Project description

Walnut Creek/Raccoon River

Hanson constructed a total of four miles of levees and 600 feet of flood walls to provide 100-year flood protection to portions of Des Moines, Iowa.  Design and construction involved building these structures:

• levees of semi-compacted impervious material with 10-foot top width and side slopes of one vertical on three horizontal;
• concrete flood walls averaging 10 feet in height and driven sheet pile 20 feet below grade with cast-in-place concrete stem wall above grade;
• design for five closure structures for vehicular and rail traffic; and
• feasibility reports.

The U.S. Army Corps of Engineers gave a rating of "excellent" for this project.

Mississippi River

Hanson inspected 160 observation wells along the Mississippi River, covering the area from Fulton, Ill., to south of Hannibal, Mo.  As part of the inspection, we located, observed and recorded the physical condition of each well; recorded water levels; performed permeability (hydrostatic time lag) tests; and reported our findings and recommendations for maintenance and rehabilitation.

For this project, we received an "excellent" rating.

Click here to see other excellent ACASS ratings.