ANCHORAGE — Ice jams that blocked two Alaska rivers broke loose over the weekend, unleashing a surge of ice and water that caused major floods, damaged homes and left behind huge chunks of ice as tall as 12 feet.

Floodwaters on the Yukon River peaked at or near record level in the small community of Circle — the highest since 1945 — said Mike Ottenweller, a forecaster with the Alaska-Pacific River Forecast Center. Flooding could continue for the next few weeks as more snow melts, he said.

The water rose quickly Saturday before retreating Sunday on the Yukon River in the state’s east and the Kuskokwim River in the southwest, the Anchorage Daily News reported. Homes were lifted off foundations, smashed into by ice, or inundated with water in communities like Circle and Crooked Creek.

Gov. Mike Dunleavy issued a disaster declaration for the Yukon River communities of Circle and Eagle, as well as Crooked Creek on the Kuskokwim and Glennallen on the Copper River.

Ice jam flooding in the spring is not unusual in Alaska, but this year the risk was higher.

“The combo of a cold April and deep snowpack really loads the dice,” said Rick Thoman, a climate specialist at the International Arctic Research Center at the University of Alaska Fairbanks.

However, Thoman said this kind of flooding is expected to become less common in the next few decades as springs warm.

Diane Olmstead, a teacher in Circle, said it took only about 10 minutes for the chilly floodwaters to rise a foot high (30 cm) after they began creeping toward the school at around 8 p.m. Olmstead said she watched a colleague get rescued from their residence and brought to the school. By about 9:30 p.m., the water “started to recede almost as dramatically as it rose,” she said.

Olmstead’s car was destroyed and she lost most of her belongings. She cried as she surveyed the damage in the community, which included one house near the river being washed away and at least seven others knocked from their foundations and battered with ice, she said.

Authorities were aware of at least three homes pushed off foundations as damage assessments were underway, said Jeremy Zidek, a spokesperson with the state’s emergency management office.

No one was hurt but emergency officials were working to transport generators, backup communication systems and clean drinking water to the village of about 75 people, roughly 160 miles northeast of Fairbanks.

Recovery will be challenging in Circle and Crooked Creek, Zidek said.

“There’s a lot of ice that’s been deposited on roads and within the community — and we’re talking about huge chunks of ice, some of them as tall as 12 feet,” he said.

Most of Crooked River’s 90 residents had evacuated to the village school, which is on higher ground, Zidek said.

However, the rising waters stranded 12 people in the second story of a home, Zidek said. An Alaska National Guard helicopter was called in to help, but a nearby helicopter from the Donlin Gold project was able to fly over and rescue three of the stranded residents. The others accessed a boat once the flood began to recede.

Zidek did not immediately have an estimate of how many homes were damaged.

Ottenweller, the river forecaster, said the water level in Crooked River was as much as 5 feet higher (1.5 meters) than in 2011, a year that marked the most extreme flooding the village saw in recent decades.