A delta not so far away…continued

I have a sand collection. I’m up to about eighty bottles. Our home décor is rapidly becoming Contemporary Sand.

I collect it on my travels, and people bring me little bags of sand. I’m not a purist — I don’t need to collect it myself. If I like the person who gives me the sand, I bottle it up.

I added new sand to my collection this week. It came from the bottom of the Mississippi River just downstream from where I live. The tale of this sand sample starts in the middle of the 20th century…

…when the people of Minneapolis were itchy for more commercial barge traffic. To attract the traffic, we had to build locks and we had to deepen the river’s channel. We asked the U.S. Army Corps of Engineers to take care of that for us. In return, the city promised to deal with the dredgings.

Today the Corps still dredges the river in several spots, and puts the sand on the west bank of the river, an industrial area buzzing with big trucks,

Upper Harbor River Terminal Services, photo by Ben Lee

and on the east bank, underneath the new I-35W Bridge. That’s where my sand sample came from.

And what do we do with the sand after the Army Corps scoops it out of the river?

We fill holes with it, according to Mike Kennedy from the Minneapolis public works department. When buildings are demolished, the resulting holes are filled with this stuff. We don’t sand our roads with it, nor do we build with it, he said, because the sand grains are rounded, not angular. They don’t stick together very well. This view is as close as my camera and my skills allow:

Last week I wrote about the river’s delta, which is so starved of sediment, it’s disappearing. I asked Dan Cottrell of the Army Corps if anyone ever considered hauling our river dredgings down to the delta where they’re apparently needed. He told me that some people had actually looked into the idea, but the costs were “tremendous.” As you can imagine.

These days our priorities may be changing. We think less about attracting barge traffic and more about attracting birds, wildlife, and people to the Mississippi. That might change the need for dams and locks on our stretch of the river, Mr. Kennedy said.

A geologist friend of mine says she will take a close look at my sand sample and analyze it for me. She can identify minerals, bugs, fossils — a sand CSI, of sorts. She might be able to identify the upstream sources of the minerals. Maybe there will be a few surprises. I’ll let you know.

Thanks to Dave for collecting my sample of sand from the big pile beneath the freeway bridge.

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5 Responses to A delta not so far away…continued

  1. Emily says:

    My favorite post yet! Your sand investigation connects so many different people from academia to city and federal agencies to your neighborhood. So many different perspectives on the sand in Minnesota’s Mississippi – who knew!

  2. Lisa says:

    I am definitely meeting and talking to some great people. But the geologist who is looking at my sand is a longtime International Sand Collectors Society compatriot. Not sure, but I think she and I are the only ISCS members from Minnesota — a select bunch.

  3. Joyce Sidman says:

    I can’t wait to hear what’s in the Mississippi sand. And I’d say you’re meeting some dang interesting people through this blog.

  4. Dave says:

    As my parents and MPR’s Kate Smith taught me to say, you’re welcome.

  5. Vicky says:

    I’ve been waiting for this one. . . I love the close-up of the sand and, of course, your sand collection! 🙂 Good job, and good information!