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.