BILLINGS, Mont. (NewsNation) — Unprecedented flooding tore through Yellowstone National Park wiping out miles of roads and bridges and swamping hundreds of homes in surrounding communities, and the roiling waters now threaten to cut off fresh drinking water supplies to Montana’s largest city.

Officials asked Billings residents Wednesday to conserve water because the city was down to a 24- to 36-hour supply after a combination of heavy rain and rapidly melting mountain snow raised the Yellowstone River to historic levels that forced them to shut down its water treatment plant.

“None of us planned a 500-year flood event on the Yellowstone when we designed these facilities,” said Debi Meling, the city’s public works director.

While expressing optimism the river would drop quickly enough for the plant to resume operations before tanks were drained, the city of 110,000 stopped watering parks and boulevards, and its fire department filled its trucks with river water.

The National Weather Service in Billings said the river was expected to crest Wednesday evening and drop below minor flood stage, 13.5 feet, by mid- to late Thursday.

The sudden flooding earlier this week drove all but a dozen of the more than 10,000 visitors out of the nation’s oldest park.

Remarkably no one was reported hurt or killed by raging waters that pulled homes off their foundations and pushed a river off course — possibly permanently — and may require damaged roads to be rebuilt a safer distance away.

While the Yellowstone flood is rare, it is the type of event that is becoming more common as the planet warms, experts said.

“We certainly know that climate change is causing more natural disasters, more fires, bigger fires and more floods and bigger floods,” said Robert Manning, a retired University of Vermont professor of environment and natural resources, “These things are going to happen, and they’re going to happen probably a lot more intensely.”

Park officials say the northern half of the park is likely to remain closed all summer, a devastating blow to the local economies that rely on tourism.

The rains hit just as area hotels filled up in recent weeks with summer tourists. More than 4 million visitors were tallied by the park last year. The wave of tourists doesn’t abate until fall, and June is typically one of Yellowstone’s busiest months.

Meantime, as the waters recede, parks officials are turning their attention to the massive effort of rebuilding many miles of ruined roads and, possibly, hundreds of washed-out bridges, many of them built for backcountry hikers. Yellowstone Superintendent Cam Sholly said assessment teams won’t be able to tally the damage until next week.