The Whetstone River is a tributary of the Minnesota River, approximately 35 miles long, beginning in the Coteau des Prairies region in South Dakota. Historically the Whetstone River flowed into the Minnesota River just south of Ortonville. The river was diverted into Big Stone Lake in the 1930’s to increase Big Stone Lake levels during times of drought. The Whetstone River currently flows into Big Stone Lake, just upstream from the Big Stone Lake Dam.
In recent years, high flows have caused flooding in Big Stone Lake, with the Whetstone River contributing a substantive amount of water. The Upper Minnesota River Watershed District (UMRWD) plans to restore ecological services by reestablishing continual flow to an estimated 9,000 feet of open channel known as the Whetstone River Restoration Project. 
The UMRWD’s proposed Whetstone River Restoration Project is located in the abandoned historic Whetstone River channel south of Ortonville. This historic channel was abandoned after the1930’s diversion and currently only has flows from adjacent land.
The Whetstone River Restoration will hydrologically and ecologically reconnect a portion of the Whetstone River to the Minnesota River.
By default, this will improve conditions within Big Stone Lake reducing nutrient loads, improving water quality and reducing flooding.
In addition, the project will restore floodplain wetlands for additional flood storage, duck and wildlife habitat, as well as restore a wildlife corridor allowing fish passage upstream.
2024 Funding Update – Pending 2025 legislative action, the project will have secured all funding necessary for construction in MN and SD.
2025 Update– The UMRWD is currently working on obtaining project approvals from the USACE and various state agencies in Minnesota and South Dakota. Preliminary design plans were submitted to the USACE in late 2022 to continue working through their individual permitting process.
An EA-EAW was completed in early 2023.
As part of the permitting process, analysis was recently submitted on the potential impacts of the project (at the request of the USACE).
Questions can be directed to our Executive Director, Amber Doschadis at 320-839-3411 or [email protected]