Collapse: How Societies Choose to Fail or Succeed

by Jared Diamond

  Within the Bitterroot, people build trophy homes next to or surrounded by flammable forests at the urban/wildland interface and then expect the government to protect those homes against fires. In July 2001, when my wife and I went for a hike west of the town of Hamilton through what had been the Blodgett forest, we found ourselves in a landscape of fire-charred dead trees killed in one of the big forest fires whose smoke had filled the valley during our summer 2000 visit. Blodgett-area residents who had previously blocked Forest Service proposals to thin the forest demanded then that the Service hire 12 big firefighting helicopters at a cost of $2,000 per hour to save their homes by dropping water on them, while the Forest Service, obeying a government-imposed mandate to protect lives, people’s property, and then the forest in that order, was simultaneously allowing expanses of public timberlands far more valuable than those homes to burn. The Forest Service subsequently announced that it will no longer spend so much money and endanger firefighters’ lives just to protect private property. Many homeowners sue the Forest Service if their house burns in a forest fire, or if it burns in a backfire lit by the Forest Service to control a much bigger fire, or if it doesn’t burn but if a forest providing a pretty view from the deck of their house does burn. Yet some Montana homeowners are afflicted with such a rabidly anti-government attitude that they don’t want to pay taxes towards the costs of firefighting, nor to allow government employees onto their land to carry out fire prevention measures.

  The next set of environmental problems in Montana involves its soils. One “minor” and specific soil problem is that the Bitterroot Valley’s boom in commercial apple orchards, which were initially very profitable, collapsed, due in part to apple trees exhausting the soil’s nitrogen. A more widespread soil problem is erosion, resulting from any of several changes that remove the plant cover normally protecting the soil: overgrazing, noxious weed infestation, logging, or excessively hot forest fires that sterilize the topsoil. Long-timer ranching families know better than to overgraze their pastures: as Dick and Jack Hirschy expressed it to me, “We must take good care of our land, or we will be ruined.” However, one of the Hirschys’ neighbors is an outsider who paid more for his property than it could sustainably support by ranching, and who is now overstocking his pastures in the short-sighted hope of recouping his investment. Other neighbors made the mistake of renting grazing rights on their land to tenants, who overgrazed for a quick profit during their three-year lease and didn’t care about the resulting long-term damage. The net result of these various causes of soil erosion is that about one-third of the Bitterroot’s watersheds are considered to be in good shape and not eroded, one-third are at risk of erosion, and one-third are already eroded and in need of restoration.

  The remaining soil problem in Montana, besides nitrogen exhaustion and erosion, is salinization, a process involving salt accumulation in soil and groundwater. While such accumulation has always occurred naturally in some areas, a more recent concern is the ruining of large areas of farmland by salinization resulting from some human agricultural practices that I’ll explain in the next few paragraphs and in Chapter 13—particularly from clearing of natural vegetation, and from irrigation. In parts of Montana, salt concentrations in soil water have reached levels double those of seawater.

  Besides certain salts having specific toxic effects on crops, high salt concentrations exert a general harmful effect on crops similar to the effect of a drought, by raising the osmotic pressure of soil water and thereby making it harder for roots to absorb water by osmosis. The salty groundwater may also end up in wells and streams and may evaporate on the surface to leave a caked layer of salt. If you imagine yourself drinking a glass of “water” more concentrated than the ocean, you will appreciate that not only does it taste horrible and prevent farmers from growing crops, but that its dissolved boron, selenium, and other toxic ingredients may be bad for your health (and for that of wildlife and your livestock). Salinization is a problem today in many parts of the world besides the U.S., including India, Turkey, and especially Australia (see Chapter 13). In the past it contributed to the decline of the world’s oldest civilizations, those of Mesopotamia: salinization provides a large part of the explanation for why applying the term “Fertile Crescent” today to Iraq and Syria, formerly the leading center of world agriculture, would be a cruel joke.

