1/11/10

Buried stream pipes fail in West Allis


Honey Creek in West Allis in the 1960s, before burial.
Milwaukee Metropolitan Sewerage District photo.

Expensive failure of a stream burial

In the mid-1960s, over two miles of Honey Creek in West Allis near Milwaukee were buried in pipes.  In a stretch where the creek flows under the racetrack at State Fair Park, its flow is divided between four pipes of corrugated steel, bolted together.  Why the 9x13 foot pipes were made of corrugated steel, rather than more permanent concrete, was not clear.

"Water from the creek has been leaking out cracks in the bottoms of the aging pipes, eroding soil around them, said David Fowler, MMSD senior project manager.  Soil above the pipes drops down, filling voids but causing depressions on the surface, he said."

If the pipes fail, large sinkholes could form in the auto race track, making it unusable and complicating repair of the creek.

The Milwaukee Metropolitan Sewerage District has recommended spending $212,000 to repair just one 50-foot section of the four pipes under the race track.

The lessons from Honey Creek

As they say, "nature always bats last."  Sooner or later, every creek burial is going to fail, whether in 100 years or 200.  Because everything is buried, the first signs of failure are missed, and the costs of repair to underground structures can be very high.

In Madison, sinkholes are appearing over the buried creek in Glenwood Children's Park.

While burying a stream is often sold to the public as a cheap and permanent solution to stormwater problems, we see in West Allis how burial just defers the big expense to the next generation.  By that time, something like the race track has been built over the stream, and now the problem is a lot more complicated.

Some communities are now experimenting with uncovering buried streams, while others are undertaking comprehensive programs to deal with rain where it hits the ground.

Source of this story, and thanks to Kathleen McElroy for the alert.
Map of the stream.

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