As many as 500,000 people - as much as 14 per cent of the population - could leave Puerto Rico for good in the aftermath of Hurricane Maria’s destruction, a new report suggests. The exodus would have a devastating impact on the island’s already stagnant and flailing economy.

A month after the category four storm made landfall with winds of up to 155mph, the first hurricane of such strength since 1932, around 90 per cent of the island remains without electricity. Hundreds of thousands of people are scrambling to find fuel, food and clean water, and to access medical services.

A report published by the Centre for Puerto Rican Studies at Hunter College, part of the City University of New York, suggests between 114,000 and 213,000 residents will leave the island over the next 12 months.

San Juan Mayor Carmen Yulin Cruz speaks to the media as she arrives at the temporary government center setup (Joe Raedle/Getty Images)

It suggests that by 2019, up to 470,335 residents could have left for the US mainland, mostly to the states of Florida and New York.

“In other words, Puerto Rico will lose the same population in a span of a couple of years after Hurricane Maria, as the island lost during a prior decade of economic stagnation,” says the report.

“Our projections indicate that Florida is the state most likely to be affected by the exodus.”

Since the storm struck, the Trump administration has been trying to fight off accusations that it has done insufficient to help the residents of Puerto Rico, especially when compared to how it dealt with powerful storms that tore through Florida and Texas.

David Usborne drives down a road in Puerto Rico lined with collapsed telephone polls

Mr Trump, who has engaged in a series of back-and-forth insults with the mayor of San Juan, has said the island should do more to help itself. He also said the claims of Carmen Yulín Cruz, who said her residents had been left to die, were politically motivated.

The Federal Emergency Management Agency (FEMA) said this week it had 1,700 personnel deployed in Puerto Rico and the US Virgin Islands. Around 2,600 FEMA staff remain deployed to Hurricane Harvey, nearly two months after that storm hit the Gulf Coast of the mainland US.

As emergency officials appeal to islanders not to drink water that may be contaminated, CNN said 35 per cent of households still did not have access to safe drinking water.

