Thousands of Arkansas, Oklahoma and Louisiana residents braced for more flooding Wednesday, and some evacuated their homes, as forecasts of further rain drove fears that decades-old levees girding the Arkansas River may not hold.

More than a week of violent weather, including downpours and deadly tornadoes, has lashed the central United States, bringing record-breaking floods to parts of the states, turning highways into lakes and submerging all but the roofs of some homes.

“This is a flood of historic magnitude,” Arkansas Governor Asa Hutchinson told a news conference Wednesday, joined by state and federal emergency officials. He said of the Arkansas River: “It’s a beautiful sight until it comes to get you.”

Arkansas River

Flooding has already closed 12 state highways, he said, and 400 households have agreed to voluntary evacuations.

Hutchinson sent a letter to U.S. President Donald Trump Wednesday asking for a federal emergency declaration for Arkansas.

The levee system along the Arkansas River “has not seen this type of record flooding” before, Hutchinson said in his six-page letter. Hutchinson said Trump had promised assistance in an earlier conversation, several media outlets reported.

More heavy downpours were forecast through Wednesday night over much of Oklahoma and Arkansas, with between 1 and 3 inches (2.5-7.6 cm) expected, said Patrick Burke, a meteorologist at the National Weather Service’s Weather Prediction Center.

Rivers were expected to crest by early June to the highest levels on record all the way down to Little Rock, Arkansas, Burke said.

Levees tested

In Tulsa, Oklahoma’s second largest city, Mayor G.T. Bynum warned that the city’s levees were being tested “in a way that they have never been before.”

He said the 20-mile (32 km) levee system, which protects some 10,000 people, was working as designed so far and being patrolled around the clock by the Oklahoma National Guard.

Staff at the Harvest Church West Tulsa, which sits behind a levee a few blocks from the Arkansas River, moved furniture and sound and office equipment from the basement to the church’s second floor and relocated staff out of the neighborhood.

“For levees that are 70 years old, they’re holding well but they’re not designed to hold the pressure this long, which is what the fear is at this point,” Chuck Barrineau, the church’s lead pastor, said in a phone interview.

At least six people have died in the latest round of flooding and storms in Oklahoma, according to the state’s Department of Health.

300 tornadoes

More than 300 tornadoes have touched down in the Midwest in the past two weeks. Tornadoes pulverised buildings in western Ohio on Monday, killing one person and injuring scores.

In Louisiana, the Mississippi River was also at record flood levels because of record-breaking rainfalls this spring, forecasters said.

Trump authorised emergency aid from the Federal Emergency Management Agency for the state late Wednesday.

Louisiana Governor John Edwards said on Twitter: “I thank President Trump for recognizing the urgency of our request and responding so quickly.”

In Baton Rouge, Louisiana, the Mississippi rose above flood stage in early January and has remained there since, forecasters said. (Reuters)

•Flood waters surround homes in Fort Smith, Ark., May 29, 2019. Flood waters from the Arkansas River continue to rise.

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