Kswinicki / iStock / Getty Images Plus Between 2010 and 2019, six of the 15 fastest-growing cities in the United States were in Texas. Bigger cities mean less land to soak up rainwater, leading to increased flood risk. Land use, climate change making flood mitigation in Texas cities more difficult Chantal Cough-Schulze | Feb 22, 2021 Texas cities are expanding fast. Between 2010 and 2019, six of the 15 fastest-growing cities in the U.S. were in Texas. Bigger Texas cities mean less land to soak up rainwater, leading to increased flood risk. Add climate change to the equation and you have an even bigger flooding problem to solve. Buildings, roads, sidewalks and other city elements are impervious: they can’t soak up water like soil can. Instead, water runs off the impervious surfaces, flowing into neighboring streams and low-lying areas. Having faster and higher amounts of runoff results in more flooding, said Wonmin Sohn, an assistant professor in Michigan State University’s School of Planning, Design and Construction.