U wants LRT tunnel under Washington

Anna Ewart

The University is pushing hard to get a portion of the Central Corridor light-rail train built in an underground tunnel.

The Central Corridor, a light-rail line slated to go through the Twin Cities on University and Washington avenues, could go through campus at street level or in an underground tunnel.

University officials have already made it clear they want the East Bank portion of the line built below ground. The Metropolitan Council is still in the process of getting community and business input on the line’s design.

Director of Parking and Transportation Services Bob Baker said placing the line at street level on Washington Avenue would cause a number of problems.

“Washington Avenue is a main artery,” Baker said. “We need the tunnel.”

Without a tunnel, traffic and parking situations would worsen, Baker said.

Also, Washington Avenue provides access to the University’s hospital and trauma center.

Laura Baenen, spokeswoman for the Central Corridor project, said there are no cost estimates for a tunnel at this point.

Engineers and the Metropolitan Council are still studying the details of this project, which could cost more than $930 million as currently proposed. However, the cost will likely have to come down in order to receive federal funds.

On Oct. 10, the University took members of the Central Corridor Management Committee on a tour of the area that the LRT will likely pass through. The tour highlighted the congestion that already exists near Coffman Union on Washington Avenue.

As early as 2001, the Board of Regents began supporting the idea of a tunnel for the East Bank portion of the LRT.

Paul Weiblen, retired University geology professor, said the Twin Cities is lucky to have a geological makeup that would make excavating a below- ground tunnel easy.

Below ground, a 30- to 60-foot layer of limestone rests atop a layer of sandstone, Weiblen said. That sandstone is soft enough to be easily excavated, while the limestone, which is harder than concrete, could serve as a roof for the tunnel.

“This is very different than in places like Washington, D.C., or New York, where they had to excavate through crystal and rock, which is much more difficult,” he said.

Weiblen also said the University has tried to utilize this underground space in the past. A building below Andersen Library holding archives is in the layer of sandstone.

This building, which is about the size of three football fields, has had problems in the past, Weiblen said. Several years ago the limestone cracked, and contaminated water trickled into the building. A roof was built to repair the problem.

Possible difficulties aside, neighborhood resident Dean Lund said using this underground space is something Central Corridor planners should consider. If the University had a viable street-level option, a tunnel probably wouldn’t be worth considering.

“Since Washington Avenue has been the route that’s been selected, you’ve got a big problem now because it’s a traffic jam every day, twice a day,” Lund said.

Weiblen said building a tunnel is always more expensive than building another road, but putting the LRT in a tunnel through campus could end up saving the University area money.

The value of the land on Washington Avenue is considerable and most buildings are built right up to the sidewalk.

Construction of the LRT would also be easier on campus if the tunnel was built beneath plumbing and infrastructure, he said.

“You don’t have to divert traffic,” Weiblen said. “Nobody would know that they were doing that underground.”