Person-place-time analysis of vehicle fatalities caused by flash floods in Texas

Figures & data

Figure 1. Road inundation caused by flash floods in San Antonio. Courtesy of the City of San Antonio (used with permission). Available in colour online.

Figure 2. The Flash Flood Alley. Obtained from the Flood Safety Education Project http://www.floodsafety.com (used with permission). Available in colour online.

Table 1. The five states with the highest numbers of total flood fatalities, 1959–2009.

State	Number of fatalities
Texas	854
Pennsylvania	265
California	248
South Dakota	244
Virginia	237

Table 2. Flood fatalities classified by flood type.

Flood type	Fatalities	Percentage
Flash flood	584	68%
Flood	221	26%
Flood due to tropical storms	42	5%
Coastal/tidal/river flooding	7	1%

Table 3. Number of motor vehicle-related flood fatalities classified by age. The age is not provided in Storm Data for 149 fatalities.

Age group	Fatalities	Percentage
0–9	26	13%
10–19	26	13%
20–29	39	19%
30–39	17	8%
40–49	24	12%
50–59	28	14%
60–69	21	10%
70–79	14	7%
80–89	7	4%

Table 4. Number of flash flood fatalities classified by activity/location. The activity/location is not provided in Storm Data for 144 fatalities.

Activity/location	Fatalities	Percentage
Boat	8	2%
In water	65	15%
Mobile home	6	1%
Permanent home	10	2%
Vehicle	351	80%

Figure 3. Motor vehicle-related flash flood fatalities in Texas from 1959 to 2009. Available in colour online.

Figure 4. Motor vehicle-related flash flood fatalities in Texas and mean precipitation in the Flash Flood Alley region by month. Available in colour online.

Table 5. Texas counties with the highest numbers of vehicle fatalities caused by flash floods.

County	Fatalities
Bexar	30
Tarrant	30
Travis	24
Dallas	22
Harris	16
Kerr	16
Edwards	12
Bell	11
Real	9
Burnet	8

Figure 5. Map of motor vehicle-related flash flood fatalities by Texas county. Available in colour online.

Table 6. Number of motor vehicle fatalities caused by flash floods classified by time of occurrence. The time is not provided in Storm Data for 45 fatalities.

Time	Fatalities	Percentage
Morning	84	35%
Afternoon	57	10%
Night	165	55%

Figure 6. Map of some of the low water crossings in San Antonio. Courtesy of the City of San Antonio (used with permission). Available in colour online.

Table 7. Examples of Storm Data descriptions of the circumstances that led to vehicle fatalities caused by flash floods.

Date	County	Storm Data narrative
8/16/2007	Bexar	The area of extremely heavy rainfall associated with the remains of Tropical Storm Erin continued to spread northwestward across Bexar County, with a general 4 to 5 inches of rain over the county. Near midnight a young woman was driving with three friends and a baby near North Star Mall when she accidentally drove her sport utility vehicle into deeper water where it was slammed against a bridge and then was swept into a drainage ditch. The three other adults in the vehicle were able to get the baby out of the vehicle through the window and escape. But when the three looked back for the driver, she was gone. Her body was found later by emergency responders when the water receded.
9/05/2007	Bexar	Up to 2 inches of rain fell over the northwestern part of the county. At around 1:00 am a man and a woman were washed away in a four door sedan as they attempted to cross the Tower View Bridge on Scenic Loop Road, which was in flood due to Helotes Creek. The man was later rescued with minor bruises to his arms and torso. The woman's body was found less than a mile downstream at 3:19 pm.
3/30/2008	San Augustine	Widespread flooding reported across the northern portion of the county. Flooding was severe on County Road 21 in town and at the circle and along County Road 103. Three foot of water was also reported over Highway 3079. One fatality was reported when two people driving on State Highway 21 ran into a ditch and became caught in swift moving water. One occupant in the vehicle was swept away in the vehicle.
4/12/2009	Harris	Heavy rainfall persisted across the county as several thunderstorms produced rainfall totals of 8 to 10 inches across the county. Numerous roads were closed in areas of the county, including Jersey Village, Houston Heights, La Porte, Pasadena, Webster, and near the Houston Hobby airport. The highest one hour rainfall total was 6.90 inches recorded at Bay Area Blvd and Clear Creek. This exceeds the highest one hour rainfall rate measured during Tropical Storms. In the northern part of the county five children were killed after the car they were riding in inadvertently drove into a drainage ditch that was filled with nine feet of water from the heavy rainfall. Two adults and one child were able to escape the floodwaters, but the five younger children, all under 7 years old, were not able to escape.
5/03/2009	Upshur	Numerous counties and parishes were flooded with rainfall amounts in excess of 6 inches in a 12 hour period common. A 78 year old man drowned when flood waters swept away his automobile on a rural northwestern Upshur County Road. The man was found in his back seat on Fox Road.
10/21/2009	Burnet	A woman was killed while trying to cross a low water crossing. Karen Eichelberger, age 47, was driving home after working in Austin this Wednesday night. She tried to cross the flooded low water crossing on Deer Springs Drive in her neighbourhood when her 1994 Jeep was apparently forced off the road and into the creek. Her body was found one half mile downstream from where the Jeep was located.