Alyeska Seeks Land to Armor the Pipeline Against Floods

Alyeska Pipeline Service Company is asking the state for more land on the North Slope to help shield the Trans-Alaska Pipeline from flooding — a request that lands as North Slope rivers run high again this week.

The Alaska Department of Natural Resources posted a proposed decision June 10 on an amendment to the TAPS right-of-way lease, covering two sites near Umiat. The key piece is a buried rock sill at Pipeline Milepost 28.3 intended to protect the pipeline from future flooding, alongside a storage and staging area nearby.

The concern behind that kind of armoring is well established along this corridor, where the pipeline and the Dalton Highway run beside braided, flood-prone rivers like the Sagavanirktok. In spring 2015, massive overflow and flooding of the Sag River washed out several sections of the Dalton Highway, closed the road for 28 days, and prompted two state disaster declarations — after which the state rebuilt and raised that stretch of road seven to ten feet to reduce the risk of future closures. The river has menaced the route repeatedly since, including a 2023 washout that eroded the Dalton to its centerline at Milepost 403.5.

A year ago this week, it happened again. Flooding severed the Dalton Highway on June 14, 2025, stranding freight carriers, disrupting fuel and equipment deliveries, and posing risks to petroleum operations — damage that drew another state disaster declaration, with the state noting that nearly half of Alaska's budget depends on oil and gas production. That is the stakes behind a buried rock sill: the line carrying the Slope's crude, and the road that supplies the field, both sit within reach of rivers that have proven they can take them out.

DNR's proposed decision is open for public comment; interested parties should consult the full notice for deadlines and submission details.