The Houston area was under threat of worsening flood conditions Saturday, a day after heavy storms slammed the region and authorities warned those in low-lying areas to evacuate ahead of an expected “catastrophic” surge of water.

A flood watch remained in effect through Sunday afternoon as forecasters predicted additional rainfall Saturday night, bringing another 1 to 3 inches of water to the soaked region and the likelihood of major flooding. In total, about 11 million people in Texas and Oklahoma are under flood warnings and watches this weekend. 

Friday’s storms forced numerous high-water rescues, including some from the rooftops of flooded homes. Nearly 200 such rescues have been recorded. One such incident was caught on camera, as someone filmed a large truck being swept away as its driver jumped from the cab. The driver was later rescued. 

Officials redoubled urgent instructions for residents in low-lying areas to evacuate, warning the worst was still to come.

“This threat is ongoing and it’s going to get worse. It is not your typical river flood,” said Harris County Judge Lina Hidalgo, the top elected official in the nation’s third-largest county. 

She described the predicted surge of water as “catastrophic” and said several hundred structures were at risk of flooding. There had already been at least two dozen water rescues in the county, in addition to getting 30 pets to safety. Schools in the path of the flooding canceled classes and roads jammed as authorities closed highways taking on water.

For weeks, drenching rains in Texas and parts of Louisiana have filled reservoirs and saturated the ground. Floodwaters partially submerged cars and roads this week across parts of southeastern Texas, north of Houston, where high waters reached the roofs of some homes. Hundreds of structures are flooded, and more are dealing with power outages. 

More than 11 inches of rain fell during a 24-hour period that ended Friday morning in the northern Houston suburb of Spring, according to the National Weather Service.

In the rural community of Shepherd, Gilroy Fernandes said he and his spouse had about an hour to evacuate after a mandatory order. Their home is on stilts near the Trinity River, and they felt relief when the water began to recede on Thursday.

Then the danger grew while they slept.

“Next thing you know, overnight they started releasing more water from the dam at Livingston. And so that caused the level of the river to shoot up by almost 5 or 6 feet overnight,” Fernandes said. Neighbors who left an hour later got stuck in traffic because of flooding.

In Montgomery County, Judge Mark Keough said there had been more high-water rescues than he was able to count.

“We estimate we’ve had a couple hundred rescues from homes, from houses, from vehicles,” Keough said.

In Polk County, located about 100 miles northeast of Houston, officials have done over 100 water rescues in the past few days, said Polk County Emergency Management Coordinator Courtney Comstock.

She said homes below Lake Livingston Dam and along the Trinity River have flooded.

“It’ll be when things subside before we can do our damage assessment,” Comstock said.

The U.S. Coast Guard said they evacuated via helicopter an hours-old baby from Cleveland, Texas amid the floodwaters. The baby, who was just 12 hours old, was reportedly experiencing low oxygen levels at Texas Emergency Hospital. The hospital does not have a neonatal intensive care unit, and flooding made it impossible to transport the baby to another facility via ambulance. The helicopter crew transported the baby, mother and a paramedic to Texas Children’s Hospital in Houston. The baby is in stable condition, the Coast Guard said. 

Authorities in Houston had not reported any deaths or injuries. The city of more than 2 million people is one of the most flood-prone metro areas in the country and has long experience dealing with devastating weather.

Hurricane Harvey in 2017 dumped historic rainfall on the area, flooding thousands of homes and resulting in more than 60,000 rescues by government rescue personnel across Harris County.

Of particular concern was an area along the San Jacinto River in the northeastern part of Harris County, which was expected to continue rising as more rain falls and officials release extra water from an already full reservoir. Judge Hidalgo on Thursday issued a mandatory evacuation order for those living along portions of the river.

Most of Houston’s city limits were not heavily impacted by the weather, except for the northeastern neighborhood of Kingwood. Officials said the area had about four months of rain in about a week’s time. Houston Mayor John Whitmire said rising flood waters from the San Jacinto River were expected to impact Kingwood late Friday and Saturday.

Shelters have opened across the region, including nine by the American Red Cross.

The weather service reported the river was above 69 feet around noon Friday and expected to crest at 78 feet (23.7 meters) Friday night. The river is expected to fall below the flood stage of 58 feet on Tuesday afternoon, according to the weather service.

The greater Houston area covers about 10,000 square miles — a footprint slightly bigger than New Jersey. It is crisscrossed by about 1,700 miles of channels, creeks and bayous that drain into the Gulf of Mexico, about 50 miles to the southeast from downtown.

The city’s system of bayous and reservoirs was built to drain heavy rains. But engineering initially designed nearly 100 years ago has struggled to keep up with the city’s growth and bigger storms.

Residents in rural central and west Texas are also working to recover from tornadoes that left a trail of damage. In Hawley, Texas, two people were hurt Thursday, and the twisters left a trail of damage. This weekend’s storms pose the threat of more tornadoes. 

Texas isn’t the only area facing severe weather this weekend. Americans from Louisiana to Oregon are under the threat of severe, slow-moving storms. In Oregon’s Cascades region, a winter weather warning was issued as the region braces for at least a foot of snow, according to local media. 

Vice President Kamala Harris canceled a planned trip to a music festival in Las Vegas, Nevada after the event was canceled due to a high wind warning. Organizers said they are expecting winds between 30 and 35 miles per hour, with gusts of up to 60 miles per hour.