The objective of this chapter is to control
soil erosion and sedimentation caused by development activities in
the Village of Rye Brook. Measures taken to control erosion and sedimentation
shall be adequate to ensure that sediment is not transported from
the site, or excessively within the site, by a storm event of a ten-year
frequency or less.
The following principles shall apply to all development activities within the Village of Rye Brook and to the preparation of submissions required under Article
III of this chapter:
A. Selection of control measures. The selection of erosion
and sedimentation control measures shall be based on assessment of
the probable frequency of climatic and other events likely to contribute
to erosion, site and subsurface soil conditions, and on an evaluation
of the risks, costs, and benefits involved.
B. Protection of adjacent properties.
(1) Properties adjacent to the site of a land disturbance
shall be protected from sediment deposition. This may be accomplished
by preserving a well-vegetated buffer strip around the lower perimeter
of the land disturbance, by installing perimeter controls such as
sediment barriers, traps, filters, dikes, or sediment basins, or by
a combination of such measures.
(2) Vegetated buffer strips may be used alone only where
runoff in sheet flow is expected. Buffer strips should be at least
20 feet in width. If, at any time, the Superintendent of Public Works/Village
Engineer determines that a vegetated buffer strip alone is ineffective
in preventing sediment movement onto adjacent property, additional
perimeter controls must be provided.
[Amended 10-27-2020 by L.L. No. 9-2020]
C. Cut and fill slopes. Development shall reflect the topography and soils of the site so as to create the least potential for erosion. Areas of steep slopes where high cuts and fills may be required shall be avoided wherever possible. Where areas of steep slopes cannot be avoided, development on slopes of 15% or greater shall require a steep slope work permit in accordance with Chapter
213, Steep Slope Protection.
D. Vegetation. Natural vegetation shall be retained and
protected wherever possible. A permanent vegetative cover shall be
promptly established on denuded areas not otherwise permanently stabilized.
Permanent vegetation and related structures shall be installed as
soon as practical, or within the time specified in the permit. Permanent
vegetation shall not be considered established until a groundcover
is achieved which, in the opinion of the Superintendent of Public
Works/Village Engineer or designated agent, is mature enough to control
soil erosion satisfactorily and to survive a ten-year frequency storm.
[Amended 10-27-2020 by L.L. No. 9-2020]
E. Stabilization of denuded areas and soil stockpiles.
(1) Permanent or temporary soil stabilization, in accordance
with the approved soil erosion control plan, must be applied to denuded
areas within 15 days after final grade is reached on any portion of
the site. Soil stabilization must also be applied within 10 days to
denuded areas which may not be at final grade but will remain dormant
(undisturbed) for longer than 21 days.
(2) Soil stabilization refers to measures which protect
soil from the erosive forces of raindrop impact and flowing water.
Applicable practices include vegetative establishment, mulching, and
the early application of a gravel base on areas to be paved.
F. Sediment basins. Sediment basins, debris basins, silt
traps or filters shall be installed and maintained to remove sediment
from runoff waters from land undergoing development.
G. Timing and stabilization of sediment trapping measures.
Sediment basins and traps, perimeter dikes, sediment barriers and
other measures intended to trap sediment on-site must be constructed
as a first step in grading and must be made functional before upslope
land disturbance takes place. Earthen structures such as dams, dikes,
and diversions must be seeded and mulched within 10 days of installation.
H. Stabilization of waterways and outlets. All on-site
stormwater conveyance channels shall be designed and constructed to
withstand the expected velocity of flow, without erosion, from a ten-year
frequency storm. Stabilization adequate to prevent erosion must also
be provided at the outlets of all pipes and paved channels.
I. Storm drain inlet protection. All storm drain inlets
which become operable during construction shall be protected so that
sediment-laden water will not enter the conveyance system without
first being filtered or otherwise treated to remove sediment.
J. Working in or crossing watercourses.
(1) Construction vehicles should be kept out of watercourses
to the greatest extent possible. Where in-channel work is necessary,
precautions must be taken to stabilize the work area during construction
to minimize erosion and control downstream sedimentation transport.
The channel (including bed and banks) must be restabilized immediately
after in-channel work is completed.
(2) Where a live (wet) watercourse must be crossed by
construction vehicles regularly during construction, a temporary stream
crossing must be provided.
K. Stormwater management criteria for controlling off-site
erosion.
(1) Provisions shall be made to accommodate the increased
runoff caused by changed soil and surface conditions during and after
development. Drainageways shall be designed so that the final gradients
and the resultant velocities of discharges will not create additional
erosion.
(2) Stormwater management design will follow the procedures
and methodology set forth in the Westchester County Best Management
Practices Manual for Stormwater Runoff and the NYSDEC Division of
Water Technical and Operations Guidance Series Nos. 5.1.8 and 5.1.10
unless a comprehensive stormwater management plan has been adopted
by the Village.
L. Underground utility construction. The construction,
installation, maintenance or repair of underground utility lines shall
be subject to the following criteria:
(1) No more than 500 feet of trench shall be opened at
one time.
(2) Where consistent with safety and space considerations,
excavated material shall be placed on the uphill side of trenches.
(3) Trench dewatering devices shall discharge into sediment
traps and filters in a manner which will not introduce sediment-laden
water or otherwise adversely affect flowing streams, drainage systems,
or off-site property.
M. Construction access routes. Wherever construction
vehicle access routes intersect paved public roads, provisions shall
be made to minimize the transport of sediment (mud) by runoff or vehicle
tracking onto the paved surface. Where sediment is transported onto
a public road surface, the roads shall be cleaned thoroughly at the
end of each day. Sediment shall be removed from roads by shoveling
or sweeping and transported to a sediment control area. Street washing
shall be allowed only after sediment is removed in this manner.
N. Disposition of temporary measures. All temporary erosion
and sediment control measures shall be disposed of within 30 days
after final site stabilization is achieved, unless otherwise authorized
by the Superintendent of Public Works/Village Engineer. Trapped sediment
and other disturbed soil areas resulting from the disposition of temporary
measures shall be permanently stabilized to prevent further erosion
and sedimentation.
[Amended 10-27-2020 by L.L. No. 9-2020]
O. Maintenance. All temporary and permanent erosion and
sediment control practices shall be maintained and repaired as needed
to assure continued performance of their intended function.
P. Aesthetics. In the design of erosion control facilities
and practices, aesthetics and the requirements of continuing maintenance
shall be considered.
Q. Review by the Westchester County Soil and Water Conservation
District. The Westchester County Soil and Water Conservation District
may be consulted for review and recommendations for all erosion and
sediment control plans for proposed developments submitted to the
Village of Rye Brook.