Design of Confined Placement Areas in Sabine-Neches Waterway, Texas

The objective of this study is to use sediment settling data to analyze and predict performance of 15 Confined Placement Areas (CPAs) as part of the 50 year dredged material management plan. Two modules of the Automated Dredging and Disposal Alternatives Management System (ADDAMS), DYECON and SETTLE, were used to design CPAs. Design variables for CPAs include dike height, weir length, surface area, flow path length and effluent total suspended solids (TSS) concentration requirements. After sensitivity analyses of design parameters were performed, design curves were developed and presented as formatted graphs showing the relationship among maximum dredged volume, dike height and effluent TSS concentration for all 15 CPAs. It was found that the number of hours of dredging per day and the re-suspension factor could result in sharp changes in projected effluent TSS concentrations. The influence of these design variables was not well understood by operation engineers and SETTLE users before.