The purposes of this article are as follows:
A.
To promote the public health, safety and welfare by
the protection of steep slope areas and by encouraging the retention
of open space located and designed so as to constitute a harmonious
and appropriate part of the physical development of Willistown Township.
B.
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 regrading of steep slope areas.
C.
To limit soil erosion and the resultant destruction
of the land, siltation of streams and damage to the property of individuals.
D.
To protect low-lying areas from flooding by limiting
the increase in stormwater runoff caused by grading of sloped areas,
changes of ground cover or the erection of structures.
E.
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.
F.
To allow the continuing replenishment of groundwater
resources and the maintenance of springs.
A.
Compliance. No area within the Steep Slope Conservation District shall hereafter be used without full compliance with the terms of this article, Chapter 139, Zoning, and other applicable regulations.
B.
Steep Slope Conservation District overlay concept.
The Steep Slope Conservation District shall be deemed an overlay on
any zoning district(s) now or hereafter enacted to regulate the use
of land in Willistown Township.
(1)
The Steep Slope Conservation 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 Conservation District, as defined herein, and said
uses are in conflict with the permitted uses set forth in this article.
These regulations apply only to those portions of a tract or lot which
come under the Steep Slope Conservation District; portions not under
the district shall conform to the standards of the underlying zoning
district.
(2)
In those areas of the Township where the Steep Slope
Conservation District applies, the requirements of the Steep Slope
Conservation District shall supersede the requirements of the underlying
zoning district(s).
(3)
Should the Steep Slope Conservation District boundaries
be changed 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 article.
(4)
For any parcel or any part thereof on which the Steep
Slope Conservation District is an overlay, should the underlying zoning
classification(s) be changed as a result of legislative or administrative
actions or judicial decision, such change(s) in classification shall
have no effect on the boundaries of the Steep Slope Conservation District,
unless an amendment to said boundaries was included as part of the
proceedings from which the subsequent change(s) originated.
C.
Preservation of other restrictions. It is not intended
by this article to repeal, abrogate or impair any existing easements,
covenants or deed restrictions. However, where this article imposes
greater restrictions, the provisions of this article shall prevail.
D.
Municipal liability. Any determination that a proposed
use complies with this chapter or any approval of a subdivision or
land development plan or any issuance of a building permit within
or near the Steep Slope Conservation District shall not constitute
a representation, guaranty 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 Conservation District boundaries or land uses
permitted within said district will always be totally free from the
adverse effects of erosion or other effects of nearby steep slopes.
A.
The Steep Slope Conservation District consists of
two areas which are delineated and defined as follows:
[Amended 3-13-2023 by Ord. No. 2-2023]
(1)
Prohibitive
slope. Prohibitive slopes are those of greater than 25% slope as based
upon and mapped using two-foot contours from a topographic survey
of the property or on the United States Geological Survey (USGS) Topographic
Maps of the Regional Base Map Series of 1973 for the Malvern, Media,
Valley Forge and West Chester Quadrangles (i.e., sloping more than
25 feet vertical over a distance of 100 feet horizontal), where such
slope exists for five contiguous contour intervals in any continuous
horizontal increment along the slope of 50 feet or more.
(2)
Precautionary
slope. Precautionary slopes are those of 15% to 25% slope as based
upon and mapped using two-foot contours from a topographic survey
of the property or on the USGS Topographic Maps of the Regional Base
Map Series of 1973 for the Malvern, Media, Valley Forge and West Chester
Quadrangles (i.e., sloping 15 feet to 25 feet vertical over a distance
of 100 feet horizontal), where such slope exists for five contiguous
contour intervals in any continuous horizontal increment along the
slope of 50 feet or more.
B.
Whenever there is a difference between the Zoning
Map overlay and the two-foot contours from a property survey or the
applicable United States Geological Survey Topographic Map, the two-foot
contours from a site survey or Topographic Map shall determine the
boundaries of the Steep Slope Conservation District.
[Amended 3-13-2023 by Ord. No. 2-2023]
C.
