During the weekend of October 17 and 18, 1998, torrential rains fell over south and southeast Texas. Up to 22 inches of rain fell, resulting in flash flooding from San Antonio to Austin followed by record breaking river floods along the Guadalupe and several other south Texas rivers the following week.   All of the ingredients for extremely heavy rains came together over south Texas the morning of Saturday, October 17, 1998. A strong upper level trough and surface front were approaching from the west while a persistent low-level southeast flow of very moist air covered south Texas.

In addition, a plume of moist air was streaming across the area from Hurricane Madelain off the west coast of Mexico.  Storm conditions began about 5 a.m. Saturday over San Antonio and in the words of the National Weather Service, “developed explosively.”  The storm spread north to Austin. A cold front arrived Saturday night, supporting and intensifying the already heavy weather. Several tornadoes were spawned by the arrival of the front, followed by torrential rains.  

As the initial flood wave moved down the rivers Saturday night and Sunday, up to an additional foot of rain fell on the drainage areas. When the event ended, as much as 22 inches of rain had fallen over parts of south and southeast Texas, with many areas receiving over one foot of rain.  By Sunday, October 18, the heavy rains tapered off, and the event became a major river flood affecting seven river basins, draining approximately 10,000 square miles. Three drowned on the north side of San Antonio after 15 inches of rain fell. The San Antonio airport recorded 11.26 inches of rainfall, a new record for the day and the month.  (Source: http://www.srh.noaa.gov/ewx/html/wxevent/2005/Midoct.htm)


The Flood of 1998 will not soon be forgotten in San Antonio. During the 24-hour period of October 17-18, San Antonio experienced an unprecedented amount of rainfall which reached 19 inches in some areas of the city. Due to the convergence of mid and high level moisture from Hurricanes Madeleine and Lester in the Pacific and the early morning arrival of a micro-scale disturbance, the rainfall was far greater than anticipated.

The storm and rainfall on these days were monumental in scope, qualifying as a 100¬year flood and in some areas approached a 500-year flood. With this record-level storm, the City was pressed to deal with the devastation caused by such a natural disaster. The City's reaction was quick and decisive. Below are some highlights of the extent of the storm to this unprecedented catastrophe.

•    11 lives lost due to vehicles in flooded areas
•    192 rescues by San Antonio firefighters, saving 461 men, women and children from rising waters    .
•    5,184 calls for service to the San Antonio Police Department
•    123 major accidents handled by the Police Department
•    Over 1,200 dwelling units and businesses sustained damage
•    Over $115 million in damage to public and private property throughout San Antonio
•    Over $71 million in damage to City of San Antonio facilities
•    3 command centers set up to provide relief assistance to more than 5,500 flood victims
•    Over 10,000 immunizations administered to flood victims and others assisting in clean up efforts
•    $250,000 of voucher assistance distributed
•    480 tons of debris collected from 576 miles of street
•    21,375 tons of debris collected from approximately 8 miles of channel

(Source: City of San Antonio Flood of 1998 After Action Report)

1978 – Flooding

On September 13, 1978, 5.13 inches of rain fell in the pre dawn hours to around sunrise in just several hours in San Antonio.  This caused flooding during in the early morning, including the early morning rush hour, on roads and highways.
(Source: http://www.srh.noaa.gov/ewx/html/wxevent/Climate_Narratives/sepclimate.htm)

1973 – Flooding

In late September 1973, another flood event in San Antonio left 6.54 inches of rain September 26th and 0.87 inches September 27th.  This rain event produced a 24 hour record of 7.28 inches for San Antonio, later broken October 17 to 18, 1998 when 13.35 inches of rain fell in 24 hours.  (Source: http://www.srh.noaa.gov/ewx/html/wxevent/Climate_Narratives/sepclimate.htm)

1946 – Flooding

Twenty Five years after the Flood of 1921, another flood came to San Antonio in September of 1946, when heavy rains and floods came to San Antonio in the mid and late part of September 1946, leaving 15.78 inches of rain for September 1946. September 1946 was the wettest September of record for San Antonio, and 3rd wettest all time month.  Floods in September 1946 cost San Antonio six lives and $2.1 million in property damage.  Rainfall up to sixteen inches fell in south and southeast San Antonio and the San Antonio River peaked at 33.8 feet.  (Source: http://www.srh.noaa.gov/ewx/html/wxevent/Climate_Narratives/sepclimate.htm)

1935 – Flooding

The April showers of 1935 may or may not have brought May flowers. If they had, they would almost certainly have been swept away into the Gulf of Mexico. Central and South Central Texas experienced heavy rains that Spring which greatly affected Austin, San Antonio and lesser cities like Junction, Uvalde and D'Hanis.

In 1935, while Austin was receiving its deluge, San Antonio was hit even harder with 14.07 inches in May with 8.41 inches the next month. The stores around Alamo Plaza were flooded in late May.  (Source: http://www.texasescapes.com/TexasRivers/Texas-Flood-of-1935.htm)

September 7, 1921 Flooding

The San Antonio River floods on this day in 1921, killing 51 people and causing millions of dollars in damages. The flood was caused by some of the heaviest rainfall ever recorded in Texas.  The San Antonio River winds through southwest Texas, an area that is generally dry. However, on September 7, a storm stalled over the town of Taylor and dumped an astounding 23.11 inches of rain on the area in less than a day. It was the heaviest single day of rainfall in the state to that time.  The immense amount of rain quickly overwhelmed the river. Taylor is located 30 miles upstream from San Antonio, so the resulting flash flood went barreling toward the city. Most of the victims were trapped in their cars by the surprise flood and drowned. Five to 10 feet of water submerged the city’s streets, delaying an evacuation.  The city was under water for nearly a week following the flood. The flood was responsible for at least $5 million in damages in the then-small city. In the aftermath, San Antonio embarked on a 10-year overhaul of its levee system. (Source: http://docs.lib.noaa.gov/rescue/mwr/049/mwr-049-09-0494.pdf)