Mississippi River Locks and Dams 2–10 Miter Gates Replacement

U.S. Army Corps of Engineers, St. Paul District
Published Sept. 25, 2017
Updated: March 29, 2022

Locks and Dams (LD) 2 through 10 have used the same miter gates since their construction in the 1930s. Over time, the gates have been damaged and distressed, which has led to serviceability and safety issues. This project will replace the gates and the anchorages system, increasing navigational longevity and operational readiness while decreasing repair costs and downtime due to maintenance or failure.


Upper Mississippi Locks and Dams 2 through 10.


In order to allow watercraft to pass through stretches of river of various depths, Congress authorized a series of locks and dams along the Mississippi River. An integral part of those locks are miter gates.

Miter gates are comprised of two leaves that provide a closure at one end of a lock at a “miter” or angle. Each lock has a set upstream and downstream. In addition to other systems, these gates allow water levels within the lock to go up and down.


Two U.S. Army Corps of Engineers’ districts — St. Paul and Rock Island — have been collaboratively working on the design of new miter gates for the Upper Mississippi.

The Lock and Dam 2 miter gates were awarded in fiscal year 2015, and fabrication was completed in 2017. New anchorages have been designed and awarded in 2019. The St. Paul District installed the new Lock and Dam 2 anchorages and gates in 2021.

In fall 2018, the Corps awarded a fabrication contract for gates at Locks and Dams 5A, 8 and 10. Fabrication began in fiscal year 2019 with installations planned for fiscal years 2022 and 2024 (Locks 8, 5A and 10, respectively).

The design of new anchorages for Locks and Dams 5A, 8, and 10 has been completed. This installation was completed during the winter closure of 2021-2022.  Design for miter gates at Locks and Dams 6, 7 and 9 was completed and scheduled for award in spring 2022.  Design for miter gates at Locks and Dams 3, 4 and 5 will occur in fiscal year 2022 and will be ready for award in spring 2023 pending federal funds.


Congress authorized the Upper Mississippi River 9-Foot Channel Navigation Project as part of the Rivers and Harbors Act approved July 3, 1930.


Miter gate replacement design and construction at the locks and dams are accomplished with 100% federal funds.

FY 2021:

Completed Design Gates at LDs 6, 7 & 9         $600,000

Award for LDs 5A, 8 & 10 Anchorages        $10,000,000

Installation of LD 2 Gates                                $1,300,000

FY 2022:

Award of Gates at LDs 6, 7 & 9                     $18,000,000

Awards for LDs 6, 7 & 9 Anchorages              $1,200,000

Installation of LDs 5A & 8 Gates                      $1,800,000