Crystal, New Hope and Golden Valley look for permanent fix for water pipe that broke twice

First came the flood, then the giant sinkhole.

Twice in just over a year, a major water main carrying water from Minneapolis to Crystal, New Hope and Golden Valley burst, flooding roads and opening up a sinkhole 20 feet deep — and officials are now concerned it could happen again.

On Dec. 3, the three suburbs plan to hire a consultant to analyze options for a long-term fix to the 2-mile line that runs from Minneapolis to a Crystal reservoir, passing through Robbinsdale, where it burst last September for the second time in 15 months.

It follows an inspection last month of a 2,700-foot portion of the line, finding several weak spots in Robbinsdale that could potentially break again.

"The pipe overall is in good shape, but that doesn't help if there are weak spots," Crystal City Manager Anne Norris said. "We need to come up with a long-term maintenance plan."

By January or February, the Joint Water Commission — which includes leaders from Crystal, New Hope and Golden Valley — hopes to come up with financial and construction plans to fix the 51-year-old line. And Robbinsdale leaders will be eagerly awaiting the repairs.

"Obviously, we're concerned with the disruption to our businesses and our residents," Robbinsdale Mayor Regan Murphy said. "We're in a position that we want to make sure it doesn't happen again."

"We were shocked by last year's failure; We had never had any issues with the pipe," said Tom Mathisen, Crystal's director of Public Works.

Then, two months ago, a second break about two blocks away flooded County Road 9 with knee-deep water and damaged eight homes and businesses.

"It just opens up like a sardine can all at once," Mathisen said of the water main break.

The second break surprised officials even more because, after the previous one, a study was done last December, and it found that there were no leaks in the line.

So last month, the commission hired a consultant for $85,000 to inspect the joints of the concrete, steel-bound pipes in Robbinsdale, using electromagnetic equipment. They found that about 9 percent had weak, vulnerable spots that had deteriorated.

The line, which was built in 1963, was expected to last 80 years, Mathisen added.

"It's pretty urgent," he said of a fix, "because we're going to have to use that line next summer."

Until then, the commission is restricting the water from being fully pressurized to relieve some of the stress on the line; that doesn't affect Golden Valley, New Hope and Crystal homeowners. If a fix isn't in place by next summer, the cities could temporarily use water that goes to a Golden Valley reservoir instead.

The total damage cost from September's break isn't tallied yet, but damage to homeowners' property is covered by the cities' insurance, Mathisen said. Road-related repairs cost an estimated $250,000.

The cities will soon have cost estimates for a permanent fix. Current County Road 9 road reconstruction includes replacing nearly 50 percent of the water pipes on the line by Aug. 1, but the commission will still have to reimburse the county for the water pipe replacement. That leaves the commission with about 1 mile that will need to be replaced or fixed, which could cost millions.

"At least they can plan for it," Murphy said about construction with a future project, "If it's going to provide a long-term solution that's something people can get behind."

Kelly Smith • 612-673-4141