But how can homeowners determine whether they live in a flood zone and what level of risk they face?įEMA regularly creates and updates detailed flood zone maps that outline risks at the community level. In fact, almost 20% of all flood insurance claims and one-third of federal disaster assistance go to homeowners who live outside of high-risk zones, according to FEMA. While it’s true that flood hazard zones are more likely to experience a major flood event, almost everyone lives in an area with at least some risk. During periods of above-average rainfall, local drainage systems can be overwhelmed and fail to direct water away from residential and commercial areas. Surface-water flooding: Also known as stormwater or rainfall flooding, this type of event is common in low-lying regions where rainwater and runoff can pool together. This type of flood cost Midwestern states more than $6.2 billion in 2019, The Chicago Tribune reported.ģ. Riverine floods occur when a body of water overflows its banks, either slowly or rapidly (flash flooding). Riverine flooding: Rivers and streams are also common sources of flooding, though these events are much harder to predict. Homes that are located along the coast can quickly become inundated with tidewaters, which is why FEMA considers these areas high risk.Ģ. Coastal flooding: Tropical storms and hurricanes can produce heavy storm surges, which may disrupt the tide and push ocean water inland.
typically fall into one of three categories:ġ. According to the Penn Institute for Urban Research, floods in the U.S. This explains why coastal regions are often classified as high-risk zones, along with areas that are in close proximity to lakes, rivers and streams.
The maps are intended to predict which areas have a 1 percent chance in a given year of a major flood.įEMA did not immediately respond to a message seeking comment.In many cases, flooding is the result of severe weather events like hurricanes, tropical cyclones, heavy rainfall and storm surge. (Photo by Joe Raedle/Getty Images)Īccording to their research, FEMA's flood plain maps for that area missed about 75 percent of the damages from Ike, Allison, and three other storms. Harvey, which made landfall north of Corpus Christi on August 25, dumped around 50 inches of rain in and around areas of Houston and Southeast Texas. HOUSTON, TX - SEPTEMBER 03: LaMarcus McCray and Allan Sommer (L-R) pupsh a boat through a flooded neighborhood as they help bring items out of a friends home in an area where a mandatory evacuation is still under effect after it was inundated with flood water after torrential rains caused widespread flooding during Hurricane and Tropical Storm Harvey on Septemin Houston, Texas. Researchers at Rice University and Texas A&M University at Galveston studied one section of southeast Harris County, which includes Houston, over a decade-long period that did not include Hurricane Harvey, but did include storms from Hurricane Ike in 2008 and Tropical Storm Allison in 2001.
HOUSTON (AP) - A study of part of southeast Houston suggests that the Federal Emergency Management Agency's flood plain maps were woefully out-of-date long before Hurricane Harvey ravaged the Texas Gulf Coast.