Pulitzer Prize winner John McPhee writes with a style informed by the journalist he was and the sciences he has explored for The New Yorker magazine for decades. When you read a piece by McPhee, you hear honest echoes of the people and places and concepts he explores.
I just re-read my favorite McPhee bit, Los Angeles Against the Mountains from The Control of Nature. Perhaps because at the time, I lived near those “over-steepened slopes” of the San Gabriel Mountains, I first read this piece with a distinct frisson. McPhee tells of the debris flows, a little-known regional problem.
The source material for a multi-ton flow builds up over decades, and needs specific triggering conditions to mobilize, making this a particular problem in a place where even last week is ancient history. Without realizing the danger, developers, realtors, home buyers, and other new-comers to the area are often led to occupy hazardous properties. The good news, as they say, is that 30, even 50, years may go by without a killer debris flow.
The bad news is that when it does come, you can’t outrun it. And everything it sweeps through is added to the tonnage of the flow: cars, refridgerators, garden sheds, iron gates. Los Angeles has tried to control the flows by trenching debris basins above the built-up areas, and (theoretically, anyway) emptying them periodically so the flows are trapped.
And it would work, too, except that people keep building their houses above the basins. Right in the path of the next debris flow.