The landscape plan shall identify existing and
proposed trees, shrubs, ground cover, natural features such as rock
outcroppings, and other landscaping elements. The plan should show
where they are or will be located and planting and/or construction
details. When existing natural growth is proposed to remain, the applicant
shall include in the plans proposed methods to protect existing trees
and growth during and after construction.
Stormwater management areas include detention
basins, drainage ditches and swales, and wetlands areas. Sensitively
designed basins and swales can benefit the health, welfare, and safety
of residents. This may involve integration of these areas as aesthetic
landscape features, naturalized wetland areas, or active and passive
recreation areas, in addition to their stormwater management function.
A. Stormwater detention basins. One of the following
landscape concepts, or an alternative concept complying with the standards
set forth above, shall be used:
(1) Reforestation.
(a)
This landscape treatment is appropriate for
detention basins and drainage areas that are not highly visible or
are adjacent to areas of mature woodlands or wetlands. It reverts
the disturbed area to a revegetated, stable, low-maintenance, natural
landscape asset over time.
(b)
The area shall be graded creatively to blend
into the surrounding landscape and imitate a natural depression with
an irregular edge. This shall include gentle berming. Linear, geometric
basins are unacceptable.
(c)
The quantity of trees to be planted on the interior
of the basins shall be equal to the number of trees that would be
necessary to cover the entire area, based upon a twenty-foot-by-twenty-foot
grid to the high water line or outflow elevation. Of this number,
10% shall be two-and-one-half-inch to three-inch caliper, 20% shall
be one-inch to two-inch caliper, and 70% shall be six-foot- to eight-foot-high
whips.
(d)
The trees shall be planted in groves and spaced
five feet to 15 feet on center.
(e)
No trees shall be planted within the two-year
storm frequency elevation.
(f)
The ground plane shall be seeded with a naturalization,
wildflower, and/or meadow grass mix. The species indigenous to the
area and/or tolerant of typical wet/dry floodplain conditions.
(g)
Plantings shall not be located within 20 feet
of low flow channels or any other associated detention utilities to
allow for maintenance.
(h)
The perimeter area (slopes above the high water
line) shall include shade trees (approximately 80/1,000 linear feet),
evergreen trees (approximately 40/1,000 linear feet), ornamental trees,
and shrubs screening drainage structures and creating visual interests.
(i)
Provision for emergency access as well as general
maintenance of the basins shall be reviewed by the Township Engineer.
Plantings shall be designed to disguise yet not hinder vehicular access.
(j)
Plantings are not permitted upon any emergency
overflow berms associated with a detention basin unless approved by
the Township Engineer.
(2) Recreation/open space feature.
(a)
This landscape concept is appropriate in situations
where a basin is the largest or only portion of open space in an area
or is adjacent to existing open space and recreational open space
is desired. It is also appropriate for smaller, highly visible basins
where a visually pleasing open area is desired.
(b)
The objective in these situations is to integrate
the area into the landscape using topography and plantings in order
to complement the function of the area and to provide a visually interesting
landscape feature and/or recreation space.
(c)
The area shall be graded creatively to blend
into the surrounding landscape and imitate a natural depression with
an irregular edge. This shall include gentle berming.
(d)
Provide perimeter plantings, including shade
trees, formally or informally, evergreen trees to create and screen
views, and small trees and shrubs to provide a continuous landscape
strip screening drainage structures and creating visual interest.
(e)
Integrate buffer plantings with perimeter plantings
where applicable.
(f)
The following are guidelines for plant quantities:
|
Type
|
Quantity
|
---|
|
Shade trees
|
80/1,000 linear feet
|
---|
|
Evergreen trees
|
40/1,000 linear feet
|
|
Ornamental trees
|
10/1,000 linear feet
|
|
Shrubs
|
50/1,000 linear feet
|
(g)
To provide recreational open space, concentrate
frequently flooded detention in a basin area (five- to ten-year storm
volume) and provide a gently sloping, less often flooded, area (ten-
to one-hundred-year storm volume) as a recreational open field space.
Provide ballfields and/or open play areas integrated with plantings
in a park-like manner.
B. Stormwater retention basins.
(1) This landscape treatment can take on a variety of
landscape forms, from formal reflecting pools and canals or entry
fountain features to natural park-like lakes and ravines.
(2) Water fountains and features are encouraged in the
design of research, office and industrial parks.
[Amended by Ord. No. 98-11]
(3) The water's edge shall be easily maintained and stable.
Possible treatments might include rip-rap, stone walls, natural plantings,
decking, and bulkheads.
(4) The planting of the perimeter of the feature shall
accentuate views and interest and integrate pedestrian paths, sitting
areas, and other uses.
(5) Plantings shall include formal or informally massed
deciduous and evergreen trees and shrubs to screen and frame views
with ornamental trees, shrubs, and grasses used for visual interest
or special effects. A continuous landscape area shall be provided.
(6) If used as a recreational feature, the connection
to the water must be addressed and controlled. The types of uses shall
be specified, and the plantings and pedestrian spaces shall be integrated
with these uses.
(7) Plants with pervasive root systems shall not be located
where they may cause damage to drainage pipes or other underground
utilities.
(8) All engineered basin structures shall be designed
to blend into the landscape in terms of construction materials, color,
grading, and planting.