Recently, the United States, especially Houston, Texas and Ellicott City, Maryland, have felt the effects of powerful storms and devastating flooding. Such devastations have brought to our attention the need to address potential deficiences in our way of thinking and management.
Hurricane Harvey which lasted from August 17, 2017 to September 2, 2017 was the most "significant tropical cyclone rainfall event in United States history".1A third of homes in the 500-year floodplain (where there is only supposed to be a 0.2 percent chance of flooding each year) received flood damages. In fact, Hurricane Harvey marks the third consecutive year that homes in this floodplain have flooded.2 Because of this weather event, some have begun to question the accuracy of 100-year floodplain maps or whether the 500-year floodplain may be becoming the 100-year floodplain. The 100-year floodplain map (the land that has a 1% chance of flooding annually) is what the Federal Emergency Management Agency (FEMA) uses to administer the federal flood insurance and City governments use to regulate development.3 Only homes in the 100-year floodplain are required to have federal flood insurance. So, to avoid this requirement, companies have increased development in areas beyond the 100-year floodplain.1 In fact, CoreLogic (a property information company) reported in 2017 that over 50% of Houston's moderate- to high-risk homes for flooding are located outside of FEMA-designated flood zones, meaning they didn't have flood insurance.2
To read the complete article, please click on The New 500-year Floodplain