A North Slope river keeps chewing toward the pipeline, and Alyeska keeps armoring it

The Sagavanirktok River is working its way toward the Trans-Alaska Pipeline, and for the second time this year, the pipeline's operator is asking the state for room to stack rock in the river's way.

Alyeska Pipeline Service Company wants to add about 26.1 acres of state land along the Sag's east bank to the pipeline's right-of-way lease, creating four stockpiles of riprap between 77 and 82 miles south of Deadhorse. The purpose, in the state pipeline coordinator's words, is to head off "an unforeseen rapidly eroding bank towards the pipeline" — armor stone staged and ready where the river is cutting closest to the buried line.

It's part of a pattern that's hard to miss on the North Slope. An earlier filing this year sought land for a rock sill and staging area farther north, after a spring breakup thinned the pipeline's cover at an old oxbow. Arctic rivers fed by faster snowmelt and shifting channels keep finding the pipe, and keeping them off it has become recurring work — each fix modest, the direction unmistakable.

The Department of Natural Resources published the application July 22 and is taking public comment as part of its review. It's a request, not an approval, and the terms could change.