Minnesota is one big step closer to completing a massive clean-up effort of the St. Louis River estuary near Duluth.
In October the Minnesota Department of Natural Resources finished a three-year, $18 million project restoring 230 acres of coastal wetland habitat at Kingsbury Bay and Grassy Point, where the St. Louis River widens before it reaches Lake Superior.
It was one of the agency’s largest-ever habitat restoration projects. It required the removal of about 130,000 cubic yards of wood waste covering the river bottom near Grassy Point — up to 16 feet thick in places — that was dumped decades ago by two timber mills built on stilts over the water.
A mile and a half upstream, about 140,000 cubic yards of sediment that were deposited in Kingsbury Bay by erosion and a massive flood in 2012 were also removed, to improve habitat and improve access for boaters and anglers.
Altogether, enough debris was pulled out of the river to cover a football field 140 feet deep, said Melissa Sjolund, the DNR’s St. Louis River and Lake Superior program supervisor.
"Just thinking about that massive volume of sediment and wood that we dredged out of the river, you can see why it took us three years to do this, and why we are so excited that they are complete," Sjolund said.
Some of the recovered old lumber dredged out of the water was used to create small, new islands near Grassy Point, to provide shoreline habitat for birds and wildlife, and to help shelter the bay from wind and waves to foster fish habitat and to create places for aquatic plants to colonize.
The sediment removed from Kingsbury Bay was used to cap the new islands, which were seeded with native grasses and flowering plants. It was also used to cover the river bottom where the wood waste was removed, to reestablish communities of tiny plants and microorganisms that form the base of the food chain, but had been starved to death by the thick layer of wood.
Next spring, the Minnesota Land Trust will lead an effort to plant native trees, flowers and shrubs on the new islands.
All of this work is part of a long-term effort to restore habitat and clean up legacy pollution left behind from more than a century’s worth of industrial development along the St. Louis River.
A total of 17 sites were identified in the St. Louis River Area of Concern in need of habitat restoration. A partnership of federal, state and tribal agencies has completed nine of the projects. Sjolund said the goal is to complete the work by 2025.
“We hope the restored habitats will not only benefit estuary fish and wildlife populations, but also help connect the community to this beautiful and unique resource,” Sjolund said.
Your support matters.
You make MPR News possible. Individual donations are behind the clarity in coverage from our reporters across the state, stories that connect us, and conversations that provide perspectives. Help ensure MPR remains a resource that brings Minnesotans together.