St Louis River Estuary: The stories and the science

A dredge in the harbor with a freeway on shore nearby

21st Avenue West Restoration Site

Where have all the wetlands gone? Decades of dredging and filling displaced the shallow, sheltered aquatic habitats once common in this area. With well-designed placement of clean sediment dredged from the shipping channels, natural resource managers expect wetland vegetation will return to this site off of 21st Avenue West, and with it, the bugs, fish and birds that live there.

At the base of the Blatnik Bridge, the 21st Ave West restoration site is a complex of open water flats and shallow sheltered bays impaired by historical industrial activities. The 350-acre bay receives treated wastewater discharges from the Western Lake Superior Sanitary District (WLSSD) wastewater treatment plant and stormwater runoff from the City of Duluth. The adjacent land is occupied by the Canadian National Ore Docks, numerous industries, and Rice's Point, a popular public boat access.

What is happening now?

After construction restores depth diversity in this bay in 2018, plants and insects will begin their natural recovery.  With time, they will again support productive spawning, nursery and foraging areas for both prey fish (like minnows) and game fish (like walleye, muskellunge, lake sturgeon, smallmouth bass, bluegill and black crappie). Periodic sampling of the underwater vegetation and insects will assess the rate of recovery.

This project is one of the designated habitat restoration actions completed as part of the Remedial Action Plan for the St Louis River Area of Concern, funded through the Great Lakes Restoration Initiative.

Unique site characteristics

  • Two creeks, Miller and Coffee, discharge to the project area at the northernmost point of the site. Both creeks receive runoff from highly urbanized watersheds, with the headwaters of Miller Creek draining Duluth's largest commercial shopping area. The streams contribute large amounts of sediment to this small bay, and the City of Duluth dredges the sediment on a regular basis to protect culverts under the I-35 freeway. Learn more about how Duluth residents can prevent stormwater pollution here.
  • The 21st Avenue West Restoration Site is the location of the WLSSD outfall, where an average of 43 million gallons per day of treated wastewater enters the bay. Restoration project planners have ensured that constructed habitat features (shoals, islands) don't interfere with the flow of this outfall.
  • Interstate Island is a Wildlife Management Area created from dredged materials years ago and is maintained to be free of woody vegetation to provide nesting habitat for the common tern, a threatened species in Minnesota and endangered species in Wisconsin, albeit with significant competition from ring-billed gulls. In 2015, the island received clean sand to enhance lost nesting area for threatened bird species. This is part of an additional Minnesota Department of Natural Resources wildlife restoration project.

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