West Brandon Road Flood Analysis and Culvert Replacement

West Brandon Road Flood Analysis and Culvert Replacement – Columbia, MO

This project illustrates I&L’s flood analysis, culvert replacement, and construction services capabilities. The City of Columbia, MO retained I&L to evaluate stormwater flooding and erosion problems and develop culvert replacement alternatives and construction plans for the selected alternative. The project also included relocation of a sanitary sewer that runs underneath a residential structure.

The undersized culvert adjacent to West Brandon Road frequently overtops the road and leads to a split flow condition, cutting off access to West Brandon Road. The previous roadside swale solution alleviated some of the frequent overtopping issues but not all flooding.

Phase 1: Included a flood study, alternatives analysis, and approach selection. The results were documented in a Stormwater Flood Study Memorandum. The study included hydrology development for the watershed, lidar and topographic survey, and development of a 2D HEC-RAS Model of the existing conditions and proposed alternatives. The model evaluated the downstream flooding and erosion impacts associated with each alternative. The City is currently reviewing the Memorandum to determine the preferred design approach.

Phase 2: Includes development of the selected alternative into construction plans and bid documents, including the relocation of an existing sanitary sewer to address deteriorated condition and alignment conflicts. I&L is also providing geomorphic analysis, permitting, bidding services, cost estimating, open house, easements, and final design plans and specifications.