Flood — Central Beaufort Sea Coast, Alaska

2023-06-07 to 2023-06-14 · near Deadhorse, Central Beaufort Sea Coast, Alaska

Event narrative

The main flow of the Sagavanirktok (Sag) River was diverted to the farthest west channel of the river due to aurfeis blocking the channel. The Sag River was pushed up against the Dalton Highway and began to erode the road near Milepost 403.5. On June 7th the road was closed at Milepost 403.5 due to the Sag River eroding the highway to the centerline with the threat of a total washout. This closure shut off the only road access to the oil fields on the North Slope of Alaska. The AK Department of Transportation immediately began hauling rock from a quarry 150 miles away in order to secure the road. The road reopened to one lane traffic on June 8th, although the threat of erosion continued for another week. Runoff from heavy rain and snowmelt in the headwaters of the Sag River reached Milepost 403.5 of the Dalton Highway on June 14th.

Wider weather episode

An area of of resistant aufeis in the main channel of the Sagavanirktok (Sag) River during spring breakup forced the Sag River flow toward Milepost 403 of the Dalton Highway. The high flow from snowmelt and a heavy rain on snow event in the Brooks Range on June 10th exacerbated the impacts to the Dalton Highway.

View location on OpenStreetMap → (70.0858, -148.5534)

Source: NOAA Storm Events Database, event_id 1120484. Narrative written by the NWS forecast office that issued the report.