The forecast predicts sunny skies, clear
nights. And in Texas that doesn't mean a thing.
Few weather events equal the flash flood in
excitement. The very phrase sounds dangerous, conjuring
visions of torrential rain that quickly transforms front
yards into lakes and quiet streets into raging rivers and
threatens to sweep the whole neighborhood into the Gulf
of Mexico. One minute the sun is shining, the birds are
singing, and the brook is babbling; the next, the sky
darkens, the rain begins, and it's time to batten down
the hatch. Little white lines of type float across the
bottom of the TV screen, and an intrusive beeping sound
announces the potential for flash flooding--a watch is
declared if flooding is imminent or already occurring in
the vicinity. Either way, it's time for constant
vigilance, for no event wreaks havoc quite so quickly or
thoroughly as the flash flood.
Although Texas is a land of contrasts,
you usually have to drive a thousand miles to discover
that fact. A flash flood can save you the mileage. Within
hours, drought can turn to flood. The rains that fell
over the Hill Country on August 2, 1978, for example
broke a severe six-week dry spell by dumping more than
twenty inches of precipitation in the headwaters of the
Guadalupe, Medina, and Sabinal rivers in a few hours,
causing record flow rates and numerous deaths.
If Texas seems to get more than its share of
flash floods, that's because its location between the
Rocky Mountains and the Gulf attracts both rain-laden
cold fronts from Canada and warm, moist air from the
south. As such systems stall and dissipate over Texas,
they drop intense rains over small areas. In 1921 a
rainstorm moved north from Mexico before becoming
stationary over Central Texas. On September 9 the system
set a U.S. record by unleashing 36 inches of rain in
eighteen hours on the farming community of Thrall. The
flash floods spawned in the area killed 215 people.
The sparsely vegetated limestone
terrain of the Hill Country and Edwards Plateau is
especially prone to flash floods, as is evidenced by the
numerous low-water-crossing signs and flood gauges posted
along normally idyllic shallow rivers, streams, and dry
washes. Add a thin layer of saturated topsoil and miles
of pavement, and you have the ingredients for a
full-blown gully washer or frog drowner.
Every Texan worth his barometer
understands that the flash flood's inherent danger is its
potential to strike almost any rivulet anytime. You expect
the Mississippi to spill its banks on a semiregular
basis. A creek that you normally ford in one giant step
doesn't command that kind of respect until it rains and
rains some more. How many times have otherwise sensible
people hopped in their cars to see which bridges have
washed out instead of staying home as the weatherman
advised? Low-water crossings mark the graves of many
fool-hardy souls unaccustomed to the vagaries of Texas
weather. "I can make it" are the famous last
words of tinhorns before they gun the engine and try to
plow through a raging torrent. "A lot of newcomers
are lost in Volkwagens that way," says meteorologist
James C. Fidler.
Then there are those who understand the
risks but nonetheless regard flash floods as sport. When
desert rats in the Big Bend spot a heavy thunderstorm in
the distance, they consult a set of topographical maps,
calculate the direction of the runoff, and head for a dry
wash. If their predictions are correct, they are rewarded
with an ominous rumble that heralds a flash flood's
arrival. They compare the spectacle of water barreling
through the wash and crumbling banks along its way to the
calving of glaciers.
My respect for flash floods was
instilled on Memorial Day weekend, 1981, when seven
inches of rain fell on already saturated ground in
Austin. Shoal Creek jumped its banks and threatened to
flood my downtown office. Before I could reach the place,
my car was met by a rush of water and began to float
away. I jumped out, took refuge in the second floor of
the building, and watched as the water carried several
cars, the garage, and the back stairway toward Town Lake.
As quickly as four feet of water had entered the
building, it retreated, leaving a thick layer of mud as a
calling card. By the time a rescue boat puttered to the
front porch, I could slosh through the muck unassisted.
Thirteen lives were claimed by the waters that night. I
got out easy, losing only my record collection and a few
sundry possessions, but I experienced a brush with death
that I will never forget. |