Boundary interpretation and appeals procedure.
(1)
Each application for construction or land disturbance within the Steep Slope Conservation District shall be submitted in accordance with § 73-33A below. Any area of the Steep Slope Conservation District that falls within the subject lot or lots shall be interpolated and shown on the site plan required under § 73-33A(1) through shading of such area or areas. The site plan shall contain a certification by the registered professional engineer or surveyor having prepared the plan as to the accuracy of the slopes as depicted on the plan. Areas shown as less than 10% slope may be based on United States Geological Survey information. Any area shown as 10% to 25% shall be delineated on the basis of an actual topographic survey of the site where those areas are proposed for disturbance.
[Amended 3-13-2023 by Ord. No. 2-2023]
(2)
Where the exact location of the boundaries of the
district in relation to a given parcel is in question, the applicant's
site plan may be supplemented by a topographic survey of the property
and any other documentation deemed pertinent. The Township Engineer
shall evaluate all such material submitted and shall make a written
report of the results of his determination, a copy of which shall
be provided to the Board of Supervisors.
(3)
Any party aggrieved by any such determination of the
Township Engineer or other decision or determination under this section
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.
A.
Standards applicable to all uses within the Steep
Slope Conservation District.
(1)
All grading shall be minimized, and no grading shall
be undertaken within any area of the Steep Slope Conservation District
except where approved in conjunction with a use permitted under the
terms of this article.
(2)
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. Where standard grading is undertaken,
the use of retaining walls shall be minimized. Where grades require
a retaining wall, design plans indicating the need for the wall, its
height and its impact upon the landscape shall be submitted for review
by the Township Engineer.
(3)
On any lot containing an area or areas of prohibited
or precautionary slope, the total amount of impervious surface that
may be installed or maintained within the total area or areas of such
slope shall not exceed 50% of the maximum amount of impervious surface
permitted for such use on any lot in the underlying base zoning district.
Provision shall be made and approved by the Township Engineer for
control of runoff from impervious surfaces to prevent erosion.
B.
Uses permitted in areas of prohibitive slope. The following are the only uses permitted as of right in areas of prohibitive slope, provided that they also are in compliance with the base zoning district and all other provisions of this chapter and Chapter 139, Zoning:
(1)
Parks and outdoor recreational uses, consistent with
the goals of watershed protection.
(2)
Logging and woodcutting, where such activity is limited
to highly selective removal of trees. Maximum precautions shall be
taken to avoid destruction of or injury to understory brush and trees.
(3)
Grading for the minimum portion of a driveway necessary
to access a single-family dwelling when it can be demonstrated that
no other routing which avoids slopes exceeding 25% is feasible.
(4)
Yard area of any permitted building, so long as such
building is itself not within the prohibitive slope area, unless permitted
as a conditional use.
C.
Uses permitted in areas of precautionary slope. The following are the only uses permitted as of right in areas of precautionary slope, provided that they also are in compliance with the base zoning district and all other provisions of this chapter and Chapter 139, Zoning:
(1)
Parks and outdoor recreational uses, consistent with
the goals of watershed protection.
(2)
Tree farming, forestry and other agricultural uses
when conducted in conformity with conservation practices, including
minimum tillage methods, approved by the Soil Conservation Service
or the Chester County Conservation District.
(3)
Access roads for the passage of emergency vehicles.
(4)
Accessory uses (excepting swimming pools) necessary
for the operation and maintenance of the above-permitted uses.
(5)
Yard area of any permitted building.
D.
Conditional uses in areas of prohibitive and precautionary slope. The following uses shall be permitted in areas of prohibitive and precautionary slope as a conditional use when authorized by the Board of Supervisors, subject to the requirements of this section and § 139-118.1 of Chapter 139, Zoning, of this Code. In making its determination, the Board shall give particular consideration to the criteria and standards in § 73-33B below.
(1)
Any structure permitted by right, special exception
or conditional use according to the terms of the underlying base zoning
district.
