DUBUQUE, Iowa (AP) — Commercial traffic along the Mississippi River will be blocked in Dubuque while workers make temporary repairs to cracks in part of a lock and dam. The Telegraph Herald reports that officials discovered the damage to Dubuque’s Lock and Dam No. 11 on Tuesday morning. Aaron Dunlop is the operations manager for the Mississippi River Project with the U.S. Army Corps of Engineers. He says a routine inspection uncovered cracks at a mitre gate connection point, which is a mechanism that controls the lock’s water level. He says the repairs will likely take a few days.

The closure comes less than two weeks after navigation on the river fully opened for the season. Corps figures say nearly 6,000 vessels passed through the lock and dam in 2016.