LWI Region 3 Modeling Overview

Pumps on detention outlet: Two additional pumps, each rated at 800 cfs, were placed at the detention basin outlet. These pumps operate during peak flood conditions and discharge water back into Bayou Lafourche, controlled by flap gates to prevent any reentry into the detention pond. Levee and flap gates protecting South Monroe: The new levee system includes secondary flap gates to block backwater entry into the detention area from the south. This system ensures that even during high tailwater stages in Bayou Lafourche, no flow travels southward into low lying neighborhoods. Figure 6-2 schematically shows the overall flood mitigation configuration, including levees, detention pond, pumps, and gates. Model results for the March 2016 flood showed that implementing these combined measures reduced the water surface elevation in the downstream reach of Young’s Bayou by approximately 1.0 to 1.2 ft, substantially lowering the flood risk in the most impacted urban areas. The improvement in water surface elevation is presented in Figure 6-3.

Figure 6-2: Schematic of the proof-of-concept geometry highlighting the levees, detention pond, pumps and the gates along Young’s Bayou.

Figure 6-3: Showing the improvement in water surface elevation compared to the March 2016 calibrated event.

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Consequence Modeling