Expert says Rocheport Bridge blast likely had little to no effect on Missouri River

ROCHEPORT, Mo. (KMIZ)

Clean up continues after 6 million pounds of steel was dropped into the Missouri River when the Rocheport Bridge was demolished on Sept. 10.

Rocheport resident Brett Dufur was on a boat downstream when the bridge came down.

"It was absolutely one of the loudest explosions I've ever heard in my life," Dufur said.

He has been a river guide on the Missouri River for 20 years now, and said he was shocked to see the amount of debris and wildlife in the water after the blast.

"There was kind of a hush that fell over the boaters out there, because I think everyone was shocked by what we were experiencing," Dufur said. "Everywhere you looked, there was another dead bird, face down, wings spread out, floating down the river."

However, the Missouri Department of Transportation says environmental impacts have been minimal. MoDOT Central District spokesperson Marcia Johnson told ABC 17 News in an email that the blast demolition is a common practice for this type of river bridge.

"The team worked closely with MoDOT's environmental division, the Corps of Engineers, the Coast Guard, Missouri Department of Conservation and Fish & Wildlife and others to ensure a successful blast with minimal environmental impacts," Johnson said.

Johnson also said a "scare charge" was set off prior to the main blast in an attempt to send wildlife, such as fish and birds, away from the site. However, she said some pigeons returned to the area before the main blast was set.

Fish, however, were likely already out of the area, according to University of Missouri School of Natural Resources adjunct professor Robb Jacobson.

"I think because they've been working on that bridge site for a long time, that they sort of chased the fish out of there," Jacobson said.

In fact, Jacobson said the bridge demolition likely had little to no effect on the Missouri River. He said the river is very dynamic, and already sees around 55 million tons of sediment traveling through it each year.

"It's a system that's already had so much done to it that when other smaller or transient things are done to it, like the bridge falling in the river, it doesn't have that much of a relative effect," Jacobson said.

He also said the river regularly transports a lot of wood, so the lumber being carried downstream is somewhat of a natural process, as well.

Johnson said the lumber seen after the blast was likely from blast boxes built around the explosives to help minimize debris.

In a Superintendent Talk on Saturday, Lunda Construction project manager Talat Mansour said there are about 400 feet of debris from the blasted truss in the water, and it will be another week or two until everything is picked up out of the water.

MoDOT received a permit for this project through the U.S. Army Corps of Engineers. Public Affairs Specialist with the Corps of Engineers Kansas City District, James Lowe, said in an email that effects from the demolition were evaluated and authorized.

"We did not identify any significant effects resulting from the demolition of the old bridge, and even though the bridge demolition clean-up has taken longer than normal, our analysis is still accurate," Lowe said.

In an environmental analysis for the project, published in 2021, MoDOT reported all project activities will comply with the Corps of Engineers and Missouri Department of Natural Resources permits and certifications.

It states water pollution would be controlled using things like slope drains, ditch checks and silt fences.

An earlier environmental analysis -- published in 2020 -- went in-depth about specific species in the area of the project. It stated the bridge area is not a critical habitat for pallid sturgeon, which are on the federally endangered species list.

Missouri Department of Conservation Policy Coordinator Jordan Meyer said the bridge demolition date was chosen around the sturgeon's spawning time so it wouldn't impact the habitat further.

"All of the measures and all of the ways they went about doing this project were to minimize impact to species entirely," Meyer said.

MoDOT environmental analysis reports also stated the entire bridge replacement project will impact 42.78 acres of wetlands, with more than 35 acres experiencing permanent impacts.

"Complete avoidance of impacts to wetlands would not be possible due to the nature of the project," the 2020 report states.

It stated MoDOT would initially attempt to avoid environmental impacts wherever possible. Then, impacts would try to be minimized through best management practices, and unavoidable impacts would be compensated through a process known as compensatory mitigation.

Mansour said impacts to the Katy Trail have been minimal throughout the process, as well.