Flooding causes damage and brief closure of Alaska’s only road to the North Slope

Jun 08, 2023 | 10:24 pm ET

By Yereth Rosen

Flooding causes damage and brief closure of Alaska’s only road to the North Slope

The north end of the Dalton Highway, the only access road to Alaska's North Slope, is seen on April 14, 2015. Flooding near the northern end of the road caused a brief closure this week. The Arctic setting and permafrost terrain make maintenance and operation of the Dalton Highway challenging. (Photo provided by Alaska Department of Transportation and Public Facilities),

The sole road connection to Alaska’s North Slope oil fields was closed briefly on Wednesday and Thursday when floodwaters ate into a large chunk of roadway.

The closure was near the northern end of the Dalton Highway, the 414-mile road that connects Livengood, a community 80 miles north of Fairbanks, to Deadhorse, the oilfield center adjacent to the Prudhoe Bay oil field. The highway is used primarily as a supply and service route for North Slope oil operations, though there is some public use for recreation, sightseeing and hunting.

The site, between miles 404 and 405 of the highway, closed Wednesday evening and reopened early Thursday afternoon, said Kaitlin Williams, a spokesperson for the Alaska Department of Transportation and Public Facilities. After floodwaters rose on Wednesday, traffic there was reduced to a single lane that workers tried to keep open, Williams said. “They were in the area working to attempt to prevent a washout,” she said, but the washout occurred anyway.

Now the road is back to a single lane, and disruption to traffic has not been too bad, she said.

Work will shift later on from emergency response to a longer-term construction project, Williams said. “They’ll reopen the road to a full-functioning road,” she said.

The Dalton Highway, which parallels the, Trans Alaska Pipeline, is seen on July 3, 2014, just north of Coldfoot, a community 60 miles north of the Arctic Circle. In view next to the highway is the middle fork of the Koyukuk River, and looming in the background are mountains in the Brooks Range. The Dalton Highway is the only road leading from the established highway network to the North Slope, and it is a vital supply route for North Slope oil operations. (Photo by Bob Wick/Bureau of Land Management) — The Dalton Highway, which parallels the, Trans-Alaska Pipeline, is seen on July 3, 2014, just north of Coldfoot, a community 60 miles north of the Arctic Circle. In view next to the highway is the middle fork of the Koyukuk River, and looming in the background are mountains in the Brooks Range. The Dalton Highway is the only road leading from the established highway network to the North Slope, and it is a vital supply route for North Slope oil operations. (Photo by Bob Wick/Bureau of Land Management)

Unplanned emergencies like this are an occasional challenge on the Dalton Highway that add to the known, long-term deterioration.

Floods and erosion are among the regular challenges to Dalton Highway maintenance and operation. The highway runs over permafrost, through mountainous areas and alongside braided rivers, all features that are affected by climate change that is accelerated in the Arctic.

This summer, some of that longer-term construction is underway at the southern end of the Dalton Highway. It is part of a $175 million multiyear program to improve safety, according to the department. This year’s work, between Miles 18 and 37, includes embankment stabilization, some realignment and the start of a bridge-replacement project.

A pair of extreme events occurred in 2015 from flooding of the Sagavanirktok River. The road was closed for a week at its northern end for flooding that March and then for another 18 days in May of 2015, when more severe flooding inundated a larger area, including Deadhorse and some surrounding areas. The flood washed out several sections of road, and damages to 24 road miles prompted emergency repairs that cost $17 million, according to the Department of Transportation and Public Facilities.

Notable scheduled construction projects in past years included specialized paving for permafrost zones, and a rerouting to avoid a “frozen debris lobe,” which is a creeping and thawing mass of ice, rock and vegetative matter. The lobe is one of about two dozen the state has identified moving down mountain slopes within a mile of the highway.