Location: Mill Rd & East St, Town of Pittsford, Monroe County
Client: Monroe County Department of Transportation
Project Type: Transportation
Completed: 2020
Engineers/Inspectors: Cole Papasergi, Bob Bringley, Greg Suraci
Project Description:
Marathon Engineering was retained by the Monroe County Department of Transportation (MCDOT) to provide professional engineering services for a culvert replacement project. Monroe County owns and maintains two existing culverts located under East Street (County Road 56) in the Town of Pittsford. Both culverts were undersized and had passed their design life span.
Alternatives to full replacement were considered including rehabilitation, relining, and partial replacement; but it was determined that full replacement was necessary. Several conceptual designs were explored to determine a preferred replacement option for each culvert. Multiple stream alignments, culvert configurations, and culvert types were evaluated.
Thorough investigations (including but not limited to geotechnical, environmental, historical, traffic, hydrologic, and hydraulic considerations) of the culverts and surrounding areas were performed to determine the best and most economical options for each culvert. A complicating factor in this project was a tributary merging with Mill Creek directly at the outlet of the south culvert, and the overall proximity to the downstream confluence with Irondequoit Creek. We performed an expansive hydraulic analysis, coordinated with the municipality and regulatory agencies, and were able to demonstrate inconsequential impacts to flood elevations as a result of our designs.
The North Culvert, originally constructed in 1939 at the intersection of Mill Road & East Street, was a 4’ wide by 4’ high, three-sided reinforced concrete box with cast-in-place headwalls on the west side and a junction box on the east side of the culvert. The water was then piped along the eastern side of the road. This configuration forced a “hairpin-like” stream alignment which had inefficient water flow and an increased risk of compromising the road from erosion of the banks.
The replacement design utilized a 66” steel reinforced polyethylene pipe that was designed with baffles to retain sediment within the pipe providing a natural stream bottom. This realigned the stream to improve water flow through the area and avoid further erosion of the roadway by daylighting of a significant amount of the stream that was previously piped near the outlet.
The South Culvert, originally built in 1930 and located approximately 500’ south of the intersection of Mill Road, was a 10’ wide by 8’7” high, three-sided reinforced concrete culvert with cast-in-place headwalls. This culvert was undersized and resulted in a wide floodplain with water overtopping the road during extreme storm events. The selected design option was a new 22’ wide by 10’ high, 4-sided reinforced concrete box with the stream realigned to improve water flow through the area. The downstream municipality expressed concerns with increases in flows for lesser storm events; we were able to address these concerns with additional modeling of the drainage areas and hydraulic analysis of multiple rainfall levels.
Throughout construction we provided Resident Project Representation (RPR) services, including construction supervision and inspection work. The resulting culvert improvements ensure the drainage and roadways will continue to provide service to vehicular traffic for years to come.
