Design, Bid and Construction Oversight for Drainage Improvement Projects
The Town of North Andover selected Weston & Sampson to design, bid, and oversee construction of the Adams and Autran Avenue Drainage Improvement Projects. The projects consisted of evaluating and designing drainage improvements along Adams and Autran Avenues to alleviate erosion caused by stormwater runoff.
The Adams and Autran Avenue drainage areas consist of approximately 20 acres. The work fell within the 100-foot wetland buffer zone and the 25-foot no disturbance zone of the resource area defined by the stream. The streets are located parallel to one another and both discharge into a stream located at the lower end of each street. There were no drainage systems on either street and stormwater flow travelled overland along the road edges. This condition, combined with steeply sloped streets, resulted in erosion along the road edges , causing undermining of pavement and damage to lawns and driveways of residents. In addition, the large drainage flows and high velocities at the bottom of the streets caused erosion along the banks of the receiving stream.
The key focus of the projects included remediating the erosion along the streets and where stormwater discharges into the stream. Weston & Sampson’s work included:
- Performed instrument survey to locate existing utilities and ground elevations.
- Conducted site visits during large storm events to observe stormwater flows.
- Developed a computer model of the stormwater drainage system and the tributary drainage areas utilizing HydroCAD 8.0.
- Prepared submittals to local and state agencies to acquire necessary permits, and attending conservation commission meetings.
- Designed a new drainage system, including approximately 4,000 linear feet of 12-inch to 36-inch reinforced concrete pipe (RCP) and corrugated polyethylene (HDPE) pipe.
- Evaluated and designing sediment removal/dredging and erosion control of existing stream.
- Designed of new headwall.
- Utilized Best Management Practices (BMPs) to reduce sediment and pollutant loading to existing stream.
Weston & Sampson also provided resident representative inspection during construction of the improvements.