2009 Alaska floods

The winter of 2008–2009 brought unusually heavy snowfall to much of Alaska. Kotzebue, on the Bering Sea coast, received a record 102 inches of snowfall—more than double the average of about 40 inches.^[1] In other locations, winter snowfall did not set records but still was heavier than average. Fairbanks, Alaska's second-largest city, received 71.5 inches of snow and experienced unusually cold temperatures for the first three months of the year, preventing early melting of the snowpack.^[2][3] Snow also fell heavily in Lake Minchumina and the Alaska Range.^[4][5] At Eagle, the ice on the Yukon River was 55 inches thick—over 40 percent greater than normal.^[6]

By mid-April, concerns were raised that the heavy snowpack would pose a problem if it melted quickly. "There's plenty of snowpack out there to cause problems this year," warned a National Weather Service meteorologist at the time.^[6]

In Fairbanks and most of Interior Alaska, temperatures remained below freezing for most of April and temperatures did not hit 50 degrees until April 26.^[7] After that date, temperatures rose rapidly. By April 28, the snowpack at Fairbanks International Airport had melted, leaving only snow berms and piles.^[7] The next day, Fairbanks recorded a record high temperature of 74 degrees. On April 30, Fairbanks set an all-time high temperature for the month of April when the thermometer reached 76 degrees. Record high temperatures also were recorded at Eagle, Delta Junction, and other towns in central Alaska.^[8] In less than one week, central Alaska residents went from skiing to swatting mosquitoes.^[9] The warmup was so rapid that on May 1, the Alaska Division of Forestry issued its first wildfire alert of the year.^[10] By that date, however, rivers across central Alaska were already flooding.^[11]

The Tanana River valley was the first area of Alaska to experience spring flooding. On April 28, the ice on the Salcha River broke up, flowed into the Tanana River, and formed an ice jam. The jam partially dammed the river, flooding low-lying areas of the town of Salcha.^[11] High temperatures during the following couple of days added to the ice jam, and several families were forced from their homes by the rising water. Fairbanks North Star Borough officials set up a self-serve sand bag station at the Salcha Fairgrounds, and residents near the river erected impromptu levees.^[12] The Salcha ice jam broke loose on April 30, causing flood levels to decline dramatically. Record-high temperatures that day caused jams to form on other rivers in the area, however.^[13]

On the Chatanika River, a jam caused a flood that threatened several homes before the ice broke loose and dropped water levels to near normal.^[13] By May 1, almost the entire Fairbanks North Star Borough was directly threatened by some sort of flooding. In Fox, small-stream flooding caused a house to be evacuated. Flooding was reported in North Pole and in rural areas of the borough.^[14] On May 2, high water on the Chena River swept through Fairbanks, causing flooding in low-lying areas.^[15] The high water caused the U.S. Army Corps of Engineers to consider closing the floodgates at the Chena River Lakes Flood Control Project, a structure built to protect Fairbanks from flooding.^[16] The high water registered just below the threshold to close the gates, however, and they remained open throughout the flood. By May 5, the water receded in Fairbanks and the surrounding area as the Tanana River drained floodwater into the Yukon.^[17] The draining high water ripped a barge away from its moorings in the Tanana River near Nenana, causing it to float down the Yukon River until it was arrested by a helicopter.^[18]

On May 6, multiple ice jams formed on the Kuskokwim River near the villages of Upper and Lower Kalskag. These jams caused the snowmelt-bolstered river to flood areas around both villages, forcing residents to take action.^[19] After the jams broke and flowed downriver, they re-formed near Akiak. The resulting flood caused the evacuation of more than 10 percent of the town's residents to nearby Bethel, while many of the remaining residents sought shelter in the local school.^[20]

On May 3, an ice jam formed on the Susitna River, causing flooding that washed out the tracks of the Alaska Railroad. Large chunks of ice also were pushed onto the tracks, making work difficult for crews assigned to repair the rail line.^[21] The incident severed rail traffic between Fairbanks and Anchorage until May 7, when track repairs were completed and the railroad resumed service.^[22]