In pictures: Houston overwhelmed by 'unprecedented' floods

AFP/Getty The city is pictured beneath clouds as a whole highway is overwhelmed by flood waters almost reaching the over-road signageAFP/Getty
Water is so deep in places in Houston that it almost reaches signage over roads
AFP A whole road is pictured submerged with Houston skyline in the distanceAFP
Much of the city's road system has been overwhelmed by floodwaters
AFP Flood victims in Red Cross blankets look for clothing at a shelter in the George R. Brown Convention CenterAFP
Many shelters have been set up, including at a convention centre
AFP Flood victims receive food at a shelter in the George R. Brown Convention CenterAFP
Officials say 30,000 people are expected to be housed in these emergency shelters
AFP Car is pictured totally under water beneath pouring rain and floodwaterAFP
Scores of vehicles are submerged across the city, with some owners having to be freed by emergency workers
Reuters Evacuees leave a US Coast Guard helicopter after being rescued from flooding due to Hurricane Harvey in HoustonReuters
The coastguard has been among the rescuers working to help stranded residents
Reuters A man is pictured with a small child on board a rescue helicopterReuters
Helicopters had to winch people up to evacuate them to safety
Reuters A couple are pictured with two dogs inside a coolerboxReuters
Many evacuees prioritised rescuing their pets above their belongings
Reuters A resident is moved from a rescue boat on to 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.
Reuters Photograph from high rise shows the scale of flooding overwhelming HoustonReuters
Aerial photographs from the city's high-rises show how overwhelmed Houston's infrastructure has become
Reuters A woman is pictured on an inflated airbed with her small dogReuters
A woman and her dog awaited assistance on a floating airbed
AFP A woman is carried after being rescued from a hotel by boat due to heavy flooding by Hurricane Harvey in HoustonAFP
At a news conference, the Federal Emergency Management Agency called on ordinary citizens to "get involved" in the unprecedented rescue efforts