Posted on October 11, 2022
A stone’s throw away from downtown St. Paul, Minnesota, along a Mississippi River backwater area lies a somewhat hidden area that is brimming with construction activity this summer.
Pigs Eye Lake, a 500-acre backwater lake created by the Mississippi River locks and dams, is ground zero for an environmental enhancement project that is innovating the way the Corps of Engineers manages dredged material, or river sand, removed from the 9-foot navigation channel, said Nate Campbell, St. Paul District project manager. “This is a win-win-win project for the U.S. Army Corps of Engineers; our partner, the Ramsey County Parks and Recreation; and the environment,” said Campbell. “This project allows the Corps to beneficially reuse its dredged material in a way that enhances the local environment.”
Aaron McFarlane, St. Paul District biologist for the project, said the Pigs Eye Lake plan includes building six islands to create bird and fish habitat while reducing erosion caused by waves. He said the material to construct the six islands is river sand that is coming from a few miles downstream of the project within an area of the river known as Pool 2. McFarlane said the project began in June and progress is already visible within the area. He said he anticipates the contractor completing the base for the islands this year, followed by the placement of fine materials in 2023 and vegetation planting in 2024.
As the islands rise above the water, birds can already be seen landing on the newly placed sand. LS Marine, from Inver Grove Heights, Minnesota, is the contractor in charge of implementing the years of planning efforts between the Corps of Engineers and its project partner. The contractor is creating the islands by hydraulically placing material at each island because this method requires less boat traffic and is more efficient than mechanically transporting it to the islands.
This is all a part of the plan, according to Campbell. He said the Corps and Ramsey County Parks and Recreation began studying this project in 2015. He added that the team has coordinated with other partners throughout the entire process to include working with the city of St. Paul, Ramsey County, Ramsey-Washington Metro Watershed District, Metropolitan Council, Minnesota Pollution Control Agency, Minnesota Department of Natural Resources, National Park Service, and the U.S. Fish and Wildlife Service. In addition to the partners, Campbell said the team has also coordinated with the Friends of the Mississippi River and Friends of Pool 2.
From concept to implementation, the vision for this project has been two-fold, said Campbell. “The focus has always been about improving the environment and seeking opportunities to beneficially reuse river sand,” he said. “This is an innovative solution to the Corps’ channel maintenance requirements in the fact that we are finding opportunities for the beneficial reuse of river sand rather than simply placing it at a location and walking away.”
Campbell said the innovation is helping save tax dollars, too. He said the project is saving money by not needing to purchase material to build the islands. Historically, a project like this would require a contract to provide material for the construction, which creates additional costs toward project completion. He said the cost savings for this project are considerable as the team estimates needing around 400,000 cubic yards of material to build the islands.
In addition to the project savings from reusing the river sand for environmental enhancement projects, Campbell said it also creates more immediate storage capacity for the placement sites along the river when dredging is required to maintain the navigation channel. He added that this project, also known as a Continuing Authorities Program Section 204 project, is the first of its kind within the St. Paul District. Section 204 projects are ecosystem restoration projects that make beneficial use of Corps’ dredged materials. Campbell added that the while the Pigs Eye Lake project is the first Section 204, there is another project nearing construction at Upper Lake Pepin near Red Wing, Minnesota.
Campbell said that while the Pigs Eye Lake project was developed under a new program, it builds on years ecosystem restoration projects the Corps has constructed through the Upper Mississippi River Restoration Program. “We are drawing on our 35-plus years of experience creating islands for successful habitat enhancement within the Upper Mississippi River to ensure the project’s success at Pigs Eye Lake.”