Lately, we’ve seen a national trend of dams being eliminated after they reach the end of their useful life. This is due to multiple factors including environmental concerns, costs of rehabilitation, permit restrictions, and public opinion. While many of these removals are justified not many dams are re-built. That’s why the state-owned Little Falls Dam project, located at the Willow River State Park near Hudson, Wisconsin in St. Croix County is so exciting.
The original high-hazard dam was constructed in 1892. While it had undergone numerous improvements throughout the years, it did not have adequate spillway capacity and there were safety concerns related to the structure. For these reasons, the dam was intentionally breached in the fall of 2015.
The Wisconsin Department of Natural Resources (WDNR) undertook a strategic alternatives analysis, which included public opinion solicited from local residents and public user groups. The park is one of the most highly attended in Wisconsin, and the reservoir created by the dam is an important draw to the park. After an extensive alternative analysis considering alternatives for removal, repair, and replacement, the DNR decided to replace Little Falls Dam.
After a Quality Based Selection process (QBS), Mead & Hunt was awarded the design along with construction administration. The design needed to pass the 1,000-year flow (Q1,000), provide a cold water draw for fish habitat, minimize the need for park personnel to operate the gates, control the release of the sediment downstream, and minimize the impact on the landscape.
Mead & Hunt completed the design of the 26-foot-high dam in the spring of 2016. The concrete dam consists of an overflow spillway, crest gate spillway, intake tower and non-overflow structures. The bids came in under the available budget, so the project moved forward. The dam is scheduled to be completed this winter while the reservoir is scheduled to be refilled in the spring of 2020. You can view the live construction of this project here.
This is a unique and rewarding project to be a part of and the entire construction team is anxiously awaiting its completion. The new dam will provide a lake for swimming, canoeing, kayaking, and fishing in the scenic Willow River State Park for future generations to enjoy.
