FAIRBANKS — It may be a 20-foot-wide trail to begin with, but the far-northern section of the Dalton Highway, ravaged by ice and floodwaters this spring, is expected to be open to 24-hour traffic Friday morning.
The long-term solution is to elevate about 17 miles by adding more than 2 million tons of gravel to the surface, raising the road from 7 to 9 feet in many spots. It would take about 40,000 truckloads of rock to reshape the road above the flood level.
Dave Miller, the northern region director of the state Department of Transportation, told a Fairbanks group Tuesday that rebuilding and raising the road grade to avoid a repeat next year is a key goal, with some of the work to continue next summer. He said road crews are confident that the 20-mile section of the road where the worst pockets of damage occurred will be passable this week, with traffic led by pilot cars in some one-lane zones.
"We can get a pickup from one end to the other now, which we couldn't before. So they've pioneered in a goat trail basically," he said, speaking to residents who meet weekly to discuss energy issues under the auspices of the Fairbanks Economic Development Corp. "We'll start out with just a couple trucks and make sure that we don't have a mess."
Emergency repairs are expected to cost about $15.5 million, most of that to be paid for with federal highway funds. About 45 trucks have been hauling gravel, while bulldozers and excavators continue to piece the road back together from the unprecedented damage, the origins of which are traced back to heavy rainfall in the Brooks Range last summer and fall.
The Sagavanirktok River froze to the bottom this winter, and the additional water draining from the Brooks Range turned into heavy overflow on the North Slope. Miller said it's not clear to anyone if this is a sign of things to come or an event that might happen every half-century. "Looking out at a sheet of ice that goes for two miles and is four-and-a-half feet above the level of the road was pretty daunting," he said.
"The Sag River froze to the bottom, and that's what started moving the water over the top. And once it started it came quick," he said.
Gov. Bill Walker declared a disaster April 7, and road crews built snow berms to keep the overflow, known by the German word "aufeis," from the road. "There wasn't a blueprint for how to deal with this," Miller said. "The road was the low spot and we had as much as four-and-a-half feet of aufeis on both sides and water trying to flow between it."
The initial flooding occurred in subfreezing temperatures, and part of the temporary solution was to turn the Dalton into an ice road. He said DOT officials and hydrologists knew the situation would be tenuous at breakup, but the water problems were worse than they had expected.
When the weather began to warm, the worst problems occurred from Mile 394 to Mile 414, with the water flowing east to west at Mile 394 and the opposite direction farther north. "It took about two miles of the road out all the way down to tundra," at a spot where the gravel was 2.5 feet thick, he said.
A bulldozer sank and had to be pulled out. After that, the road crews left most of the clearing to excavators.
In terms of timing, Miller said, there is some consolation that the flooding occurred when the state had a major $27 million reconstruction project set for this summer from Mile 401 to 414. The project, under contract to Brice Inc., has been expanded by 4 miles and the proposed road grade has been raised.
Instead of just raising the grade by 4 to 5 feet, which was aimed at allowing the winter winds to blow the snow off the highway, the contractor will add much more material with the goal of keeping the road surface high and dry. "We want to be three feet above the high water mark there, to be able to ensure the road stays open. That's the normal design criteria."
In addition, Cruz Construction has been hired to work on emergency repairs to get the road into shape. There is a project planned for 2016 to raise the grade of a 20-mile section south of where Brice will be working this summer.
Adding gravel to the road has one financial benefit. It will eliminate the need to place 4 inches of foam insulation below the rock.
The foam boards are expensive to buy, transport and install. Avoiding that cost means it will be cheaper to just increase the depth of the gravel, Miller said.
Miller said federal authorities acted quickly to assist the state and expedited permit approvals.
The high water has also led to road-raising activities on the oil fields. BP began work May 21 to redirect flood waters, install culverts, raise roads and build berms, according to the Army Corps of Engineers. The work "will be completed over the next two months as needed to stabilize infrastructure," the Corps said.