Grindstone River

Hinckley dam

Grindstone River dam project March 2020 update

The dam on the Grindstone River at Hinckley in 2008.Mandatory public meetings postponed

Since the last public meeting conducted in Hinckley in December 2018, progress has been made towards future removal of the Grindstone River dam in Hinckley. 

DNR staff spent considerable time during the summer of 2019 further exploring alternatives to removal, specifically the rock arch rapids option that would allow for retention of the current reservoir pool, and is also the project alternative preferred by the City of Hinckley. These efforts included meetings with a downstream landowner and multiple site visits by engineering staff. 

As suspected earlier in the project, constructing a rock arch rapids at this location contains many elements that complicate its feasibility – including the need to construct large containment berms and obtain easements from adjacent landowners, the existence of drainages in the location of the necessary berms, increased project costs, construction/maintenance access issues, FEMA floodplain concerns, and significantly reduced ecological benefit to the river system (as compared to dam removal). These concerns were shared with DNR leadership in late summer, and they reaffirmed their support to move forward with the dam removal alternative.

Since removal of the dam will result in the elimination of the Grindstone Reservoir, a DNR public water basin, Minnesota Environmental Review Rules state that preparation of an Environmental Impact Statement (EIS) is mandatory. The need for an EIS was not anticipated because artificial impoundments are not always designated as public water basins, and an EIS has not been required on previous dam removals conducted by the DNR.

There are several steps to the EIS process, including public engagement. It is anticipated that the EIS will add at least one year to the planning process. DNR staff have been working on the first stage of the EIS process in recent months.

Public meetings are a mandatory part of this process. The first was planned for mid-April to discuss the proposed project, the EIS process and public engagement in the EIS development. Since the DNR is not able to conduct this required public meeting as planned, the EIS process specific to the Grindstone Dam project is on hold.

The EIS is intended to fully describe known negative impacts of a proposed activity and identify ways to avoid or minimize these impacts. This will ultimately improve outcomes for the project and better prepare the DNR for permitting and construction.

While the environmental review process takes place, DNR staff will be working on other aspects of the project that will allow us to move forward as quickly as possible once the EIS process is completed. Please continue to check our office webpage for updates, call our office at 320-384-7721 or send an email to [email protected]. We will also use our website and local newspapers to communicate information about the next public meeting once rescheduled.