Floodwall Replacement

In FY22, the President’s Budget allocated funds to initiate the investigation and design phases of the Cairo, IL Floodwall Replacement Project, a critical infrastructure initiative aimed at protecting the historic city of Cairo from a potential future flood event. This project seeks to replace approximately 2.4 miles of floodwall, along with associated closure structures, while ensuring the current level of protection against the Project Design Flood (PDF) is maintained.

The scope of the project includes the permanent closure of unused or abandoned openings in the floodwall and potential realignment to optimize performance. Located on the right descending bank of the Ohio River near river mile 957, the project spans from the north end at STA 8/8+60 to the south end at STA 10/30+80. Prior to the Value-Based Design Charrette (VBDC) the Project Development Team create a baseline approach for the project to be compared against to additional courses of action (COAs) developed by the Value Team as comprehensive solutions to the project.  This baseline concept included replacing the existing floodwall within its current footprint, utilizing T-Section floodwall where feasible and I-Section floodwall in more constrained areas.

Key challenges identified by the District include minimizing land acquisition, railroad disruptions, and operational impacts to industry located adjacent to the floodwall alignment. Minimizing impacts to the railroad and industry being the two largest challenges facing the project.  The Value Team developed alternatives that not only address each of these challenges but also minimize ongoing operations and maintenance tasks for the City of Cairo and its stakeholders.

The Value Team developed three COAs as potential solutions to the project. The COAs were developed by combining various ideas identified by the Value Team to create a comprehensive approach to the project.  COA1 was the most economical approach, COA2 was the most value added option, and COA3 was the best performing option. These COAs were intended to display potential solutions to the project and convey that additional combinations of these ideas are possible to develop other comprehensive approaches.  Some of the more significant accepted ideas included offsetting the alignment of the floodwall landward to utilize the existing wall as temporary flood protection thereby eliminating the need to construct this costly item, creating an emergency action plan to replace segments of the wall to expedite the clearing of debris near the site to allow rail traffic to be maintained and allow for sealing of the wall penetration in the event of rising river water levels, and constructing a levee in lieu of a floodwall in less constrained areas of the project alignment.  The accepted alternatives resulted in an estimated potential cost avoidance to the project of 18%.