November 27, 2021

Inspecting, updating culverts as important as bridges

Kevin Conlon/city editor

A Cortland County highway crew installs a culvert in October on Taylor Valley Road in Taylor. County and state officials say that while inspecting culverts isn’t mandatory, it’s good management and fixing problems can improve public safety.

The winds swept through Cortland County fast, the rain heavy on Oct. 31, 2019, and into the next day. When everything quieted down, cones were placed on the sides of roads and the culvert — and bridge — on Taylor Valley road was washed out.

The road was too dangerous to pass. But Taylor Valley isn’t the first and likely won’t be the last culvert in the county to wash out.

A heavy rainstorm in 2017 left areas of Cortland County flooded and highway crews were fixing roads and culverts for weeks.

“Culverts: there are many, many more of them and they tend to fail — some of them are 100 years old,” said Bruce Geiger, the legislative representative for the New York State County Highway Superintendents Association.

Repairing or replacing old culverts — and the mechanisms to make that happen — are an important public safety concern, said Todd Gadd, the Wyoming County highway superintendent and New York State County Highway Superintendents Association president.

“When it comes to infrastructure, if that culvert washes out, it’s just like a bridge,” Gadd said. “If that washes out, you can’t go across the road.”

But inspections of culverts aren’t mandated by the state, as bridges are, and there are no real standards for creating culverts, either.

Public safety Gadd said that during his time as the Wyoming highway superintendent, he saw several storms where debris blocked a culvert. It can cause flooding, true, but it can also cause a culvert to become misaligned, which can be especially dangerous.

Culverts are underground, invisible, Gadd said. People will drive on a flooded road thinking the culvert is still there — out of sight, out of mind.

“They just drive over them and people don’t realize they went over them,” Gadd said.

So ensuring the stability of a culvert is just as important as ensuring the stability of bridges, Gadd said.

Inspecting culverts is not required by the state, he said. But it is a best practice.

It’s a practice that Cortland County Highway Superintendent Charlie Sudbrink has been following for the 116 culverts the county oversees.

“The inspections are carried out using the NYSDOT (New York State Department of Transportation) bridge inspection manual as guidance,” said Matt Burns, the senior engineer for the county, in an email. “Depending on the structure, things such as abutments, wingwalls, approaches, stream channel, deck, superstructure are inspected to look or any sort of failure or issue that may lead to failure.”

The manual rates subcategories on a one through seven scale, with one being the least sound and seven the most.

Of the county’s 116 culverts, 33 had a rating of four or lower, according to inspection records received via a Freedom of Information Law request.

“If culvert is rated four or lower inspections are carried out every two years,” Burns said. “If culvert is rated five or above, inspections are carried out every five years.”

Age tends to be the most common problem. “Weathering issues would be a close second,” Burns said.

The county prioritizes low scoring culverts with high traffic flow for repair or replacement, Burns said, but other factors can change the selection process.

Burns also said a rating “will not necessarily shut down the road over a culvert, since it would be case-by-case situation.”

Gadd said highway departments should look at collaborating with other county agencies like a Soil and Water Conservation District on water flow and the structural integrity of culverts because they understand how culverts work.

Collaborating on culverts “Our interest in culverts is related to their ability to perform the intent — convey water — in an environmentally sound manner,” said Amanda Barber, the manager of the Cortland County Soil and Water Conservation District.

Barber said the district can assess a culvert’s water flow capacity.

“This is influenced by the size, shape, slope, and manner of installation,” Barber said. “The volume is often compared to flow expected during different size storm events. So evaluating capacity is a way to evaluate risk of over-topping, failure or damage during flooding.”

Barber said the district may also be called in to evaluate erosion at a culvert’s inlet or outlet. The district’s focus is erosion that inhibits the flow of water and also aquatic life. But that evaluation can provide details on road stability, too.

“Erosion potential is impacted by the design and installation of the structure, but also can be influenced by the culvert itself and the same factors influencing capacity,” Barber said.

Building culverts Culverts can come in various sizes and designs, said Shaun Ketchuck, who handles sales and estimating at Holbrook’s Precast Inc. in Killawog. There are no particular standards for building one — the company does what the client wants and calls on an engineer to inspect its safety.

Culverts can be three-sided or four-sided, depending on the project. The time to make culverts can vary. For one of Holbrook’s jobs it took 17 pours in a mold over 17 days to make a 65-foot culvert.

“We’re not engineers, so we have what the customer is looking for size-wise and length wise — like dimensions essentially — and then we kind of relay that information on to an engineering department,” he said.

Finding funds But in order to fix culverts there needs to be funding, some of which can come from collaborations with agencies like a Soil and Water Conservation District, which Barber said has received grants to assess culverts using the North Atlantic Aquatic Connectivity Collaborative and culvert conditions.

“The information collected, combined with information from local towns, has been used to develop priority roadstream crossing sites for SWCD

(Soil and Water Conservation District) assistance,” Barber said. “Our goal is to help find resources to help communities replace and/or repair aging infrastructure, but to do so in a way that also prevents or corrects associated issues like erosion and habitat.”

The district has four grants to do work within the Cayuga Lake watershed, Skaneateles Lake watershed and the Trout Brook watershed.

“We are working with the towns of Virgil, Scott, Cortlandville and Solon, the county highway department, and Buckeye Pipeline to assist with right-sizing and stabilizing culverts or crossings, incorporating passage and channel stabilization, to improve our infrastructure, protect water quality and enhance habitat,” Barber said.

Culverts on a federal road can get federal funding, but other roads must look to the state, Gadd said. Until recently, culverts were a lower priority than roads or bridges.

“Funding is always critical,” Gadd said. “Culverts were so important that they (the state) opened it up.”

Now, counties can use Consolidated Local Street and Highway Improvement program funds or Bridge New York funds for culverts.

“More of a percentage of that has been dedicated for culverts, just because of the scope of how many culverts there are,” Geiger said.

Be alert, be aware Even if there isn’t enough funding to replace a culvert, highway departments can still ensure safety. They can perform routine inspections “to try to catch them (deficiencies) before something catastrophic happens,” Gadd said.

They can also educate drivers, so people don’t travel on flooded roads.

“When you have those flooding events, there’s often messaging out there to stay alert,” Gadd said. “Don’t just assume something is there. You don’t want to just keep driving through because maybe that culvert has washed away.”