US Army Corps of Engineers
St. Paul District Website Website

Mississippi River Locks and Dams 2–10 Non-Structural Embankment Repair

Published March 22, 2019
Updated: April 16, 2020
Purpose

The non-structural embankment repair projects at Locks and Dams (LD) 2 through 10 will address restoring embankments to meet current design standards. Most dam embankments are currently protected from the erosive forces of water by a layer of riprap placed along the embankment’s length. When the riprap eventually erodes, the embankment itself will erode if more protection is not added.

Location

Upper Mississippi Locks and Dams 2 through 10.

Description

The U.S. Army Corps of Engineers has designed and placed berms and small islands to assist in reducing wave action and wind fetch within pools created by the locks and dams. Reducing these forces increases the longevity of the embankment protections. An example of this repair is the embankment at Lock and Dam 4 (photo above), where the Corps placed dredge material to create a berm for terrestrial habitat.

Status

For the programmatic review of the non-structural embankments adjacent to structures, the Corps prepared a draft problem appraisal report (PAR). The PAR has three goals:

  1. Identify programmatic rehabilitation and repair needs,
  2. Programmatically evaluate and screen alternative measures, and
  3. Prioritize locks and dams for funding and subsequent repairs.

After the PAR, the Corps completes feasibility reports with integrated environmental assessments for individual projects identified during the PAR.

The Corps initiated the first feasibility report at Lock and Dam 2 in fiscal year 2017 and will complete the report in fiscal year 2020. Plans, specifications and a contract award for a protective island upstream of Lock and Dam 2 will be completed in fiscal year 2020.

Additional non-structural embankment repair at the other locks and dams will continue in future fiscal years.

Authority

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

Funding

Embankment rehabilitation work at the locks and dams is funded completely by the federal government.

FY 2019:
Design for LD2 Protective Island                    $500,000

FY 2020:
Design for LD2 Protective Island                    $150,000
Construction for LD2 Protective Island      $5.6 million