(Adds NHC statement, details of latest deaths, planned Pence visit, 250,000 without power, Reuters property damage estimate)
LAKE CHARLES, La./HOUSTON, Aug 30 (Reuters) - Tropical Storm Harvey spun across southeastern Texas into Louisiana on Wednesday, sending more people fleeing for shelter after swamping Houston with record rains and flooding that killed at least 25 and drove tens of thousands from their homes.
The storm has forced 32,000 people into shelters since coming ashore on Friday as the most powerful hurricane to hit Texas in half a century. On Wednesday, it pummeled the coast from Port Arthur, Texas, to Lake Charles, Louisiana.
Harvey weakened to a tropical depression on Wednesday night, the U.S. National Hurricane Center said, but the forecaster warned that "catastrophic and life threatening flooding will continue in and around Houston, Beaumont/Port Arthur, eastward into southwest Louisiana for the rest of the week."
Among the latest deaths reported were a married couple who drowned while driving through high water near Simonton, Texas, Major Chad Norvell of the Fort Bend County Sheriff's Office said on Twitter. The Houston Chronicle identified the victims as Donald and Rochelle Rogers of Katy, Texas.
Houston's KHOU-TV reported that an infant girl was swept away after her parents got out of their pickup truck near New Waverly, Texas, and tried to carry her across rushing water.
Police in Harris County, home to Houston, said 17 people remained missing.
Busloads of people fleeing floodwaters around Port Arthur arrived in Lake Charles, joining local residents who had already packed into shelters to escape waterlogged homes. About 254,000 homes and businesses were without power in Texas and Louisiana, according to figures from four utilities.
Harvey was forecast to drop a further 3 to 6 inches (7.5-15 cm) of rain on Wednesday, with a storm surge of up to 4 feet (1.2 m) along the western part of Louisiana's Gulf Coast, although the Houston area was finally expected to get a break with no rain forecast for Thursday or Friday.
The floods shut the nation's largest oil refinery in Port Arthur in the latest hit to U.S. energy infrastructure that has sent gasoline prices climbing and disrupted global fuel supplies.
ANOTHER WEEK OF FLOODING
Moody's Analytics is estimating the economic cost from Harvey for southeast Texas at $51 billion to $75 billion, ranking it among the costliest storms in U.S. history.
At least $23 billion worth of property has been affected by flooding from Harvey just in parts of Texas' Harris and Galveston counties, a Reuters analysis of satellite imagery and property data showed.
"The worst is not yet over for southeast Texas as far as the rain is concerned," Governor Greg Abbott said.
He warned residents of storm-hit areas to expect floodwaters to linger for up to a week and said the area affected was larger than that hit by 2005's Hurricane Katrina, which killed more than 1,800 people in New Orleans, and 2012's Superstorm Sandy, which killed 132 around New York and New Jersey.
The population of Houston's metropolitan area is about 6.5 million, far greater than New Orleans' at the time of Katrina. Abbott asked that the federal government spend more on rebuilding Texas' Gulf Coast than it did after the earlier storms.
A day after visiting Texas to survey the damage, U.S. President Donald Trump pledged on Wednesday to stand by the people of Texas and Louisiana.
"We are here with you today ... and we will be with you every single day after to restore, recover and rebuild," he said during an appearance in Springfield, Missouri.
The storm made it less likely Trump would act on his threat to shut the federal government over funding for a border wall with Mexico, Goldman Sachs economists said. They now estimate that probability at 35 percent, down from 50 percent previously.
Vice President Mike Pence and several Cabinet secretaries will travel to Texas on Thursday to meet with residents affected by the storm as well as local and state officials, Pence's press secretary said.
CLEAR SKIES IN HOUSTON
Clear skies in Houston on Wednesday brought relief to the energy hub and fourth-largest U.S. city after five days of catastrophic downpours. The first flight out of Houston since the storm hit had boarded, city officials said on Wednesday evening. Mayor Sylvester Turner said he hoped the port of Houston would reopen soon.
But disruptions lingered and even some of the people helping evacuees in Houston said they had lost their homes.
Even those who safely evacuated found further suffering as floodwaters inundated part of Port Arthur's Bob Bowers Civic Center, forcing evacuees into the bleachers.
A shelter in Lake Charles was bracing for about 1,500 people rescued from floods by the U.S. Coast Guard, said Angela Jouett, who is running the shelter.
Among them was Jacelyn Alexander, 41, who woke up at 4 a.m. when her neighbor in an Orange, Texas, apartment complex warned her the building was flooding. She flagged a rescue boat and escaped.
"I can't move. I'm wet and tired. I'm trying to find my family," said Alexander, who last spoke with her parents early in the morning when her father told her by phone he had declined a rescue.
Disputes flared at some shelters, with at least one arrest reported.
Harvey made landfall for a third time early on Wednesday, and was about 50 miles (80 km) north of Lake Charles, near the Texas border at 4 p.m. CDT (2100 GMT), the U.S. National Hurricane Center said.
Texas officials said close to 49,000 homes had suffered flood damage, with more than 1,000 destroyed. Some 195,000 people have begun the process of seeking federal help, FEMA said.
The nation's largest refinery, Valero Energy Corp's facility in Port Arthur was shut, according to sources familiar with plant operations.
The storm has shut about one-quarter of U.S. fuel production, sending gasoline futures surging to a two-year high on Wednesday.
Royal Dutch Shell sent staff back to the Perdido oil and gas platform in the U.S. Gulf of Mexico to begin to restart production.
(Additional reporting by Richard Valdmanis, Mica Rosenberg, Marianna Parraga, Gary McWilliams, Ernest Scheyder, Erwin Seba, Ruthy Munoz, Peter Henderson and Andy Sullivan in Houston, David Gaffen in New York, James Oliphant in Springfield, Mo., Jon Herskovitz in Austin, Texas, and Brendan O'Brien in Milwaukee; Writing by Scott Malone and Dan Whitcomb; Editing by Tom Brown and Peter Cooney)