  Montana’s main form of salinization is one that has ruined several million acres of cropland in the northern Great Plains as a whole, including several hundred thousand acres in northern, eastern, and central Montana. The form is called “saline seep,” because salty water building up in the ground in an uphill area percolates through the soil to emerge as a seep in a downhill area up to half a mile or farther distant. Saline seeps frequently become bad for neighborly friendship when the agricultural practices of one farmer uphill cause a saline seep on a downhill neighbor’s property.

  Here is how a saline seep arises. Eastern Montana has lots of watersoluble salts (especially sodium, calcium, and magnesium sulfates) present as components of the rocks and soils themselves, and also trapped in marine deposits (because much of the region used to be ocean). Below the soil zone is a layer of bedrock (shale, sandstone, or coal) that has low permeability to water. In dry eastern Montana environments covered with native vegetation, almost all rain that falls is promptly taken up by the vegetation’s roots and transpired back into the atmosphere, leaving the soil below the root layer dry. However, when a farmer clears the native vegetation to practice crop-and-fallow agriculture, in which an annual crop like wheat is grown during one year and the land is left fallow the next year, there are no plant roots to take up rainwater falling in the fallow year. That rainwater accumulates in the soil, waterlogs it below the root layer, and dissolves salts that then rise into the root zone as the water table rises. Because of the impermeable underlying bedrock, the salty water doesn’t drain deeply into the ground but emerges somewhere downhill nearby as a saline seep. The result is that crops grow more poorly or not at all, both in the uphill area where the problem arises and in the downhill area where the seep emerges.

  Saline seeps became widespread in much of Montana after 1940 as a consequence of changes in agricultural practices—especially the increasing use of tractors and more efficient soil tilling devices, weed-killers to kill weed plant cover during the fallow period, and more land under fallow each year. The problem must be combatted by various intensive types of farm management, such as sowing salt-tolerant plants in the downhill seep areas to start reclaiming them, decreasing the length of fallow time in the uphill area by a crop schedule known as flexible cropping, and planting alfalfa and other perennial water-demanding crops with deep roots to take up excess water from the soil.

  In the areas of Montana where agriculture depends directly on rainfall, saline seeps are the main salt-related form of land damage. But they are not the only form. Several million acres of agricultural land that depend for their water on irrigation rather than on rainfall are distributed patchily throughout the whole state, including in my summering areas of the Bitterroot Valley and Big Hole Basin. Salinization is starting to appear in some of those areas where the irrigation water contains salt. Another form arises from an industrial method to extract methane for natural gas from coal beds by drilling into the coal and pumping out water to let methane escape to the surface. Unfortunately, the water contains dissolved salt. Since 1988, the adjacent state of Wyoming, which is almost as poor as Montana, has been seeking to boost its economy by embarking on a big program of methane extraction by this method, yielding salty water that drains from Wyoming into southeastern Montana’s Powder River Basin.

  To start to understand the apparently intractable water problems that bedevil Montana along with other dry areas of the American West, think of the Bitterroot Valley as having two largely separate water supplies: irrigation from ditches fed by mountain streams, lakes, or the Bitterroot River itself, to water fields for agriculture; and wells drilled into underg
round aquifers, which provide most of the water for domestic use. The valley’s larger towns provide municipal water supplies, but houses outside those few towns all get their water from individual private wells. Both the irrigation water supply and the well water supply are facing the same fundamental dilemma: an increasing number of users for decreasing amounts of water. As the Bitterroot’s water commissioner, Vern Woolsey, explained it succinctly to me, “Whenever you have a source of water and more than two people using it, there will be a problem. But why fight about water? Fighting won’t make more water!”

  The ultimate reason for decreasing amounts of water is climate change: Montana is becoming warmer and drier. While global warming will produce winners as well as losers in different places around the world, Montana will be among the big losers because its rainfall was already marginally adequate for agriculture. Drought has now forced abandonment of large areas of farmland in eastern Montana, as well as in adjacent areas of Alberta and Saskatchewan. Visible effects of global warming in my summering areas in western Montana are that snow in the mountains is becoming confined to higher altitudes and often now no longer remains throughout the summer on the mountains surrounding the Big Hole Basin, as it did when I first visited in 1953.

