The 94-year-old Mississippi River bridge between southwest Wisconsin and Lansing, Iowa, that’s been temporarily closed twice during construction of a replacement will be permanently closed this fall. Iowa DOT engineer Clayton Burke said the new bridge is being built 25 feet from the Black Hawk Bridge.
“To keep everything safe, we’ve decided to demolish that first before we continue with construction of parts of the new bridge,” Burke said.
Construction on a replacement bridge just north of the old bridge began in 2023 and the old bridge was temporarily closed in February of last year and again this spring to analyze shifting caused by the construction. Burke said the bridge recently moved about an inch and half as temporary piling was being installed in the river. “We found through that analysis that the bridge was still safe in its current condition so we could keep it open, but continuing construction — for the safety of the public and for the safety of the workers driving that piling right next the bridge — there was no safe way to continue construction of the new bridge while the existing bridge was there,” Burke said.
Burke said the new bridge has to be built in that spot due to regulations in the National Historic Preservation Act and the National Environmental Policy Act. “I see a lot of questions on line about, well, ‘Who in their right mind would build a bridge so close to the existing bridge?’ We got stuck with having the minimum impact on the local cultural resources and the local environment and the National Wildlife Refuge that the bridge runs through,” Burke said. “It came down to either building it that close or closing the (old) bridge in the first place, demolishing it and then building it in the same location.”
Burke said state transportation officials in Iowa and Wisconsin went with the best option for building a new bridge while maintaining traffic on the old bridge. “An almost 100 year old structure that just has timber pile in sand and just unfortunately it reacted more than anybody thought it would,” Burke said, “and we’re stuck with the situation that we’re in.”
A demolition plan is being developed, but Burke says the first stage will involve taking off the bridge deck and removing some steel beams underneath, followed by demolishing the segment of the bridge from its center to the east side because that’s closest to where construction of the new bridge had to be halted. “They will put explosives on the bridge and implode it and drop it into the river and then take all that steel out of the river and dispose of it,” Burke said.
The date for the work hasn’t been announced. Burke indicated that during the navigation season for barges, the Coast Guard typically issues permits that allow no more than 72 hours for demolishing a bridge and fishing the debris out of the river. “In our case, it’s looking like we will close it this fall and then the implosion of the bridge will happen after the navigation has closed so we won’t have to worry about barge traffic,” Burke said.
While there’s no river crossing between Wisconsin and Lansing, Iowa, Burke said a water taxi is an option, but officials hope to find a car ferry. “It’s been quite a challenge to actually locate a vessel that we wouldn’t have to cut in pieces and transport across the country, which would take a while,” Burke said, “but we do have a couple of leads.”
The other challenge for the car ferry idea is ice that may form on the Mississippi in the winter, but Burke said construction crews working on the bridge may be able to break the ice and create a path for the car ferry.
