Water levels rose in already-submerged Houston early Monday as yet more rain was predicted across a region suffering from widespread flooding and more than 1,000 rescues in the wake of Hurricane Harvey.
Harvey has been blamed in at least two deaths in Texas, including one person who was found drowned inside their vehicle, according to officials.
The Army Corps of Engineers announced early Monday that it had begun releasing water from both major Houston-area dams — something that had never been done before. That decision came after levels in the Barker and Addicks reservoirs "increased dramatically" — by more than six inches per hour. Earlier Sunday, officials had said they did not plan to open the Barker dam until 11 a.m. on Wednesday.
“If we don’t begin releasing now, the volume of uncontrolled water around the dams will be higher and have a greater impact on the surrounding communities,” the corps' Col. Lars Zetterstrom said.
Opening the reservoirs will increase water levels in downtown Houston.
More than 20 inches of rain had fallen on areas near the country's fourth-largest city in 24 hours as of Sunday night, the National Weather Service said. And 15 to 25 more inches of rain could fall on a swath of the upper Texas coast to Lafayette, Louisiana, by Friday.
"Results could be devastating if any of these rains fall where catastrophic flooding has already occurred," the NWS warned.
More than 290,000 customers in the region were without power as at 5:30 a.m. ET Monday, utility companies said.
Dallas said it was preparing to open its "Mega Shelter" in the Kay Bailey Hutchison Convention Center to handle a stream of people displaced from Houston and other coastal areas.
Harvey weakened to a tropical storm but still posed a danger of devastating floods. Around 250 roads and highways in the state have been closed by floodwaters, Texas Gov. Greg Abbott said.
"People need to know that there are large and growing rescue teams that will be working around the clock to evacuate people in need," Abbott said on MSNBC, adding that 3,000 members of the National Guard had been activated.
Forecasters warned that the flooding in Texas could be historic.
The National Weather Service said average rainfall amounts in Harris County had already eclipsed the amounts seen in devastating Tropical Storm Allison in 2001 — and in about half the time.
A Houston woman whose home flooded early Sunday said the water began to build at 3 a.m. and did not stop. "I was thinking of writing my Social Security number on my arm," she told MSNBC.
Thousands of calls for help came in to first responders, and the city's mayor pleaded with people to call 911 only in life-threatening emergencies.
Houston police on Sunday night issued a call for boat owners to volunteer.
The U.S. Coast Guard sent assets from as far away as Maine and California to help, Vice Adm. Karl Schultz said. Helicopters and numerous boat crews were being used to assist in rescues, he said.
People were rescued from "pretty much everywhere," said Cmdr. Jim Spitler, commanding officer of Air Station Houston. "Most of them are rooftops, but they've been on top of cars, they’ve been on bridges, they’ve been in their attics."
He repeated warnings from authorities not to retreat to attics amid rising water, because people can be trapped and it makes rescue difficult, and he encouraged people who need help to mark their roofs.
The National Hurricane Center said the Houston area could see a total of 50 inches of rain. The storm was causing "unprecedented flooding" in southeastern Texas, it added.
"This is a life-threatening situation," said Michael Palmer, lead meteorologist for The Weather Channel.
Harvey was about 20 miles east of Victoria at 11 p.m. ET Sunday, with maximum sustained winds of 40 mph, the hurricane center said. The center of the storm is forecast to move off the middle Texas coast on Monday and meander just offshore through Tuesday.
President Donald Trump will travel to Texas on Tuesday. He signed a disaster declaration to help get federal funds to stricken areas. Abbott said Sunday that he expanded an initial request to 18 counties, including Harris County, where Houston is located, and that it had been approved.
Abbott praised the White House response and said he had spoken with Trump personally.
Brock Long, administrator of the Federal Emergency Management Agency, said Sunday that the recovery effort would take years.
"This is a long game. It's going to take a long time to heal," Abbott added. He called Harvey "a horrible tragedy."
Harvey caused damage along the Texas Gulf coast and inland, and the city of Rockport north of Corpus Christi was hit hard, officials said. Port Aransas was reportedly without power, water and telephone service, and every business in town was damaged.
Flood watches from San Antonio to Lafayette, Louisiana, covered 13 million people and were expected to be in place through midweek.
Stephanie Gosk and Aaron Franco reported from Houston. Phil Helsel reported from Los Angeles. Erin Dean reported from New York. Jason Cumming reported from London.