(3)
Sealed public water supply wells, where approved by
all regulatory agencies.
(4)
Sanitary or storm sewers, where approved by all regulatory
agencies.
(5)
Extractive uses, including borrow pits, within areas
of precautionary slope only, when operated in accordance with recognized
conservation practices and, as applicable, where approved by all regulatory
agencies.
Administration of this section is governed by Article XIX, Administration, of Chapter 139, Zoning. In addition, the following requirements shall apply:
A.
Application procedures.
(1)
Before a permit is issued for any construction or
land disturbance activity on land within or affecting the Steep Slope
Conservation District, the following material, in full or in pertinent
parts, shall be submitted for review by the Township Engineer:
(a)
An earthmoving plan of the property which indicates
existing grades, with contour lines for any area designated for disturbance
at two-foot intervals for existing slope up to and including twenty-five-percent
grade and five-foot intervals for existing slope above 25%. Proposed
grades within the area of any proposed activity, disturbance or construction
also shall be shown. All areas within the Steep Slope Conservation
District shall be shaded accordingly.
(b)
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.
(c)
Architectural plans, elevations and sections.
(d)
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.
(e)
Plan, profile and typical cross sections of
any proposed street, emergency access or driveway, with the seal of
a registered professional engineer thereon.
(f)
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.
(2)
No approval or building permit shall be authorized
by the Zoning Officer, and no conditional use shall be granted by
the Board of Supervisors, without the Township Engineer's review of
this material and his recommendation thereon.
B.
Additional criteria for review of conditional uses.
In evaluating any application for a conditional use, the Board of
Supervisors shall evaluate the consistency of the proposal with the
following criteria:
(1)
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:
(2)
Disturbance shall be minimized where the length or
area of prohibited or precautionary slope, both on the site and on
adjacent lands within 200 feet of the site, is extensive.
(3)
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.
(4)
Removal of or disturbance to existing vegetation on
the site shall be minimized. The proposed impacts on existing vegetation
shall be evaluated in terms of the potentially detrimental effects
on slope stability, transpiration 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.
(5)
Important visual qualities of the site shall, to the
maximum extent feasible, be retained; in addition to vegetation, these
may include hilltops or ridgelines, rock outcroppings and the natural
terrain and contours of the site.
(6)
Road construction shall follow the natural topography,
with cuts and grading minimized.
(7)
Innovative, imaginative building techniques that are
well-suited to slope conditions shall be encouraged, consistent with
other applicable codes and regulations.
(a)
Every attempt shall be made to situate dwellings
and accessory buildings below ridgeline elevations to preserve existing
vistas. To achieve this objective, dwellings and accessory buildings
should be sited entirely below the elevation of the nearest ridgeline,
unless the applicant demonstrates that this is clearly infeasible.
(b)
Where the applicant contends that the siting
of dwellings entirely below ridgelines is infeasible, approval of
his proposed siting shall be contingent upon the submission of individual
lot landscaping plans and approval of those plans by the Board of
Supervisors. Such plans shall identify the dimensions of each proposed
dwelling, the architectural style proposed and the location of each
dwelling and shall demonstrate how the dwelling will be effectively
screened from adjacent tracts. Such siting shall comply in all other
relevant respects with the provisions of this article and the underlying
base zoning district.
(8)
The equilibrium of the slope, as characterized by
the existing interrelationships among the soil, water and vegetation,
shall be disturbed as little as possible.
Following the adoption of this article, any use or structure which is situated within the boundaries of the Steep Slope Conservation District and which does not conform to the permitted uses specified in § 73-32 above shall become a nonconforming use or structure, regardless of its conformance to the district in which it is located without consideration of this article. The expansion or continuance of said nonconforming use or structure shall be governed by the requirements of §§ 139-90 and 139-91 of the Code of Willistown Township. However, the Zoning Hearing Board shall also ensure that the standards contained in § 73-33B above are applied to the expansion or continuance of said nonconforming use or structure.
