Steuben County, NY
EDR assisted with the development site-civil engineering consisting of access road and the stormwater management design for a commercial-scale 290-megawatt (MW) wind power project in multiple locations in the Towns of Cameron, Canisteo, Greenwood, Jasper, Troupsburg and West Union in Steuben County, New York.
Project features included the installation and operation of 86 wind turbines, installation and operation of 5 meteorological towers, 34 miles of permanent turbine access roads, buried electrical interconnect lines, a collection substation, and an operations and maintenance (O&M) building. Stormwater from the site discharges into a variety of named and unnamed tributaries including Bennetts and Colonel Bills Creeks, which ultimately discharge into the Canisteo River.
The pre-construction condition of the site is primarily active agriculture and woods. The post-construction condition of the site will remain mostly active agriculture, with the wind turbines and access roads located to minimize impacts to both farming and existing natural resource areas. The turbines will be accessed by a network of gravel access roads that consist of a 16-foot-wide travel lane, and profile slopes that range from approximately 1% to 12%.
A stormwater analysis of the site was conducted using Hydraflow Hydrographs Extension for AutoCAD Civil 3D. This software was used to perform a United States Department of Agriculture (USDA) Soil Conservation Service (SCS) Technical Release No. 55 (SCS TR-55) and TR-20 (SCS TR-20) hydrologic analysis of the site. Given the large area covered by the Project, additional software was used in the watershed analysis. Watersheds and flow paths were delineated using the ArcHydro tool within ArcGIS (GIS) which identified 327 watersheds ranging from 3 to 631 acres. The total watershed area modeled was 9,900 acres. In the post-construction conditions, adjustments were made to account for the change in land use from tree-clearing activities and the addition of impervious access roads and crane pads. The nature of wind development allows for a minimal increase to impervious areas. As a result of the minimal impervious increases, CNs were not changed for any watersheds, thus storm flows were not increased.