Flood in Taiya Inlet, Alaska

The water levels along the Taiya River were running above normal from previous rain events and was about one foot below bankful. Moderate rain along with very warm temperatures associated with a strong atmospheric river moved over the northern inner channels of Southeast Alaska through the afternoon and evening hours of October 12th. The strong low level winds along with abundant sub-tropical moisture being transported over the complex terrain of the region produced very high rain amounts with 1.5 to 2 inches falling in 12 hours across the headwaters of the Taiya River basin. This first wave of precipitation and subsequent runoff caused the Taiya River to rise more than 2 feet to be above moderate flood stage of 17 feet by the early morning hours of October 13th. Heavy rain continued with another 1.5 to 2 inches in 12 hours and the combination of the heavy precipitation along with ice melt from the glaciers in the headwaters continue to cause a tremendous amount of runoff. The Taiya River rose rapidly through the day and it finally crested at 20.1 feet. This was a new record crest for the river that broke the old record from 2002. The river slowly receded but it did not go below flood stage until the early morning hours of October 14th. There was an impressive amount of flooding from this record event with the Dyea road being flooded between the Taiya River bridge to the McDermott driveway. The Dyea road was eventually closed by the Skagway Police in the morning of October 13th due to significance of the flooding after there was voluntary evacuation of the area. NPS closed both the Chilkoot trail and the Dyea campground due to the amount of flooding. There was a lot of damage to the NPS Dyea campground with it being totally inundated and sustaining significant bank erosion. The Chilkoot trail also sustained significant damage from this storm but also from previous atmospheric rivers events that NPS will be doing a lot of work over the coming spring and summer to get their infrastructure fixed and ready for the summer season. NPS also reported that the Dyea flats access road to the slide cemetery was also flooded and they closed it due to numerous washouts. This was one of the most impactful flooding events that the areas has seen in almost 20 years.

The region had been getting impacted with multiple atmospheric rivers throughout most of autumn. This has led to above normal stream flows on most area rivers and streams. A very warm and moist atmospheric river lifted out of the north Pacific and transported a significant amount of tropical and subtropical moisture into southeast Alaska from October 12th through the 13th. The deep moisture through the atmosphere along with the very complex terrain of the region produced heavy rain with amounts from 3 to 4 inches in 24 hours and near 2.5 inches in 12 hours. This heavy rain along with the very warm temperatures increased ice melt from the glaciers in the headwater of the Taiya River produced record flooding in Dyea and along the Taiya River. There was road closures along with damage to National Park Service infrastructure. The flooding lasted all day on the 13th. Additionally, this event produced strong wind gusts resulting in downed trees.