Flood in Susitna Valley, Alaska

The Yentna River at Lake Creek entered flood stage on the afternoon of August 28th, then rose to a record crest around 22.56 feet in moderate flood stage by August 29th. River levels remained near the record crest through the morning of August 31st, then began dropping back below flood stage by the evening of August 31st. Observers along the river between Skwentna and Lake Creek reported that numerous cabins in the area were flooded during this time, with many cabins also left without power due to their generators flooding.

An atmospheric river moved up from the North Pacific into Southcentral Alaska and produced widespread moderate rainfall between August 27th and August 29th. Strong southerly flow during the rainfall event caused south-facing slopes of the mountains across Southcentral to get the highest rainfall totals due to enhancement from upslope flow, including the north end of the Susitna Valley, where 2.5 to locally 6 inches of rainfall was recorded between 8/27 and 8/29. The runoff from the heavy rainfall pushed multiple waterways across the Susitna Valley into moderate flood stage from around 8/29 to 8/31, including sections of the Talkeetna River, Yentna River and Moose Creek.