Construction crews in Champlin have started removing a historic 79-year-old dam near the Mill Pond that was originally built to power a flour mill.
Built in 1936, the Elm Creek Dam needed repairs and had outlived its effectiveness, said Todd Tuominen, assistant city engineer and project manager.
The opening in the dam, or spillway, was too small to let enough water flow through during downpours, said Jason Boyle, dam safety engineer for the state Department of Natural Resources. The new dam, expected to be completed by May 2016, will have a large spillway and other waterways to control heavy rains and severe flooding.
Design plans show that, with the new structure, flood plains adjacent to the Mill Pond could be reduced by as much as 60 acres, saving residents a total of about $100,000 in flood insurance.
Improving safety was also part of the $5.65 million project.
Every spring, city crews have had to manually adjust wooden boards used for water flow near the top of the dam. It has been dangerous work, Tuominen said.
The new design now has automatic adjustments, among other advancements.
The design includes a stair-step design spillway and other characteristics of the 1930s. Many of the details were intended to recall the historic status of the original Elm Creek Dam.
Residents will also see a face-lift of the area used for recreational activities.
Tuominen said the Elm Creek Dam is a popular fishing area, but there is currently no place to walk. Erosion was so bad that officials had to close the trail near the dam two years ago.
There will be areas for people to fish, walkways around the dam, a live roof and viewing platforms. The dam will also be compliant with the Americans with Disabilities Act.
The Elm Creek Dam is just one of about 100 Minnesota dams built in the same era that need improvements, Boyle said. There are about 1,000 dams in the state, he added.
Currently, the Mill Pond is empty to treat weeds and address other issues as crews work on the dam.
The project is part of an overall goal to bring the pond back to its prime.
The Mill Pond has been the city’s focal point for many years. It has also been one of the top environmental concerns in the city, recent community surveys have shown. The pond, located behind the Elm Creek Dam and surrounded by a park, has been drained several times to help manage a weed explosion increased by sediment-laden soil that has eroded into the creek upstream.
Feedback from residents about the project has been positive, Tuominen said.
“They know it’s a necessary improvement,” he said.