While people were sleeping, Tropical Storm Harvey's bands of torrential rain whipped across the city and neighboring counties in waves.
At least one death has been attributed to the floods. The body of a woman was found floating down a street in west Houston late Saturday night.
A doctor attempted to save her, but it was too late.
WATCH: Flood victims forced to climb into attics
Overnight, families were forced to take extreme measures to escape as a deluge of rain sent rising waters into homes from one corner of the region to the next.
The Harris County Flood Control District said people were climbing into their attics just to get away from the rising water.
Two-story homes in Dickinson and areas near Clear Creek in South Houston were taking on water in their upper floors, said Jeff Lindner, with HCFCD.
Patrick Renteria managed to escape from his home near Edgebrook and Old Galveston Road in southeast Houston, but only after making calls for more than three hours for rescue.
Calls to HCFCD of people climbing into their attics. Flooding in SE Harris County is equal to or greater than TS Allison #houwx— Jeff Lindner (@JeffLindner1) August 27, 2017
Boats took him to a Texas Task Force One truck, which dropped him off near the Seller Brothers grocery store.
He fought back tears as he explained to reporter Jeff Ehling that he carried all he could in two garbage bags. That is all he has left, he said.
Renteria said there is at least three feet of water inside the home he has lived in for nearly 10 years. He said the neighborhood has never flooded as long as he's lived there.
Not far from homes taking on water, reporter Deborah Wrigley said drivers on the Gulf Freeway were facing the dual dangers of high water and people driving on the wrong side of the highway overnight.
Several times, Wrigley said there were near collisions as wrong-way drivers sped against traffic in an effort to avoid being flooded out.
WATCH: Bus and truck nearly collide on Gulf Freeway during flood
Further south down the Gulf Freeway, the National Weather Service said a tornado damaged apartment units in La Marque.
In Greenspoint, we found Houston Police Chief Art Acevedo out with his officers, evacuating residents flooded out.
We saw police loading children and families into Humvees as the waters crept up, many carrying personal belongings stuffed inside trash bags.
When the Humvees left, a line of people were left standing in the pouring rain awaiting the arrival of more vehicles that would transport them to safety.
Acevedo said despite many warnings, some people took the risk of driving during the storm and are now suffering the consequences.
"I don't think that the community realizes when we tell them stay put, they're not getting it," Acevedo said. "We had hundreds of cars along 59, 45, on the frontage road, it's all flooded. This is a multi-day event, Mayor Turner has been saying that for days, and people are just not understanding that."
ABC13 Chief Meterologist Tim Heller cautioned families who see water inching closer to their homes not to go to sleep until a plan is in place.
This is the time to raise your furniture up on blocks, bricks, books or anything you can to keep them from being drenched in water, should it come into your home.
Tim said you should consider how to store your most precious belongings so they do not get wet.
This is a serious and continuing situation, with more rain expected throughout the day and beyond.
WATCH: HPD chief says people haven't listened to warnings
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