When traffic was diverted for safety reasons across the Montello Dam embankment during a storm, the weight of the traffic showed that the embankment condition was poor. This sparked engineering studies that confirmed the embankment needed improvements for stability. We reconstructed the embankment and spillway to increase stability and reduce the risk of failure. In the process, we used a vibrating beam slurry wall for the first time on a Wisconsin dam. Using this technology saved approximately $2 million in overall project costs.
Our design replaced the earthen dike and flattened the slopes. We also replaced the overflow and gated spillways using granite stone facings to maintain the historical look and significance. We collaborated with Wisconsin Department of Natural Resources (DNR) to reduce impacts to surrounding wetlands. With the DNR, we also improved the recreational facilities. The community gained new fishing piers, a rebuilt boat launch, and parking lots. We incorporated a four-step fish ladder into the design to pass migratory fish through the dam.