At least eight people have been killed in Texas since powerful Tropical Storm Harvey struck the largest US state. More torrential rain is expected to pound the US Gulf Coast, as tens of thousands have bee displaced from their homes, officials said on Monday.
Harvey has already dumped more rain in the past few days than some affected areas normally see in a year.
Thousands of National Guard troops, police officers, rescue workers and civilians raced in helicopters, boats and special high-water trucks to rescue the hundreds stranded in the catastrophic storm that has crippled Houston, the nation’s fourth-largest city.
The storm was the most powerful hurricane to strike Texas in more than 50 years when it hit land on Friday near Corpus Christi, 220 miles (354 km) southwest of Houston.
The worst is far from over because the slow-moving storm will continue to dump rain over the next few days in an area hit by “unprecedented” flooding, the National Weather Service said.
“Additional heavy rainfall overnight is expected to worsen the flood situation in southeastern Texas and southwestern Louisiana,” the National Hurricane Center said.
Forecasts show that some spots in and around Houston could see an additional 12 inches (30 cm) of rain on Tuesday, bringing the total rainfall from Harvey to about 50 inches (127 cm) in parts of the city’s metro area.
US President Donald Trump plans to go to Texas on Tuesday to survey the damage and may also visit Louisiana, where the storm is now dumping rain.
Trump, facing the biggest US natural disaster since he took office in January, has signed disaster proclamations for Texas and Louisiana, triggering federal relief efforts.
Among the most recent fatalities from the storm was a family that included two adults and four children who were believed to have drowned after the van they were in was swept away by floodwaters in Houston, authorities said on Monday.
In scenes evoking the aftermath of Hurricane Katrina in 2005, police and Coast Guard teams have each rescued more than 3,000 people, plucking many from rooftops by helicopter, as they urged the hundreds more believed to be marooned in flooded houses to hang towels or sheets outside to alert rescuers.
Regina Costilla, 48, said she and her 16-year-old son had been rescued from their home by a good Samaritan with a boat. She worried until she was reunited with her husband and dog, who had been left behind because they did not fit into the boat.
Schools and office buildings were closed throughout the metropolitan area, home to 6.8 million people, as chest-high water filled some neighborhoods in the low-lying city.
The Federal Emergency Management Agency director Brock Long estimated that 30,000 people would eventually be housed temporarily in shelters.
Both of Houston’s major airports were shut, along with most major highways, rail lines and a hospital, where patients were evacuated over the weekend. More than a quarter of a million customers in the region were without power by Monday evening, utilities said.
The Brazos River was forecast to crest at a record high in the next two days about 30 miles (50 kms) southwest of Houston, forcing the mandatory evacuation of about 50,000 people in Fort Bend County, where officials described the predicted deluge as the worst in at least eight centuries.
Rising river and reservoir levels also forced evacuations in the counties of Brazoria and Galveston, near Houston.
As stunned families surveyed destroyed homes and roads flooded or clogged with debris, Texas Governor Greg Abbott warned Houstonians to brace for a long recovery.
“We need to recognize this is going to be a new and different normal for this entire region,” Abbott said.
Harvey’s center was in the Gulf of Mexico about 105 miles (170 km) south of Houston and forecast to arc slowly toward the city through Wednesday, adding more rain to areas already inundated.
The storm was expected to linger over Texas’ Gulf Coast for the next few days, dropping another 10 to 20 inches (25 to 50 cm) of rain, with threats of flooding extending into Louisiana.
The US Army Corps of Engineers said on Monday it was releasing water from the nearby Addicks and Barker reservoirs into Buffalo Bayou, Houston’s primary body of water, to prevent dangerous buildups.
In Rockport, National Guard troops distributed water to residents as utility crews worked to restore power, amid reports of sporadic looting.
Resident Savannah White, 20, welcomed the president's visit because she said Houston needed help.
"I'm glad to see him coming down here because it's in such bad condition," White said. "Pretty much destroyed, there's nothing left standing."
Houston did not order an evacuation due to concerns about putting its 2.3 million residents on the street, causing chaos on the roads that could be more deadly than the storm, Mayor Sylvester Turner said.
"Both the county judge and I sat down together and decided that we were not in direct path of the storm, of the hurricane, and the safest thing to do was for people to stay put, make the necessary preparations. I have no doubt that the decision we made was the right decision,” he said.
He added, "Can you imagine if millions of people had left the city of Houston and then tried to come back in right now?"
The Red Cross quickly set up the George R. Brown Convention Center and other venues as shelters.
By Monday night, 7,000 people have arrived at the shelter set up inside the George R. Brown Convention Center — which originally had an estimated capacity of 5,000.
Red Cross spokesman Lloyd Ziel said that volunteers made more space inside the center, which also was used to house Hurricane Katrina refugees from New Orleans in 2005, in part by pushing some cots closer together. A shortage of cots means some people will have to sleep on chairs or the floor.
The center settled down at night, after an occasionally chaotic day that saw thousands of evacuees arrive in the pouring rain.
In Washington, President Donald Trump's administration assured Congress that the $3 billion balance in the Federal Emergency Management Agency's disaster fund was enough to handle immediate needs, such as debris removal and temporary shelter for displaced residents.
The White House said Monday night that the president and first lady will visit Corpus Christi and Austin on Tuesday. They will receive briefings on the relief efforts by local leaders and organizations.