US Army Corps of Engineers
St. Paul District


Sandy Lake Dam Rehabilitation Project

Published Oct. 1, 2018
Updated: March 22, 2019

Sandy Lake Dam is a significant hazard dam located on the Sandy River in Aitkin County, Minnesota, 1.25 miles upstream of the junction between the Sandy River and Mississippi River.  The dam’s original purpose was to provide supplemental flow to the Mississippi River during periods of low river stages for navigation.  Construction of the locks and dams downstream of Minneapolis in the 1930s reduced the need for upstream storage for navigation, and since then Sandy Lake Dam’s purpose has shifted to flood control, recreation, fish and wildlife conservation, and water supply.  The dam is owned and operated by the U.S. Army Corps of Engineers in accordance with the 2003 Water Control Manual, Mississippi River Headwaters Project and the 2010 Mississippi River Headwaters Reservoir Operating Plan Evaluation Study.


Over its history, Sandy Lake Dam has undergone a series of modifications, repairs and periodic inspections. From 2011 to 2016, a series of above and below water inspections identified several features that had deteriorated to a point that repair or replacement were necessary to maintain the long-term stability of the structure.  These deficiencies were highlighted in the Corps’ 2016 inspection report and include:

  • Upstream Timber Apron and Cutoff – poor or unknown condition, needs replacement.
  • Lock Curtain Wall – poor condition, needs replacement or repair.
  • Concrete – areas of poor condition, needs repair.
  • Log Sluice Bay – stop logs in poor condition and difficult to operate, needs replacement.
  • Slide Gates – operable but nearing end of typical service life, need replacement.

The 2016 inspection report also recommended that a preliminary engineering report (i.e., design analysis report) be completed for the listed repairs/replacements to summarize the evaluation and development of the recommended rehabilitation plan and present preliminary design and cost estimates for proposed repairs/replacements.


The President’s Budget in fiscal year 2018 supported baseline operations and maintenance and all scheduled dam safety inspections.  Funding was used to complete the preliminary engineering report for the Sandy Lake Dam rehabilitation project, boundary surveying and rectification of fee and flowage easement lands and management of special status species at Mississippi River Headwaters reservoirs projects.

Drafting of plans and specifications for the Big Sandy Lake Dam rehabilitation construction project have begun.  The design of the repair is anticipated to be complete in fiscal year 2019.  Project will advertised for construction upon receipt of funds. 


Preliminary engineering report         $346,000

Plans and specifications                     $750,000

Construction                                     $7,500,000
(Requested in FY 2020 budget)