Modified level II streambed-scour analysis for structure I-69-64-4767 crossing Tippey Ditch in Grant 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 1-69-64-4767 on Interstate 69 crossing Tippey Ditch in Grant County, Indiana, are presented. The site is near the town of Van Buren in the northeastern part of Grant 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 11.9 feet for the modeled discharge of 2,000 cubic feet per second and approximately 19.8 feet for the modeled discharge of 3,400 cubic feet per second.