Posted on December 4, 2017
By Shannon Rousseau, KTTC
If you’ve driven by Lake Zumbro recently, you have probably noticed something a little off.
The water level is six feet below normal, but it’s an intentional move by Olmsted County. They’re doing this to see which parts of the river need to be dredged, as sediment has been building up for years.
“This is the first big project of any sort in lake restoration,” said Terry Lee, the Olmsted County Water Resources Manager. Sediment and mud have been settling in the lake since 1919. “It’s mostly on the upper end and making it’s way down.”
This won’t be the first dredging project on the Zumbro. According to Lee, there has been some spot dredging in the past. One at a marina near Fisherman’s Inn and another upstream near Sandy Point. Since 1919, those have been the only two dredging projects on the lake.
However, all of the sediment won’t be taken out. Crews will take out enough to make the entire lake recreational again. They cannot remove all of it because there is too much. And don’t expect the $7 million dredging project to happen until early 2019, according to John Helmers, the head of environmental resources for Olmsted County.
Olmsted County workers surveyed the lake on Monday using a drone. They hired an outside drone company from Savage to help collect images from above the lake.
“We’ll be looking at around a thousand photos. We’ll use all of them, stitch it together, and make a huge mosaic 3D map of the whole lake,” said Joe Elling, a drone pilot with Maverick Drone Systems.
The process to create a giant map made up of 1,000 images of the lake will only take minutes, since a computer will be putting it together for them. The end result will show county workers what parts of the lake need to be dredged.
Half of the $7 million will come from the state legislature. The other half will come from Olmsted County, Wabasha County, Rochester Public Utilities, a citizen group called “Lake Zumbro Forever,” and the Lake Improvement District, which is made up of lake homeowners. “The special [Lake Improvement] district is formed between Wabasha and Olmsted County. It allows us as taxpayers to tax ourselves to do the project,” said Lee, a member of the district.
“It’s one of the only boating lakes that we have in this region. It gets a higher per acre usage than any other lake in the state outside of the metro area. So it’s a very important recreational water body.”
Rochester Public Utilities is already in the process of raising the water level in Lake Zumbro. They will raise half a foot a day, hopefully getting the lake level back to where it needs to be sometime next week.
Source: KTTC
