FAIRBANKS—A second disaster declaration has been issued by Gov. Bill Walker due to extreme flooding from the Sagavanirktok, Kuparuk and Colville rivers. The declaration encompasses the entire North Slope Borough.

Walker verbally announced the declaration Thursday night after a flyover.

The Dalton Highway, the only road access to Alaska's oil-producing North Slope, is closed indefinitely from mile 334.5 to mile 413. The road terminates at the industrial district of Deadhorse, at mile 414.

Flooding on the Kuparuk River has shut down the private road to the Kuparuk oil field — North America's second-largest oil field, operated by ConocoPhillips. Water is rushing across a bridge over the river, according to Conoco spokeswoman Natalie Lowman.

"No immediate safety, environmental or production impacts (exist) at this time," Lowman said.

Problems began late March when water from the Sagavanirktok, or Sag, River overflowed and froze on the road. Multiple feet of ice built up, intermittently closing the highway. The Alaska Department of Transportation and Public Facilities anticipated more problems during breakup.

Those problems rose along with temperatures. Temperatures about 10 degrees higher than normal have been recorded in Deadhorse this last week, accelerating the rate of river breakup and snow melt.

Deadhorse Airport is battling floodwaters. Crews built berms and placed sandbags around the airport to stave off the flood early in the week, and runway lights were temporarily shut off.

Two worker camps on privately leased airport property had to be evacuated after losing power and being surrounded by water.

Roughly seven workers at the camp of Brice Inc. in Deadhorse were "not in immediate danger," according to company engineer Edwin Guerrero. Fuel and sewer services were unavailable at the camp, and "you can't work with three feet of water," Guerrero said.

The airport and runway are several feet above water level, and the situation is not expected to worsen. "We don't feel like it's threatened at all," said Meadow Bailey, DOT northern region spokeswoman.

The Sag River flows north from the Brooks Range to the Beaufort Sea, and large sections of the river are paralleled by the Dalton Highway and trans-Alaska oil pipeline.

Flooding has had no impact on pipeline operations, according Michelle Egan, Alyeska Pipeline Service Co. communications director. Egan said a significant portion of the pipeline adjacent to the Sag is buried and that regular flyovers have found no exposed sections of pipe.

Road repairs and travel can't commence until waters have cleared. Water depth is estimated to be 2 feet in spots, and it will take days to recede, according to a statement from DOT. No new areas of flooding have been reported since Thursday.

The disaster declaration will allow DOT to "request federal highway emergency funds and waive some state permitting requirements that could delay emergency protective measures," a news release from Walker's office states. The declaration was requested by DOT.

Walker's first disaster declaration was issued April 7 and allowed DOT to hire independent contractors to assist with operations.

Contact staff writer Robin Wood at 459-7510. Follow him on Twitter: @FDNMcity.