  The most visible effect of global warming in Montana, and perhaps anywhere in the world, is in Glacier National Park. While glaciers all over the world are in retreat—on Mt. Kilimanjaro, in the Andes and Alps, on the mountains of New Guinea, and around Mt. Everest—the phenomenon has been especially well studied in Montana because its glaciers are so accessible to climatologists and tourists. When the area of Glacier National Park was first visited by naturalists in the late 1800s, it contained over 150 glaciers; now, there are only about 35 left, mostly at just a small fraction of their first-reported size. At present rates of melting, Glacier National Park will have no glaciers at all by the year 2030. Such declines in the mountain snowpack are bad for irrigation systems, whose summer water comes from melting of the snow that remains up in the mountains. It’s also bad for well systems tapping the Bitterroot River’s aquifer, whose volume has decreased because of recent drought.

  As in other dry areas of the American West, agriculture would be impossible in the Bittterroot Valley without irrigation, because annual rainfall in the valley bottom is only about 13 inches per year. Without irrigation, the valley’s vegetation would be sagebrush, which is what Lewis and Clark reported on their visit in 1805-1806, and which one still sees today as soon as one crosses the last irrigation ditch on the valley’s eastern side. Construction of irrigation systems fed by snowmelt water from the high mountains forming the valley’s western side began already in the late 1800s and peaked in 1908-1910. Within each irrigation system or district, each landowner or group of landowners has the right to take for his or her land a specified quantity of water from the system.

  Unfortunately, in most Bitterroot irrigation districts the water is “overallocated.” That is—incredibly to a naïve outsider like me—the sum of the water rights allocated to all landowners exceeds the flow of water available in most years, at least later in the summer when snowmelt is decreasing. Part of the reason is that allocations are calculated on the assumption of a fixed water supply, but in fact water supplies vary from year to year with climate, and the assumed fixed water supply is the value for a relatively wet year. The solution is to assign priorities among landowners according to the historical date on which the water right was claimed for that property, and to cut off water deliveries first to the most junior right-owner and then to earlier right-owners as water flows in the ditches decrease. That’s already a recipe for conflict, because the oldest farms with the earliest rights claimed are often downhill, and it’s hard for uphill farmers with lower-ranking rights to see water that they desperately need flowing merrily downhill past their property and yet to refrain from taking the water. But if they did take it, their downhill neighbors could sue them.

  A further problem results from land subdivision: originally the land was owned in large blocks whose single owner of course took water from the ditch for his different fields in sequence, and who wouldn’t have been so silly as to try to water all his fields simultaneously and thus run out of water. But as those original 160-acre blocks have become subdivided each into 40 four-acre house lots, there isn’t enough water when each of those 40 house-owners tries to water and keep the house’s garden green without realizing that the other 39 neighbors are irrigating simultaneously. Still another problem is that irrigation rights apply only to so-called “beneficial” use of water benefitting the piece of land holding the right. Leaving water in the river for the fish and for the tourists trying to float down the river on rafts is not considered a “beneficial” right. Sections of the Big Hole River have actually dried up in some recent dry summers. Until 2003, many of those potential conflicts in the Bitterroot Valley were amicably adjudicated for several decades by Vern Woolsey, the 82-year-old water commissioner whom everyone respected, but my Bitterroot friends are terrified at the potential for conflict now that Vern has finally stepped down.

