Brett Coomer, Houston Chronicle / Staff photographerWhen Harris County debuts a massive overhaul of its floodplain maps later this year, the Houston area will be the first in the country to rely on a more accurate assessment of homes and businesses at risk. The update is a direct response to Hurricane Harvey, a storm so ferocious it forced the region to change its understanding of how much rainfall to plan for and which neighborhoods could flood.
FEMA's existing floodplain maps show communities their risk of fluvial, or river flooding, when a bayou, creek or lake overflows its banks and floods nearby structures. What they do not show is the risk of urban flooding, when intense rainfall overwhelms stormwater systems regardless of proximity to a bayou or other channel.
Communities across the United States are going through the process of updating their floodplain maps to align with NOAA's higher rainfall estimates. Nonetheless, Harris County has not had a comprehensive overhaul of all its floodplain maps since 2007. On the new maps, some floodplain areas likely will shrink, such as neighborhoods that benefit from the Project Brays flood mitigation work. Most floodplains, however, will increase substantially because the new rainfall estimates mean the region will be preparing for bigger storms with around 30 percent more rain than before. Harris County now will plan for 17 inches of rain in 24 hours to protect against a 100-year storm, rather than 13.2 inches.
After the new maps are released, the post-preliminary process, including an appeals period, could take up to two years. New flood insurance premiums will not take effect until the maps are complete and finalized, according to a FEMA Region 6 spokesperson.
Councilmembers in the district and all members that we voted for
Obviously a sop to the insurance companies in return for campaign donations.
Quit building on flood plains and marshes, then wouldn't be an issue.