CASA Flood Alert System for Houston using NETRAD

Flood warning systems can provide communities such as Houston, TX and institutions such as the Texas Medical Center (TMC) with important advanced warning of impending flood conditions. The Rice University/Texas Medical Center (TMC) Flood Alert System (FAS) has provided important data for predicting flood levels along Brays Bayou since 1997. Operational during more than 30 storm events, the current version, called *FAS2*, has provided invaluable information to TMC via the internet as it relates to flooding likelihood in Brays Bayou. The FAS2 utilizes available radar (NEXRAD) data coupled with real time hydrologic modeling, and provides visual and quantitative identification of severe storms producing heavy rainfall, as well as a linkage between the rainfall and likelihood of flooding. TMC has recently agreed to join CASA as a principal partner. Other partnerships with the City and TxDOT are being investigated.

The accuracy of the current FAS2 is adequate for regional events over large basins such as Brays Bayou, but is lacking for events where regional/local scale interactions, local scale precipitation, infiltration losses, or local hydraulics (storm sewers/urban drainage network) are important. In order to improve the success of FAS predictions for critical areas such as the TMC and for Whiteoak Bayou and Buffalo Bayou that impacts downtown Houston, hydraulic routing, hydrologic mechanisms, and meteorological processes all need to be better addressed in the system. In order to do so, both local and regional scale QPE, QPF and improved hydrologic/hydraulic models need to be linked in a new FAS.

The CASA radar network for Houston, NETRAD, will provide local quantitative precipitation estimates and will be integrated into real-time runoff-models that incorporate primary and secondary drainage systems. End-users will be provided with a customized product that is tailored to their needs in order to make informed decisions during severe weather events. The flood alert system FAS2 described above will provide the framework for incorporation of new NETRAD data, new urban hydrologic models, and end user interface once it is deployed in Houston. Houston has been chosen as the main test-bed for flooding associated with severe weather systems. It is the unique combination of new urban hydrologic models (that link GIS surface topography with distributed pipe networks) with new and more accurate CASA radars (with rainfall data at the scale of a city block) that allows a significant advance in flash flood prediction in flood prone areas such as Houston. Incorporation of improvements within a DCAS framework is anticipated to result in a fundamental change in the way flood forecasting is currently conducted.

Construction of Radar pole	NE view	W View
A Peregrine Falcon kept a watchful eye on the activities	Installation of Radar dome on pole
Lifting of the pole	Computer and modem box	Computer and modem box
Radar + pole		CASA NETRAD Team