The peak of hurricane season has arrived for San Antonio and South Texas, according to the National Weather Service.
The weather service reports August and September are two of the busiest months for tropical storms to move inland from the Gulf of Mexico.
The deadliest and costliest tropical storm moved over San Antonio in 1921, according to Jason Runyen, a meteorologist with the National Weather Service office in New Braunfels. It had no name because storms were not named like they are today, he said.
Runyen said the remnants of the tropical storm flooded downtown San Antonio, killing 51 residents, and leaving behind $5 million in damage.
Runyen added that part of the storm's legacy is the visible landmarks built to prevent the future flooding of downtown.
“The 1921 flood as a historical note spurred the construction of the Olmos Dam and the bypass channel through downtown San Antonio that would later become the River Walk,” he said.
Runyen said in October 1998, the remnants of two Pacific hurricanes — Madeline and Lester — delivered a one-two-punch to the area that resulted in flooding that caused 11 deaths in Bexar County and 750-million dollars in damage.
That’s because San Antonio, like Austin, is pressed up against the Hill Country in "Flash Flood Alley," where flooded low water crossings claim the lives of motorists who try to drive through them, Runyen said.
“As to the whole state of Texas, half of the flash flood fatalities in the state of Texas occur in the (Interstate) 35 corridor from San Antonio to Austin and into the Hill Country, and many of those fatalities have occurred with tropical systems,” he said.
Nefi Garza, who manages storm waters for the city’s transportation and capital improvements department, said there are 156 low-water crossings in Bexar County, which are jointly monitored with the county.
“We have a computer system that we receive notification when water begins flowing and water begins rising and it even tells us the moment water goes over the road,” Garza said.
Garza said the city relies on crews to place barricades to keep motorists out of flooded low water crossings. He added the city has tried automated systems, where lights flash and arm poles drop once a monitor detects rising water, but they became targets for thieves.
“For some reason, people like stealing the lights off of them or stealing the actual poles, so we're constantly repairing those, and so we have gone away from that and we are actually phasing those out,” he said.
The Texas Department of Public Safety also reports that most of the people killed in flooding in the state are motorists who drive into flood water.
Sergeant Orlando Moreno of the local DPS office said it only takes a foot of water to sweep a 3,000-pound vehicle off a flooded road, and you can’t always trust the flood gauge on the side of the road to judge how deep the water is.
“When water is covering the road, you can’t see what is underneath that, so sometimes the road may be washed out below the water line, and people feel like the water does not look very high, and once they enter it there is no road there and the car can become stuck and then as the water rises it gets carried off,” he said.
Moreno said in preparation for a major storm, make sure to stock up on a few days supply of water and food in case flooding and high winds knock out the power.
Moreno said be familiar with evacuation routes in advance in case a government agency asks for residents to move to higher ground.
He said the disabled and elderly have special needs during evacuations, so have those preparations in advance, too. Moreno said many people also forgot about their household pets when Harvey hit last summer.
“Pets were left behind by necessity, and so it's important to keep them in mind when you are evacuating also,” he said.
Also, for those living in a flood-prone area, buying flood insurance well in advance of potential flooding is encouraged, Moreno said.
“There are a lot of times these flood policies have a 30 day waiting period before they even take effect,” he said.
Hurricane season is over at the end of November.
Brian Kirkpatrick can be reached at tpr.org