Repair an eroding highway embankment along the Crow River.
The study area is located in a rural setting in western Hennepin County, Minnesota, approximately 40 miles west of Minneapolis, Minnesota. The Crow River, a tributary to the Mississippi River, experienced erosion on a reach north of the city of Delano, Minnesota, where the natural course of the river follows a sharp turn adjacent to County Road 50.
Erosion at the outside bend of the channel and at the toe of the bank of the Crow River threatened the stability of County Road 50 at the top of the river bluff.
Erosion was as close as 10 feet from the edge of the road and posed a potential public safety hazard. Stabilization required a complete reconstruction of the slope within the project limits.
A feasibility study was completed and approved in May 2011. A project-partnership agreement was executed July 2011 between the U.S. Army Corps of Engineers and Hennepin County, who is the local sponsor for the project. The original construction contract was awarded February 2012, and construction was completed in 2013.
Following construction, sliding of topsoil started at both the upstream and downstream ends of the project at the tie-in locations. Due to the fiscal limits in place at the time, the Corps was unable to repair the damaged slope.
In March 2017, the Corps received approval from the Assistant Secretary of the Army (Civil Works) to apply a congressionally-enacted increase of the federal Section 14 project limit to $5 million. The local sponsor and the Corps signed an amendment to the cost-sharing agreement on September 29, 2017. The Corps awarded a design-build contract for fixing the embankment in early 2019. Construction is substantially complete. Dry conditions in 2021 have made it difficult for the Corps’ contractor to establish the 70% turf cover needed to satisfy the Minnesota Pollution Control Permit prior to closing out the contract, therefore contract completion has been extended to June 2022.
Emergency Streambank Erosion or Shoreline Protection authorized under Section 14 of the Flood Control Act of 1946.
The design and implementation phase of the project is cost shared at 65% federal and 35% non-federal up to the Section 14 federal funding limit. The estimated total cost of the project is $4.2 million, including the previous construction efforts.