HOUSTON — According to the National Weather Service, rainfall in Houston can reach 40-50 inches. A flash flood warning is in effect until Monday morning.
The NWS is warning people not to travel in the affected area if they are in a safe place and are warning people not to drive into flooded roadways.
While officials coordinate the response, people on the ground are facing difficult odds. Newest information indicates five people are dead as the storm continues to pound the gulf coast of Texas with devastating rains.
Emergency crews are using choppers to rescue people trapped by flood waters. And it's only going to get worse.
About 3,000 National Guard troops have been activated and Houston schools are closed for the rest of the week. President Donald Trump plans to visit Texas as early as Tuesday.
Houston Mayor Sylvester Turner said he has no regrets about not calling for an evacuation of Houston residents ahead of Tropical Storm Harvey.
Turner reiterated at a Sunday night news conference that the best course of action was for residents in Houston and surrounding areas to stay in place.
Factors in his decision included not knowing where Harvey, when it was still a hurricane, was headed and the "crazy" logistics of trying to plan an evacuation of 2.3 million people within a couple of days.
Turner also cited the experience the city had when residents evacuated ahead of Hurricane Rita in 2005 and gridlocked local roadways, leaving many people in traffic for more than 20 hours as they fled the city and resulting in dozens of deaths. Rita had been predicted to hit Houston but ended up making landfall well east of the city.
"The decision that we made was a smart one. It was in the best interest of Houstonians," he said. "It was the right decision in terms of their safety and always we must put the interests of the city and Houstonians first. That's exactly what we did. We did what was the right thing to do."
Turner said he has no concerns that the shelter that has been set up at the George R. Brown Convention Center will turn into New Orleans' Superdome following Hurricane Katrina. At the football stadium, 30,000 evacuees spent days packed inside the sweltering dome with limited power and water and a roof that was shredded in the howling wind.
"I think in this city we know how to do it in such a way that is not chaotic. It's respectful, it's dignified," Turner said.
Turner said he wants to transition people staying at the shelter to more suitable housing as quickly as possible.
Rising floodwaters from the remnants of Hurricane Harvey chased thousands of people to rooftops or higher ground Sunday in Houston, overwhelming rescuers who fielded countless desperate calls for help.
A fleet of helicopters, airboats and high-water vehicles confronted flooding so widespread that authorities had trouble pinpointing the worst areas. Rescuers got too many calls to respond to each one and had to prioritize life-and-death situations.
The turbid water rose high enough to begin filling second floors — a highly unusual sight for a city built on nearly flat terrain. Authorities urged people to get on top of their homes to avoid becoming trapped in attics and to wave sheets or towels to draw attention to their location.
Gillis Leho arrived soaking wet at the city's main convention center, which was being used as a shelter. She said she awoke to find her downstairs flooded. She tried to move some belongings upstairs, then grabbed her grandchildren.
"When they told us the current was getting high, we had to bust a window to get out," Leho said.
Harris County Sheriff Ed Gonzalez used Twitter to field calls for assistance. Among those seeking help was a woman who posted: "I have 2 children with me and the water is swallowing us up."
Some people used inflatable beach toys, rubber rafts and even air mattresses to get through the water to safety. Others waded while carrying trash bags stuffed with their belongings and small animals in pet carriers.
As the floodwaters rose, the National Weather Service offered another ominous forecast: Before the storm passes, some parts of Houston and just west of the city could receive as much as 50 inches (1270 millimeters) of rain. That would be the highest amount ever recorded in Texas.
"The breadth and intensity of this rainfall is beyond anything experienced before," the National Weather Service said in a statement.
Average rainfall totals will end up around 40 inches (1016 millimeters) for Houston, weather service meteorologist Patrick Burke said.
Rainfall of more than 4 inches per hour resulted in water levels higher than in any recent floods and higher than during Tropical Storm Allison in June 2001, said Jeff Linder of flood control district in Harris County, which includes Houston.
The latest forecasts showed that 15 to 25 more inches (38 to 63 centimeters) was possible over the next several days, with some places getting as much as 50 inches (127 centimeters) total, the National Hurricane Center announced.
Rescue came by land, water and air.
CNN report that rescuers were able to save nursing home residents from La Vita Bella nursing home in Dickinson, Texas, after the residents were trapped in the hurricane's floodwaters.
A photo went viral on Twitter on Sunday showing residents at the nursing home sitting in waist-deep water
On Interstate 45 south of downtown, television video showed people climbing over concrete dividers to get to a high-wheel dump truck that appeared to be wheels-deep in water on a service road. They clambered up the side of the truck to get into the dump box.
In Friendswood near Houston, authorities asked people with flat-bottomed airboats or fuel for them to help rescue people.
Jesse Gonzalez, and his son, also named Jesse, used their boat to rescue people from a southeast Houston neighborhood. Asked what he had seen, the younger Gonzalez replied: "A lot of people walking and a lot of dogs swimming."
"It's chest- to shoulder-deep out there in certain areas," he told television station KTRK as the pair grabbed a gasoline can to refill their boat.
The Coast Guard, which received more than 300 requests for help, deployed five helicopters and asked for additional aircraft from New Orleans.
Staff at a Houston television station broadcasting live coverage of the floods had to evacuate after water from the nearby Buffalo Bayou started to gush into the building. The anchors and news operations at KHOU-TV moved first to a second floor before finally abandoning the station.
The director of the Federal Emergency Management Agency, Brock Long, said the government expected to conduct a "mass care mission" and predicted that the aftermath of the storm would require FEMA's involvement for years.
"This disaster's going to be a landmark event."
President Donald Trump tweeted Sunday morning that he would visit Texas.
"I will be going to Texas as soon as that trip can be made without causing disruption," the president posted on Twitter. "The focus must be life and safety."
The rescues unfolded a day after the hurricane settled over the Texas coastline. It was blamed for killing at least two people and injuring up to 14.
Anxiety ran high throughout the region between Corpus Christi and Houston because some of the areas with the greatest hurricane damage were inaccessible to rescuers.
One person was killed in Aransas County when in a fire at home during the storm, county Judge C.H. "Burt" Mills Jr. said.
Another person — a woman who tried to get out of her vehicle in high water — died in flooding in Harris County, where Houston is located, , though authorities had not confirmed a cause of death, said Gary Norman, a spokesman for the Houston emergency operations center.
Meanwhile, rainfall totals climbed by the hour. By midday, South Houston had received nearly 25 inches (63 centimeters) and the suburbs of Santa Fe and Dayton got 27 inches (69 centimeters).
The fiercest hurricane to hit the U.S. in more than a decade came ashore late Friday about 30 miles (48 kilometers) northeast of Corpus Christi as a mammoth Category 4 storm with 130 mph (209 kph) winds.
Harvey weakened Saturday to a tropical storm. By Sunday morning the system was centered about 65 miles southeast of San Antonio, with maximum sustained winds of about 45 mph (72.42 kph), according to the hurricane center, which described the flooding as "catastrophic."
Harvey arrived as the fiercest hurricane to hit the U.S. in 13 years and the strongest to strike Texas since 1961's Hurricane Carla, the most powerful Texas hurricane on record.