VILLAGE OF SCARSDALE WESTCHESTER COUNTY, NEW YORK COMPREHENSIVE STORM WATER MANAGEMENT SOUTH FOX MEADOW STORMWATER IMPROVEMENT PROJECT In association with WESTCHESTER COUNTY FLOOD MITIGATION PROGRAM Rob DeGiorgio, P.E., CPESC, CPSWQ
The Bronx River Watershed Fox Meadow Brook Bronx River Watershed Area in Westchester 48.3 square miles (30,932 acres) 15 Sub-watersheds Percent of undeveloped land in the Watershed 3.3% (0.8 acres in FMB watershed) Fox Meadow Brook (FMB) 928 acres (5.7% of watershed)
Bronx River Watershed Fox Meadow Brook George Field Park High School Duck Pond
Project Philosophy and Goals Provide flood mitigation within the Fox Meadow Brook Drainage Basin. Reduce peak run off rates in the Bronx River Watershed through dry detention storage. Rehabilitate and preserve natural landscapes and wetlands through invasive species management and reconstruction. Improve water quality. Petition for and obtain County grant funding to subsidize the project. Village of Scarsdale
Fox Meadow Brook Watershed BR-4 SR-2 SR-3 BR-7 BR-8 SR-5 Village of Scarsdale
In 2009 the Village completed a Comprehensive Storm Water Management Plan. Critical Bronx River sub drainage basin areas identified inclusive of Fox Meadow Brook (BR-4, BR-7, BR-8). 26 Capital Improvement Projects were identified, several of which comprise the Fox Meadow Detention Improvement Project. Project included in Village s Capital Budget. Project has been reviewed by the NYS DEC. NYS EFC has approved financing for the project granting Scarsdale a 50% subsidy for their local share of the costs. History Village of Scarsdale
Site Locations 7 Segments 7 Project Segments 1. George Field Park Dry Detention Pond 2. Cambridge Road Clean, Televise, Line CMP pipe, add positive drainage 3. Cooper Green Dry Detention Pond 4. Open Stream Along Post Road De-silting/re-channelization 5. Murray Hill Dry Detention Pond 6. Gravel Parking Lot at the High School Raise the lot 7. Harcourt Woods De-silting/ re-channelization
Oxford Rd Segment No.1 - George Field Park (Overview) Post Rd 0 ft Dry Detention Basin Wetland Greendale Rd 800 ft
Segment No. 1 - George Field Park (Wetland) Rehabilitated, re-constructed wetland Enhances water quality Improves bio-habitat Eliminate invasive species (Japanese Knot Weed, Norway Maples ) Dry detention 7 acre feet of storage (2,300,000 gals) 1 to 3 feet overall depth
Segment No. 1 - George Field Park (Pedestrian Bridge) Stream bank stabilization Passive recreation
Segment No. 1 - George Field Park (Outlet) Greendale Road side Grassy swale water quality improvement New trees and vegetation
Segment No. 1 - George Field Park (Section View)
Segment No. 2 - Cambridge Road Cleaning, televising, and potentially lining the drain pipe from George Field Park to Cooper Green Installing positive drainage in the low lying area WORK WILL BE COMPLETED ON PRIVATE PROPERTY AND AN AGREEMENT WILL HAVE TO BE REACHED WITH THE HOME OWNER(S) Village of Scarsdale
Segment No. 3 - Cooper Green Post Road Dry Detention Pond Pervious walkway / rain garden
Grey Twig Dogwood New England Aster Witch Hazel Cut leaf Cone Flower Native Rain Garden Plantings Wild Beramont Switch Grass Inkberry Holly Spotted Joe-Pye Weed Great Blue Lobelia Elderberry Red Milkweed Winterberry Cardinal Flower
Segment No. 3 - Cooper Green (Section View) 2,900 square feet of Rain Garden along pervious walkway One of largest Rain Gardens proposed in the Hudson Valley 2.5 acre-feet of run off storage (815,000 gals)
Segment No. 4 - Open Watercourse Re-Channelization Along Post Road The stream will be desilted to restore the optimal geometry of the stream. Work to be completed on private property requires access agreements. Village of Scarsdale
Segment No. 5 - Murray Hill/Post Road CONFLUENCE OINT OF FLOWS FLOW FROM ALONG POST ROAD (UPPER FMB) FLOW FROM MURRAY HILL ROAD 2.5 acre feet of storage (815,000 gals) Helps eliminate bottle neck at confluence at Murray Hill/Post Road more so than reducing overall peak flows Involves Land Acquisition to be determined by Board of Trustees Not part of the project planned for bidding in December 2011
