On Feb. 15, the Riverside Village Engineer made a report to the Village Board of Trustees about the U.S. Army Corps of Engineers (USACE) progress on the Groveland Floodwall project. There were some interesting points to the report. 

First, and foremost, the potential cost of the floodwall is now estimated to be $17.9 million, greatly exceeding the estimate given in March 2023 of $7.1 million. The reason for the increase was “scope change.” Unless there was something new added to the plan that has not yet been revealed, then the scope change was well known to the USACE when they stated the estimated cost last year at the board meeting. Because the estimated costs now exceed $10 million, the local share of the project will significantly increase. 

The village share could now be as much as $7.9 million with the Chicago Metropolitan Water Reclamation District (MWRD) currently only promising $2.5 million for the design and construction of the floodwall. The village would also be responsible for acquiring all property necessary for the construction of the floodwall (at their expense). 

The floodwall construction affects residents along West Avenue, south of Forest Avenue. The residents affected the most are those at the south end, which have never actually flooded. The USACE did come up with three alternatives that do lessen the cost to perhaps as little as $8.3 million. The village does not have any allocation in their current or forecasted budget to pay for the floodwall or for its maintenance.

Will the floodwall do what is promised? It may well prevent flooding to the residents on the east side of the Des Plaines River. However, contrary to presentations by the USACE, it will cause more water to be on the west side of the Des Plaines River (potentially affecting Riverside residents living there), First Avenue, Riverside-Brookfield High School, and Brookfield Zoo. 

The USACE builds a floodwall to a certain height in a river basin to prevent a flood caused by a certain amount of rainfall over the river basin. The volume of floodwater must go somewhere. If the floodwall prevents it from going to the east of the Des Plaines River, the water will go to the west. One only needs analyze the data from the USGS monitoring station on the Des Plaines River in Riverside just downstream of Barrypoint Road before and after the removal of the Hoffman Dam to see this point. The correlation between river height and flow rate changed completely after the dam was removed. A potential secondary effect of the floodwall is erosion of the banks. As a river channel is narrowed, the flow rate increases and the potential for erosion increases.

The Village of Riverside has National Historic Landmark status. That status is considered important to the village. If the floodwall is built, the first look at Riverside traveling east on Forest Avenue will be a floodwall. Not exactly a wonderful view. All access to the river will also be cut off along West Avenue. Some residents of West Avenue enjoy having access to the river for the view and use of the river. All trees and structures between the river and the floodwall, and east of the floodwall 15 feet, will have to be removed. 

Based on the survey of April 2023, the residence at the back of the 8 West Ave. property is within 15 feet of the surveyed floodwall line and would have to be removed, along with a covered deck overlooking the river and a shed. This property has never flooded, yet it is the one property most affected by the floodwall.

Based on a survey available earlier this year from the Village of Riverside, 284 residents of Riverside agreed that the village should continue to work with the USACE and MWRD on the Groveland Floodwall project. However, less than a third of the respondents (who indicated where they lived) live in a portion of Riverside that would benefit from or be affected by the Groveland Floodwall. This is not a representative voice of Riverside residents.

Lastly, the construction of the Groveland Floodwall will not eliminate the need for some residents to purchase flood insurance since the wall will not be high enough.

David C. Bartel is a Riverside resident.