Hall’s Island Reconstruction
Location: 900 Sibley Street NE, Minneapolis, Minnesota
Nominated by: Barr Engineering Co.
It’s not often that an island is built in the Mississippi River, but that is what the Minneapolis Park and Recreation Board (MPRB) did when they reconstructed Hall’s Island. The island was originally a natural feature in the Mississippi River and was the site of a bathhouse in the 1900s. In the 1960s the island was dredged and deposited on the mainland and then the channel was filled to expand the adjacent shoreline property of a lumber yard. This expansion resulted in a drastic change in the placement of demolition debris and contaminated fill along the shore. After purchasing the property in 2010, the MPRB had the vision to complete this incredible feat of engineering. The reconstruction of Hall’s Island enhances the ecological health of the river and provides a respite for community members to enjoy wildlife viewing while providing access to the river in the heart of the city.
The remediation of this area was incredibly difficult because it had to be done on a flowing river, which meant that a host of considerations had to be made about managing possible pollution and erosion into the river as well as collaboration between a variety of agencies and partners. The project started with the excavation of several hotspots contaminated by PAHs and lead. The island excavation and construction began during the winter months in 2017 and resulted in the disposal of 55,000 cubic yards of contaminated soil and the reuse of 10,000 cubic yards of clean soil and rip rap. Cover soil was then placed over contaminated soils both on the island and in the waters surrounding it. The cover soil placed under water had to be a very specific type to restore the natural habitat and support endangered mussels.
The completion of this intensely complicated project resulted in the restoration of both the channel and island and is more than just additional greenspace for an urban area. The careful planning and restoration created a variety of wildlife habitats for birds, turtles, aquatic life, and endangered mussels. The meticulous construction also helps prevent future erosion and preserve natural habitats long term. The cleanup of contaminated soils along the shoreline will also reduce the potential for leaching of contaminants into groundwater and the river, improving water quality.
The island and adjacent beach also provide a unique opportunity to urban residents in offering public access to the river where it is usually limited. Park users can now sit by the river on the beach, wade in the water, launch a canoe, or simply enjoy close-up interaction and viewing of a variety of wildlife. The transformation of that stretch of river also offers a more aesthetic view to an urban center and provides a very visible example of what can be accomplished with the remediation of contaminated and drastically altered land.
- $3,367,000 – Metropolitan Council
- $1,500,000 – Mississippi Watershed Management Organization
- $560,000 – Minneapolis Park and Recreation Board
- Minneapolis Park and Recreation Board
- Mississippi Watershed Management Organization
- Minneapolis Parks Foundation
- Minnesota State Legislature
- City of Minneapolis
- Minnesota Department of Natural Resources
- Minnesota Pollution Control Agency
- U.S. Army Corps of Engineers
- National Park Service
- Tom Leader Studio
- Barr Engineering Co.
- Veit & Company