Bringing aid to Puerto Rico Show all 20 1 /20 Bringing aid to Puerto Rico Bringing aid to Puerto Rico Crew chief Kenney shelters under the blade of an HH-60 Blackhawk helicopter from 101st Airborne Division's "Dustoff" unit preparing to take off during recovery efforts following Hurricane Maria, in Isla Grande, Puerto Rico, October 6, 2017 Reuters/Lucas Jackson Bringing aid to Puerto Rico An HH-60 Blackhawk helicopter from 101st Airborne Division's "Dustoff" unit takes off behind Crew Chief Alexander Blake and his fellow soldiers during recovery efforts following Hurricane Maria, in Morovis, October 5, 2017 Reuters/Lucas Jackson Bringing aid to Puerto Rico Crew member Bynum stands in tropical rain as a HH-60 Blackhawk helicopter from 101st Airborne Division's "Dustoff" unit prepares to take off during recovery efforts following Hurricane Maria, in Isla Grande, October 6, 2017 Reuters/Lucas Jackson Bringing aid to Puerto Rico UH-60 Blackhawk helicopter pilot Chris Greenway receives a hug from a woman thanking him for water as he works with the First Armored Division's Combat Aviation Brigade during recovery efforts following Hurricane Maria, in Verde de Comerio, October 7, 2017 Reuters/Lucas Jackson Bringing aid to Puerto Rico A man carries a case of water away from an HH-60 Blackhawk helicopter after soldiers working with 101st Airborne Division's "Dustoff" unit dropped off relief supplies during recovery efforts following Hurricane Maria, in Jayuya, October 5, 2017 Reuters/Lucas Jackson Bringing aid to Puerto Rico Crew chief Alexander Blake from 101st Airborne Division's "Dustoff" unit loads water into a helicopter during recovery efforts following Hurricane Maria, in Isla Grande, October 5, 2017 Reuters/Lucas Jackson Bringing aid to Puerto Rico Residents wait for soldiers in UH-60 Blackhawk helicopters from the First Armored Division's Combat Aviation Brigade to deliver food and water during recovery efforts following Hurricane Maria, in San Lorenzo Reuters Bringing aid to Puerto Rico An HH-60 Blackhawk helicopter from 101st Airborne Division's "Dustoff" unit lands in a field to avoid lightning during recovery efforts following Hurricane Maria, in Manati, October 5, 2017 Reuters/Lucas Jackson Bringing aid to Puerto Rico Residents hold their hands aloft to signal that they need water as UH-60 Blackhawk helicopters from the First Armored Division's Combat Aviation Brigade fly past during recovery efforts following Hurricane Maria, near Ciales, October 7, 2017 Reuters/Lucas Jackson Bringing aid to Puerto Rico Tropical rain splashes on a runway as HH-60 Blackhawk helicopters from 101st Airborne Division's "Dustoff" unit wait for weather to clear during recovery efforts following Hurricane Maria, in Isla Grande, October 6, 2017 Reuters/Lucas Jackson Bringing aid to Puerto Rico Pilot Eldwin Bocanegra Torres speaks with residents isolated by landslides in the mountains after unloading water and food from a helicopter during recovery efforts following Hurricane Maria, near Utuado, October 10, 2017 Reuters/Lucas Jackson Bringing aid to Puerto Rico Residents stand in front of wind-damaged trees as they wait for soldiers in UH-60 Blackhawk helicopters from the First Armored Division's Combat Aviation Brigade to deliver food and water during recovery efforts following Hurricane Maria, in San Lorenzo, October 7, 2017 Reuters/Lucas Jackson Bringing aid to Puerto Rico The contents of a home are seen from the air during recovery efforts following Hurricane Maria near Utuado, October 10, 2017 Reuters/Lucas Jackson Bringing aid to Puerto Rico Thomas looks out of the window of an HH-60 Blackhawk helicopter from 101st Airborne Division's "Dustoff" unit, loaded with relief supplies, during recovery efforts following Hurricane Maria in Isla Grande, October 6, 2017 Reuters/Lucas Jackson Bringing aid to Puerto Rico A message written on the rooftop is seen from the air during recovery efforts following Hurricane Maria near Humacao, October 10, 2017 Reuters/Lucas Jackson Bringing aid to Puerto Rico A HH-60 Blackhawk helicopter from 101st Airborne Division's "Dustoff" unit lands in a field during recovery efforts following Hurricane Maria in San Sebastian, October 6, 2017 Reuters/Lucas Jackson Bringing aid to Puerto Rico Sergeant First Class Eladio Tirado, who is from Puerto Rico, looks for a landing spot for a UH-60 Blackhawk helicopter from the First Armored Division's Combat Aviation Brigade, during recovery efforts following Hurricane Maria near Ciales, October 7, 2017 Reuters/Lucas Jackson Bringing aid to Puerto Rico Boys carry water away from an HH-60 Blackhawk helicopter after soldiers working with the U.S. Army's 101st Airborne Division's "Dustoff" unit dropped off relief supplies during recovery efforts following Hurricane Maria, in Jayuya, October 5, 2017 Reuters/Lucas Jackson Bringing aid to Puerto Rico Sergeant First Class Eladio Tirado from the First Armored Division's Combat Aviation Brigade, who is from Puerto Rico, speaks with residents as he helps during recovery efforts following Hurricane Maria, in San Lorenzo, October 7, 2017 Reuters/Lucas Jackson Bringing aid to Puerto Rico Residents peek through a fence at helicopters from 101st Airborne Division's "Dustoff" unit that had parked in a locked field during recovery efforts following Hurricane Maria, in Lares, October 6, 2017 Reuters/Lucas Jackson

Professor Edwin Meléndez, Director of the Centre for Puerto Rican Studies at Hunter College and co-author of the report, said the depopulation they estimated for Puerto Rico, using an econometric model of the costs of storms over the last 60 years, would be similar to that experienced by New Orleans, after Hurricane Katrina struck in 2005. Today, the Louisiana city’s population is 20 per cent less than it was before Katrina hit.

He told The Independent the major driver for people leaving Puerto Rico was employment opportunities. He said following Maria, infrastructure had been badly damaged, hotels were not hiring people and around 80 per cent of agricultural crops had been destroyed.

He said others researchers had found Maria could lower Puerto Rican incomes by up to 20 per cent over the next 15 years, a cost of $180bn to the island’s economy.

“We will need to wait for the release of data on employment and net movement of passengers in the months after Hurricane Maria to fully assess the exodus of Puerto Rico residents to stateside communities,” his report adds.