Collapse_ How Societies Choose to Fail or Succeed - Jared Diamond [31]
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