Using Survey Data and Hec-Ras Modeling to Assess a Riffle-Remediation Structure on the Big River, Bonne Terre, Missouri

Nichole Renee Weedman

Abstract

Sediment transport and deposition in river channels can vary for many reasons including flooding, dredging, channel velocity, and grain size. On the Big River, the Army Corps of Engineers constructed a riffle ramp structure to trap and remediate lead-contaminated sediments. The performance of the structure is unknown. The goal of this study is to evaluate the storage capabilities of the riffle structure. To do this, survey data was collected to analyze sediment storage and entered into the HEC-RAS 5.0 to model the hydraulics of the channel before and after the riffle installation. Samples were collected to assess the level of lead contamination. The results indicate the riffle structure has caused the deposition of approximately 61,898 ft3 of sediment.