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Hydrologic Design of a Storm Detention Basin: Beau Bassin Watershed, LA


Problem Statement

Flash flooding is a hazard in many parts of the world. In south Louisiana, the terrain is particularly flat with a minimal natural slope to support efficient drainage. Flash flooding is common in urban areas where runoff from rainfall quickly accumulates in coulees and cannot drain fast enough. A flash flood is a sudden and rapid rise in stream water depth resulting from heavy, localized rainfall. With a growing population, developing neighborhoods in terrain susceptible to flash floods have become more common and therefore increased the potential for damage to private property and public infrastructure.

Hydrologists are frequently required to design flood protection infrastructure to protect people and property from the impacts of flash flooding. This module is based on a localized student flood protection project for the Beau Bassin Coulee in Carencro, Louisiana.

Module Overview

In this module you will use the engineering design process to design a detention basin for use in protecting an area of urban development from flooding. In doing so, you will learn about specific topics in hydrology.

Topics Covered

Watershed Properties, Precipitation, Runoff and Infiltration, Modeling Using HEC-HMS



Learning Objectives

At the end of this case study, you should be able to describe and implement the steps involved in: delineating a watershed, acquiring and analyzing precipitation and soils data, developing a design storm hyetograph, developing a runoff hydrograph, and designing a detention basin to provide flood protection.

This will be accomplished through activities within each section. Results from each activity will be recorded in specified results templates. The results templates for each activity can be found at the beginning of each activity. The results templates are organized such that results from one activity can easily be used in successive activities.

Course Authors

Emad Habib, PhD, PE

University of Louisiana at Lafayette. Contact:

Olivia LaHaye, Graduate Research Assistant

University of Louisiana at Lafayette. Contact:

Target Audience

Junior/Senior Hydrology and Water Resources Engineering Courses

Tools Needed

Computer with access to Internet, Excel, and free HEC-HMS software

Expected Effort

The module developers estimate that this module will take between 30 to 35 hours to complete.