  Bitterroot irrigation systems include 28 small privately owned dams constructed across mountain streams, in order to store snowmelt water in the spring and to release it for irrigating fields in the summer. These dams constitute ticking time bombs. They were all built a century ago, to weak designs now considered primitive and dangerous. They have been maintained poorly or not at all. Many are at risk of collapses that would flood houses and property lying below them. Devastating floods resulting from failures of two such dams several decades ago convinced the Forest Service to declare that a dam’s owners, and also any contractor that has ever worked on the dam, bear the liability for damages caused by a dam failure. Owners are responsible for either fixing or removing their dam. While this principle may seem reasonable, three facts often make it financially onerous: most of the present owners bearing the liability get little financial benefit from their dam and no longer care to fix it (e.g., because the land has been subdivided into house lots, and they now use the dam just to water their lawns rather than to earn a living as farmers); the federal and state governments offer money on a cost-sharing basis to fix a dam, but not to remove one; and half of the dams are on lands now designated as wilderness areas, where roads are forbidden and repair machinery must be flown in by expensive helicopter charters.

  One example of such a time bomb is Tin Cup Dam, whose collapse would inundate Darby, the largest town in the southern Bitterroot Valley. Leaks and the dam’s poor condition triggered lengthy arguments and lawsuits between the dam’s owners, the Forest Service, and environmental groups about whether and how to repair the dam, climaxing in an emergency when a serious leak was noted in 1998. Unfortunately, the contractor whom the owners hired to drain the dam’s reservoir soon encountered heavy rocks whose removal would require big excavation equipment to be flown in by helicopter. At that point the owners declared that they had run out of money, and both the state of Montana and Ravalli County also decided against spending money on the dam, but the situation remained a potentially life-threatening emergency for Darby. Hence the Forest Service itself hired the helicopters and equipment to work on the dam and billed the owners, who have not paid; the U.S. Department of Justice is now preparing to sue them in order to collect the costs.

  The Bitterroot’s other water supply besides snowmelt-fed irrigation consists of wells for domestic water use, tapping into underground aquifers. They, too, face the problem of increasing demand for decreasing water. While mountain snowpack and underground aquifers may seem to be separate, they are in fact coupled: some runoff of used irrigation water may percolate down through the ground to the aquifers, and some aquifer water may originate ultimately from snowmelt. Hence the ongoing decrease in Montana’s snowpack forebodes a decrease in the aquifers as well.

  There is no doubt about increasing demand for aquifer water: the Bitterroot’s continuing population explosion means more people drinking more
water and flushing more toilets. Roxa French, coordinator for the local Bitter Root Water Forum, advises people building new houses to drill their wells deep, because there are going to be “more straws in the milkshake”—i.e., more wells drilled into the same aquifer and lowering its level. Montana law and county regulations about domestic water are currently weak. The well that one new house-owner drills may lower the water level of a neighbor’s well, but it is difficult for the latter person to collect damages. In order to calculate how much domestic water use an aquifer could support, one would have to map the aquifer and to measure how rapidly water is flowing into it, but—astonishingly—those two elementary steps have not been accomplished for any Bitterroot Valley aquifer. The county itself lacks the resources to monitor its aquifers and does not carry out independent assessments of water availability when it is considering a developer’s application to build a new house. Instead, the county relies on the developer’s assurance that enough well water will be available for the house.

  Everything that I have said about water so far concerns water quantity. However, there are also issues of water quality, which rivals western Montana’s scenery as its most valuable natural resource because the rivers and irrigation systems originate from relatively pure snowmelt. Despite that advantage, the Bitterroot River is already on Montana’s list of “impaired streams,” for several reasons. The most important of those reasons is buildup of sediments released by erosion, road construction, forest fires, logging, and falling water levels in ditches and streams due to use for irrigation. Most of the Bitterroot’s watersheds are now already eroded or at risk. A second problem is fertilizer runoff: every farmer growing hay adds at least 200 pounds of fertilizer to each acre of land, but it is unknown how much of that fertilizer ends up in the river. Waste nutrients from septic tanks are yet another increasing hazard to water quality. Finally, as I already explained, toxic minerals draining out of mines are the most serious water quality problem in some other parts of Montana, though not in the Bitterroot.