Sustainable Community: Storm Water Management & Erosion Control

Drainage, Stormwater Management and Erosion Control

Stormwater Pollution Prevention Plan (SWPPP): A Master SWPPP has been prepared for the layout in Master Development Plan in accordance with applicable NYSDEC regulations. The Town of Amenia has found that the preparation of a Master SWPPP was adequate under SEQRA to demonstrate the review of soil erosion control and stormwater management issues. As part of the site plan review process, a detailed final SWPPP will be prepared. This final SWPPP will be reviewed by the Town Engineer, other Town Consultants and the NYSDEC. The SWPPP will also include a detailed erosion and sediment control (E&SC) plan designed in accordance with and approved by the NYSDEC. This plan will identify specific E&SC measures that will be implemented to protect adjacent aquatic resources. This will include a Phasing Plan for soil disturbance.
Erosion control measures are designed to minimize soil loss. Sediment control measures are intended to retain eroded soil and prevent it from reaching water bodies or adjoining properties.

Temporary erosion and sediment control measures that will apply during construction generally include:

Stabilized Construction Entrance
Dust Control
Temporary Soil Stockpile
Temporary Seeding
Stone Inlet Protection Barrier
Erosion Control Blanket
Stone Check Dams
Temporary Sediment Basin

Permanent erosion and sediment control measures to be implemented after completion of construction include the following:

Establishment of Permanent Vegetation
Rock Outlet Protection
Other mitigation measures include:
Cutting of existing vegetation will be minimized by field surveying each building site including trees 8" caliper and larger prior to site plan submission and custom designing each building for the site;
Roadways have been aligned along contour lines to reduce grading impacts and steep road/drive grades; and
Impacts from grading activities will be temporary and be fully mitigated by use of low retaining walls, soil stabilization and re-vegetation with native species where appropriate.
Housing units located on steep slopes are designed with terracing. The floor grades will be split from front to back or back to front adjacent to topographic slopes.
A more detailed geotechnical evaluation will be performed in support of final site design during Site Plan Review.
Use double silt fencing in all areas of special concern, i.e., all wetlands and upslope of the Cascade/Amenia Brook and all other streams.
Limit construction traffic/ heavy equipment to specifically marked travel lanes only, to minimize compaction of soils on steep slopes greater than 15%
Erosion control measures will be installed before construction of the proposed project begins. Stabilized construction entrances, silt fences, sediment traps and water quality basins will be constructed to prevent soil erosion, sedimentation in surface water bodies, and tracking of soil onto adjacent roads. All erosion and sediment control structures will be designed in accordance with the New York State Standards and Specifications for Erosion and Sediment Control.

Stormwater pollutant controls utilized during construction will include, but are not limited to, the following:

Stabilization of construction entrances to reduce the tracking of sediment onto public roadways and permanent traffic corridors to avoid "routes of convenience" that are potentially more detrimental.
Employment of dust control measures including the use of water trucks to reduce dust generated on site.
Temporary stockpiling of materials, such as topsoil, in areas away from storm drainage, water bodies and/or courses, and encircled by silt fence barriers to prevent sedimentation.
Placement of silt fencing, along the perimeter of areas to be disturbed to reduce sediment loss.
Temporary seeding and mulching on all disturbed areas, including topsoil stockpiles, where there will not be any further disturbance for longer than 7 days to minimize erosion and sediment loss.
Placement of stone inlet protection barriers consisting of concrete blocks surrounded by wire mesh and crushed stone around catch basins to keep sediment from entering the catch basins and storm sewer system.
Installation of erosion control blankets on all slopes exceeding 3:1 to provide temporary erosion protection, rapid vegetative establishment, and long-term erosion resistance to shear stresses associated with high runoff flow velocities associated with steep slopes.
Installation of stone check dams within drainage ditches to reduce the velocity of stormwater runoff, to promote settling of sediment, and to reduce sediment transport offsite.
Construction of temporary sediment basins to intercept sediment laden runoff and reduce the amount of sediment leaving the disturbed areas and to protect drainage ways, properties, and rights-of-way.
Soil disturbances will be limited to 5 acres or less at any one time. If more than 5 acres will be disturbed at any one time, permission form the NYSDEC will be required.

Construction housekeeping practices will be implemented to help maintain stormwater quality. These measures include:

