The American Southwest has always been parched, so water supplies become overextended as farms and cities grow. John Fleck’s Water is for Fighting Over examines legal and political fights and settlements for water from the Colorado River.
From this experience we can find lessons learned and paths to share water.
Water rights went to the first users — farmers — just as in California. From page 19,
The most important legal principal undergirding the Colorado River’s water allocation asserts that the first communities to put water to “beneficial use” get first dibs in times of scarcity. It is called “the doctrine of prior appropriation,” and in the West, that most often means agriculture. The result is that half of the Colorado River’s water is consumed by pasture and cattle feed crops, … the West’s lowest-value crops.
Users want the cheaper water, which is groundwater. In the 1940s, cities in Los Angeles overpumped groundwater, causing salt water to intrude into the aquifer. They needed to import water to replace the groundwater, but the imported water from the Colorado River was expensive. From page 90, “without an effective groundwater-management scheme, communities had an enormous incentive to just keep pumping cheaper groundwater while their neighbors shouldered the costs of the imported-water fix.”
The water available for farms and urban users is variable, and sometimes we get it wrong. From page 17,
The Colorado River’s problem is simple: there is not enough water to enable everyone to use the amount to which they are legally entitled. … The roots of the problem like in mistakes made in the early twentieth century. … twenty years of data was sufficient to give the compact’s negotiators confidence that they had at least 17 million acre-feet on the average to work with, and likely more. …
What they did not grasp until years later was that their twenty-year baseline was unusual. How unusual? With the advent of tree-ring reconstructions of past climate, we know know it was the wettest twenty-year period in at least 500 years.
Colorado River reservoirs are running out of water. From page 195, as the reservoir behind Hoover Dam continues to drop, Las Vegas is “building a new intake that is deeper in the reservoir, and a new pumping station to handle the deeper water.” This might not be enough. From the Washington Post,
A new study, just released last week in the journal Water Resources Research, suggests that future warming could cause the river’s flow to decline by as much as 35 percent by the end of the century.
In fact, the authors point out, rising temperatures are likely already responsible for a substantial portion of the river’s troubles today. Historical data indicate that the current drought has caused greater flow reductions in the Colorado River than previous droughts — yet the declines in precipitation associated with the current drought are not as severe as they’ve been in the past. According to Brad Udall, senior water and climate research scientist at the Colorado Water Institute and co-author on the new study, the major difference today is that the region is hotter than it used to be.
“We strongly believe — and the study supports the idea — that the reason these flows are down is because of these very warm temperatures,” he told The Washington Post.
Water is a shared resource that can lead to problems: the tragedy of the commons. From page 90,
The commons is a resource to which many different users have access and cannot be excluded. A pasture on which anyone can graze their stock is the classic example, and groundwater basins from which lots of people can pump water share many of the same characteristics. By “tragedy”, Hardin means not imply a bad outcome but, quoting the philosopher Alfred North Whitehead, “the solemnity of the remorseless working of things”. His formulation suggested a sort of inevitability as self-interested consumers trashed their world. A sheepherder grazing on common land has a personal incentive to add one more sheep, Hardin argued, because the benefit of that one sheep accrues to the herder. The overall harm to an increasingly damaged commons, meanwhile, is borne by all.
These problems can be solved through informal talks, a tool in common-pool resource management. From page 93, from work that won the 2009 economics Nobel Prize
Ultimately, you often need to develop formal governmental and legal institutions, but at the beginning, non-binding communication–just finding a way to get together and chat–can play a crucial role. Ostrom called it “cheap talk”. In lab experiments, Ostrom and others found that “cheap talk” made people more likely to cooperate successfully. In the field, they found again and again, it worked.
Farms and cities can moderate water use, quieting fears of turning the faucet and having no water. From page 84, describing Arizona’s experience with a shortfall of water, “Overall groundwater pumping for agriculture dropped by almost helf from its 1975 peak of 5 million acre-feet per year to 2.6 million acre-feet per year in 2010. From 1980, when the groundwater law was passed, to 2010, Arizona’s population more than doubled to 6.4 million, but its total water use declined by 24 percent.”
California is an arid region where water is a critical, shared resource. We can learn from the Colorado River experience.