In Pictures: Heavy rain causes havoc in Houston

A resident walks down a flooded street in the upscale River Oaks neighbourhood of Houston after it was inundated with water from Hurricane Harvey (27 August 2017)Getty Images

Heavy rain in the aftermath of Hurricane Harvey has caused chest-high flooding in some parts of the city of Houston.

A man helps a neighbour down a street in Houston after rescuing her from her home in his boat in River Oaks, Houston (27 August 2017)Getty Images

Some roads have turned to rivers along which the only way to rescue evacuees was by boat.

Flooded in central Houston (27 August 2017)Reuters

More than 25in (64cm) of rain has fallen in some parts of Houston, with a further 12 to 25in (30-64cm) expected over the next few days, the National Weather Service forecast.

Volunteers and officers from a neighbourhood security patrol in Houston help to rescue residents in River Oaks, 27 August 2017Getty Images

Such heavy rainfall in Houston is unprecedented, officials say, with recent rainfall equalling the average for an entire year.

A resident of Bayou on the Bend watches the first floor flood as the Buffalo Bayou continues to rise in Houston (27 August 2017)Getty Images

Overwhelmed emergency services have cautioned residents to head for high ground or climb onto rooftops - but not into attics - so they can if necessary be picked up by rescue helicopters. More than 1,500 rescues have been carried out so far.

Mist covers central Houston after Hurricane Harvey inundated the Texas Gulf coast with rain and caused widespread flooding (27 August 2017)Reuters

Houston has opened numerous community centres for people forced out of their homes because of the bad weather but the mayor has urged people to remain in their homes and not call the emergency services unless they face life-threatening situations.

Flooding in Houston (27 August 2017)Reuters

Insurance experts have warned that flood damage across Texas from the bad weather may equal the trail of destruction left by Hurricane Katrina in 2005 - that was the most expensive natural disaster in US history.

A resident is moved from a rescue boat onto a kayak in Dickenson, Texas (27 August 2017)Reuters

Emergency 911 operators in Houston received 56,000 calls over a 15-hour time period - seven times more than during a usual working day.

A stranded motorist escapes floodwaters on Interstate 225 after Hurricane Harvey inundated the Texas Gulf coast (27 August 2017)Reuters

The centre of the storm is estimated at the moment to be about 125 miles away from Houston, but it is forecast to move closer to the city by Wednesday.

Volunteers and officers from a Houston neighbourhood security patrol help rescue residents in River Oaks (27 August 2017)Getty Images

The swift rise of the flood waters caught the authorities off guard, which is why Houston residents with boats are playing an increasingly important role in the rescue effort.

A pick-up truck passes a warning sign on southbound Interstate 45 north of Houston, TX, as heavy rains from the remnants of Hurricane Harvey continue to flood many areas of the city (27 August 2017)EPA

The flooding had led to the closure of nearly every major road in Houston, with local media reporting that more than 170 roads are now waterlogged.

A gauge shows the depth of water in an underpass on Interstate 10 which has been inundated with flooding from Hurricane Harvey (27 August 2017)Getty Images

The bad news for the people of Houston is that there is no sign of the rain easing up over the next few days.

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