Weather, Development, Bad Land Spell Flooding for the Houston Area With AM-Texas Floods, Bjt
HOUSTON (AP) _ It’s no mystery why rice grows well in southeastern Texas.
The soil - high in clay and low in sand - doesn’t absorb water well. Rain hitting the ground puddles quickly, making it ideal for farmers raising rice or crawfish.
Combine the soil quality with a development boom and more than 2 feet of rain in 48 hours, and you’ve got a disaster.
Some 10,000 area residents forced from their homes by flooding that began Sunday were discovering that the hard way.
Houston is on a coastal plain along the Gulf of the Mexico. North and east of Houston run the Trinity, the Brazos and the San Jacinto rivers.
″We are at the mouths of the streams where all the water is being funneled on us,″ said Carl Norman, associate professor of geology at the University of Houston. ″So in addition to the rainfall locally, we are getting rainwater funneled from tens to hundreds of miles inland. So we have to expect floods periodically.″
Houston and the areas in a 50-mile radius saw their greatest development from the 1960s to the oil bust of the 1980s. During that period, subdivisions flourished, and as they did the already poor land was covered with asphalt and concrete, increasing runoff by reducing places water can penetrate.
The soil is relatively impermeable and reaches the saturation point quickly, Frank Fisher, a biology professor at Rice University. Rainwater, instead of soaking in, runs off.
Floods, particularly in the downtown Houston area, were periodic in the 1800s and early part of this century.
When settlers first tried to tame the swamp that became Houston in the 1800s, the first thing they did was tear out vegetation in the bayous surrounding the area to move water faster to the Gulf of Mexico.
Since then, Houston has tried to improve the natural drainage system around the nation’s fourth-largest city. A few bayous, like the Brays Bayou in southeastern Houston, have been lined in concrete.
Engineering has improved the situation but not resolved it.
Two years ago, monsoon-like downpours turned Interstate 10 into an instant downtown river, covering hundreds of cars and sending motorists scrambling up freeway embankments.
Experts debate whether this latest flood is indeed the 100- or 500-year flood, but they’ll continue to study the water’s pathway as a possible key to better flood control. And there’s still no controlling the weather.
″Some places got 28 inches in a matter of days,″ Fisher said. ″The capacity of the streams to carry this off, it’s just not there.″
Normal rainfall for the area is roughly 48 to 50 inches for an entire year.
″I’ve lived here for 30 years and I don’t remember seeing this amount of rainfall in this short amount of time period,″ Fisher said.