The purpose of the Steep Slope Protection (SSP) Overlay District
is to conserve and protect those areas having slopes as defined herein
from inappropriate development as well as to permit and encourage
the use of said areas for open space purposes in order to constitute
a harmonious aspect of the continuing physical development of the
Township. In implementing these principles and the general purposes
of this chapter and the Upper Allen Township Comprehensive Plan, the
following specific objectives are intended to be accomplished by this
article:
A.
To combine with other zoning requirements, as an overlay zoning district,
certain restrictions for steep slope areas to promote the general
health, safety and welfare of the residents of the Township.
B.
To prevent inappropriate development of steep slope areas in order
to avoid potential dangers for human usage caused by erosion, stream
siltation, and soil failure leading to structural collapse or damage
and/or unsanitary conditions and associated hazards.
C.
To minimize danger to public health and safety by promoting safe
and sanitary drainage.
D.
To relate the intensity of development to the steepness of terrain
in order to minimize grading, removal of vegetation, runoff and erosion,
and to help ensure the utilization of land in accordance with its
natural capabilities to support development.
E.
To promote only those uses in steep slope areas that are compatible
with the preservation of existing natural features, including vegetative
cover, by restricting the grading of steep slope areas.
F.
To promote the ecological balance among those natural systems elements
(such as wildlife, vegetation, and aquatic life) that could be grossly
affected by inappropriate development of steep slope areas.
G.
To prevent the development that would cause excessive erosion and
a resultant reduction in the water-carrying capacity of the watercourses
which flow through or around the Township with the consequences of
increased flood crests and flood hazards within the Township and to
both upstream and downstream municipalities.
H.
To minimize the potential harmful effects to individuals and adjacent
landowners in the Township and/or other municipalities caused by inappropriate
grading and development on steep slopes.
I.
To advise those individuals who choose, despite the dangers, to develop
or occupy land with steep slopes; to protect residents from property
damage and personal injury due to runoff, erosion, or landslides attributable
to a nearby development on steeply sloped land.
J.
To protect the entire Township from inappropriate development of
steep slope areas which could have an effect upon subsequent expenditures
for public works and disaster relief and, thus, adversely affect the
economic well-being of the Township.
K.
To promote the provisions of safe and reliable access ways, parking
areas, and utility systems serving development on or around steep
slope areas, where more sensitive grading and floodplain is essential.
A.
The Steep Slope Protection (SSP) Overlay District shall be defined
and established as those areas of the Township having slopes of 15%
or greater as determined from topographic studies or evaluation. The
slope shall be determined prior to excavation, grading, or other movement
of soil or rock. Any lot which contains land which lies within the
SSP District (i.e., with slopes of 15% or greater) shall be subject
to the regulations of the Steep Slope Protection Overlay District.
B.
All lots within the SSP District with average slopes, as defined
herein, of less than 15% would not be subject to the provision of
this article, unless the requested use, including yard requirements,
would be on any portion of the lot exceeding a slope of 15% or the
requested use is for parking areas in the excess of a slope of 6%.
The Steep Slope Protection Overlay District shall be deemed
to be an overlay zoning district on any zoning district now or hereafter
enacted to regulate the use of land in Upper Allen Township.
A.
The SSP District shall have no effect on the permitted uses or regulations
in the underlying zoning district, except where the development intended
is to be located within the boundaries of the SSP District, as defined
herein, is in conflict with the permitted uses or regulations set
forth in this section.
B.
In those areas of Upper Allen Township where the SSP District applies,
the requirements of the SSP District shall supersede any less stringent
requirements of the underlying zoning district.
C.
Should the zoning classification of any parcel or any part thereof
on which the SSP District is an overlay be changed, such change in
the classification shall have no effect on the boundaries of the SSP
District, unless an amendment to said boundaries was included as part
of the proceedings from which the change originated.
An initial determination as to whether the SSP District regulations apply to a given parcel shall be made by the Zoning Officer. Any party aggrieved by the decision of the Zoning Officer, either because of an interpretation of the location of the SSP District boundary or because the criteria used in delineating the boundary, as set forth in § 245-9.6 herein, are incorrect because of changes due to natural or other causes, may appeal such decision to the Zoning Hearing Board as provided in Article XIX of this chapter.
For any lot created after the effective date of this chapter,
which contains land included in the Steep Slope Protection District,
the following land use and development regulations shall apply.
A.
The average slope of the entire lot shall be determined according
to the formula:
|
S = (0.0023/A) x I x L
|
|
Where:
| |||
|
S
|
=
|
Average slope in percent
| |
|
0.0023
|
=
|
A factor for the conversion of square feet into acres
| |
|
I
|
=
|
Contour interval (in feet) of a topographic map of the parcel
| |
|
L
|
=
|
Combined length (in feet) of or along all contour lines measured
| |
|
A
|
=
|
Acreage of the subject parcel's buildable area
| |
B.
