The Decatur bridge carries Iowa 175 and Nebraska 51 traffic over the Missouri River between Onawa, Iowa and Decatur, Nebraska. It was closed June 27th after Missouri River flooding caused severe riverbank and bridge berm erosion along the east side of the bridge.
A contractor has constructed a U-shaped rock berm that begins north and ends south of the crossing. The purpose of the berm is to help prevent further erosion from occurring, which could result in loss of the roadway approach to the bridge and threaten the abutment. The rock berm is designed to stabilize the embankment and reduce the churning motion of the floodwaters next to the abutment, which contributes to the loss of soil.
An inspection of the abutment and embankment area will be performed by the Iowa DOT as soon as it can be done adequately and safely. Reopening of the bridge/road is dependent on a positive bill of health, meaning it is safe for travel. No timetable has been set to perform the work since the water level is too high and current too swift.