In 2013, the Minnesota Department of Natural Resources prioritized 12 sites in and around the St. Louis River for habitat restoration. The agency combined the Grassy Point and Kingsbury Bay sites into a single project to restore 240 acres of fish and wildlife habitat. As the DNR’s engineering consultant for the project, Barr began working with stakeholders in 2017 to design a project that included dredging, island building, and thin-layer sediment covers to restore habitats. Material reuse within and between project areas was critical in making best use of restoration funds.
More than 100,000 cubic yards of sawmill waste lying at the bottom of Grassy Point was used to expand an island and create a shallow, sheltered bay. Another 100,000 cubic yards of organic-rich sediment from Kingsbury Bay was dredged to create deeper-water habitat and placed at Grassy Point to provide a fertile benthic environment.
Barr’s team performed an environmental investigation and used dredge-elutriate testing to confirm that removing and reusing the wood waste wouldn’t contaminate the site. We then performed hydrodynamic modeling to evaluate the restoration’s effect on the river’s behavior and hydraulic and hydrologic modeling to address potential erosion issues. We also conducted a geotechnical investigation and modeling to design a stable wood-waste island. During the final phase of work, completed in fall 2021, Barr provided construction administration, engineering, and quality control.
Vice President Senior Environmental Consultant
Water Resources Engineer
Senior Geotechnical Engineer