In all areas of the Township where the slope is 15% or greater, such as to be considered a "steep slope," as defined in Article II, the minimum lot size for a parcel of land having such steep slope shall be:
(1)
Three acres when the percent slope of the site is 15% or more.
(2)
Five acres when the slope of the site is 18% or more.
(3)
Ten acres when the slope of the site is 20% or more.
(4)
Exception: The lot sizes set forth in Subsection B(1) through (3) above will not apply in those circumstances where the lot owner or any developer can provide a contiguous area of the lot which does not have any of the steep slope averages set forth above and is at least the size of the minimum lot sizes for the zoning district in which the lot is located. When this exception is selected by the lot owner or developer, the area of the lot which is steep area (i.e., that portion not included in the area selected by the lot owner/developer for meeting the zoning district minimum lot size) shall not be used for any land development except for a driveway easement access or public utility access to the said lot and is intended to remain in a natural state or condition so far as is possible.
C.
Any lot which shall have an average slope of at least 15% but not
more than 18% shall have a maximum impervious surface area of 20%
of the lot area, of which no more than 1/2, or 10% of the lot area,
shall consist of buildings.
D.
Any lot which shall have an average slope of at least 18% but not
more than 25% shall have a maximum impervious surface area of 10%
of the lot area of which no more than 1/2, or 5% of the lot area,
shall consist of buildings.
E.
All freestanding structures, buildings and substantial improvements
(with the exception of utilities where no other location is feasible)
are prohibited on slopes of 25% or greater. Never shall more than
5% of the area be regraded or vegetation cover disturbed by the exceptions,
if they are granted.
F.
All swimming pools, junkyards, sanitary landfills, and outdoor storage
of vehicles or materials are prohibited on slopes of 15% or greater.
G.
Driveways and roadways shall not exceed a slope of 10% within 25
feet of the street right-of-way lines. Parking areas shall not be
in excess of 6%. Access drives shall not be in excess of 4% within
75 feet of the intersecting street center line.
H.
Applicants for permits required by this chapter shall present evidence
of approval of any required erosion and sedimentation plan or any
required stormwater management plan prior to the issuance of any permit.
A.
All uses permitted within the underlying zoning district, except those specifically prohibited in § 245-9.5 above, shall be permitted by special exception in the Steep Slope Protection District, if the use would be on any portion of the lot exceeding a slope of 15% or the requested use is for parking areas in excess of a slope of 6%.
B.
Any application requesting a special exception for a use permitted herein shall be accompanied by a plan certified by a registered professional engineer, a registered surveyor, or a registered landscape architect. In addition to any information required for an application for a special exception set forth in § 245-19.13, such plan shall show:
(1)
The location of the proposed use with respect to the areas of
the lot determined to have slopes in excess of 15%.
(2)
The location of the proposed use with respect to existing development
within the property.
(3)
Nature of the proposed use.
(4)
Topographical surveys showing the contours of the property in
two-foot intervals. The plans shall also include a reference benchmark
used.
(5)
Typical tract cross sections at a scale of not more than one
inch equals 100 feet and typical tract cross sections at a vertical
and horizontal scale. There shall be a minimum of one cross section
for the first five acres or less of lot or tract area and one cross
section for each five acres or portion thereof thereafter.
(6)
Calculations to determine the average slope of the lot in accordance
with this article.
(7)
Surface view of construction, grading or fill elevations.
(8)
Size, location and arrangement of all proposed and existing
structures on the site, as well as specifications for building construction
and materials and storage of materials.
(9)
Location, elevation, and specifications for water supply, sanitary
facilities and streets, including entrance drive.
(10)
A soils engineering report regarding site characteristics of
the subject property, to include the nature, types, distribution,
and suitability of subsurface soils for load bearing, stability, and
compaction; extent, description, and location of exposed rock; erodibility
of surface soil; engineering and conservation techniques to be used
to prevent erosion and alleviate environmental problems created by
the proposed development activities; permeability and available water
infiltration capacity; depth to bedrock and seasonal high-water table;
the means of accommodating stormwater runoff; proposed modifications
to the existing topography and vegetative cover; and the location,
type and intensity of vegetative cover on the subject property.
(11)
A geophysical-hydrologic report investigating conditions of
the subject property's underlying geologic formation and the hydrological
characteristics of the proposed development. Such report shall demonstrate
that any adverse impacts of the proposed development can be addressed
in such a manner as to prevent the hazards to life and property and
to maintain amenable site features for stormwater management, soil
erosion and sedimentation control, vegetative cover and exposed rock
stability.
C.
The applicant for any special exception shall request the review
and recommendations of the Cumberland County Conservation District
at least 45 days prior to the hearing by the Zoning Hearing Board
and shall present evidence that such review has been requested.
D.
The applicant shall request, at least 45 days prior to the hearing
before the Zoning Hearing Board, the review and recommendations of
the Township and shall present evidence that such review has been
requested.
