The first time I drove to Great Falls after moving back to Valier in 1999 and got close to town on highway 89, I gaped and gasped. Suddenly, with my City of Portland “flood plain lady” eyes, I saw nothing but potential disaster. Now it’s here. There were dikes and levees, there were some houses that were plainly built to some kind of flood plain standards (high foundations, bedrooms on the bottom floor with easy egress, etc) but like so many settlements, Great Falls is built on the confluence of rivers because those were the first highways and because settlements need water. Also, rather uniquely for this state, the actual Great Falls were and are a major source of hydroelectric power, enough for metal refining.
But the pressure to build and the low prices that go with previously flooded places like Sun River combine to encourage outlaw housing. Some people have the idea if they get established there, the government will be obligated to maintain levees and supply insurance. But not this government, not now.
The journalists are pointing out over and over and again and again that no one properly understands the rule-of-thumb about flooding, which does NOT mean that in a “hundred-year” flood plain there will only be one flood every century. It means that every year there is a one per cent chance of flooding. In fact, since weather patterns tend to persist for a few years (even this year’s rogue pattern is not that different from last spring) there tend to be clusters for a few years.
Anyway, what the engineers did in hopes of getting some kind of provisional order was to guesstimate the volume of water likely to travel through a flood plain, use the isometric height contour maps to get a kind of estimated boundary, and then draw an imaginary line. It’s all “if-then” thinking and since people are constantly filling in and leveling the land, the surveyed contour maps are soon out-dated. In the Nineties the Portland Site Development team was constantly having to make decisions with major financial consequences for builders according to maps that were largely fantasy.
Now, of course, with GPS and satellite imagery, things are slightly better, but the whole concept needs to be rethought because of Global Warming. Global Warming does NOT mean that the planet will soon be toastier (though that, too) but more relevantly means that the dynamics of weather will be radically changed because they will be driven faster and harder by the increased energy we call “warmer.”
I read stacks of information on what happens to houses in floods. First of all, they float off their foundations, since they are built like upside-down boats. In some places the house sills may be bolted to the foundation and that’s a good thing (for earthquakes, too). When a floating house is surrounded by water up to a height of about a third, it is likely to turn turtle, though it might not go all the way over and end up on its side.
But the real danger is from floating debris crashing into the house, whether or not it is waterborne. Other houses, big trees, and things like propane tanks that might explode, or cars which float as well as houses. Then, of course, the infrastructure of piping and wiring throughout a town is likely to be damaged with bad consequences. We’re sweating our sewer system at the moment, including the settling lagoon. I’ve got a sump pump running in the basement and am badly in need of enough of a rain break to repair my gutters. Valier is built on gumbo, ancient volcanic dust, which when dry is like cement with big cracks from shrinkage but when wet turns to sticky pudding and will not support weight. The water is not coming in through cracks in the foundation, but welling up at the bottom from the saturated water table.
Yesterday I zoomed north to Shelby to pick up some supplies and also out of curiosity to see the Marias River, which comes out of some of the highest snowpack in the Rockies. Sure enough, it’s way out of its banks and carrying debris, like trees, from banks that have caved. I didn’t expect caving at the cut-down of the exit to the town, but crews were trying to figure out what to do. The sliding dirt wasn’t falling on the road yet. In Billings, the badlands rimrocks that rise above residential neighborhoods are loosing boulders big enough to crush houses. A house there just exploded from accumulated natural gas, probably released by shifting pipes.
Infrastructure includes vital transportation. Water is taking out roads, large and small, and bridges, of course, but I did not know that it could warp and shift railroad track. Though farmers are always begging for water in this dry country, the timing is lousy. No one can get a wheeled vehicle into the field to plant and what was planted before the deluge is now rotting and floating. No sunshine to drive roots into the ground and call out foliage.
This was supposed to be another high-productivity year for Montana, much needed because other areas around the planet are having atypical weather patterns that have diminished their crop yields. The planet’s reserve is drawn down, more than it would have been if so many grains weren’t grown now to produce ethanol. Everything is connected.
FEMA is maxing out. People have figured out how to game the system, and maybe the worst consequence of that is those who legitimately need help get short-sheeted. Montana’s Governor Schweitzer has advised towns not to depend on the National Guard, which will be busy doing other things than sandbagging, like rescues and preventing looting. Maybe all those people who want to build houses on beaches will think again, as will those who want to build in scenic but combustible forests. In many cases we are living in exciting places with as much expensive technological and fuel support as we would need in outer space. Air conditioning is all that keeps trailers in the SW from baking their occupants to death. Moving one’s house (an RV) to fit the weather is a good (old) idea except for the cost of the fuel. It worked better with horses.
In this rural community we cope pretty well. Infrastructure isn’t that dependable even in the best of times. So we depend on common sense, ingenuity and community memory. For many of us, that goes back to 1964 which was NOT a hundred years ago. I’m intrigued with the idea that this is related to sunspot activity, which is increasing greatly. Floods may be nothing compared to the loss of our satellites. The planet IS a space ship. Sometimes flying blind.