Back From the Flood: Waymo Restarts San Antonio Rides With Water-Avoidance Upgrades

Waymo has restarted paid robotaxi service in San Antonio five months after a flash flood swept an empty vehicle off the road, with software and map changes aimed at standing water, TechCrunch and local outlets reported.

Sam Okonkwo, Robotaxi · Sept. 17, 2026 · 5-6 min

TechCrunch

SAN ANTONIO - Waymo has restarted its robotaxi service in San Antonio five months after an empty vehicle was swept away in a flash flood, returning paid rides after software and operational changes meant to detect and avoid standing water, TechCrunch reported.

The resumed service covers a 60-mile area that includes downtown and San Antonio International Airport, with dozens of vehicles, according to the San Antonio Express-News, which first reported the restart. Airport trips are included, local stations said.

Multiple Waymo robotaxis got stuck during heavy flooding in April. The vehicles slowed but did not stop as they approached waterlogged streets. The most serious case was April 20, when an unoccupied Waymo entered floodwaters on an Interstate 35 frontage road at Salado Creek and was swept away. No one was injured. The car was recovered days later.

Waymo paused San Antonio passenger service after that incident, its longest stoppage in the city. In May the company filed a voluntary software recall with NHTSA covering 3,791 vehicles across its U.S. fleet. NHTSA said the software could allow a vehicle to slow and then drive into standing water on higher-speed roadways, raising the risk of a loss of control.

Waymo said Thursday it completed software updates and operational changes aimed at improving how its vehicles detect and avoid floodwaters. The company said it reviewed potential flooding zones across San Antonio using several data sources and added location-specific limits in high-risk areas. It also adjusted weather alerts and operating triggers so it can change service quickly during heavy rainfall, and it uses National Weather Service and local guidance to monitor conditions.

The company said the latest updates improve the Waymo Driver's ability to detect flooded roads and navigate away from them when necessary, and that those improvements have already been tested in other cities that continued operating through the summer. Waymo briefly paused operations in other Texas cities around the April storms and has since resumed those services. It now offers paid rides in 15 U.S. cities.

"Safety is our highest priority," Robert Chen, Waymo's product lead for weather, said in a statement. "We took the time to implement key software updates and operational improvements around flood waters, and have thoroughly validated our technology on local roads."

Waymo told the Express-News the software changes will help robotaxis better detect and avoid standing water. The company also said severe weather may cause another temporary pause when needed, with service resuming when it is safe to do so.

The April 20 incident was not the city's only high-water problem. An earlier flood-related case occurred near McCullough Avenue and Contour Drive. Waymo has said it identified an area of improvement on untraversable flooded lanes on higher-speed roads and put mitigations in place, including refining extreme-weather operations and limiting access to areas where flash flooding might occur.

San Antonio launched in late February. The local fleet remains a few dozen cars, smaller than markets such as San Francisco. Riders are back on the app. Whether the water-avoidance stack holds will be tested the next time the city's creeks rise.

Sam Okonkwo, Robotaxi. Sam Okonkwo is a senior correspondent covering robotaxis, fleet ops, and paid driverless service. Previously reported transport tech for trade titles; based in Austin.