Weeks before the devastating flood in Kerrville would put a national spotlight on rural Texas’ underfunded flood warning systems, experts in San Antonio — considered a regional leader on the issue — were also caught off guard by rapidly-rising water.
Unusually heavy rain on June 12 caused more than a dozen vehicles to be swept off of San Antonio’s Perrin Beitel access road into the creek below it on the city’s Northeast Side. Search and rescue operations were also concentrated at Leon Creek near Highway 90 and Callaghan Road.
On this week’s episode of the bigcitysmalltown podcast, producer Cory Ames joins San Antonio River Authority (SARA) Deputy General Manager Rick Trefzer and Brendan Gibbons, board chair of River Aid San Antonio, to discuss how even some of the state’s most sophisticated flood control efforts failed to prevent the tragedy, which left 13 people dead.
“[We’re] trying to be the leader in the region for flood communication, flood planning … so our team was able to produce a report that really outlined what the conditions were of that event and some observations of things that could be improved,” he said, referencing a 36-page document the agency shared with the San Antonio Report.
San Antonio has spent the last century pioneering innovative flood solutions after a series of deadly floods in the early 1900s caused leaders to threaten to pave over the San Antonio River’s iconic downtown curve — home to the Riverwalk.
Today the city’s river authority is a partner with FEMA to update the region’s floodplain models, and its team of experts continuously monitor the potential for rain events, allowing them to manage rising water through a series of gates, dams and an underground tunnel.
But this June’s heavy rain surpassed professional estimates, Trefzer said, coming in at six to seven inches in a matter of two to three hours — compared to the two to four inches predicted by the National Weather Service.
“By 4 a.m. or 5 a.m. you were starting to see people starting to move around the city, and so that area, not being lit and not a low water crossing, contributed to people kind of coming onto this intersection … not knowing that there was two to three feet of water on the road.”
Under normal conditions, that level of water has the ability to pick up a car and move it. But Trefzer said these cars were thrust into a creek that had taken on more water runoff due to recent development in the area, and hasn’t undergone some of the flood mitigation efforts San Antonio is finding success with elsewhere.
“It’s well documented that the amount of impervious cover has an impact on how drainage happens, and the impact that it has when it gets into storm systems,” Trefzer said.
“We all know the development’s not going to stop, and so the decisions that we make related to nature-based solutions or how we design these drainage systems will have an impact in the future.”
San Antonio has been spending big on such efforts elsewhere in the city — through the Mission Reach project south of downtown and the forthcoming West Side Creeks restoration process — both of which involve removing old-school concrete channelizations and bringing land back to its natural state to reduce the volume and velocity of flowing water.
In the case of Beitel Creek, Trefzer said, an old channelization system shot the cars downstream at a rapid speed, slowing only when they reached a stretch where a county naturalization project had taken place.
“As tragic as it is, that’s where most of the vehicles had stopped, because of this improvement that was invested in many years ago to bring the land back to its natural state, slow the water down, let it infiltrate.”
As Texas lawmakers convene for a special session, Trefzer said that his agency will be looking to them to help fund additional flood control efforts they’ve already been researching on behalf of the entire region.
“We’ve done a lot of work studying some of these issues, and [plan to say] here are the recommendations that might address some [of them], obviously, not all, because the cost is so high,” he said.
Still, Trefzer cautioned, most modern flood infrastructure isn’t designed to support water rising at the levels of the San Antonio or Kerrville incidents, which have become more common as the region bounces rapidly between severe drought and flood conditions.
Such large-scale events will likely require continued improvements to warning systems, he said, and SARA is already working on ideas like integrating dangerous water crossings into navigation apps.
“We also know it’s difficult if you’re in transit, [and] most of these things are happening in a vehicle,” he said. “So we’re trying to find ways to push that information versus having people pull it.”
