By Jesse Winter

ABBOTSFORD, British Columbia (Reuters) – Receding floodwaters helped a Canadian town avoid disaster on Thursday as the province of British Columbia faced up to what one expert said was the costliest natural disaster in the country’s history.

More than 18,000 people were stranded after a series of floods and mudslides destroyed roads, houses and bridges while blocking off entire towns and cutting access to the country’s largest port.

Premier John Horgan declared a state of emergency on Wednesday and said the death toll would most likely rise from the one confirmed fatality.

At one point the city of Abbotsford, to the east of Vancouver, feared the waters would overwhelm their pumping station and force the evacuation of all 160,000 residents.

But late on Wednesday, mayor Henry Braun said the situation was improving.

“Throughout the day water levels have continued to abate,” he told reporters. “There’s a recovery coming. We are still focusing … on getting out people and keeping them safe, but the recovery is just around the corner.”

Residents in Merritt, which has been cut off for almost four days, told CTV on Thursday that the waters there were also starting to drop.

Late on Wednesday, emergency workers were able to temporarily open a narrow road to Hope, which had also been cut off since Sunday. Once people had left, the road would be closed again, the provincial government said.

One of those who managed to get out was Simon Fraser University professor Enda Brophy.

“If there’s anything to be learned from this experience, it’s we are woefully underprepared for the environmental disasters that are on the way. We can barely cope with the ones that we have,” he said by phone.

When the waters do recede, the province can start to look at the massive task of repairing smashed infrastructure.

“Easily the costliest natural disaster in Canadian history. Won’t even be close,” tweeted University of Calgary economics professor Blake Shaffer, a specialist in climate policy.

The most expensive natural calamity in Canada so far was the wildfires that hit Alberta’s oil-producing region of Fort McMurray in May 2016. Insured losses cost C$3.6 billion.

The federal government in Ottawa is promising to send hundreds of air force personnel to British Columbia, and says thousands more are on standby.

(Reporting by David Ljunggren in Ottawa, Ismail Shakhil in Bengaluru and Anna Mehler Paperny in Toronto; writing by David Ljunggren; editing by Jonathan Oatis)