16 Mar 2017

Lock and Dam 5A, Embankment and Levee Certification

The LD5A embankment is located along the Mississippi River about 3-1/2 river miles above the City of Winona, Minnesota, and about 3 river miles below Fountain City, Wisconsin. The St. Paul District is responsible for operation and maintenance of the LD5A embankment, as part of the LD5A dam project, authorized for the purposes of navigation and recreation. The Winona, Flood Risk Management Project was authorized by the Flood Control Act of 1958, of which the LD5A embankment was used as part of the line of protection. The LD5A embankment is approximately15,500 feet in length from its high ground tie-in point at Minnesota City, Minnesota, to the southern tie-in with the Winona FRMP.

16 Mar 2017

Pokegama Dam Slurry Trench Project, Grand Rapids, Minn.

Pokegama Dam was constructed in 1884. The main embankment was constructed with a pervious, rock and clay-filled timber structure core and covered with sandy material. In 1941, a sheetpile wall was installed upstream of the timber core to minimize unwanted seepage (flow) through the embankment. The existing sheetpile wall has been effective at controlling seepage, but its overall condition is currently in question. Without an effective seepage barrier, the water levels could rise throughout the embankment causing downstream slope instability, which would threaten the integrity of the dam.

16 Mar 2017

Mississippi River Lock and Dam 6, Guidewall End Cell

The purpose of this project is to extend the longevity of the lower guidewall at Lock and Dam 6 and to reduce operability issues and required maintenance. The end cell will provide adequate protection of the end monolith along the lower guidewall, while the existing crib grouting component will add stability. Lock and Dam 6 is located in Trempealeau, Wisconsin roughly 20 miles north of La Crosse Wisconsin.

14 Mar 2016

Mississippi River Locks and Dams 2–10 Tow Rail System

The tow rail system is integral to the operation of each of the Mississippi River Locks and Dams 2 through 10. It is attached to the top of the lock guidewall and helps guide tows through the lock chamber. Each system is comprised of an operating unit, rail and traveling kevel or “mule.” The Locks and Dams 2 through 10 tow rail systems have been deteriorating over the past several years, requiring rehabilitation of these systems.

2 Oct 2015

Mississippi River Locks and Dams 2–10 Guidewall Crib Repairs

Guidewalls are integral to each of the Mississippi River Locks and Dams 2 through 10. Guidewalls are long extensions of the lock walls, in either the upstream or downstream direction, that are parallel to the lock wall. These walls 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. The guidewalls are constructed of multiple 35 to 40 feet length concrete monoliths with rock filled timber cribs beneath and behind them.