Landscaping shall be required in and around
all stormwater management basins as follows:
A. All areas of stormwater management basins, including
basin floors, side slopes, berms, impoundment structures or other
earth structures, shall be planted with cover vegetation, such as
lawn grass or naturalized plantings specifically suited for stormwater
basins. (See the Recommended Plant Material List for recommended plants for stormwater basins.)
(1) Lawn grass areas shall be sodded or hydroseeded to
minimize erosion during the establishment period and, once established,
these areas shall be maintained at a height of not more than six inches.
(2) Naturalized cover plantings, such as wildflowers,
meadows and nonaggressive grasses specifically designed for the permanently
wet, intermittently wet and usually dry areas of stormwater basins
may be planted as an alternative to lawn grass, provided that:
(a)
The plantings provide continuous cover to all
areas of the basin.
(b)
The plantings do not interfere in the safe and
efficient function of the basin as determined by the Township Engineer.
(3) Trees and shrubs shall be allowed in and around stormwater
basins, provided that they do not interfere with the proper function
of the basin and no trees are planted on or within 30 feet of an impoundment
structure or dam.
B. Basin shape shall incorporate curvilinear features
to blend with the surrounding topography.
C. Minimum grades inside stormwater basins shall be 2%,
and maximum side slopes of the basin shall be 33% (3 to 1 slope).
The following standards shall apply to all plant
materials or transplanted trees as required under this article:
A. Plant specifications.
(1) All plants shall meet the minimum standards for health,
form and root conditions as outlined in the American Association of
Nurserymen (AAN) Standards.
(2) All plant material shall be hardy and within the USDA
Hardiness Zone 5 and 6 applicable to Berks County, Pennsylvania.
(3) Canopy trees, sometimes called shade trees, shall
reach a minimum height and spread of 30 feet at maturity as determined
by the AAN Standards and shall be deciduous. New trees shall have
a minimum caliper of 2 1/2 inches at planting.
(4) Ornamental trees or large shrubs shall reach a typical
minimum height of 15 feet at maturity based on AAN Standards. Trees
and shrubs may be deciduous or evergreen and shall have a distinctive
ornamental character, such as showy flowers, fruit, habit, foliage
or bark. New ornamental trees shall have a minimum height of six feet
or 1-1/2-inch caliper. New large shrubs shall have a minimum height
of 2 1/2 to three feet at time of planting.
(5) Evergreen trees shall reach a typical minimum height
of 20 feet at maturity based on AAN Standards for that species and
shall remain evergreen throughout the year. New evergreens shall have
a minimum height at planting of six feet.
B. Maintenance.
(1) Required plant material shall be maintained for the
life of the development to achieve the required visual effect of the
buffer or screen. It shall be the ultimate responsibility of successive
property owners to ensure that the required plantings are properly
maintained. Dead or diseased plant material shall be removed or treated
promptly by the property owner and replaced as soon as possible, but
no later than the next growing season.
(2) Safety. All sight triangles shall remain open and
clear, and any plant material that could endanger safety, such as
unstable limbs, shall be removed and the plant material replaced,
if necessary. It shall be the responsibility of the property owner
to maintain all plantings and architectural elements to ensure a safe
environment.
(3) Maintenance guidelines for the plantings are encouraged
to be published by the planting plan designed to be used by grounds
maintenance personnel to ensure that the design's buffering and screening
concepts are continued.
(4) All subdivision and land development record plans
shall contain the following note: "The property owner shall be responsible
for the perpetual maintenance of the buffer screen and site element
screens."
C. Landscape bond.
(1) Any tree or shrub that dies within 18 months of plantings
shall be replaced by the current landowner or developer. Any tree
or shrub that, within 18 months of planting or replanting, is deemed,
in the opinion of the Township Supervisors, not to have survived or
not to have grown in a manner characteristic of its type, shall be
replaced. Substitutions for certain species may be made only when
approved by the Board of Supervisors.
(2) The developer or landowner shall deposit with the
Township a sum of money in the form of cash, certified check, letter
of credit or bond equal to a minimum of 15% of the total landscaping
costs to cover the cost of replacing, purchasing, planting and maintaining
all dead, dying, defective or diseased plant material for a period
of 18 months after final plan approval.