People seek shelter at the George R. Brown Convention Center in Houston. (John Taggart/For The Washington Post)

Harvey has driven nearly 35,000 people to emergency shelters across Texas, including 10,000 who were holed up in a downtown convention center on Wednesday waiting out the extensive flooding that has paralyzed this city.

Six days after the storm made landfall south of here, people continued to stream into the George R. Brown Convention Center and spilled over into other shelters as residents were forced from their homes due to record-setting rain and the resulting floods. The displaced milled in large halls and corridors, a somber and impatient crowd that officials said could be out of homes for a month or more as the low-lying city empties trillions of gallons of rainfall.

John Boyce, a 49-year-old cabdriver, fled his home over the weekend. He went from a rescue boat to a truck to a hospital, where he traded his soaked clothes for paper scrubs, and then by bus to the convention center Monday morning. There, he received fresh donated clothes, a blanket and a cot.

His life now is a lot of waiting.

Evacuees and volunteers at Purple Heart Recreational Center's ad hoc shelter described the conditions Aug. 29 in Lake Charles, La., where Tropical Storm Harvey continues its downpour. (Tom Moore,Monica Akhtar/The Washington Post)

“Wake up, stand in line to get breakfast, stand in line to brush your teeth, stand in line to use the bathroom, stand in line to do something with FEMA, stand in line for lunch,” he said as he stood in line for a lunch plate of spaghetti with meat sauce, salad and steamed carrots. He applied for Federal Emergency Management Agency aid and figured he’ll leave town to live with family in Dallas or Alaska. As soon as he can.

A huge population has been sheltered, clothed and fed in scores of shelters across the coastal region of Texas and Louisiana, and that population has been growing precipitously as reservoirs have overflowed, rivers have swelled to record crests and towns have been overwhelmed with water — some to the rooftops.

“This is so big we can only compare it with Katrina, and it’s heads and tails above Katrina,” said Holly Brundage, 64, a disaster mental health worker with the Red Cross who also aided with Katrina evacuation in Mississippi, referring to the large number of displaced from Harvey and what she considers to be a far more organized response.

Inside the convention center, throngs of volunteers register evacuees, administer light first aid, serve food, sort clothing, distribute supplies, and usher crowds amid a heavy presence of Houston police and state troopers. There is a children’s playroom full of toys and sleeping areas for families, men and women.

“This is a very solemn experience,” said Debbie Jared, 67, who works in the Aldine, Tex., school system, as she waited in line to volunteer. “You see the depth of humanity.”

A mega-shelter sprang up overnight Tuesday into Wednesday at the NRG Center, south of downtown Houston, after local officials became frustrated with overcrowding and delivery delays at Houston’s other shelters. By Wednesday afternoon, 900 people had arrived, and nearly twice as many were expected by day’s end.

Houston’s floodwaters are receding, but they remain dangerously high in many areas

At a glance, it seemed to have everything that someone with nothing might want: a pharmacy counter built out of plastic crates, a doctor, kennels for pets, a hot kitchen. And most of all, space — thousands of empty chairs at empty tables, and cavernous halls around the clusters of beds.

At one end of the center, from a small corner piled with toys, Angel McGee had procured a stuffed unicorn and walked with it down a great hall, back to her family’s collection of cots.

“It’s a little bit fun, but a little bit not,” the 11-year-old said.

The not-fun part, explained Angel’s mother, Lonetta Woodley, had been getting kicked out of a house where she, her mother and four children had sheltered from the hurricane. They then walked in the rain until they found refuge in a crowded high school in northeast Houston. They were bused to NRG the next day.

“I’m safe in here,” Woodley said through tears. “But, you know, after we gotta leave, where am I gonna go?”

Michelle McGowen, 35, walked around the shelter at a San Antonio middle school in her socks because none of the shoes that had been donated fit her.

On Friday night, as the storm moved through her home town of Aransas Pass on the coast, an uncle who stayed behind provided regular updates about McGowen’s mobile home, where she lives with her boyfriend and two young sons.

“He said the doors were falling off, windows were shattering in, and it was rocking back and forth,” McGowen said. “We’ve started from scratch before; we can do it again.”

On Saturday morning, she sat on a bench outside of the shelter with her sons before breakfast was served. As she watched them play, someone stole her phone from behind her on the bench. McGowen and her boyfriend kept both of their debit cards in her phone case, so they were gone as well.

The couple hasn’t heard from their family since Friday. McGowen said she borrowed someone’s phone to leave a Facebook message for her aunt, telling her the family was safe. Her sons, ages 9 and 11, ran around in the grass outside carrying fans they made out of green and black construction paper. They hope to be able to go to the movies, museums and zoo later this week after a disability check arrives on Friday.

Others had been through so many makeshift homes in the past week that they had no emotion left to show.

Ramon Meza, 50, said he slept in his truck outside an abandoned gas station for three days after water took his home in northeast Houston.

He made his way to a Walmart after he ran out of food, he said. But the store had no food, so by Tuesday he had found a school shelter. There, he had to sleep outside on the concrete with his dog, which was not allowed to come in.

Now at the NRG shelter, with his dog safe in a kennel, Meza had a bed indoors and was sitting in a half-empty dining room about to have his first hot meal in days. He has no long-term plans other than finding his truck.

How did he feel about all that? Meza just shrugged and bit into his burger.

Brittney Martin in San Antonio and Leslie Fain in Lake Charles, La., contributed to this report.