The purposes of this article are to:
A.
Ensure development that minimizes stormwater impacts.
B.
Ensure the preservation of wooded hillsides, thereby furthering the
respective objectives of this section.
C.
Minimize short- and long-term soil erosion within land development
and subdivision sites.
D.
Minimize the impact on streams, wetlands, and steep slopes.
E.
Ensure the safety and integrity of structures constructed within
the sites of land developments and subdivisions through proper construction
in consideration of mine overburden and construction on slide-prone
soils.
A.
The following standards shall apply to all grading and disturbance
of land with slopes of 25% or greater.
(1)
Slopes between 25% and 40%. No more than 30% of slope areas with
existing grades between 25% and 40% shall be stripped of vegetation
or disturbed through grading. Grading and clearing for roads on these
slopes shall be limited to that necessary to accommodate the cartway
and shoulders or berms. Wherever possible, roads should follow the
contours of the land.
(2)
Slopes exceeding 40%. No development or disturbance shall be allowed
on slopes exceeding 40%. Limited disturbance for utilities may be
allowed where no reasonable alternative location exists.
B.
Where construction is proposed in accordance with this section, within
or disturbing steep slopes, the applicant shall include a geotechnical
report, acceptable to the Township Engineer. The report shall demonstrate
a safety factor of 1.5 of greater and shall outline a revegetation
plan ensuring immediate and long-term stability.
A.
No land development involving construction of buildings and no subdivision
of land intended to create lots for building construction shall be
approved on a site which has been undermined at shallow depths or
in an area where there is evidence of past subsidence unless the applicant
demonstrates that the proposed subdivision or land development will
be safe and will not create hazards for adjacent properties. Evidence
of safety shall be one of the following.
(1)
If the site or any area of the site has been undermined and
has 100 feet or less of overburden, evidence of the safety of the
proposed subdivision or land development shall require site investigation
and certification in writing by a professional engineer, experienced
in subsidence risk assessment, that the proposed development will
be safe.
(2)
If the site has been undermined and has more than 100 feet of
overburden, a subsidence risk assessment included in a geotechnical
report by a professional engineer and written certification that the
proposed subdivision or land development will be safe may be required
if the Township, Township Engineer, or applicant has knowledge of
any past occurrences of subsidence in the general vicinity of the
site.
B.
The Board may require the installation of certain construction measures
accepted by the Township Engineer as per recommendations of the risk
assessment required, as a condition of building permit(s) on the site.
The Board may further require the inclusion of such standards in the
plan covenants, as a note on the plat, or through a developer's
agreement applicable to the developer's heirs and assigns.
No grading, removal of vegetation, construction or other disturbance
shall be permitted on soils that are classified as slide-prone or
unstable in the Soil Survey of Allegheny County or on any other areas
of a proposed development site that exhibit signs of instability,
except in accordance with the provisions of this section.
A.
Disturbance of landslide-prone areas of construction thereon shall
be severely limited.
B.
Disturbance of unstable areas may be permitted, where alternative
site designs have been exhausted, and where the developer demonstrates
to the satisfaction of the Township Engineer through a geotechnical
report that the proposed disturbance will not cause sliding or movement
or any unsafe condition either on the development site or on any property
adjacent to it.
C.
Evidence of the safety of any proposed disturbance shall require
site investigation and certification in writing by a registered soils
engineer, engineering geologist or professional engineer with experience
in soils engineering that the proposed activity will not create or
exacerbate unsafe conditions.
A.
Setback or open space easement required. No grading, cutting, filling,
removal or vegetation, or other disturbance of land shall be permitted
within the required setback.
B.
The minimum setback for watercourses shall be 20 feet, measured from
the top of the channel bank. In addition, land development involving
the construction of new buildings shall not be permitted within 100
feet of the top of the bank of the Monongahela River.
C.
The setback for wetlands shall be 50 feet for wetlands one acre or
greater and 25 feet for wetlands less than one acre or at a variable
setback depth, based on a wetland management plan prepared by a certified
professional wetlands biologist. In no case, however, shall the setback
be less than 10 feet from the delineated edge of a wetland less than
one acre in extent; or 20 feet from the delineated edge of a wetland
one acre or more in extent.
D.
Minor earth disturbance and construction within the area of the required
setback or easement, required for development in other areas of the
site, may be allowed in accordance with all regulations of the Department
of Environmental Protection and Township floodplain regulations, where
applicable.
E.
Construction may also be allowed within the required setback area
of rivers to enable the development of uses that require proximity
or access to the river, in accordance with applicable federal, DEP
and municipal regulations.
F.
This section shall not withstand the ability of a developer to utilize
wetland mitigation measures offered by the DEP. Approval of all applicable
permits, associated bonding, and other commitments guaranteeing the
completion shall then become a condition of approval to be provided
prior to plan recording.
