Flood Event Modeling Program


Harris County Flood Control District


Service: Floodplain Management

Flood Event Modeling Program

Harris County

This flood event modeling program was developed with an overall goal of creating a system that utilizes existing technology to provide a state-of-the-art computer software package to monitor flooding in real-time. Using current, available technology, Walter P Moore developed this package as a web-based intranet tool that can be used as a planning and information resource. The goals were to: better understand the ability of current hydrologic and hydraulic models to reflect observed flooding conditions in order to provide information for improving model effectiveness; provide real-time and post-event evaluations of the effectiveness of county flood management facilities to reduce flooding; and support existing local agency staff during flood alert operations.

The design team developed the computer-based system to take radar-based rainfall estimates and import them into a HEC-HMS hydrologic model for a watershed. The output data is then put into a HEC-RAS (unsteady) hydraulic model for the stream system, and then that is fed into ArcGIS to produce the inundation maps in real-time. Since one component of the system is running in HEC-RAS, additional data such as profiles and hydrographs at various points along the stream system are available to the user as the event occurs.