Wednesday, May 11, 2011

FLOODS AND MAMMALS

Roger, our Water Master, must manage problems large and small but everyone enjoyed kidding him about the muskrat who decided to live in the sewage lagoon, busily burrowing into the berm wall that kept the odorous liquid confined.  It took weeks of plotting and patient waiting to pot the little beady-eyed, rat-tailed beast while enduring the advice of everyone in town.  But he did it.
In Portland, OR, where I grew up, the Vanport Flood of 1948 which destroyed the flood plain where the Willamette ran into the Columbia displaced a whole population.  Afterwards there were levees built to contain such events.  By the Nineties, when I was clerking for the Site Development team, which was responsible for the approval of plans that might be in the flood plain, those levees had aged, the sea-going ships that could come up the Columbia were much bigger with more powerful wakes that eroded the banks, and the nutria had managed to perforate the levees.  
Nutria are a South American sort-of-cross between a muskrat and a beaver.  In Louisiana in 2005 there were so many and they had done so much damage (they are capable of chewing up houses and vehicle tires) that there was a bounty on their heads.  After Katrina, teams of shooters went out to get them and thoughtfully fed them to the alligators.  Ecologically sound recycling.  
They aren’t native to Portland but people imported them to raise for fur, then discovered they were a lot of work for little return and just dumped them out to wander.  (No 'gator on hand.)  Nutria don’t like Montana weather, but Oregon suited them okay.  We tried suggesting a nutria hunt but PETA, PAWS and HSUS would have put a bounty on OUR heads.  When we had a scary flood in the Nineties, the water could be seen bubbling through the nutria burrows onto the delta of land.  
By that time the area had been restricted to crops, campgrounds, and playing fields so that no people would be lost in their homes, but there was constant political pressure to allow building there.  Everyone had forgotten about the Vanport Flood of 1948.  They hadn’t been born and didn’t live in Portland then anyway.  The politicians almost succeeded in building a prison there, on grounds that if the inmates all drowned, no one would care about a bunch of criminals anyway.  My boss quietly testified that his brother was a prison guard and he was very fond of his brother.  They hadn’t thought of that.  I expect that there were people fond of those criminals as well.
We also spent a lot of time responding to beaver damage, not because of burrowing but because of their dams.  They could throw one up so quickly that when people got up to go to work their roads had flooded in the night.  I think there was a way to “disappear” those beaver, officially or not.  But beavers can also work against floods if they are up in the mountains and foothills where they impound small streams, creating trout ponds that keep the water cold deep into summer.   One could make a case that killing all the beaver in order to make hats was a cause of early small towns along the rivers being flooded.
The Corps of Engineers has done their best to replace beaver dams with mighty concrete structures (far more elaborate than the little earth dam that holds Lake Francis next to Valier) but now we admit that the practice destroys salmon access to the gravelly cold and fast water just below beaver dams where the salmon spawn.  The beavers, with only inclined terrain and access to sticks, no cost necessary, knew better because they had evolved with the salmon to fit what was needed.
The North American continent, due to plate tectonics, is creased and depressed down the more-or-less middle, so that when the glaciers melted ten thousand years ago, the water drained to the Gulf of Mexico, and has been doing that ever since.  The whole east slope heads south down that way, creating what amounts to a huge network of water highways, navigable right up to the center of Montana.  Lewis and Clark used it.  Later it brought artists and aristocrats right into Blackfeet country.  Also, engineers and irrigation developers built dams that the government failed to inspect or regulate, so that when they burst in 1965, once again people died.  One of the lessons of the beavers is that dams require constant maintenance.
But humans are slow learners.  In the Nineties there was another major several-region downpour that swelled the Willamette, the Columbia and a host of tributaries.  In Portland the seawalls, necessary from the earliest years of settlement, had been lowered because they were “ugly” and blocked the view.  Our engineers were seriously dubious that the levees would hold and the airport tractored the giant passenger planes up to the highways (that is, “higher” highways) in an attempt to save them.  
The big question facing the mayor was what to tell the people in the shopping center at Jantzen Beach and the other businesses that had been built in the floodplain, as well as housing developments that had somehow managed to bend, redefine, or ignore the rules.  The quants claimed that if the area were evacuated so-and-so many people would die in the chaos and such-and-such amounts of money would be lost because of loss of business and if the levies held anyway, the City of Portland would be sued for the estimated loss of money on grounds that it was a “taking,” a loss of income due to government decision.
In the end all the contractors in town came to the Portland downtown waterfront with plywood and plastic sheeting to create a temporary extension of the seawall, even as U-Haul trucks lined up to haul off the contents of the lower floors of banks and businesses.  It was barely enough to prevent real flooding and soon the businesses were complaining that the used materials were ugly and should be removed at once.  The levees held, so the mayor did not have to live with those consequences of an underwater shopping center.  

We aren't the smartest mammals in the pond.

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