Haines Falls, N.Y.—Here are some things my children and I weren’t thinking about as we scampered outside our house in the Catskill Mountains during an afternoon lull in Tropical Storm Irene, elated by our suddenly torrential waterfalls, eager to pose in front of them for pictures to send to our friends: We weren’t thinking about orographic enhancement, because, of course, we had never heard of it. Orographic enhancement is the meteorological phenomenon that made Irene rain harder when it hit the mountains (wet air forced upward cools and condenses). We weren’t aware that a tropical storm as big as Irene—520 miles across when it first came ashore—has the reach to keep sucking up moisture from the ocean even as its winds swirl inland. That means that it doesn’t dry out as fast as it otherwise would, and it rains harder and longer.
We were aware, from my generally ineffectual attempts to garden, that the sides of our mountain hold very little topsoil and that the bedrock in places lies only a few inches down. But we didn’t realize that this meant that comparatively few underground aquifers or deep root systems were available to absorb or slow Irene’s water as it sluiced downward.
We didn’t know any of this because, like Hans Castorp on his magic mountain, we were enjoying the last outburst of innocence I think we’re going to be allowed in this age of extremes. We whooped at the strange sights. We ran around after being cooped up all morning. At that point, we didn’t know that the water arcing balletically over our heads and the falls misting up as they fell were flooding parts of the town below us, Palenville, and that more water was flooding towns all around us, Lexington and Windham and Prattsville, and, in the case of Prattsville, almost entirely wiping it out. Nor did we know that the caretaker of our mountaintop community, whose family has lived on the mountain for generations, may have saved us from flooding of our own by spending the two days before the storm clearing stray branches and large, loose rocks out of every streambed in the vicinity, so that swollen creeks wouldn’t dam up and overflow. This was an act of forethought that would never have occurred to me, a resident of cities most of my life.
IN THE LAST QUARTER of the nineteenth century, people turned against the kind of American Romanticism inspired at least partly by mountains, particularly by the mountain I live on: Kaaterskill High Peak, whose sweeping views of the Hudson Valley and the Berkshires beyond made it a favorite of the artists of the Hudson River School. If you were going to enjoy their paintings, you had to be willing to gaze dreamily across valleys into a brilliant or reddening sky and overlook the unpleasant realities below, such as the clear-cutting of the hemlock forests depicted in some paintings as virgin and untouched.
Yet a certain Hudson River-style obliviousness remains with us when we think about extreme weather. Even now, weather correspondents love to obsess over hurricane satellite images, with their wind-speed probability charts and their gorgeous, wheeling clouds. But what do these pictures—taken from 22,300 miles away—have to teach us about the effects of a storm on our own backyards? What we need is local knowledge of the kind afforded by, say, hydrology. We need to become familiar with such concepts as “time of concentration.” That’s the time it takes for water to run off from the furthest point of a watershed to whatever drains the water out of it, such as a stream. The shorter the “time of concentration,” the bigger the “peak discharge.” In other words, the faster water plunges from all points toward a central gathering spot, the more cubic feet per second rush into the body of water, and the more likely it is to flood. Thus, the foot or so of rain that fell in the Catskills during Irene caused the Schoharie Creek to rise more than nine feet above its flood level, and houses alongside it to wrench free of their moorings and rush down rivers that had previously been streams.
Three days after Irene, the children and I finally made our way to Windham, 16 miles from our house. We had volunteered to do cleanup and given our names to someone at the Windham Command Center who had promised to get them to the National Guardsmen manning checkpoints. Otherwise, I was told, only permanent residents of the town were allowed in or out.
We had seen videos of Windham, most of them loud. The water of the Batavia Kill had whitecaps as it rushed through Main Street and elsewhere, and the videos recorded their roar. But, by the time we arrived in town, the place was quiet in a way that seemed sullen, almost embarrassed, despite the scurrying about of cleanup crews and National Guard trucks. It was not until we were sent out with a crew of other mothers and children to sweep the sidewalks and clear the yard of a financial adviser’s office in a Victorian house on Main Street—light duty, because of the children; other crews shoveled mud from basements and carried strips of siding or soggy drywall to dumpsters—that we understood what it means for a town to be ripped in half by water. Floods destroy the barriers that hold things in place in normal life. Dirt rises; pavement is plowed under. Private property spills into the street, either because the water has ripped off the walls of houses or because its owners have dragged their stuff outside to dry.
We bought a second home in the Catskills because we love the area, but it didn’t hurt that the house sits high above the coastline. This was our global-warming refuge. Researchers now theorize that warmer oceans won’t spawn more hurricanes, but will lead to bigger ones that may last longer and may penetrate further north. What other as-yet theoretical meteorological effects are headed our way? I’m too ignorant to say. What I’m planning to do, for now, is learn from our caretaker’s example and keep our culverts and streambeds clear, have the drains in our basement snaked every year, stockpile sand bags, buy extra shovels and a wheelbarrow and an industrial-strength dehumidifier, and bone up on my mountain geology. I’m hoping that the next time the water comes, whether in a tropical storm or a nor’easter that drops more snow than we’ve seen yet in these snowy mountains, I’ll have some slight inkling of what to expect.
Judith Shulevitz is a contributing editor for The New Republic. Her book, The Sabbath World: Glimpses of a Different Order of Time (Random House), appeared in paperback this spring. This article appeared in the October 6, 2011, issue of the magazine.