Effects of Urbanization on Floods in the Houston, Texas Metropolitan Area

Rainfall and runoff data from drainage basins in the Houston metropolitan area and a 60-year rainfall record for the National Weather Service station, Houston-City, were used to simulate 60 annual flood peaks at 26 sites. Selected frequency characteristics, based on these simulated annual peaks, are related to drainage area and percentage of impervious area. These relations, which may be used to estimate the flood characteristics at ungaged sites, indicate that in the Houston metropolitan area, complete urbanization increases the magnitude of a 2-year flood nine times and increases the magnitude of a 50-year flood five times.