The Lockport Lock and Dam is undergoing repairs for several weeks beginning on Tuesday.

The U.S. Army Corps of Engineers will conduct “critical repairs” with the primary objective to replace pieces on the downstream gates, according to a news release from the USACE.

These assemblies function as the primary hinges for the 60-foot gates – the tallest on the Illinois Waterway – and have been without major repair since opening in 1986, according to the release.

The replacement is seen as critical “as the gates must withstand the immense structural forces” generated by Lockport’s 39-foot maximum lift, the USACE said in the release.

The need for this repair was identified in 2025 during the installation of new upstream gates.

During that project, inspection teams discovered cracks in the pintle sockets in the downstream gates, according to the release.

The work is scheduled to last through May 19.