Modified level II streambed-scour analysis for structure I-465-131-5256 crossing Williams Creek in Hamilton County, Indiana

Level II scour evaluations follow a process in which hydrologic, hydraulic, and sediment transport data are evaluated to calculate the depth of scour that may result when a given discharge is routed through a bridge opening. The results of the modified Level II analysis for structure 1-465-131-5256 on Interstate 465 crossing Williams Creek in Hamilton County, Indiana, are presented. The site is near the city of Indianapolis and is in the southwestern part of Hamilton County. Scour depths were computed with the Water Surface PROfile model, version V050196, which incorporates the scour-calculation procedures outlined in Hydraulic Engineering Circular No. 18. Total scour depths at the piers were approximately 6.5 feet for the modeled discharge of 4,300 cubic feet per second and approximately 9.8 feet for the modeled discharge of 7,310 cubic feet per second.