Material resulting from the clearing and grubbing operation will be stockpiled up-slope from adequate sedimentation controls.
Areas designated for equipment cleaning, maintenance, and repair will be protected by a temporary perimeter berm.
Detergents will not be used for large scale washing (i.e., vehicles, buildings, pavement surfaces, etc.).
A Spill Prevention and Response Plan will be developed for the site detailing the steps that need to be followed in the event of an accidental spill.
Construction materials shall be stored in a dedicated staging area designed to minimize the impacts of the construction materials on stormwater quality.
Weekly inspection of all erosion and control measures by a NYS DEC qualified inspector.
Compliance with NYS DEC Phase II Stormwater Management.
Placing substantial parking underground
Installing roof gardens on the two largest parking structures on the site which serve the hotel/spa and the clubhouse
Using pervious materials on many sidewalks and patios
Using pervious materials at the winery restaurant parking and draining through a buffer planting area.
Implementation of the NRMP which includes stormwater controls, Integrated Pest Management, and specific monitoring requirements for surface water and groundwater. The NRMP will include a management plan for alternative road de-icing compounds where practicable.
The Habitat Management Plan will be implemented as a mitigation measure. This document describes a system of vegetated buffers throughout the project site, ranging from very narrow aquatic habitat buffers to larger buffers of 100 feet or more to effectively protect certain water resources, habitats and water quality.
The Habitat Management Plan describes a system of vegetated buffers throughout the project site, ranging from very narrow aquatic habitat buffers to larger buffers of 100 feet or more to effectively protect certain water resources, habitats and water quality.
Riparian and bank stabilization improvements to Amenia Cascade Brook are included in the proposed project plan, along with significant floodplain revegetation in this area. The NYS DEC will review mitigation project activities in close proximity to the stream.
Most of the existing golf course provides for no buffers along wetlands or streams; as mitigation, the Habitat Management Plan proposed for the new golf course improves upon the existing condition in terms of water feature improvements, at least some vegetated buffers around most water resources, and the riparian enhancements listed above.
Enhancement of NYSDEC Adjacent Area for Wetland L/LL (AM-15), Stream Restoration, and Pond Enhancement. These activities are illustrated on DEIS Figure 5-12, "Stream, Pond & Wetland Enhancement Plan".
The project will not have any direct impacts to the State-regulated Wetland L/LL (AM-15). Enhancement and wetland mitigation are proposed within the 100 foot regulated adjacent area, approximately 2.75 acres, a majority of which contains existing golf course fairway and 925 linear feet of cart path. These activities may include cart path removal and planting of shrub or tree vegetation to enhance the buffer's habitat values.
Treat all stormwater generated from the commercial and residential development and the roadways serving that development to the East of Hudson standards as shown in Chapter 10 of the New York State Stormwater Management Design Manual (August 2003). These are the treatment standards required within the New York City watershed, a phosphorous restricted watershed and because of the sensitivities of the Amenia Cascade Brook and the Dec Wetland am-15 these standards are deemed appropriate mitigation for the intensity of this development. It is the preference of the Town to utilize a "treatment train" which includes a series of vegetated stepped biofiltration wetlands for the stormwater outflow to pass through prior to directly discharging into the receiving waters of Amenia Cascade Brook and AM-15. These stepped biofiltration wetlands will further reduce the pollutant loads and will reduce the flashiness of stormwater entering the receiving waters. If, at the time of Site Plan review, the applicant wishes to use an alternative management practice, the applicant must demonstrate the alternative will achieve a pollutant removal and detention of water that is equal to or greater than the stepped biofiltration wetlands. It is noted that a treatment train design approach is not necessary for stormwater management facilities which discharge into receiving waters which ultimately convey run-off (i.e. existing tributary upstream ponds, stream, drainage ditches, etc…) into Cascade Amenia Brook or Wetland AM-15.
In the South Lawn Neighborhood area adjacent to DEC Wetland AM-15 extra environmental protections will be utilized including that certain developed areas slope away from the DEC wetland and any proposed underground chambers or cleaning devices are being secondarily run through stepped bio- filtration to clean the storm water.
Locating stormwater ponds at least 100 feet from the Amenia Cascade Brook and the Wetland L/LL (AM-15).
The design will avoid point discharges and will use level spreaders for stormwater outflows into vegetative buffers in stream buffer and wetland buffer areas unless during Site Plan review the applicant can demonstrate that a level spreader is inappropriate and will result in a greater impact to the environment than a point discharge.
Retaining all existing forest area within buffers and on undeveloped slopes.
Re-vegetation of the adjacent hillside south of the Miller house which slopes down to stream R/S with plants that will stabilize the slope and prevent erosion.
Stream V (channel and banks) just north of Route 44 exhibits severe erosion. Bank stabilization and re-vegetation, along with removal of the existing brush and other debris from the banks of the stream is recommended in this area.
Stream V (south of Route 44). This stream channel is severely eroded just before it enters the Amenia Cascade Brook. While an erosion control plan has been presented in the Habitat Management Plan, this plan will be refined during Site Plan review and preparation of the Final SWPPP and which will subject to review and approval by the Planning Board during Site Plan review. The use of check dams is recommended, and details will require review before they are finalized.
Require a 150 foot vegetated buffer along headwater streams R/S and V unless the applicant can demonstrate during Site Plan review that a buffer of less than 150 feet in limited areas is needed. This 150 foot buffer does not apply to the proposed improvement of the existing driveway of the house where Block V will be located, which will become an access road into the winery restaurant and Vineyard Cottage area. Permeable surfaces will used as practicable in this area. It is noted that several units in the current plan are inside the 150' buffer.
Biomonitoring will be used to inform mitigation for impacts to stream flow, in-stream biota and water quality. When the data is collected and evaluated, effective mitigation will be developed and achieved during Site Plan review.