Houston Approves New Flood Construction Rule

April 5, 2018
Houston City Council voted 9-7 to approve a new zoning rule

Hurricane Harvey is the reason Houston's City Council voted 9-7 to approve a new zoning rule on Wednesday in an attempt to prevent the losses experienced in last year's flood disaster.

Houston  city officials said 80 percent of the homes damaged by Harvey would have been protected had they been built to the specifications of the new rule.

Under Wednesday's approved new rule, new structures in the 100-year and 500-year flood plains must be constructed 2 feet above the ground or above the projected water level in a 500-year flood, described as an event in which 17 to 19 inches of rain falls in 24 hours. Estimates are there is a 0.2 percent chance of such an event happening in any given year.

Houston is the only major (4th largest) city in the country that does not have zoning requirements. Estimates are 25 percent of Harris County (Houston) is in the 100-year flood plain and 33 percent of the county is located in the 500-year flood plain.

Houston’s previous rule required buildings to be constructed 1 foot above the water level in a 100-year flood, described as an event in which 13 to 14 inches of rain falls in a 24 hour period. That earlier rule applied only to property in the 100-year flood plain. In reports following Harvey, it was discovered the local governments had no survey maps for residents and contractors to consult before building.

Harris County approved a similar rule in December. The new zoning rule is set to take effect September 1.

image: FEMA