Village’s landmark dam passes inspection

The Village of Grafton’s Bridge Street Dam received a clean bill of health in a recent inspection.

The dam, which was built in 1918, has required several costly repairs in the last decade but the most recent inspection does not call for any major renovations.

“The inspection went well,” Public Works Director Amber Thomas said.

A review of the dam was completed on June 16, 2021 by Beecher-Hoppe Associates, using for the first time drones to take pictures of the dam’s surface. The inspection report was then submitted to the Wisconsin Department of Natural Resources, which responded with a letter on Dec. 20, 2021.

In the letter, the DNR gave the dam a rating of “Fair” because it meets requirements but some concrete deterioration was found during the inspection.

While in compliance, the DNR will require the village to update its inspection, maintenance and emergency action plans by September.

Thomas said the plans were last updated in 2018 and that village staff should be able to easily update the plans before the DNR deadline.

The DNR also recommended that the village install a safety cable across the river to warn boaters of the dam — a project that may improve the dam rating.

Other recommendations include that the village continue to monitor the concrete deterioration of the dam’s support piers and perform a concrete evaluation of the spillway in the next several years.

No action was taken on the recommendation but Thomas said it may be considered at future meetings.

The dam has cost the village hundred of thousands of dollars since a binding referendum in 2010 ensured the dam would be saved at least until 2019. With costs for repairing the dam reaching into the millions, village trustees discussed the prospect of razing the structure years ago before a campaign was organized to preserve it.

 In June 2013 the village borrowed $1.2 million to cover dam improvements that repaired both abutments, widened the spillway, installed a hydraulic gate, raised the grade of the river walk and rebuilt the overlook area. The DNR covered $354,000 of the cost through a state grant.

A $7,000 repair was also made on an overhanging buttress in fall 2018.

The village will need to contract an engineer to complete another inspection of the dam in 2024 and the DNR will complete its own inspection of the structure in 2027.