Upper Miss Lock And Dam 2 Dewatered For Maintenance

As part of its ongoing work to inspect and repair severallocks on the Upper Mississippi River, the St. Paul Engineer District dewatered Lock and Dam 2 at Hastings, Minn., on February 14 for inspection and repairs. With navigation at a pause, crews drained the lock chamber to inspect and repair the 90-year-old concrete walls.

Work on the $3.5 million maintenance and repair project began in December; it was the first dewatering for the lock chamber in 15 years.  The repairs will include replacing any concrete that requires it, as well as components of the lock’s operating system, including four valves dating to the 1940s.

Three other locks that closed December 4 will also be inspected and  repaired. Locks and Dams 2 and 4 will remain closed through March 5, while Locks and Dams 3 and 7 will stay closed through March 15. Lock and Dam 3, near Welch, Minn., and Lock and Dam 7, near La Crescent, Minn., will be closed for guidewall maintenance. These repairs include divers inspecting the foundations, or cribs, anchored into the riverbed upon which the guidewalls sit. The divers will then install forms around the cribbing and pump grout into them to help fill voids in foundations that were constructed in the 1930s.

Lock and Dam 4, near Alma, Wis., will also receive some updates. Maintenance is scheduled for the guidewall end cell, or circular structure at the end of the guidewall. Repairs include sheet pile and concrete placement.

Some 6 million tons of commodities passed through Lock and Dam 2 in 2023.