Navigation: Mississippi River End Cells

U.S. Army Corps of Engineers, St. Paul District
Published March 16, 2017
Updated: April 15, 2024


The Lock and Dam 2 through 10: Lock GuideWalls – Distress Repair Recommendations project has been on-going since the mid-1990s. Over the years, distresses of the guidewalls have been observed. These distresses have led primarily to serviceability and safety issues associated with the kevel on the upper guidewall. In addition, the guidewall end monoliths have been used by the towing industry as targets when landing on each wall. These repeated impacts have contributed to the separation of the end guidewall monoliths, as well as, caused severe concrete damage leading to significant and costly repairs. The purpose of the end cell projects is to extend the longevity of each site, and to reduce operability issues and required maintenance.


Locks and Dams 4, 5, 5A, 7.


Guidewalls are long extensions of the lock walls, in either the upstream or downstream direction, that are parallel to the lock wall. At each of the Mississippi River Locks and Dams 2 through 10, guidewalls serve primarily to guide the long tows into the lock and to provide mooring facilities for tows too long to be accommodated in a single lockage.

Periodic inspections have found cracks on monoliths along the guidewalls at several locks. Often tow traffic mentions movement in the guidewalls.

Engineers recommend that every end monolith located on each upper and lower guidewall for Locks 2 through 10 have an end cell designed and constructed.


The Corps has evaluated the other lock and dam sites within the district for future construction projects. Plans and specifications for the downstream end cell at Lock and Dam 4 started in fiscal year 2022. A construction contract award was awarded in fiscal year 2023 and is currently under construction. A design contract is scheduled for award in fiscal year 2024 for Lock 5.  Pending available funding a design contract for 5A and 7 end cells are scheduled to be ready to award by the end of fiscal year 2024.


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


Funding for the construction of the end cell at Lock and Dam 4 was received in fiscal years 2023 and 2024. Funding for the design of the end cell at Lock and Dam 5 was largely received in fiscal years 2023 and 2024. Funding for scope of work for Locks and Dams 5a and 7 were received in fiscal years 2023 and 2024.

Guidewall end cell design and construction at the locks and dams is completed with 100% federal funds. Estimated project cost per site                   ~$6,500,000