Central Texas Flood of October 1998

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Estimated rainfall according to the USGS

The October 1998 South Texas Flood was a flood event that resulted in the deaths of 31 people - mostly from drowning - in the southern and southeastern parts of Texas on the weekend of October 17 and 18, 1998. Most affected were San Antonio and the areas east of it. The storm was one of the most damaging in recorded meteorological history in the United States . In some cases, precipitation amounts of more than 500 mm were measured and the property damage totaled more than 750 million US dollars .

Meteorological assessment

The storm originated when a very strong high altitude trough coming from the western United States collided with warm, humid air that had been stuck over southern Texas for two days. In several places in the affected area, the temperature was around 24 ° C this weekend. Also nearby was the residual depth of Hurricane Madeline , which had previously dissolved in the Gulf of California . For October 16, the National Weather Service predicted significant rainfall that was simply missing one factor to turn into a catastrophic rainstorm. That factor was a cold front, and one was steadily moving in from the western United States. The meteorologists warned that the probability of a flood would be very high if this cold front arrived at the same time as the heavy rain. At 3:30 p.m. Central Standard Time on October 17, the New Braunfels National Weather Service issued the flash flood warning for all counties in south, central south, and southeast Texas.

Between midnight and four in the morning, individual rain shower areas and thunderstorms began to form, which were still very far in front of the approaching cold front. During the following hours, the storm did not organize itself very strongly until a convection formed over the northern part of Bexar County with the city of San Antonio . After that, the storm developed rapidly and the strength of the system increased until the cold front hit. As a result of this intensification, the convection quickly spreads across other counties, such as Travis County , to which the city of Austin belongs.

Rescue workers cross a flooded street.

The cold front hit the south and southeast of the state on Saturday evening, October 17, 1998. As a result, the thunderstorm area intensified until heavy rain began to pour over the entire affected region . The water levels in rivers and other bodies of water swelled rapidly, including the San Marcos River , Canyon Lake , Guadalupe River, and Medina River . The rain caused widespread flash floods in urbanized areas of San Antonio and Austin. The heavy rains lasted all day on October 18, until they finally subsided and moved towards the coast and finally crossed the sea. Seven different catchment areas , which drain an area of ​​almost 26,000 km², were affected by the flood. The rain event caused record water levels in 15 lakes and rivers monitored by the United States Geological Survey .

Effects

Flood damage in south Texas

The urbanized areas around San Antonio and Austin and the surrounding suburbs were hardest hit by the heavy rain event. The area with the highest rainfall, the greatest flood damage and the most fatalities extends over the four counties of Travis Bexar, Guadeloupe and Caldwell , including the two major cities of San Antonio and Austin. For a small area in Caldwell County, the United States Geological Survey estimated the amount of rain to be about 740 mm. This included Lockhart , which was inundated by the San Marcos River, as well as the towns of San Marcos , New Braunfels and Kyle .

Waters Location of the level Maximum value Remarks
Water levels from the 1998 Texas Flood
Cypress Creek Hockley 19.37 m High since 1960.
Onion Creek Driftwood 7.60 m Highest value since records began.
Sandy Creek Louise 7.60 m Highest value since records began.
Guadalupe River Louise 9.97 m Highest value since records began in 1915.
Plum Creek New Braunfels 10.70 m Highest value since records began.
Guadalupe River Gonzales 15.38 m Highest value since records began in 1905.
Guadalupe River Cuero 15.19 m Highest since records began before 1900.
Guadalupe River Victoria 15.19 m Highest since records began before 1840.
San Antonio River San Antonio 3.79 m Highest value since records began.
San Antonio River on Loop 410 San Antonio 11.03 m Highest value since records began.
Salado Creek San Antonio 7.02 m Highest value since records began.
Leon Creek San Antonio 8.70 m Highest value since records began.
San Antonio River Elmendorf 19.58 m Highest value since records began.
Cibolo Creek Selma 10.80 m Highest value since records began.
Cibolo Creek Fall City 12.20 m Highest value since records began.
Kelly (1999), pp. A1-A2

Victim

31 people were killed in 24 different incidents as a result of the floods in nine different counties. 29 of these deaths were caused directly and two indirectly. Of the 31 victims, 24 (or 77%) died from drowning , of which 22 were caused by the driver of a car driving a car on a road in flood caused by the heavy rain. There have been 16 unrelated incidents of this type, four of which resulted in multiple deaths. Trucks , vans or sport utility vehicles were involved in 63% of these incidents . The remaining causes of death included three cases of cardiac arrest , three cases of multiple trauma, and one case of hypothermia .

See also

literature

Web links

Individual evidence

  1. ↑ Kelly (1999), p. 1
  2. ^ Max Mayfield: Hurricane Madeline Preliminary Report ( English ) National Hurricane Center. 1998. Archived from the original on January 2, 2014. Retrieved April 26, 2008.
  3. ↑ Kelly (1999), p. 3
  4. ↑ Kelly (1999), pp. 3, 5
  5. ↑ Kelly (1999), p. 8
  6. ↑ RM, Jr. Slade, Persky, Kristie: Floods in the Guadalupe and San Antonio River Basins in Texas, October 1998 ( English ) In: Texas Water Science Center . US Geological Survey. August 22, 2005. Retrieved June 27, 2008.
  7. ^ Storm-Related Mortality - Central Texas, October 17-31, 1998 ( English ). Retrieved March 9, 2011.