Houston as a Model City: Meeting the challenges of an environmental crisis
Storms and flooding: Houston’s natural hazards
by Vicki Wolf, June 2006

A little more than 40 feet above sea level and about 40 miles from the gulf coast, Houston is naturally prone to flooding and vulnerable to hurricanes. But development of the area, without plans to preserve nature’s flood control resources, is making it worse. Development on the gulf coast continues to grow, increasing flood problems and adding to the number of people who need to be evacuated during a hurricane.

Houston’s original ecosystem has been paved over by expanding development. The combination of prairie and forest handled water pretty well, according to Karl Hacker, an ecologist and attorney on the faculty of the School of Public Health at The University of Texas Health Science Center at Houston (UTHSC). Replacing vegetation with concrete has increased flooding problems.

Even though 100 year floods (which have a 1 percent chance of occurring in any given year) have occurred eight times in the past 35 years, and three 500 year floods (which have a 0.2 percent chance of occurring in any given year) have occurred in that same time period, no comprehensive flood plan exists that makes protecting the public a higher priority than facilitating more development, according to Jim Blackburn, Houston environmental attorney. “To date, the preferred flood program has been one that interferes as little as possible with the real estate development process,” Blackburn stated in a 2001 presentation on managing flooding in Houston. “Until the public is clearly established as the “client” of our flood management actions, our flooding problems will continue.”

Blackburn also says flood plain mapping is incorrect, and for the city and the county to continue to knowingly publish incorrect information on this critical issue is “committing fraud.”

After the 2001 Tropical Storm Allison, the Harris County Flood Control District (HCFCD) received funding to update Flood Insurance Rate Maps, using brand-new, NASA developed technology, according to Heather Saucier, spokeswoman for the Harris County Flood Control District. The problem is that these maps, which are based on topography and land elevation, show only flooding risks from bayous, creeks or rivers topping their banks during 100 year and 500 year floods. “They do not show flooding that can occur from underground storm sewers exceeding their capacity or from water trying to reach a bayou,” Saucier says.

To improve flood control, HCFCD has spent $750 million widening and deepening major bayous and excavating massive stormwater retention basins – large holes in the ground adjacent to bayous that catch water when bayous overflow their banks. The City of Houston has more than $350 million allocated in its five-year plan to update its underground storm sewer capacity. But Blackburn says trying to control flood waters through engineering is not the best way to deal with flooding in Houston. “Flooding cannot be controlled in Houston, not in the traditional, engineering-solution manner that we have been following,” Blackburn says. He suggests comprehensive flood management that would include: realization of the implications of land development patterns; regulation of land development activities; plans for surviving the flood event; effective post-flood event services; appropriate flood plain maps and policies and flood mitigation planning (www.blackburncarter.com/news/Managing_Flooding_in_Houston/2001.html).

Development without thorough consideration of consequences from Houston’s natural hazards also increases risks for people and property should a hurricane spiral its way into the city. Houston and Harris County come in third and fourth for repetitive flood damage in the United States, just behind Louisiana coastal areas.

The government encourages building on the gulf coast. Federally subsidized flood insurance is provided and evacuation plans have coastal residents leaving first. These arrangements reduce personal risk and make it more inviting for people to invest in coastal properties.

“If there were no flood insurance program, a person would build a $60,000 shack instead of a million dollar dream home,” Blackburn says. He adds that the federal flood insurance program is almost bankrupt.

Blackburn says development should be regulated in relation to the level of evacuation required when a storm comes through. “We need a cap on the number of folks we let move into the coastal areas,” he says.

As with flood plain mapping, accurate information about the possible effects of hurricanes is important. Blackburn says many buildings would be flooded if a hurricane made a direct hit on Houston because surge tide levels are higher than authorities have reported, and building elevations are too low.

Another very serious concern is the release of hazardous chemicals, radioactive material and other toxins that could be life-threatening in a hurricane. A graphic shown by Blackburn at the City of Houston’s recent Environmental Summit shows the area between the gulf coast and the City of Houston covered with chemical plants, radioactive material storage and refineries. It would be difficult to follow the usual unintended hazardous chemical release protocol of “shelter in place” if people were faced with an approaching hurricane. Surrounding areas also would be threatened by toxins that are easily carried by air.

While it may be more comfortable and convenient now to avoid thinking about worst case scenarios, an appropriate reining in of development and regulation to preserve the protection that nature provides is critical to managing storms and flooding in Houston. Useful, accurate information and comprehensive planning that makes the public good a priority can move Houston closer to being a model city when it comes to surviving natural hazards.

Harris County Flood Control has given a formal response to this article. To read their response click here.