Flooding has cut off the regional center from other towns in the Yamalo-Nenets autonomous region - washing away roads and rail lines - and the local government has started subsidizing helicopter flights in and out of the city.
The flooding also has separated Nadym, a city of 50,000 near the Arctic Circle, from its oil, gas and food storage sites on the other side of the river.
No food shortages have occurred, but the city administration has banned gasoline sales, Alexander Kiyashko, a spokesman for the mayor's office, said Tuesday.
The only way to get from many outlying towns to Nadym, the site of a major regional airport, is now by helicopter, which for many people is prohibitively expensive. So the city and regional administrations have agreed to subsidize two-thirds of the cost of the 750 ruble ticket.
"So far there is no panic," Kiyashko said.
He estimated that the flood has caused $4 million in damages so far. It has destroyed at least 10 kilometers of road leading north from Nadym, and damaged rail lines along the highway.
The city was flooded last Wednesday, when ice on the Nadym River, at least twice as thick as usual, started breaking up and blocked the river. The water rose 82 centimeters above flood levels and washed away chunks of the highway and railroad on both sides of a bridge.
The administration blamed the flood on a record cold winter and a sudden thaw at the end of May. Since the city is located close to the Arctic Circle and only the few upper centimeters of soil thaw during the summer, the soil doesn't soak up the water and even a small rise in river levels can cause flooding.
"Here is tundra. It's like a cup; the water doesn't go into the ground, it just rolls over, flooding everything," Kiyashko said. "But we haven't had anything like this for at least 25 years."
Two people died in a car accident last week when their vehicle skidded off the collapsed highway. In Old Nadym, a city 20 kilometers north of Nadym, dozens of people had to be moved when water damaged a local electrical station, cutting electricity in three apartment buildings.
It was not clear when the floods would ease. Rain continued falling in Nadym on Tuesday, and night temperatures dropped to minus 2 degrees Celsius.
Obskaya Guba, a large gulf to the north of the city, was still under ice, making it difficult to predict whether new floods could come, Kiyashko said.