Erdman Anthony provided preliminary design, final design, and construction support services for a cost-effective and environmentally conscious solution to replace an aging three-sided concrete culvert carrying an unnamed Oatka Creek tributary (a regulated waterway) under North Road in Wheatland, New York. Our design process considered environmental sensitivities and several alternative materials, including metal, concrete, and plastic pipes. An option was identified that met two important goals: to fit within the county’s budget and to be hydraulically efficient.
The existing culvert was 4.75 feet wide by 5 feet high by 54 feet long. The replacement culvert is an 81-inch-span by 59-inch-rise by 99-foot-long corrugated-metal pipe-arch culvert. Its invert is buried 21 inches to provide a natural stream bottom through its entire length, which allows fish and invertebrates in the waterway to move freely. The culvert’s length includes 4-foot-long sloped ends.
The plastic coating, laminated on both the interior and exterior of the corrugated metal pipe, extends the life of the pipe by as much as 80 years. This solution realized a 20 percent cost savings over a precast-concrete span.
The replacement culvert is 45 feet longer, which provides for an additional 18 feet of improved and unobstructed roadside safety and a clear zone in accordance with current AASHTO and NYSDOT standards. The safety accrual realized by the dramatically increased length of the replacement culvert also meant that our design did not require guiderails.
Hydraulic analysis determined that the size of the culvert opening we designed would be hydraulically equivalent to existing conditions, mitigating impact on abutting landowners upstream and downstream, and contributing to balance in the ecosystem.
Lastly, this Bridge NY-funded project met or exceeded U.S. Army Corps of Engineers and NYS Department of Environmental Conservation requirements.
Sustainable Design Impact
This project met or exceeded state DEC regulatory requirements, and burying the culvert’s invert 21 inches made way for a natural stream bottom that now allows aquatic marine life to move freely.