Flood in Susitna Valley, Alaska

The Susitna River at Sunshine crested at 27.66ft on 9/21/12 at 23:00 AKDT. Damages in the Susitna Valley were extensive, with several railroad bridges and smaller roads flooded and washed out. Most of the homes destroyed and damaged were in the Susitna Valley. on 9/24/12 a 51 year old man died while attempting to cross a swollen creek in a remote hunting area.

A series of strong, wet storm systems hit Southcentral Alaska in mid-September. Each storm followed nearly the same track along the Alaska Peninsula then along the Bering Sea coast, setting up a strong moist fetch into the Southcentral Alaska. This resulted in widespread flood damage over a large area. Storm total precipitation ranged from 21 to 27 inches along the eastern Kenai Peninsula, while further inland between 6-12 inches of rain fell along the Talkeetna Mountains north to the headwaters of the Nenana River. A large number of roads and bridges were affected; damage to the Alaska Railroad was severe enough to shut down the rail service for several days. Almost 60 homes were either severely damaged or destroyed and over 700 other homes were either affected or sustained minor damage; most of the damage occurred along the Little Susitna River and Willow Creek. State estimates of damage to individual property approached $3.5 million, public infrastructure exceeded $19 million statewide, and the military base in Anchorage sustained an addition $3.5 million in flood damages. There was one fatality associated with the flooding. On September 24, a 51 year old man died while attempting to cross a swollen creek on his ATV.

In addition to flooding, the storms brought strong east and southeast wind to an area from southeast Prince William Sound, to Cordova, through Portage Pass, along Turnagain Arm and along the Anchorage. The first strong storm resulted in wind through the Chugach Mountains with an unofficial peak wind of 120 mph measured by a spotters home weather system in Bear Valley. In the other wind-prone locations, peak wind was generally around 70 to 75 mph, with 90 mph in reported in Portage Valley.