An Operational Radar-based Flood Warning System for Highly Urban Areas in Houston, Texas

As non-structural tools, radar-based flood warning systems can provide accurate and timely warnings to the public and private entities in urban areas that are prone to flash floods. The wider spatial and temporal coverage from radar increases flood warning lead-time when compared to rain and stream gages alone. Thus the radar-based flood warning systems have become more prevalent in the past decade to provide the information necessary to mobilize the evacuation of people and property prior to flooding in critical areas

This paper will present an operational radar-based flood alert system for the highly urbanized Rice University and the Texas Medical Center (TMC) areas in Houston, Texas. This radar-based Flood Alert System (FAS) has been providing important warning information for the critical medical facilities for more than 50 events since 1997. The system utilizes NEXRAD Level II radar rainfall data coupled with a real-time hydrologic model (RTHEC-1) to deliver warning information with 2 to 3 hours of lead time and a forecast R2 value of 93% to facility personnel in readily understood format. A user-friendly dashboard enables users to visualize rainfall maps, Google Maps based inundation maps, hydrologic predictions, and real-time monitoring at the bayou. This paper will discuss the evaluation of its reliable performance during the recent events occurring in 2012 and 2013. Due to its excellent performance, Texas Medical Center has included FAS3 into their FEMA Success Story as a good example to demonstrate the significant value of the radar-based flood warning system. Having a significant role in the communication of flood information, FAS marks an important step towards the establishment of an operational and reliable flood warning system for flood-prone urban areas.