Duluth, a second tier Minnesota city on Lake Superior, has been flooding. This is a little unusual; heavy rains following a period of saturation have caused a local river that is usually not even heard of to grow very large and cause flooding that a lot of people haven’t seen before.

The polar bear and the seal were able to leave their enclosures in the high water. The bear was darted and is safely put away somewhere, the seal is said to have taken a stroll around the neighborhood. But the barn animals, apparently including cattle, ovicaprids, and donkey have all perished in the flood.

This raises an interesting point. The flooding risk to a given piece of land is pretty much known in the US for everywhere. It seems like it would be a fairly easy task to determine if animal enclosures or other areas in a zoo are at risk of being flooded like this, and then to redesign to allow for animals to escape to somewhere. One would think that his would be a responsibility automatically addressed by Zoo managers. I’m fairly sure the federal governing body for Zoos is, at least in part, the USDA. Perhaps they have an opinion on this.

In this particular case, it seems (subject to revision) that a particular culvert had become blocked with debris, and thus water backed up into the zoo. Eventually, the culvert was totally washed out which presumably would have allowed flood water to recede. It is possible to re-engineer culverts to avoid this sort of thing from happening. An assessment of the likelihood of flooding here may well have led to such a fix prior to the incident.

Should existing zoos be assessed for future flood risk?

Here’s a local news story.

Yes, the animals were contained within the property, but not necessarily alive. My sense is that he already knows the state of the animals but is letting the Zoo folks handle the news.

And yes, the “Highway 61″ mentioned in the news is, indeed this one:

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Photo of bear by *clairity*

Comments

  1. #1 Markk
    WI, US
    June 20, 2012

    Where can I get on the committee to define “tiers” for cities…

  2. #2 Greg Laden
    June 20, 2012

    It is a common term referring to population size. All the cities that are large but not the biggest one/two are on tier two.

    In Minnesota we have to use the term because the word “city” has no meaning here. All polities with municipal governments, pretty much, are cities. When we go up north we go to a “city” with a population of 278.

  3. #3 Sondra Gibson
    Montana
    June 20, 2012

    I just cannot understand why the barnyard animals died. They should have been the easiest to rescue – not being dangerous or wild. Why in the world wasn’t the zoo prepared for this? The rain/storm was not unexpected. A responsible zoo would have had overnight caretakers on duty who could have called for help when the water started backing up. Very sad.

  4. #4 Greg Laden
    June 20, 2012

    We can only guess at this point, Sondra. Even if they had overnight caretakers and people on call, they may well have been focusing on the possible escape of lions, tiger, and the polar bears. Three or four days ago 11 cattle were killed in a storm on the other side of the twin cities. A large part of the problem is that animals cant escape their enclosures, which is almost always, but not always, a good thing.

    In my view, as I suggested in the OP, the real problem may be a lack of consideration of the flooding threat and engineering to address that. Since I wrote this post I heard that a roughly similar flood happened about 60 years ago so a) this is rare and not on people’s minds but b) as you say, it is a known phenomenon that could have been expected.

  5. #5 MadScientist
    June 20, 2012

    Most people (with the notable exception of many geologists and geotechnical engineers I’ve met) seem to have a remarkable gift of Flood Denialism (even the creationists who promote a mythical flood deny the reality of real ones). I see subdivisions going up on what are very obviously flood plains and interviewing oldies in the area you find sure enough that there were a few big floods many decades ago. Ah, but no – people believe silly things like “that only happens once every 200 years” even though there is absolutely no evidence for such claims.

    Anyway, Flood Denialism + cost of flood mitigation = hardly anyone ever bothers. Now my granddad did think about floods when he built his house and the first floor sits 4 feet off the ground. That was fine for 60 years but the encroachment of the city and subsequent choking of the river eventually led to a 10-foot flood rather than the usual 1-2′ floods I remember as a child. Back in 1998 I was in a town where people built right over a creek – I was asking what sort of retard would build on a creek that runs into a fairly large collector area and people just insisted that “it never floods; that’s an old dry creek bed”. And then it rained.

  6. #6 lorn
    June 21, 2012

    From a construction and landscaping point of view how hard could it be to provide a hillock or raised platform for the animals? I’m pretty sure such platforms could be landscaped into the enclosure scenery. Cost might be a few thousand per animal.

    Of course I don’t want to point fingers. Many, most, zoos seem to be running on very tight budgets and preparing for a once in a century flood has to take second fiddle to keeping the animals fed and healthy in the near term.

    Planning and organized rescue efforts are also expensive.

  7. #7 Greg Laden
    June 21, 2012

    Yeah, I was thinking that one way would be to have many of the enclosures backed on a large raised area that is just open or wild space separated from the walled off enclosures by one or two rises that the animals normally could not go above, unless there was water rising. Or, gates or walls that opened or folded down if water was rising. The trick is to make it as automatic as possible without electricity and robust.

  8. #8 Eric Lund
    June 21, 2012

    people believe silly things like “that only happens once every 200 years” even though there is absolutely no evidence for such claims

    In this case, I can’t blame the laypeople for thinking that. The problem is that the so-called experts believe it. The standard statistical methods they use to estimate the mean recurrence time systematically underestimate the probability density in the tail of the distribution (to say nothing of the effects of changing climate). An example from my area: the state highway to the next town south closes due to flood waters in what is supposed to be a 100-year flood. We have had at least half a dozen such floods in the last 15 years, including two in the same month.

    how hard could it be to provide a hillock or raised platform for the animals?

    Easy to do if you are building from scratch. Quite a bit harder if you are retrofitting. Most people don’t consider the worst case scenario until it happens (this is true not only of floods but a variety of other natural hazards), so it’s likely that the folks who originally designed the enclosures didn’t consider the flooding possibilities.