Analysis of 1989 Floods in Harris County, Texas

On May 17 and 18, 1989, a severe thunderstorm stalled over Harris County, Texas, producing over fourteen inches of rain in a twenty-one hour period. Slightly more than one month later on June 26th, tropical storm Allison moved inland from the Gulf of Mexico and dumped over twelve inches of rainfall in eighteen hours. Severe flooding resulted from both storms, prompting the Harris County Flood Control District (HCFCD) to commission a study to characterize the frequency of both the rainfall and flooding associated with each event. In addition, the computer models developed for the Harris County Flood Insurance Study and used by the HCFCD to predict the impacts of proposed development, bridge and channel projects on the eight watersheds were analyzed using the recorded data for each storm.