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How a gurgling spring washed out a major interchange
Published September 23, 2001 - Minneapolis Star Tribune
by Steve Brandt
The gurgling flow of Camp Coldwater Spring can fill a bathtub in less than 30 seconds. That's enough force to wash out a multimillion-dollar state road project.
The Minnesota Department of Transportation (MnDOT) announced last week that it is canceling construction of the partially built Hwy. 55/62 interchange because of a law protecting the spring. The newly passed law prohibits agencies from impairing the spring.
The department wants the Legislature to change the law. Even if it spent an additional $4 million to $8 million to try to make sure the $16 million interchange doesn't draw ground water away from the nearby spring, MnDOT argues, it couldn't guarantee that the road wouldn't impair the spring. And it argues that even if that modification satisfied watershed regulators, any citizen could sue.
"I'm disappointed that MnDOT is taking the position of 'My way or no highway,'" said Rep. Mark Gleason, DFL-Richfield, a sponsor of the law.
How did the dispute reach an impasse that will stall the half-done $16 million project at least until mid-2002, meaning more delays for at least 50,000 motorists a day?
Interviews with participants suggest that the following factors played a role:
* Protests against the reroute of Hwy. 55 north of the spring initially focused more on trees and parks than on the largely invisible and highly technical issue of whether the highway's sewers would divert ground water.
* The spring and much of the surrounding federal land northeast of Minneapolis-St. Paul International Airport constituted a regulatory black hole.
No water agency had jurisdiction over the spring until May 2000, three months before the intersection construction began.
* An earlier drive to pass a Coldwater protection law by a small group of reroute opponents who focused on water issues stalled for two years when a rogue protester damaged the cause in 1999 by throwing a pie in the face of a state senator.
* Once the spring-protection law passed this past May, with intersection construction already underway, House Republican legislators quashed a last-minute special-session compromise by the law's sponsors to loosen its restrictions.
* MnDOT ignored warnings from the Minnehaha Creek Watershed District that the longer it waited to investigate the road's potential effect on the spring, the more expensive the cost of addressing problems would be.
How quickly the logjam is broken depends in part on the legislative strategy MnDOT adopts to change the law. Waiting until the end of the 2002 session to slip an amendment into a larger transportation bill, the tactic Gleason expects MnDOT to use, takes longer. But it may have a higher chance of success than full hearings where spring defenders could testify.
Complex terrain
The hydrogeology of the Coldwater area is complex and not fully understood, even where soil borings and monitoring wells have pierced layers of soil and rock near the proj ect. Without full-scale excavation, there is no certainty about how water flows through glacial deposits and layers of bedrock laid millions of years ago.
A MnDOT spokesman said this week that there was no discussion of possible spring effects in the project's environmental impact statement. Initial concern by water regulators was over the effect of construction on ground water seepage in the gorge below Minnehaha Falls. But as construction moved south, concern about the spring intensified.
The spring is held by some Indians to be sacred, and its waters refreshed the soldiers who built Fort Snelling in the early 1820s and the small settlement that grew outside the fort.
MnDOT had dismissed the issue by pointing to the 300 yards between the intersection and spring. The Minnehaha Creek Watershed District, which had earned a reputation for taking on big public agencies over water issues, first had its hydrogeologic consultant examine spring-flow issues in the spring of 2000. The district's bid to expand jurisdiction over much of the area initially was rebuffed by a state agency, but it ultimately was awarded custody of the spring.
The consultant, Kelton Barr, raised initial questions in May 2000. With added data, he concluded by late summer that the spring's flow would be reduced by pumping needed to permit construction as well as by storm sewers to be laid under Hwy. 62.
Debate over dye tests
By last March, the watershed was pushing MnDOT to permit dye tests to explore the ground water connections that Barr suspected existed between the intersection and the spring. After an initial favorable reaction from project officials, MnDOT raised barriers to routine tests that a veteran dye tester, University of Minnesota geologist Calvin Alexander, described as specious. The state agreed to raise the elevation of one storm water pond to above the ground water level.
With the Watershed District threatening court action, two dye tests were permitted in early May, but neither was at the crucial intersection where MnDOT's temporary and permanent drain systems would be at their lowest points MnDOT said its project schedule didn't permit turning off drainage pumps so that ground water patterns could return to normal for the test.
So the Watershed District sued, and a judge ordered MnDOT to turn off the pumps for four weeks. When test dye showed up at the spring, the district seemed vindicated, but the battle wasn't over. MnDOT's view was that although dye showed a connection, it didn't show much else about the nature of that link. Prodded by the judge, the two sides reached an agreement to remove the storm water pond and use a blanket of clay or other material below the sewers to minimize their drawing off the ground water that surrounds the low-lying roadway.
But that fell apart when a neutral consultant hired by both sides applied a higher standard in evaluating the proposed design and concluded that it wouldn't work.
That consultant recommended that a concrete barrier go under the roadway, weighted with pig iron or similar material to keep ground water pressure from floating it.
MnDOT disagreed strenuously with the higher standard but initially didn't object to the concrete barrier, which would look something like a bike fender turned upside down with its arc mostly flattened.
Department officials say they were willing to go along with the clay barrier, despite their skepticism about the interchange-spring link, because they felt that the $600,000 cost would be cheaper than further delay. But when the barrier concept mushroomed to several million dollars, they balked and filed to dissolve the legal agreement.
Hennepin County District Judge Frank Knoll, who had ruled in the watershed's favor earlier, questioned MnDOT lawyers closely at a hearing last week. And the group of spring supporters asked to join the lawsuit. So MnDOT announced it would halt the proj-ect except to make a better bypass for traffic over the winter.
Department officials say they'll reopen bids on the projct if the Legislature eases the law. One key legislator, Rep. Carol Molnau, R-Chaska, said legislators need to study the financial and legal issues before they can address the matter.
© 2001 Star Tribune |
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