The devastating Hurricane Harvey could not have come at a worse time for mum-to-be Andrea Smith.

As Houston was devastated by terrifying floods , the 32-year-old went into labour.

She was trapped in her apartment, along with husband Greg, and the couple, who are both doctors but not trained in obstetrics, were preparing to have an emergency home birth .

But just as they feared the worst a dump truck made it through the deep flood waters that had formed a lake outside their home and kindhearted neighbours rushed to help.

Firefighters and people living close to the couple formed a massive human chain to pull the expectant mum to safety.

Andrea and Greg with their healthy baby girl
Neighbours formed a human chain to rescue the couple (
Image:
@calliecalliejo/Twitter)

The amazing rescue operation was captured in mobile phone footage and shows Andrea being helped to the waiting truck, with her husband just behind her.

And by Monday morning the delighted couple had welcome little daughter Adrielle into the world, reports the Daily Mail .

Andrea, who was 38 weeks pregnant when Hurricane Harvey struck, and Greg are believed to have only moved to Houston last month.

She works in geriatrics while her husband is a pediatrician.

One of the scenes of devastation in Houston (
Image:
Los Angeles Times)
Cars have been completely submerged by the flood waters (
Image:
REUTERS)
Many people have been rescued in boats (
Image:
AFP)

Tens of thousands of people have been forced to leave deluged homes and caused damage estimated at tens of billions of dollars, making it one of the costliest US natural disasters.

For Houston, there is some relief in sight, with forecasters saying five days of torrential rain may come to an end as the storm that has lingered in the Gulf of Mexico, picks up speed and leaves the region later today.

Harvey was expected to produce an additional 6 to 12 inches (15 to 30 cms) of rain to the north and east of Houston as it moves into southwestern Louisiana.

Civilian rescuers are seen before they set off on a flooded road to search for survivors (
Image:
AFP)
People walk their dogs through he flooded streets (
Image:
AFP)

It may take days for all flood waters, which have spilled over dams and pushed levees to their limits, to recede, local officials said.

City officials were preparing to temporarily house some 19,000 people, with thousands more expected to flee.

As of Tuesday morning, nearly 50,000 homes had suffered flood damage and 18 people are feared to have died.