On Tuesday, I told you about the sinkhole that yawned under the Miracle Mile construction project, a sinkhole that's now been plugged by an additional $648,475 in tax-increment financing from the city.

Sinkholes go with the territory around here. Southeast Minnesota's karst landscape is riddled with what the Miracle Market LLC people called "unconsolidated bedrock material," and every now and then a major building project hits a vein.

Jeff Green, a dedicated Answer Man reader and an equally dedicated groundwater hydrologist at the Department of Natural Resources office in Rochester, enjoyed my Tuesday column and noted the pothole at Miracle Mile is not the only one that builders have hit recently. He says another local project hit one recently; I'm checking to confirm that. I've also heard concerns at the site of a third project as well.

Going way back, Jeff says he's heard contractors hit one during construction of Mayo's Guggenheim Building in the early 1970s.
"What they are likely dealing with is St. Peter sandstone that has collapsed into a void in the Prairie du Chien Group carbonate bedrock," Jeff says. "The sloughing sand visible in the cut at the Paragon Chateau theaters is an example that you can see in an outcrop."

Jeff says he's been the karst special for DNR in Southeast Minnesota for 27 years "and I never cease to be amazed at things like this that occur on, and in, our landscape."

For the record, the most recent Minnesota Geological Survey identified about 700 sinkholes in the county -- and there are certainly others lurking. At Miracle Mile, the developer says they couldn't anticipate the subterranean hole because the shopping center was right on top of it.

And I shouldn't have to tell you what area city says it's the sinkhole capital of the United States.

More on the Rochester Y

Speaking of sinkholes, the Rochester Area Family YMCA hit a nasty financial one in the past few years, and last Wednesday the Y membership voted to be absorbed by the YMCA of the Greater Twin Cities. That change became two days later, on Sept. 1.
One of my intrepid research associates was curious about what that means for local control. Does the local Y board of directors still exist, for example?

Here's what we were told by Joan Schimml, senior director of communications and marketing in Minneapolis:

"The Rochester YMCA still exists as a branch of the YMCA of the Greater Twin Cities and will no longer operate independently. The current Rochester board will continue to serve the Rochester YMCA as a community advisory board. We are looking at the structure of the community board and at what new community board members to invite to join and what current board members want to remain on the board."

The Rochester Y website says the current board members are Ann Beatty, the chairwoman (called the chief volunteer officer, in Y-land); Lance Resner, vice CVO; Richard Decker, treasurer; Gene Dankbar, secretary; Mark Adafin; Dr. John Bachman; Debbie Beauchene; "Bucky" Beeman; John Gressett; Jorrie Johnson; Colleen Landherr-Maddox; Al Lun; Dan Nistler; Doug Rovang; and Kevin Lund.

According to Y officials, the new advisory board will support "activities for the Rochester community that includes opening doors and advocating for support of YMCA programs and services as well as seeking philanthropic support needed to sustain scholarships and services."

When we asked if there's a capital campaign in the offing to cover costs and make improvements in the facility at 709 First Ave. SW, the Y said, "We currently are making small improvements to the facility to ensure a safe and healthy environment for our members. At the same time, we are assessing community needs to determine any other large facility needs. We will then develop a comprehensive plan which will determine funding needs and if approved, we will discuss how best to have a campaign if that is the best way to fund the major improvements."