The purpose of this article is to preserve critical
slope areas in the Borough of Woodcliff Lake. These regulations are
necessary to minimize the adverse impacts commonly associated with
disturbance of "steeply sloped areas," which are defined for the purposes
of this article as a slope of minimally 15%. Development on grades
of 15% or greater generally requires additional safeguards against
erosion and other conditions such as siltation, surface water runoff
and pollution of potable water supplies. The most appropriate method
of alleviating such conditions is through the regulation of disturbance
to soil and vegetation in critical slope areas. Such regulation promotes
the public health, safety and welfare of Woodcliff Lake.
The following definitions are applicable to
this article:
DISTURBANCE
Any interference, alteration or change to the natural terrain
(including soil and vegetation or any other element of the environment).
This term includes any activity involving the clearing of vegetation,
grading or filling of a site but does not include maintenance or refurbishing
of existing topographical or previously constructed conditions, or
the installation of ground cover, gardens, shrubs or other vegetation
that does not alter or change the natural terrain (including soil
and vegetation) or any other element of the environment.
EMBANKMENT
An elevated deposit of soil, rock or other materials either
constructed or natural.
GRADE
The percent of rise or descent of a sloping surface. For
example, a fifteen-percent grade corresponds to a fifteen-foot vertical
change in elevation for every 100 feet of horizontal distance. (Refer
to accompanying "Slope Diagram" for further clarification).
GROUND COVER
Grasses or other plants and landscaping grown to keep soil
from being blown or washed away.
RETAINING WALL
A structure constructed and erected between lands of different
elevations to protect structures, create a horizontal surface for
lawn or recreation and/or to prevent erosion.
SLOPE
The deviation of a surface from the horizontal, usually expressed
in percent.
All applications for minor and major subdivision
or site plan approval or for permit for construction, grading or clearing
of any lot, unless not included within the definition of "disturbance"
under this article or exempted herein in this chapter, shall be evaluated
by the applicant for the presence of critical slope areas, as defined
herein.
A. Slope categories. Unless exempt, the applicant shall
prepare and submit a slope analysis for the entire site (including
proposed roadways and common areas, and each proposed or existing
lot). The property shall be evaluated to determine the presence of
critical slope areas in the following categories:
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Table 1
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Slope Category
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Percent Grade
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1
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15% to 19.99%
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2
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20% to 24.99%
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3
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25% or greater
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B. Slope analysis. The slope categories shall be identified
on a plan drawn at a scale as required by the Borough's site plan
or subdivision submission requirements. It shall show the existing
and proposed topographic contours at two-foot intervals within the
subject property and delineate the categories of critical slope areas
as shown in Table 1 above. Existing contours at ten-foot intervals
shall be shown for a minimum distance of 25 feet beyond the property
boundaries.
C. Additional information required. The analysis provided
by the applicant shall contain the following additional information:
(1)
It shall delineate and quantify those areas
proposed for disturbance. The applicant shall provide a table showing
the calculation of disturbed area in square feet and as a percent
of the lot area, for each proposed lot:
(2)
It shall identify the location of all trees
of eight inches in caliper or greater (measured three feet above the
natural grade), and contiguous wooded areas, along with the proposed
limits of disturbance.
(3)
It shall identify soil types present on the
property, with specific reference to highly erodible soils as identified
by the United States Department of Agriculture Soil Conservation Service.
(4)
Details on how the proposed construction will
minimize adverse impacts upon the existing natural features (including
but not limited to ponds, vegetation and rock formations) of the lot
shall be provided.
(5)
The location and details of swales, detention
basins and other facilities for the disposition of all stormwater
shall be provided.
(6)
The disposition and extent of topsoil to be
removed or filled shall be indicated.
(7)
Plans and specifications for any retaining walls,
steps, fences or other protective structures shall be provided.
(8)
Elevations and sections of structures and related
improvements shall be provided.
Provision shall be made for any structure or
protective measures that may be required for the protection of the
public safety, including but not limited to retaining walls, embankments,
head walls and fences.
A. Erosion control ground cover. Proposed slopes between
2:1 and 3:1 (ratio of vertical distance to horizontal distance) shall
require plant material and ground cover suitable for erosion control.
B. Requirement for retaining walls. Proposed changes in grade in excess of 3:1 (ratio of vertical distance to horizontal distance) shall be supported by retaining walls or by erosion control ground cover in accordance with §
380-111A.
C. Retaining walls. Retaining walls typically are necessary
components for development in critical slope areas. Therefore the
following regulations are established for retaining walls in critical
slope areas:
(1)
Retaining walls shall not have any continuous
exposed wall face in excess of three feet in height measured from
the lowest elevation of the finished grade, except that age-restricted
multiunit housing in the ARHO District shall be permitted to have
retaining walls with wall faces up to six feet in height. If a fence
is required atop a retaining wall, the height of the fence shall not
be considered in measuring the height of the retaining wall.
[Amended 9-6-2005 by Ord. No. 05-10]
(2)
In any embankment which is constructed by the
use of retaining walls, each wall shall also be subject to a maximum
height limitation of three feet and shall be tiered at every three-foot
interval of height.
(3)
Each tier shall be set back a minimum of three
feet to provide for the placement of landscaping on the tier.
(4)
Plantings shall be required at each tier level
(except the top level adjoining a lawn area) to minimize the appearance
of the wall's height and enhance its aesthetics.
(5)
Retaining walls shall not be erected within
five feet of a street right-of-way, side or rear property line and
be constructed in such a way so as to enable the property owner to
perform periodic maintenance and upkeep to the area between the retaining
wall and the right of way, side or rear lot line.
(6)
Retaining walls shall be designed to provide
for proper drainage.
(7)
The use of interlocking block materials for
retaining wall construction is encouraged
D. Embankments.
(1)
There shall be no alteration or site elevations
in excess of one foot within five feet of an adjoining property.
(2)
The maximum permitted finished grade for an embankment shall be 3:1 (ratio of vertical distance to horizontal distance) unless supported by erosion control ground cover in accordance with §
380-111A.