The City of Baton Rouge and Parish of East Baton Rouge experienced widespread flooding in August 2016 and in May 2021. The floods brought to light the current challenges regarding existing stormwater conveyance systems, development and drainage ordinances, and their impact on overall stormwater management in the Parish. HNTB was selected by the Parish of East Baton Rouge in the preparation of a Stormwater Master Plan (SMP) to addresses these and other issues. The Parish’s SMP process was broken down into three phases. Phase 1 - Outreach to key stakeholders, collection/acquisition of critical data, a preliminary flood risk assessment, and securing Hazard Mitigation Grant Program (HMGP) funding for the development of the plan. Phase 2 - Additional data collected (including survey) and development of a Geographic Information System (GIS) database of the subsurface system, modeling and analysis of the eleven (11) identified watersheds and flood hazards evaluation, and identification and evaluation of flood risk reduction solutions. Phase 3 - Development of the Capital Improvement Plan, which identified and evaluated multiple potential funding sources and prioritizes projects from the SMP This presentation will briefly discuss each phase. But will primarily focus on the data collection, modeling of the existing watersheds, and identification of proposed projects as part of Phase 2. The field survey associated with data collection documented thousands of pipes and structures throughout the parish. Unsteady, two-dimensional HEC-RAS models were used to evaluate open channel systems, and unsteady PCSWMM models with two-dimensional surface flooding capacity were used to evaluate enclosed systems.
