A levee along the Brazos River south of Houston breached today due to heavy rains from Tropical Storm Harvey, forcing officials to call for residents to evacuate low-lying areas.

Matt Sebesta, the chief administrator of Brazoria County, urged residents of the Columbia Lakes neighborhood to leave.

"They need to get out. Get to higher ground in Angleton," the county seat, he said in a televised interview.

Columbia Lakes is located about 50 miles (80 km) from Houston, close to Brazos River.

The Houston area's rivers have started to flood. Harris County officials earlier today warned resident of six northern Houston neighborhoods to evacuate around two water reservoirs that had started overflowing.

President Donald Trump touched down in storm-ravaged Texas this afternoon, taking pains not to interfere with Harvey recovery efforts.

"This was of epic proportion," the president declared as he met with local officials.

White House press secretary Sarah Huckabee Sanders told reporters travelling with Mr Trump that the president's visit would focus on coordination among the levels of government and laying the groundwork for what is expected to be a lengthy recovery effort.

"The president wants to be very cautious about making sure that any activity doesn't disrupt the recovery efforts that are still ongoing," she said aboard Air Force One shortly before it touched down in Corpus Christi.

Mr Trump, who travelled with first lady Melania Trump and Cabinet secretaries who will play key roles in the recovery, was greeted at the airport by Texas governor Greg Abbott.

Some people lining roads near the airport held American flags and waved as the motorcade passed.

Mr Trump, who wore a white cap that said "USA", was scheduled to receive briefings on relief efforts while in Corpus Christi.

He was heading to Austin afterwards to meet with state officials at the emergency operations centre. Mrs Trump wore a black baseball cap that read "FLOTUS", an acronym for first lady of the United States.

"That's a big part of what today will be about, the coordination between local, state and federal officials and laying the groundwork for the recovery effort," Ms Sanders said.

Mr Trump has appeared to relish the role of guiding the nation's response to Harvey, which made landfall along the Gulf Coast on Friday night as a Category 4 storm near Corpus Christi, and moved north-east along the Texas coast over Houston.

Authorities have rescued thousands of people left stranded by the storm.

"Recovery will be a long and difficult road and the federal government stands ready, willing and able to support that effort," Mr Trump said.

Mr Trump promised that Congress would act swiftly to approve a large recovery package to help the Gulf Coast region and said he was likely to return to Texas, and make a stop in Louisiana, during the weekend.

Vice president Mike Pence said that Harvey's relentless nature and size were "frustrating".

In a pair of interviews with radio stations serving Corpus Christi and San Antonio, Mr Pence urged listeners to continue to follow instructions from local and state authorities, saying the storm remains dangerous and that life-threatening flooding will continue.
He said he and his wife, Karen, would visit the region later this week.

Mr Trump was likely to see a largely functioning Corpus Christi, a city of 325,000, where damage was minimal.
Power has largely been restored, particularly in commercial areas. Some restaurants have reopened and stores are restocked. Hotels are jammed with evacuees from hard-hit areas to its north-east, including Houston.
Residents have been advised to boil drinking water because authorities cannot guarantee the integrity of the city's lead and steel water system.