Mat-Su

State doubles trench to safeguard highway, homes from Matanuska River

PALMER — State transportation officials are doubling the length of a trench meant to safeguard the Old Glenn Highway in Butte from the erosive force of the Matanuska River.

The Matanuska is undercutting its soft banks, putting dozens of homes between Mile 12.5 and Mile 15 of the highway in potential jeopardy, but more immediately threatening the road and utilities alongside it.

Gov. Bill Walker, responding to a request from the Matanuska-Susitna Borough, declared a disaster for the area Monday.

The Alaska Department of Transportation and Public Facilities decided Tuesday to install a 525-foot rock-filled trench near the highway even though a DOT hydrologist recommended one about twice as long. The shorter trench was expected to cost most of the $1 million in state emergency funds freed up by the declaration, officials said Tuesday.

But on Wednesday, a U.S. Army Corps of Engineers hydrologist met with DOT hydrologist Paul Janke and both agreed on a longer 1,100-foot trench, said DOT spokesperson Shannon McCarthy.

McCarthy said the new plan brings two advantages: "It protects the road and utilities but it also provides that protection for the subdivision which is near Maud Road."

She said she didn't know where the additional money would come from to expand the project.

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The trench, as planned, will be 70 feet wide and 20 feet deep, with a 6-foot layer of rock. It will extend from north of East Lee Side Circle, wrapping into a protection project installed during high water in September 2012, and extend down and around toward the river at an old gravel pit.

That's where locals are concerned the river could breach its banks and spill into a lower channel, blowing out a gravel roadbed and sending the river's main channel coursing along and maybe over the highway.

Mat-Su Borough Mayor Vern Halter and Assembly member Jim Sykes sent DOT Commissioner Marc Luiken a letter requesting the longer trench on Wednesday, Sykes said.

The work could take several weeks.

The Matanuska is notoriously unpredictable, a broad glacial river that's threatened properties in Butte, Palmer and Sutton for decades. Butte property owners are waiting to learn the status of a federal buyout.

Granite Construction, the contractor working on the Butte trench, got the job with a noncompetitive contract because of the emergency nature of the work, McCarthy said. 

Granite was working in Sutton installing a similar trench along the Glenn Highway outside of Sutton, where the river swallowed several properties and is also endangering that stretch of road.

Zaz Hollander

Zaz Hollander is a veteran journalist based in the Mat-Su and is currently an ADN local news editor and reporter. She covers breaking news, the Mat-Su region, aviation and general assignments. Contact her at zhollander@adn.com.

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