DES MOINES — Once squeezed between two tall embankments, Mill Creek inside of the Big Mill Creek Wildlife Management Area now has room to meander and expand — and more space to fish.
A collaboration between the Iowa Department of Natural Resources’ Bureaus of Fisheries and Wildlife, the restoration of 1,200 feet of Mill Creek and 12 acres of land was funded in part by the DNR’s State Land Grant. The grant was awarded by the DNR Water Quality Improvement Section with funds from the Environmental Protection Agency and Section 319 of the Clean Water Act, which provides grants for nonpoint source projects.
The renewed stretch of Mill Creek in Jackson County is frequented by anglers looking for trout and other fish. The segment is considered a priority trout stream and is the site of about 11,000 trout fishing trips each year, according to the DNR’s Bureau of Fisheries.
Nonpoint source coordinator Steve Hopkins was part of a team who awarded the grant to Iowa DNR fisheries biologist Dan Kirby in 2019. He said since the project has been completed, staff have been able to document a significant reduction in sediment going into the creek.
“This segment of Mill Creek is stunningly beautiful, but like many Iowa creeks, it was experiencing severe streambank erosion,” Hopkins said.
Before work began in late 2019, fishing access was impaired by steep banks. The water was harmed by excess nutrients leaking into the creek. Due to the straight and narrow channel, an increase in rainfall or a flood event would result in high stream power that would then cause accelerated erosion and bank slumping.
“A healthy stream will flood out of banks about two out of three years,” Kirby said. “If we have a floodplain that’s higher than the water level, the stream can’t flood out of its banks. When that happens, you put more and more water through a constricted stream channel and put more strain on the streambanks.”
The grant enabled Kirby and other DNR staff to reconnect the creek to the floodplain, planting prairie vegetation and sloping banks that were previously steep and vertical – all without negatively affecting the quality of the water. Those efforts have made the creek easier to access for fishermen.
Kirby used techniques included in Iowa’s River Restoration Toolbox to determine best practices for stream stabilization, including seeding and planting shrubs and other vegetation.
Three years after the project began, the restoration of the improved portion of Mill Creek was so effective it was cited as a success story by the Association of Clean Water Administrators during its celebration of 50 years of the Clean Water Act.
Silt fences have been removed and the stream is now able to flood over vegetation rather than be funneled through a small channel that could increase the risk of erosion.
“We identified a problem in an area that needed improvement for environmental reasons and allowed people to enjoy and use the creek more,” Kirby said.
The DNR plans to install an educational sign describing the project near the creek adjacent to a parking area in the next year.