Hurricane Harvey has made landfall, stalling over the Texas coast and expected to cause "catastrophic and life-threatening flooding".

The National Weather Service's National Hurricane Centre also predicted up to 40 inches (102 cm) of rainfall in some areas on the southeast coast.

The hurricane hit Corpus Christi as a Category 4 storm with winds of up to 130 mph (209 kmh), but it has been downgraded to a Category 1 with sustained winds of 90 mph (145 kmh).

Despite the downgrade, Federal Emergency Management Agency (FEMA) chief Brock Long called it a "deadly inland event" as the storm progressed through the night.

The major damage to schools, public buildings, and several homes has been worst in and around Rockport, Texas, a community of about 10,000 people just northeast of Corpus Christi.

Emergency personnel - including local and state authorities - in the coastal community say there’s broad damage to buildings.

Rockport Volunteer Fire Department Chief Steve Sims told ABC News that early on 26 August that firefighters were taking cover at the city’s fire station, where they have been forced to wait for conditions to improve to respond to 25 to 30 emergency calls.

"As soon as the weather permits us, the winds get anywhere reasonable. We have been working on lists trying to prioritise the calls that we have waiting."

Residents of coastal cities and seven counties were urged to evacuate, but Rockport Mayor pro tem Patrick Rios warned: "if people are going to stay here, [they should] mark their arm with a Sharpie pen with their name and Social Security number."

"We hate to talk about things like that...It's not something we like to do but it’s the reality, people don’t listen," he said to ABC News.

In the afternoon of 26 August, Texas Governor Greg Abbott added 20 counties to the state's disaster declaration.

He pledged "all available resources" to the affected counties for search and rescue efforts as well as other matters.

There have been 338,000 power outages along the coast reported.

The mayor of Port Aransas, Texas Charles Bujan reported that a local trailer park experienced "100 per cent loss" according to the mayor, but it remains unclear if all the reported deaths are from the park.

The mayor of Rockport CJ Wax reported that one person has been killed, trapped in his home during a fire sparked by the storm. He was found early morning on 26 August by firemen.

The US Coast Guard has been continuously responding to distress calls from tugboats and other boats along the coast near Corpus Christie. They have dispatched at least two helicopter crews for assistance.

Hurricane Harvey seen approaching Texas from space

The Texas Military Department had deployed approximately 700 members of the State Guard and National Guard to the coastal region just ahead of the storm as well.

By mid-morning the hurricane had been downgraded to a Category 1, but rain and high winds continued to pummel the coast as the storm stalled over the area.

Despite the downgrade, Federal Emergency Management Agency (FEMA) chief Brock Long called it a "deadly inland event" as the storm progressed through the night.

Texas officials have evacuated thousands of inmates from prisons due to flooding from Hurricane Harvey.

Prisons in Brazoria County south of Houston, Texas is in particular danger as nearby Brazos River rises.

The Texas Department of Criminal Justice (TDCJ) says about 4,500 inmates from the Ramsey, Terrell, and Stringfellow Units in Rosharon are being taken by bus to other prisons in east Texas. They are being accompanied by additional police officers and prison staff to assist with the evacuation.

Additional food and water has been delivered to the prisons receiving the displaced inmates.

TDCJ has also set up an emergency command center for the storm, which has been and will continue to operate 24 hours a day for the duration of the state of emergency period.