In 1902 a man-made reservoir was created in the Redwood River on a spot in Redwood Falls.
Known as Lake Redwood, the 67-acre reservoir has existed for more than a century.
While the idea of a lake serves various purposes, such as recreation and a place for wildlife and fish, Lake Redwood has also served another role – sediment collection.
Over the years hundreds of thousands of cubic yards of sediment has been deposited into that reservoir, and now the effort to remove that sediment, known as a reclamation, is scheduled to take place.
Kerry Netzke, executive director of the Redwood-Cottonwood Rivers Control Area (RCRCA), talked about the project at a recent landowner meeting held in Redwood Falls.
In its early years, Lake Redwood was a major recreation area, as well as a source of electricity at the dam which was built as part of the lake. The recreation opportunities have all but disappeared, with the exception of winter snowmobiling and the annual Celebrate Redwood Falls winter event, and the hydroelectric capacity has been limited due to the increased amount of sediment in the lake.
Yes, said Netzke, sediment is still being deposited in Lake Redwood, but it is coming in at a dramatically reduced rate (from 1.5 feet per year to .13 feet per year) due to management practices that are keeping more of the soil on the land.
Today the lake’s average depth is 2.8 feet, and the goal of the reclamation would be to remove up to 650,000 cubic yards of that sediment that would result in a maximum depth of 20 feet.
It was in the 1960s when the sediment levels began to become more of a concern, and in the 1990s a more concerted effort was established, based on a diagnostic study, that ultimately led to the allocation in 2019 of state bonding funds in the amount of $7.3 million.
Approval of the funding for the project set the process of dredging the lake into motion through the RCRCA. The process involves laying down a pipeline from the lake to a location northwest of Redwood Falls, and through that pipe the sediment will travel, along with water, via the use of a dredging machine and a series of pumps.
The pipe will run north along a portion of Laser Avenue, then west along Minnesota Highway 19 to Redwood CSAH 17 and north again where a 135-acre dewatering pond will be established.
The timeline includes securing the land for the pond in 2019, obtaining permits and putting the project out for bids in 2020, with dredging set to start in 2021 with completion of the reclamation in 2022.
- Photo by Ben Stoterau