Sinkhole Update

Sinkhole Update

Published on Oct 11, 2014 by Pat Backen


There has not been a lot of public information about the water main break since the second giant hole appeared on County Road 9 several weeks ago. This last week finally provided some answers on a number of fronts.

The Joint Water Commission (a legal entity formed by the cities of Golden Valley, Crystal and New Hope) owns the pipe that broke and is responsible for the repair and maintenance of the pipe. They have done a number of things to help insure that the issue does not occur again or, in the case another break does occur, the problem is caught quickly and damage is limited.

City staff, the Mayor and the Council are all closely watching the actions taken by the JWC, and are holding them to very high standards to insure that this situation does not happen again. Unfortunately the city’s power is somewhat limited – it is not our pipe, and it is not our road (it is a county road). The Mayor and city staff have been in contact with the County engineering department and County leadership. We are all hopeful that this cooperation will allow the water main to reopen , knowing it is safe and will not create “Sinkhole 3”.


In an effort to insure that the rest of the pipe is stable and another breakage does not happen, the JWC hired a firm to inspect the pipe running all the way from Minneapolis to Crystal. They used a specially designed machine, similar to an MRI, that can see the entire pipe from the inside to the outside. They also visually inspected the interior of the pipe.

Testing was completed on Wednesday and the preliminary results were very positive. The full test results will be back in the upcoming week, but the testing contractor did not see any “inside the pipe distress” that would indicate a failure could happen in the near future.

While several tests were undertaken to check the integrity of the pipe after the first break, this test was not. Last year, engineer’s thought they saw damage in the pipe that happened during initial installation. The theory was that the damage created a weak portion of the pipe, and that is what caused the break last year. This second gaping hole had the JWC engineers reevaluating that conclusion.

Water Main Road
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In addition to the testing, last week a flow monitor was installed near the start of the pipe in Minneapolis. This monitor was programmed to know what the flow should be at all times. If flow is detected when water should not be moving from Minneapolis, a valve will automatically close stopping the water and reducing any potential damage.

Every evening water starts to flow again to refill the holding tanks in Crystal. While water is being transferred, the monitor will know what the flow rate should be. If rates alter from this level, again the valve will close automatically, without manual intervention.

In both these scenarios, the closure of the valve should prevent any major damage (i.e. another sinkhole forming). There would of course be a need to repair any further breaks, and road closures would likely need to occur.

Insurance Claims

Eight homes and businesses were damaged when the break happened. Six homes on Scott Avenue were the hardest hit, with sewage backing up into their basements. All of them were fully or partially finished, and all were a total loss.

The JWC’s insurance company took a very long time determining if and how claims would be paid, extending self declared deadlines twice. Typically insurance claims are only paid if there is negligence on the part of the insured. For example, if a force of nature had caused the pipe to break, it is not the fault of the JWC and claims would not be paid. They finally reached a decision Friday that property owners only need to prove that their damage resulted from the break in the line and do not need to prove that the design, construction or maintenance of the line was at fault. This decision will save a tremendous amount of hassle (and legal fees) for the effected properties.

Fortunately, the city council enacted a new policy less than two months ago that helps homeowners when sewer backups occur through no fault of the city or the homeowner (for example, a neighbor flushes something down their toilet that clogs the line and creates a backup in another home). We are one of a handful of cities that have a policy like this, and it enabled effected properties to get their homes cleaned up quickly and at no cost to them. The city covers the cost and has submitted a claim for reimbursement to the JWC and their insurance company. We expect this cost will be taken care of as part of the overall break in the water main.

Road Reopening

The reopening of the road was put off so that testing could be done. As part of the repairs, a manhole is being added at the break. This is a “custom” piece and is being manufactured specifically for this section of pipe. Once it is set in place, there is another week or more of construction to finish up. While the final schedule is still somewhat up in the air, the pieces are coming together and all lanes should be open to traffic in the next two to three weeks.

Everyone involved – Robbinsdale staff and council, the County and the Joint Water Commission – are all hopeful (and committed) that once the pipe is re-installed and water starts flowing again we have seen the last of the giant holes appearing in town.