Our sympathies are with the victims and others affected by the mudslide last week in Washington. This Washington Post site provides some useful graphics showing the causes of the mudslide. Near-record rainfall in the area contributed, but the illustrations also show how the river eroding the toe of the slope was part of a much longer process.
In the New York Times, writer Timothy Egan—author of a book on the Dust Bowl, among others—published a blunt article over the weekend arguing that the slide was not—or at least should not have been—an unforeseen event, as one Snohomish County official called it. He cites a 1999 US Geological Survey report that predicted a catastrophic slide in the area—although not, of course, exactly when such an event might occur. (The USGS has pointed out that despite its report warning of the risk, it has no jurisdiction to determine zoning in such areas.) He also says that excessive logging activity, beyond the legal limits, seems to have occurred in the area above last week’s mudslide, possibly contributing to the event as it has in many other places around the world.
“Most of us live with the danger of wildfire, earthquake, tornado, flooding, drought, hurricane or yet-to-be-defined and climate-change-influenced superstorm,” he writes. “A legacy of settlement is the delusion that large-scale manipulation of the natural world can be done without consequence.”
Egan draws a comparison with the 9.2 magnitude earthquake in Alaska in 1964—something he acknowledges was beyond anyone’s control. Still, he notes, because of that earthquake and others, we have put in place building codes and standards to reduce our risks from seismic activity. Perhaps this mudslide will lead to zoning changes or restrictions in other areas of recognized risk.