The remnants of Tropical Storm Imelda that flooded parts of Texas left at least two people dead and rescue crews with boats scrambling to reach stranded drivers and families trapped in homes.
Floodwaters had started receding in most of the Houston area, according to Houston Mayor Sylvester Turner said on Thursday night.
Police Chief Art Acevedo said law enforcement officers planned to work well into the night to clear freeways of vehicles stalled and abandoned because of flooding.
Officials in Harris County, which includes Houston, said there had been a combination of at least 1,700 high-water rescues and evacuations to get people to shelter during a relentless downpour that drew comparisons to Hurricane Harvey two years ago.
More than 900 flights were canceled or delayed in Houston.
The National Weather Service said preliminary estimates suggested that Jefferson County was deluged with more than 40 inches (102 centimeters) of rain in a span of just 72 hours, which would make it the seventh wettest tropical cyclone in U.S. history.
Even when Houston was finally rid of the worst, downtown highways remained littered with abandoned cars submerged in water. Thousands of other drivers were at a practical standstill on narrowed lanes near flooded banks.
Imelda made landfall as a tropical storm near Freeport, Texas, on Tuesday.
The Associated Press contributed to this article.