For all new subdivision and site plans within the Township,
a grading plan shall be submitted for review and approval.
A.
In general, each residential subdivision lot shall drain from the
front of the house to the road and from the rear of the house to the
rear of the lot. Rear to front surface drainage should be avoided
and will be permitted only under extreme conditions.
B.
Drainage for each site or lot must be self-contained so that drainage
across adjacent sites is avoided, unless easements are provided for
that purpose.
C.
Drainage for subdivision lots must be directed to either the side
lot lines, the rear lot lines, the front yard line, or a swale located
a minimum of 10 feet from the house.
Minimum ground slope for any part of the site shall be 2%, except
that the minimum ground slope away from any building shall be 5% for
the first 10 feet away from the building.
Generally, the maximum ground slope for any part of the side
shall be 25% (one vertical to four horizontal). Slopes exceeding 33%
(one vertical to three horizontal) shall be protected with grouted
concrete riprap, an approved geotextile fabric, or retaining wall,
or other approved soil erosion preventative.
The maximum side slope of landscape berms shall be 33% (one
vertical to three horizontal) with a four-foot-wide crest area.
A.
The high point of the swale located 10 feet from a building shall
be a minimum of 0.5 foot below the proposed finished ground elevation
of the building.
B.
Generally, the ground elevation at a building shall be elevated above
the center-line elevation of the road on which it fronts.
C.
Generally, surface drainage generated from areas larger than 0.3
acre shall not drain across walkways at a point discharge. At no time
shall building or paved areas drain across walkways (except in single-family
detached-unit residential areas).
D.
A minimum of 0.6 foot of vertical drop shall be provided from the
front (and side on corner lots) property line to the top of curb.
E.
In no case shall the surface drainage be directed to the footing
drains and discharged by pump.
Plans shall be presented on sheets not exceeding 24 inches by
36 inches at a scale not smaller than one inch equals 100 feet. Larger
scales, such as one inch equals 40 feet, may be required for clarity
of presentation. Plans shall also show at least, but not limited to,
the following information:
A.
North arrow, legend and scale.
B.
Proprietor's name.
C.
Legal description with property lines bearings and dimensions.
D.
Existing topography, including all natural and man-made features
with existing contour elevations at two-foot intervals extending 100
feet beyond the site boundary.
E.
All proposed and existing storm drainage facilities.
F.
All existing utilities showing invert elevations and rim elevations
at all structures.
G.
All proposed utilities showing the rim elevations of all structures.
H.
Bench marks (USGS datum shall be used).
I.
Center line of street stationing with center-line elevations at fifty-foot
intervals.
J.
Top-of-curb elevations opposite each lot corner. All pavement grades
shall be shown to hundredths of a foot. Ground grades may be shown
to tenths of a foot.
K.
Proposed ground elevation at each lot corner.
L.
Proposed grade elevations with the use of contours in all nonpaved
areas.
M.
Drainage flow arrows indicating the direction of surface water drainage.
N.
Elevation of high point, changes of grade, and low point of all swales
and ditches.
O.
Finish grade elevations for each building. If the finish grade for
a house is uniform on all sides, the finish grade elevation shall
be placed inside a rectangular box situated on the lot according to
the required front and side yard setback. Proposed finish building
grades for site plan developments shall be shown at all corner and
other locations requested by the Director.
P.
Proposed elevations for sidewalks, top of curb and other locations
as may be required to establish drainage patterns.
