Trade-Offs

While I’m glad that Abrahm Lustgarten is highlighting the issues regarding the depletion of the Colorado River in his post at Pro Publica:

Earlier this month, the Bureau of Reclamation released lesser-noticed projections for water levels, and they are sobering. The figures include an estimate for what the bureau calls “minimum probable in flow” — or the low end of expectations. Water levels in Lake Mead could drop by another 40 vertical feet by the middle 2023, ultimately reaching just 1,026 feet above sea level — an elevation that further threatens Lake Mead’s hydroelectric power generation for about 1.3 million people in Arizona, California and Nevada. At 895 feet, the reservoir would become what’s called a “dead pool”; water would no longer be able to flow downstream.

The bureau’s projections mean we are close to uncharted territory. The current shortage agreement, negotiated between the states in 2007, only addresses shortages down to a lake elevation of 1,025 feet. After that, the rules become murky, and there is greater potential for fraught legal conflicts. Northern states in the region, for example, are likely to ask why the vast evaporation losses from Lake Mead, which stores water for the southern states, have never been counted as a part of the water those southern states use. Fantastical and expensive solutions that have previously been dismissed by the federal government — like the desalinization of seawater, towing icebergs from the Arctic or pumping water from the Mississippi River through a pipeline — are likely to be seriously considered. None of this, however, will be enough to solve the problem unless it’s accompanied by serious efforts to lower carbon dioxide emissions, which are ultimately responsible for driving changes to the climate.

Meanwhile, population growth in Arizona and elsewhere in the basin is likely to continue, at least for now, because short-term fixes so far have obscured the seriousness of the risks to the region. Water is still cheap, thanks to the federal subsidies for all those dams and canals that make it seem plentiful. The myth persists that technology can always outrun nature, that the American West holds endless possibility. It may be the region’s undoing. As the author Wallace Stegner once wrote: “One cannot be pessimistic about the West. This is the native home of hope.”

I’m sorry that the post is as superficial as it is. It does have some interesting tidbits of information. For example:

Like the record-breaking heat waves and the ceaseless mega-fires, the decline of the Colorado River has been faster than expected. This year, even though rainfall and snowpack high up in the Rocky Mountains were at near-normal levels, the parched soils and plants stricken by intense heat absorbed much of the water, and inflows to Lake Powell were around one-fourth of their usual amount. The Colorado’s flow has already declined by nearly 20%, on average, from its flow throughout the 1900s, and if the current rate of warming continues, the loss could well be 50% by the end of this century.

and this:

Since about 70% of water delivered from the Colorado River goes to growing crops, not to people in cities, the next step will likely be to demand large-scale reductions for farmers and ranchers across millions of acres of land, forcing wrenching choices about which crops to grow and for whom — an omen that many of America’s food-generating regions might ultimately have to shift someplace else as the climate warms.

and this:

A breathtaking amount of the water from the Colorado — about 10% of the river’s recent total flow — simply evaporates off the sprawling surfaces of large reservoirs as they bake in the sun. Last year, evaporative losses from Lake Mead and Lake Powell alone added up to almost a million acre feet of water — or nearly twice what Arizona will be forced to give up now as a result of this month’s shortage declaration.

How superficial? For one thing as far as I can tell the 40 million people they cite as being dependent on the Colorado only includes people in the U. S. Since many people in Mexico also depend on the Colorado for water, it suggests that the 40 million is a grave understatement.

Additionally, California, Arizona, Nevada, Utah, and Colorado are all more dependent on real estate sales as a percentage of GDP than the other states in the U. S. Said another way an increasing population is “baked into” the economic projections for those states. Paradoxically, California is also more dependent on agriculture for its economy than most other states. If you see a conflict there, you’re not mistaken.

Also conspicuously missing is the conflict between increasing dependence on hydroelectric power in California in particular and the decreasing ability of the Colorado to support hydroelectric power generation.

Finally, there are three ways to address the problem being called out by the article: fewer people, more efficient resource utilization, and increasing the amount of water carried by the river. Of those the last two are those emphasized. There is little attention paid to the relative costs of each strategy. A little cost-benefit analysis would be informative.