Segment No. 6 - High School Parking Lot Flood Mitigation Chronic flooding at High School lot. Identified Project in Village s Comprehensive Plan. Beneficial re-use of excavated soils. 20,000 cubic yards of soil to be un-earthed at George Filed Park and Cooper Green About 12,000 14,000 cubic yards can be beneficially re-used to raise the lot. Saves the Project over $300,000 in disposal costs. Saves the Project over $250,000 in imported fill costs. Green Solution smart planning Village of Scarsdale
Harcourt Woods Re-Channelization Restore optimal stream geometry Village of Scarsdale
Project Benefits Virtually no project within the 15 Bronx River watershed sub-basins reduces existing peak flow run off rates to any appreciable extent..until now. Fox Meadow Brook
Project Benefits NOW George Field Park Revised Flood Plain (3-4 inches precip) Cooper Green
Peak Flow Reductions* Project Benefits Peak Flow Reductions* George Field Park Sub-basin Cooper Green Murray Hill 70% reduction in peak flows 58% reduction in peak flows Major benefit is to DELAY the peak flow to the confluence point For 3.5 inches of rain storm event (flash events and 24 hr sustained events) Village of Scarsdale
Peak Runoff Reductions To the Bronx River (%) Project Benefits Peak Flow Reductions* 50% 25% FMB Bronx River Sub-basin (one of fifteen Bronx River sub basins) 30% reduction in peak flows 0 % 3.5 4.5 5.0 6.0 7.0 Storm Intensity (inches) Village of Scarsdale
If each of the fifteen Westchester County subwatersheds that flow to the Bronx River could reduce peak flows for a 3 to 5 inch rain event by 30%, it would result in a significant reduction in flooding impacts. Project Benefits Fox Meadow Brook
Project Benefits Effective in reducing flooding in flash storm events as well as sustained events. Eliminates invasive species & deteriorated trees and vegetation. Introduces constructed wetland to George Field Park & Rain Gardens to Cooper Green. Improves water quality. Village of Scarsdale
Estimated Construction Costs Segment No. 1. George Field Park Wetland & Dry Detention $1,300,000 2. Cambridge Road Drainage Inlets, Cleaning, Televising & Lining $ 300,000 3. Cooper Green Rain Garden & Dry Detention $ 700,000 4. Open Watercourse re-channelization along Post Road $ 150,000 6. High School Parking Lot Flood Mitigation $ 600,000 7. Harcourt Woods re-channelization $ 100,000 TOTAL $3,150,000 6. Murray Hill Dry Detention Pond $ 600,000* * CONTINGENT ON LAND ACQUISITION AND DEMOLITION (ESTIMATED AT $2M-$3M) WHICH IS NOT INCLUDED IN THIS COST ESTIMATE Village of Scarsdale
Project Schedule Public Bidding December 2011 Contract (s) Award February 2012 Start of Construction March/April 2012 Substantial Completion December 2012 Growing Seasons 2012-2014 Village of Scarsdale
Questions? Village of Scarsdale
Sheldrake Watershed SR2 Garden Rd Cushman Rd Sheldrake Rd Fenway West Pond 2009 Comprehensive Plan Summary SR- 2 199 acre watershed Cushman Road Culvert 2-yr flow = 124 cfs SR3 SR4 Fenway Irrigation Pond Murray Hill 3 Pond Area Cayuga Pond Middle School SR-3 271 acre watershed One of the most heavily flooded sub basins in the Village Fenway Irrigation pond replaced with groundwater pond 2-yr flow = 418 cfs SR-4 50 acre watershed SR5 Scarsdale Medical Group Outflow to New Rochelle SR-5 173 acre watershed 2-yr flow = 515 cfs
Sheldrake FEMA Designated Flood Zones N Fox Meadow Fenway Golf Club Cayuga Pond Heathcote Bypass Sheldrake Source: FEMA Issued Flood Maps
Sheldrake Watershed Aerial Fenway West Pond Murray Hill Ponds Fenway Irrigation Pond Cayuga Pond Middle School
Sheldrake SR3 Area SR-5 Middle School SR-3 Murray Hill Ponds SR-2 Fenway Irrigation Pond Cayuga Pond SR-5 SR-4
SR-5 Sheldrake Conceptual Improvements 1 Middle School SR-3 2 SR-2 3 Fenway Irrigation Pond Cayuga Pond 3 1 Segment #1 Culvert improvements on Sheldrake, Cushman and Garden Roads, Pipe/watercourse cleaning on Garden/Cushman/Sheldrake Roads. Greater detention capacity at Fenway West Pond to increase pond storage detention capacity. Segment #2 - Murray Hill 3 Pond de-silting to increase storage capacity. Creation of fore bay in Pond No.1 and spillway/control gate modification for outlet. Cleaning of open watercourse to Cayuga Pond. SR-5 Segment #3 Cayuga Pond enlargement, de-silting, fore bay installation and improvements to spillway with control gate with control SR-4 outlet. Cleaning/ Improvements to culverts and open watercourse at Catherine, Cayuga, Seneca to Middle School/.Quaker Center.