TRAVERSE CITY, Mich. (AP) — The company that operates dual oil pipelines in a key Great Lakes channel says a gap has opened between one pipe and the lake bed that’s wider than allowed under an agreement with the state of Michigan.

Enbridge Inc.’s Line 5 carries crude oil between Superior, Wisconsin, and Sarnia, Ontario. A 4-mile (6.4-kilometer) section runs across the bottom of the Straits of Mackinac linking Lakes Huron and Michigan.

Erosion sometimes creates gaps between sections of the pipe and the lake bottom. Under a state-granted easement, those gaps cannot exceed 75 feet.

Company spokesman Ryan Duffy said Wednesday one of them has reached 81 feet.

He says the company is awaiting government permits to install screw anchors for additional support in that spot and others along the underwater line.