Most Central Corridor Light Rail construction in the Twin Cities so far has actually been work to relocate utility lines that run under streets.
A few weeks ago, dozens of buildings along University Avenue in St. Paul had to be evacuated after an Xcel Energy crew moving utility lines inadvertently caused a leak. They were making way for light rail construction; natural gas seeped into the air for two hours.
At the corner of 6th Street and Cedar Avenue in downtown St. Paul last weekend, an Xcel Energy crew of about 15 men prepared to break into the surface of the street. It's slow work; they thought it would take two days to get into the ground. But workers had already blocked off an area about the size of a bus in the middle of the narrow street. Cars squeezed past on both sides.
The small spaces under the street that hold utility lines are about 2.5 square feet. Everything from water and sewer pipes to phone lines has to fit inside. These pipes and cables have to be moved before light rail construction can proceed.
As one of the largest private utilities, Xcel moves its lines first, at its own expense. The Central Corridor project pays contractors to relocate public lines.
Foreman John Hunn said lines on this street have to be moved several feet lower. He said it would take about a week.
"There's a lot of other utilities that have to come in through here once we're out of here. The impact at least to the downtown here will get worse before it gets better," Hunn said.
Because St. Paul is a relatively old city, many unknown utilities are buried in the ground. That complicates things.
"Every time you come across something you have to identify it and do due diligence to find out who owns it or who did own it and deal with it appropriately," Hunn said.
Hunn said over the years, he's accidentally hit other utility's lines.
"But we do our best to try to avoid that," Hunn said.
Mistakes like the recent natural gas leak are rare. But Hunn acknowledged the work will go on for at least another year — and he has to get it done with about 45 workers assigned to his department.
"We try to give them breaks, try to rotate people in and out so they don't get burnt out," Hunn said. "This is a very large project but we only have so many resources to do it."
Managers of the Central Corridor Light Rail Project had to do a lot of planning before Hunn's crew could start work. The light rail project's office is in a building just off University Avenue in St. Paul.
Last week that stretch of University was reduced to one lane in each direction and dozens of cars and trucks were backed up at a four-way stop. In the middle of the road, workers were relocating utility lines.
"There is so much under the streets that you may not think about," said Laura Baenen, Central Corridor project communications manager. "Different governments have fiber optics down there ... it's very complex, and trying to coordinate this relocation is very complicated."
Baenen said the trick is to shift the work to accommodate traffic.
"You work on one side of the street at a time," she said. "It's like making a hospital bed with the patient still in it. You can't dump the patient out; you have to keep them in the bed. So you shift them to one side and that's really how construction works."
University Avenue businesses said the utility work so far has been hard to handle. Many, though, said they'll be happy if it pays off with more customers once the light rail line is running in a few years. The line will link St. Paul and Minneapolis.