By Bob Uphues
A closer look at the Army Corps of Engineers plans for proposed flood-control measures in Riverside has revealed some issues that might receive pushback from West Avenue residents.
On Sept. 3, the Army Corps released its latest Upper Des Plaines Riverside watershed report, which proposes a host of flood-mitigation projects along the river from Racine, Wis., to Riverside.
The Army Corps is soliciting comments from the public related to the plan, which can be found on their website at, until Oct. 2. Comments can be submitted via a form on that web page; by mail to U.S. Army Corps of Engineers, Chicago District, 231 S. LaSalle St., Suite 1500, Chicago, Ill. 60604, Attn: Peter Bullock; or by email to UDPR&T@usace.army.mil.
In our initial report on Sept. 18, Landmark used the term "levee" to describe the structure being planned behind properties on West Avenue. A levee already exists north of the Forest Avenue bridge, along the entire length of Groveland Avenue. The levee is an earth berm topped by a concrete cap.
However, what is being proposed for the riverbank south between the Forest Avenue bridge and the railroad bridge is a floodwall, not a levee. The two terms are not interchangeable.
Levees, according to Army Corps Project Manager Jeff Zuercher, are typically "constructed of a clay core that is keyed into the ground, to ensure that there is no seepage underneath, and covered with topsoil and grass."
Floodwalls are entirely different. A floodwall is constructed by driving steel sheet piling into the ground and then pouring concrete over the sheet piling to form a wall.
That is what West Avenue property owners will be looking at as they gaze westward from their backyards if the plan is built as proposed, not at a grass-covered earth berm.
A floodwall was chosen over a levee because the area behind the West Avenue properties is restricted, said Zuercher.
"Floodwalls are used when land is scarce (as they are usually only about 1.5 to 2 feet wide)," Zuercher said in an email. "Levees are used when land is not an issue, because they are much cheaper to construct."
Zuercher said the Army Corps expects to get feedback from residents who might be opposed to such a solution.
"The flood wall is our best option in that area, and we look forward to getting the feedback," Zuercher said. "We'll try to work with the community as much as possible."
Additionally, the plan calls for a "road closure structure" — basically a floodgate — that would span the width of Forest Avenue during severe high-water events, tying the Groveland berm to the West Avenue floodwall.
"The road closure will only be for high-water times," said Zuercher. "It will be a gate of some kind. There are many options."
The plan also calls for pump stations and gate wells "intended to mitigate interior drainage issues."
The Sept. 18 story mentioned that the Groveland levee would be raised 2 feet. That would be accomplished, according to the plan, by driving sheet piling into the existing levee to achieve that height. The sheet piling would then be covered with a steel cap.
The raised levee would tie into Park Place, which the plan proposes raising to the height of the levee in order to serve as a de facto berm along the north side of Riverside's most flood-prone area.