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 West Whiteland
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:
(1) Minimizing disturbances to vegetative ground covers.
(2) 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 slopes 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 ground resources
and the maintenance of springs.
Administration of this article is governed by Article
XX of this chapter. In addition, the following requirements shall apply:
A. Application procedures. With a conditional use application
and before a permit is issued for any construction, development or
improvement on land within or affecting the Steep Slope Conservation
District, the following material, in full or in pertinent part, shall
be submitted for review by the Township Engineer:
(1) A grading plan of the property consistent with §
325-70A above which indicates existing grades with existing contour lines at two-foot intervals from field survey and also indicates proposed grades within the area of any proposed construction, development or improvement with proposed contour lines at two-foot intervals. All areas of prohibitive and/or precautionary slopes shall be shaded accordingly. Prohibitive and precautionary slopes shall be differentiated.
(2) A site plan indicating existing and proposed structures,
other impervious surfaces, storm drainage facilities and other utilities
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. The total impervious coverage proposed in the precautionary
slope areas shall be indicated.
(3) Architectural plans, elevations and sections.
(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) An erosion and sedimentation control plan, including
a construction schedule and sequence and provisions for monitoring
of the erosion and sedimentation control devices.
(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 development in steeply sloped areas including without limitation,
those related to access, erosion, water runoff, structural failure
and collapse, and soil subsidence. No building permit shall be issued
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.
[Amended 3-10-2004 by Ord. No. 310]
B. Standards and criteria for review of conditional use
applications. Each instance of disturbance to areas of precautionary
slope within a single application shall be considered separately for
conditional use approval. In evaluating any application for conditional
use approval within areas of precautionary slope, the Board of Supervisors
shall determine the consistency of the proposal with the following:
(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:
(a)
The steepest areas of precautionary slope, i.e.,
those approaching 25%.
(b)
Soils with seasonal high water table.
(c)
Underlying geology which comprises, or contributes
to, a major ground water resource including the flow of existing springs.
(e)
Springs, watercourses and areas adjacent to
watercourses.
(f)
Significant specimen vegetation.
(2) Disturbance shall be minimized where the length or
area of precautionary slope 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 elevated in 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.
(5) Important visual qualities of the site shall, to the
maximum extent feasible be retained; in addition to vegetation, these
may include hilltops/ridgelines, rock outcroppings and the natural
terrain and contours of the site.
(6) Road construction shall follow the natural topography,
with cuts, fills and grading minimized. Cuts and fills shall not exceed
10 feet except where no feasible alternative exists, in which case
cuts and fills shall not exceed 15 feet.
(7) Innovative, imaginative building techniques that are
well-suited to slope conditions shall be encouraged, consistent with
other applicable codes and regulations.
(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.
(9) Erosion and sedimentation control measures considered
adequate by the Board are proposed by the applicant.
Following the adoption of this chapter, 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 §
325-71 of this article shall become a nonconforming use or structure, regardless of its conformance to the district in which it is located without consideration of this chapter. The expansion or continuance of said nonconforming use or structure shall be governed by the requirements of Article
XVIII of this chapter. However, the Zoning Hearing Board shall also ensure that the standards contained in §
325-72B of this article are applied to the expansion or continuance of said nonconforming use or structure.