As the design of the city's wetland along Firesteel Creek is nearly complete, the project is starting to take shape for construction to begin this winter or early spring 2022.
During Monday’s special Mitchell City Council meeting, Public Works Director Joe Schroeder unveiled the wetland design that’s about 95% done, which will cover roughly 30 acres of land along Firesteel Creek, about 2 miles west of Lake Mitchell.
The roughly $29,000 design of the wetland that Ducks Unlimited has been working on for the past year will aim to reduce the phosphorus and sediment flowing into the lake.
“This design does not include a weir structure, or dam,” Schroeder said, noting the plan entails excavating dirt to create the wetland, located on the creek north of the former Kelley house that the city has listed on the market.
Initially, the construction of a dam in the wetland area was discussed when the city purchased the 371 acres in 2019. Instead, crews will excavate dirt in four adjacent areas surrounding Firesteel Creek to form the wetland. According to Schroeder, the cattails that will be planted in the wetland will capture the phosphorus and sediment in such a way that eliminates the need for a dam to be constructed.
“So it comes through and allows the sediment to basically slow down and settle into those cattails. The cattails will then eat the phosphorus out of the material, so it should work very well, especially with the large area we have where the cattails will be,” he said.
As for the timeline of the project, Schroeder said the goal is to open bids in the fall for construction work to begin either in the winter or early spring 2022.
City Administrator Stephanie Ellwein said the design phase and entire scope of the wetland project, including the construction work, is being funded in full by nonpoint source grants through the State Revolving Fund (SRF) communities that’s available for communities taking on projects to improve wastewater, stormwater and drinking water projects.
For the wetland project, the city has secured roughly $1.1 million in nonpoint source grants.
“Everyone keeps thinking we are going to be spending more and more money on the wetland, but the project is funded entirely through grants. The only money the city has into this wetland project is the purchase of the Kelley property,” Ellwein said.
Working upstream the Firesteel watershed
Since the city’s wetland project began taking shape two years ago, Mitchell Mayor Bob Everson said it's led to a growing number of agriculture producers with land stretching through the Firesteel Creek watershed who are making efforts to minimize grazing, along with practicing other sustainable farming methods.
With the partnership the city has formed with Ducks Unlimited and Steve Donovan, a biologist and former manager of conservation programs with Ducks Unlimited, it paved the way to begin improving the Firesteel watershed more aggressively by working with landowners and farmers upstream to help restore Lake Mitchell.
Firesteel Creek has a watershed that encompasses 350,000 acres, which collects around 900 parts per billion of phosphorus each year, contributing to the algae growth in the lake where the the creek flows into. The watershed stretches north from Lake Mitchell through Aurora County and into Wessington Springs in Jerauld County. Previous studies on the lake found that roughly 53 percent of the phosphorus and sediment entering the lake is coming in from Firesteel Creek, while 47 percent of it is in the lake itself.
The city’s mission of working with landowners to reduce creek runoff throughout the Firesteel watershed received a big boost from the $1.1 million North American Wetlands Conservation Act (NAWCA) grant. During Monday’s council meeting, Donovan explained how the NAWCA grant will be utilized to help minimize grazing, restore wetlands and replace marginal cropland by planting grasses aimed at improving the watershed.
“We have grant dollars for about 1,000 acres of grassland seeding. The idea here is to take dollars and spend them on private land that is marginal cropland, and the landowner has decided he’s really not making money on farming these poor soils that are contributing to water quality problems and wants to plant it back to grass,” said Donovan, who was selected to administer the city’s NAWCA grant funds. “We have about $63,000 for livestock water, and we have about $83,000 for fencing. We’ve got $185,00 earmarked for land leases, which is more of an incentive for a landowner who wants to put marginal cropland back to grass.”
For Council President Kevin McCardle, seeing the progress the city's had with landowners upstream marks a milestone achievement for the lake restoration efforts.
“You have to clean the water coming into the lake before you start cleaning the lake itself,” McCardle said.
Donovan said there have already been some landowners with land along the Firesteel watershed looking to participate, with one mulling ways to build a wetland in the Mitchell area.
While working with agriculture producers who farm within the Firesteel watershed is a priority for the city to address Lake Mitchell’s algae woes that have been plaguing the body of water for decades, Donovan said it’s just as important to work with landowners who farm subwatersheds, or adjacent watersheds to Firesteel’s.
“As a biologist, I would say that this is a huge watershed, and the phosphorus that’s driving the algae problem is coming from every corner of the watershed. So we need to do projects throughout the watershed,” Donovan said. “We have some opportunities to do some of those projects, and those will have a big impact on the water quality in the lake as well, perhaps even bigger. We could put 40 to 50 acre wetlands in some of those sub watersheds up there.”