When the Cottage Grove City Council unanimously passed the environmental impact study (EIS) for the Nelson Backwater Mine Project, a proposed riverbed mine off Lower Grey Cloud Island, Cottage Grove Mayor Myron Bailey was defensive about the “narrow” role of the city’s vote that night.
The city’s role, according to Bailey, was not to approve the project overall, but to determine the adequacy of the EIS by “gather[ing] the potential impacts of this proposed project to inform permitting decisions made by other agencies and we did just that.”
Bailey emphasized the years of work that had gone into the project: “The city has spent the past three years working with specialists and experts in their field including hydrologists, archaeologists, ecologists, noise specialists, geologists and engineers just to name a few. We now have a 1,000-page document that is comprised of over 100 of your comments and concerns that will be a reference for agencies such as the DNR, Army Corps of Engineers and the tribal nations to inform their decisions of permitting around the proposed project.”
Barely a month after approving that EIS, Dakota County and the Metropolitan Council filed an appeal with the Minnesota Court of Appeals seeking additional analysis for the study, citing “cumulative and long-term effects on Dakota County’s Spring Lake Park Reserve specifically and on the Regional Parks and Trails System more broadly. The City should have required the submission of additional studies, modeling, and monitoring before forwarding the Project on for federal and state permitting,” according to the Dec. 16 case filing.
While Dakota County does not comment on pending litigation, it provided the following statement to the Hastings Journal regarding the suit:
“Dakota County has invested significant public resources in the development, protection, and restoration of the Mississippi River corridor at Spring Lake Park Reserve adjacent to the proposed Nelson Mine Backwater Project. That project will impact a generation's use of Spring Lake Park Reserve, including its scenic views, recreation, natural environment, wildlife, water quality and cultural resources.
“The county, along with the Metropolitan Council, noted these cumulative and long-term effects on Spring Lake Park Reserve specifically and on the Regional Parks and Trails System more broadly in comments submitted to the city. The city should have required the submission of additional studies, modeling, and monitoring before forwarding the project on for federal and state permitting.
“Instead, the final environmental impact statement deferred key issues to future permitting, left substantive concerns unaddressed, and provided incomplete analysis on matters central to the city's statutory obligation to assess the project. Because the final environmental impact statement did not incorporate the necessary responses or additional analysis required at this stage, the city should have determined that the final environmental impact statement was inadequate.”
The case was filed Dec. 16.

The project
The proposed mine, which is owned by Amrize Midwest Inc. (formerly Holcim – MWR, Inc. and formerly Aggregate Industries), in an expansion of the existing sand and gravel mine that mines underwater river sediment using a floating twin clamshell dredge. Dredged sediment is then moved on a floating conveyor and sent to plants for processing. The current mine located at Lower Grey Cloud Island was built in the 1950s and is expected to exhaust the supply of minable material at that site within the next 4-5 years.
The expansion would be on 395 acres of privately owned land less than half a mile north of Spring Lake Park. According to a Dec. 19, 2024 presentation from Tom Schmit, US Holcim Aggregates Manager, the mine would carve a pit 200 feet deep as the company mines sand and gravel alluvium deposited above the bedrock within the back waters of the Mississippi.

Impacts
At the Nov. 5 Cottage Grove City Council meeting, several residents spoke to issues of the process and the dire environmental impacts of the proposed mine.
Among them was Whitney Clark, executive director for Friends of the Mississippi River, who challenged the legality of the city’s EIC process overall.
"The proposed project is not legal," Clark said. "City and state regulations ban mining in shoreline areas within the Mississippi River Corridor Critical Area. The city claims those rules somehow don't apply to the Nelson Mine, but they do. The city's own shoreline mining ban very clearly applies to expansions of existing mines such as this one. The language in the city's ordinance is clear."
Clark stated the city argued that mining privileges were grandfathered in, before telling them it would be "illegal" to approve an environmental impact statement with "factual inaccuracies.” Mining began on Lower Grey Cloud in the 1950s, prior to Cottage Grove’s incorporation as a city.
"It is illegal to approve an EIS with such factual inaccuracies," Clark told the city, calling on the city to halt the EIS process until deficiencies were addressed.
"Cottage Grove's insistence on pressing forward, regardless of the facts, could result in legal challenges that will cost the city and its residents for years to come," Clark said. "I urge you to halt this EIS approval process until the document accurately reflects the damage this project will cause and the legal issues associated with it.”
It was a sentiment echoed by both residents and Dakota County at that time. In an October letter to the City of Cottage Grove, Dakota County Manager Heidi Welsch called the EIS “procedurally and substantively inadequate,” because “further study, mitigation, and avoidance recommendations by Dakota County have not been addressed—or even further investigated—by the city of Cottage Grove (as the Responsible Governmental Unit) or applicant Amrize Midwest Inc.”
These same sentiments appear in the case filing: “While the FEIS acknowledges potential visual, noise, and access impacts to Spring Lake Park Reserve—and emphasizes the need for ongoing coordination with Washington County for the future Grey Cloud Island Regional Park […] the FEIS failed to include viewshed and noise quantification, park-compatibility objectives, and recreational-use displacement modeling.”
Other environmental concerns include the project’s effect on a number of species including Northern Long Eared Bats, Rusty Patch Bumble Bees, Bald Eagles, Loggerhead Shrikes, and the Henslow's Sparrow, as well as a number of species of mussel including Higgin's Eye, Pistolgrip, and Wartyback, among others. The Higgin’s Eye is listed as endangered under the Endangered Species Act.
Among the environmental concerns is an aesthetic one: floating dredges as tall as 65 feet from the proposed project could be seen from Spring Lake Park Reserve’s bluffs.
This visual impact was specifically noted alongside environmental and noise impacts by Walsch: “It is no exaggeration that millions of visitors over the course of the proposed 25-year project will now be looking at a view that frames an active mining operation. We do not think the magnitude of this impact can be overstated.”
Barring action from the court that would require additional environmental study and review, the project is currently out for state and federal review but will return before the Cottage Grove City Council for final permit review.