Flooding

County Road 9 bridge closed indefinitely, Blue Earth County discusses possible replacement project

A man looks down at a bridge
Gov. Tim Walz takes a look at the flooding and damage caused by the Blue Earth River onto the County Road 9 bridge on July 2.
Hannah Yang | MPR News

The County Road 9 bridge near Rapidan will stay closed indefinitely as county officials deemed it irreparable after last month’s flooding caused serious damage to the supports. 

Blue Earth County Commissioners met for a work session on Tuesday morning along with representatives from Minnesota Department of Transportation and the U.S. Army Corps of Engineers to receive updates on the County Road 9 bridge and the Rapidan Dam. 

Preliminary findings led county officials to believe that the County Road 9 bridge is “likely not repairable or not economically feasible to do repairs.” 

County Engineer and Public Works Director Ryan Thilges said in a phone interview that “very preliminary estimates” would be at least $15 million without including engineering and other project development costs. The impounded sediment securing the piers on top of the sandstone was flushed away by the deluge downstream, exposing them. 

The county is looking at the Federal Highway Administration emergency relief funding and state funds that are available to help fund the bridge replacement project. In the meantime, Thilges said it may be a while before drivers will have a shorter commute again and the current detour will stay in place. 

“The bridge is closed indefinitely,” he said. “It’s when you run into a situation like this and lose a bridge and don’t have plans in your program to replace it. Even if we were to get funding allocated, it could be two to three years before a new bridge is constructed. It’d be closer to three than two at least because of environmental requirements that we have to meet, project design, funding, and then getting a construction contract out the door … it’s a fairly cumbersome and lengthy process.”

Thilges said the county evaluated options such as making interim repairs to try and reopen the bridge, but based on the river scouring and the damages inflicted to the pilings on the piers and the river channel scouring continuing to erode the banks, the upkeep for repairs would be unfeasible. 

“Every time we have a significant amount of flow in the river it is not advisable that we reopen the bridge because of the instability and the concerns that the channel will continue to scour and could damage effectively if we were to make efforts to reopen the bridge every time it rains,” he said. “River flows pick back up, we’d almost have to close the road again … it would just be this vicious cycle of road closure, road opening so it really doesn’t make sense.”

Meanwhile, a century’s worth of sediment build-up behind the Rapidan Dam was unleashed downstream into the Blue Earth River, concerning water quality experts and researchers about the environmental impacts the pollution could have on the various ecosystems and wildlife. 

The Army Corps of Engineers discussed its ecosystem restoration program and possible dam removal and river restoration along with attempting to restore and protect the Blue Earth River in its current condition. The dam’s structure is still stable. 

The next Blue Earth County Board meeting is Aug. 13 at 9 a.m.