STERLING- STORMWATER DRAINAGE IMPROVEMENTS AT WACHUSETT RESERVOIR ON ROUTE 110 (METROPOLITAN ROAD)

The proposed project will eliminate sources of direct stormwater discharge and potential hazardous materials releases from Route 110 to the Wachusett Reservoir, a public water supply to over three million users. The existing drainage from the roadway is typical of rural country drainage. The north side of the roadway sheet flows directly to a wetland and a small body of water. There is a cross culvert connecting the wetland to the reservoir to the south. The south side of the roadway sheet flows directly to the reservoir. The intent of the preliminary design is to drain the entire roadway to the existing wetland to the north. The existing cross culvert between the wetland and the reservoir will be eliminated. A new 550 foot diversion pipe is proposed to carry stormwater from the wetland to the body of water to the north, which is off of the reservoir's watershed land. A Hot Mix Asphalt Type "A" Modified berm will be constructed along the side of the road closest to the reservoir's edge. Due to how longitudinally flat the roadway is in this area, three catch basins will be installed in addition to the super-elevation.