-1607 Standards and Criteria for Review of Special Exceptions.
1.
In evaluating any application for a special exception within the Steep Slope District, the zoning hearing board shall determine consistency of the proposal with the following:
A.
Disturbance to particularly sensitive features of the site shall be minimized; special emphasis in planning for the site should be given to the protection of:
(1)
The areas of steepest slope, especially those approaching or exceeding 25%.
(2)
Soils with seasonal high water table.
(3)
Underlying geology which comprises, or contributes to, a major groundwater resource including the flow of existing springs.
B.
Disturbance shall be minimized. The board should review the off-site impact of slope disturbance on adjacent lands and determine what conditions may need to be placed so as to limit the impact of slope disturbance to the subject property, as well as the adjoining properties.
C.
The proposed development, any impervious ground cover, and the resultant disturbance to the land and existing vegetative cover will not cause runoff and/or related environmental problems off the site.
D.
Removal of, or disturbance to, existing vegetation on the site shall be minimized. The proposed impacts on existing vegetation shall be evaluated to terms of the potentially detrimental effects on slope stability, transportation and recharge of stormwater, aesthetic and traditional characteristics of the landscape, and existing drainage patterns. Mitigation measures may be required by the board as it deems appropriate.
E.
The design, construction procedures and sediment and erosion control measures are such that there is no risk of damage or impairment to adjacent slopes, neighboring properties, or down-slope watercourses as a result of the proposed activities.
F.
Important visual qualities of the site shall be retained; in addition to vegetation, these may include hilltops/ridgelines, rock outcroppings, and the natural terrain and contours of the site.
G.
Road construction shall follow the natural topography, with cuts, fills and grading minimized.
H.
Innovative, imaginative building techniques that are well suited to slope conditions shall be encouraged, consistent with other applicable codes and regulations.
I.
The equilibrium of the slope, as characterized by the existing interrelationships among soil, water and vegetation, shall be disturbed as little as possible.
J.
Finished slopes of all cuts and fills shall not exceed 33%, unless the applicant can demonstrate that steeper slopes can be stabilized and maintained adequately to the satisfaction of the township.
K.
Exposed cut slopes within or below prohibitive slopes shall be minimized so that engineered retaining walls or other structures are utilized to the greatest extent practicable to maintain the stability of the disturbed slopes and reduce the risk of harm by reason of erosion and potential slope failure resulting in mud slides.
L.
In addition to all other applicable provisions of this chapter, all activities within the Steep Slope District shall conform to the performance standards set forth elsewhere in this chapter and they shall also conform to the applicable requirements of the subdivision and land development ordinance [chapter 22] and stormwater management and sediment and erosion control standards as adopted by London Grove Township.
§ 27-1608 Uses and/or Structures Rendered Nonconforming by the Adoption of This District.
Following the adoption of this part, any use or structure which is situated within the boundaries of the Steep Slope District and which does not conform to the permitted uses specified in section 27-1604 of this part shall become a nonconforming use or structure, regardless of its conformance to the district in which it is located without consideration of this part. The expansion or continuance of said nonconforming use or structure shall be governed by the requirements of parts of this chapter concerning nonconforming uses, structures, signs and lots, and zoning hearing board. However, the zoning hearing board shall also ensure that the standards contained in section 27-1607 of this part are applied to the expansion or change of said nonconforming use or structure.
