Dalton Hwy risks severe flooding after 2015 closure

ANCHORAGE — The only road leading to Alaska’s North Slope oil fields is again at risk of severe flooding during the spring thaw, with conditions similar to those that intermittently closed portions of the remote highway for more than two months last year.

State transportation crews are digging trenches near a vulnerable northern stretch of the 414-mile Dalton Highway to protect it from overflow from the Sagavanirktok River, generally referred to as the Sag River. Crews also constructed a 5-foot-tall berm over a 3-mile stretch on the east side of the highway earlier this year, Department of Transportation spokeswoman Meadow Bailey said Wednesday.

A stretch of the highway saw unprecedented flooding last year, prompting the intermittent closures. In response to the flooding, Gov. Bill Walker twice issued disaster declarations.

Dubbed the Haul Road, the mostly gravel Dalton is an often desolate stretch that begins near Fairbanks and leads to Deadhorse, the oil industry town serving Prudhoe Bay. It has been featured on the cable show “Ice Road Truckers.”

The amount and configuration of the ice surrounding the highway are similar to last year’s conditions, and so is the current snowpack, Bailey said. Officials also are watching out for a third factor, spring temperatures, which last year were unusually high in the area, hastening the rate of melting.

Temperatures in the area are expected to be above normal in April and May, according to National Weather Service hydrologist Ed Plumb. But that doesn’t necessarily mean a repeat of last year, he said.

“What really matters is how quickly it warms up,” he said.

It’s not uncommon to deal with some overflow from the river, but not at the magnitude seen last year, according to officials. This year, crews are trying to stay on top of the situation.

“We didn’t understand what was happening last year,” Bailey said. “This year, we understand.”

Last summer, crews raised several miles of roadway as much as 8 feet, launching a three-year Dalton Highway reconstruction project that is projected to cost $114 million.

Transportation officials also are working with University of Alaska Fairbanks researchers determine what’s behind the phenomenon. Among them is UAF Civil engineering professor Horacio Toniolo, who said two main factors were involved in last year’s flooding — a significant ice accumulation and a very fast rate of melting.

Researchers are now trying to determine all the various water sources that could be involved in the flooding at a level not seen before at any other time in the highway’s 40 year history, Toniolo said.

“The river was there before and the roadway was there before, and there was no problem,” he said. “So something happened.”

More in News

(Juneau Empire file photo)
Aurora forecast for the week of March 25

These forecasts are courtesy of the University of Alaska Fairbanks’ Geophysical Institute… Continue reading

The aging Tustumena ferry, long designated for replacement, arrives in Homer after spending the day in Seldovia in this 2010 photo. (Homer News file photo)
Feds OK most of state’s revised transportation plan, but ferry and other projects again rejected

Governor’s use of ferry revenue instead of state funds to match federal grants a sticking point.

The Shopper’s Lot is among two of downtown Juneau’s three per-hour parking lots where the cash payments boxes are missing due to vandalism this winter. But as of Wednesday people can use the free ParkSmarter app to make payments by phone. (Mark Sabbatini / Juneau Empire)
Pay-by-phone parking for downtown Juneau debuts with few reported complaints

App for hourly lots part of series of technology upgrades coming to city’s parking facilities.

A towering Lutz spruce, center, in the Chugach National Forest is about to be hoisted by a crane Tuesday, Oct. 27, 2015, for transport to the West Lawn of Capitol Hill in Washington, D.C., to be the 2015 U.S. Capitol Christmas Tree. (Photo courtesy of the U.S. Forest Service)
Tongass National Forest selected to provide 2024 U.S. Capitol Christmas Tree

Eight to 10 candidate trees will be evaluated, with winner taking “whistlestop tour” to D.C.

Annauk Olin, holding her daugher Tulġuna T’aas Olin, and Rochelle Adams pose on March 20, 2024, after giving a presentation on language at the Alaska Just Transition Summit in Juneau. The two, who work together at the Alaska Public Interest Research Group’s Language Access program, hope to compile an Indigenous environmental glossary. (Photo by Yereth Rosen/Alaska Beacon)
Project seeks to gather Alaska environmental knowledge embedded in Indigenous languages

In the language of the Gwich’in people of northeastern Alaska, the word… Continue reading

The room where the House Community and Regional Affairs Committee holds its meeting sits empty on Tuesday. A presentation about an increase in the number of inmate deaths in state custody was abruptly canceled here. (Claire Stremple/Alaska Beacon)
Republican lawmakers shut down legislative hearing about deaths in Alaska prisons

Former commissioner: “All this will do, is it will continue to inflame passions of advocacy groups.”

(Michael Penn / Juneau Empire file photo)
Police calls for Monday, March 25, 2024

This report contains public information from law enforcement and public safety agencies.

Employees at the Kensington Mine removing tailings from Johnson Creek on Feb. 17 following a Jan. 31 spill of about 105,000 gallons of slurry from the mine, although a report by the mine’s owners states about half slurry reached the creek 430 meters away. (Photo from report by Coeur Alaska)
Emergency fisheries assessments sought after 105,000-gallon tailings spill at Kensington Mine

Company says Jan. 31 spill poses no risk to Berners Bay habitat, but NOAA seeks federal evaluation.

Dozens of people throw colors in the air and at each other during a Holi festival gathering Monday night outside Spice Juneau Indian Cuisine. (Mark Sabbatini / Juneau Empire)
Holi festival in Juneau revives colorful childhood memories for some, creates them for others

Dozens toss caution and colored cornstarch to the wind in traditional Hindu celebration of spring

Most Read