Filed under: California, climate change, economics, futurism, Legacy Systems, livable future, Preludes, Water | Tags: Speculation, sustainability, water politics
Well, I finally finished reading Mark Reisner’s Cadillac Desert (Amazon link), and I highly recommend it, if you haven’t read it already, even though the original text was written in the 1980s. For those who haven’t read it, the thumbnail is that it’s a muckraking history of water works in the US, primarily in the western US in the 20th Century. The reason I strongly recommend it is not just for what Reisner got right (or apparently got right), but also what he got wrong, like his prediction of the huge water crisis of 2000.
I’m not going to do a book review here. Rather, I’m going to talk about some of the things I got out of it, including how hard it is to predict when water crises will hit.
Here’s the basic way Reisner learned to think of rivers. On the upstream end, water falls out of the sky or comes out of the ground. Since water’s kind of a universal solvent, it inevitably causes both erosion and dissolution. As a result, rivers have a load of dissolved minerals–salts, to oversimplify–and a load of suspended solids, which become sediments when the river lacks the energy to keep them suspended. At flood stage, those suspended solids can be house-sized boulders. In still water, even clay particles eventually settle out. Normally riverine energies are somewhere in between.
In the normal course of things, a river system either empties into the ocean, or into an inland lake like the Great Salt Lake. There, the sediments and salts build up as the water evaporates. In the western US, the great salt flats are the remnants of lakes that dried up completely, while the ocean is salty due to all the salts washing into it from the rivers and streams. In geologic time, the salts can be entombed in sediments, moved onto continents by tectonics, and so the ocean doesn’t become a huge salt flat, but you get the idea.
Also in the normal course of things, rivers irrigate riparian vegetation by flooding. This scours out the old sediments (which can contain salts due to summer evaporation) and lays down new sediments. This is the way the Nile used to work, and fresh river sediments can be extremely fertile. Tohono O’odham farmers reportedly like to farm following flash floods, for exactly this reason.
Now, let’s add some dams and irrigation canals to all this. Neither are new technologies, and they are problematic.
Here’s the first problem: when you dam a river, the sediment it carried to that point drops out behind the dam, as the stream loses energy in the reservoir. Those sediments fill up the reservoir, and it takes a lot of work to get the sediments out, and then you have to figure out where to put them so that they don’t wash right back into the river and silt up the reservoir again. Ultimately, the reservoir will silt up to the point of uselessness, and pulling sediments out is designed to prolong its useful lifespan, not to make it immortal.
And there’s a second problem: as water evaporates from the reservoir, the salt concentration in the remaining water increases. When you pull that water out to irrigate fields, evaporation, plus transpiration from the plants, pulls out still more water, leaving the salts behind in the soil. How fast this happens depends on how careless you are. To some extent, you can flush out more salty water with less salty water by irrigating more, but then that salty water has to go somewhere. Ideally it should go into the ocean. More often, it goes into someone’s field downstream, or into a place like the Salton Sea, which act(ed) as the sump for the Imperial Valley’s efforts to use salty water from the Colorado to wash salts out of their fields. Still, over time, irrigated fields salt up. This limits the crops you can grow on them, and in droughts, the salt problems get worse as water becomes less available to flush them out. According to Reisner, the only place that successfully was irrigated for thousands of years was the Nile Delta, and that was because the Nile River flushed the fields most years. Once the Aswan Dam was installed, they started having the same silt and salt problems that everyone else does. While I’m not sure he’s right for the entire world (looking at the Yellow River and Tonle Sap), I think he’s correct for arid regions.
There’s actually a third problem, too: rivers aren’t just irrigation water wasting into the ocean, they’re living systems whose life is exploitable too. All those dams harm any downstream fisheries, as well as the passage of anadromous fish like salmon and steelhead. The loss of the Nile has led to the ecological death of the Nile Delta, along with some very long-term fisheries that went away when the sediments were caught behind the Aswan Dam, rather than flushed down the Nile every year.
Now with all these problems, why dam? The answer is two-fold. First, to people adopting irrigated agriculture for the first time, the problems aren’t that obvious, while turning the desert into a paradise through hard work and faith (I’ll come back to this) is quite obvious. The second part is that, once you make millions of people and billions of dollars dependent on such systems, they’ll just have to be maintained in spite of the problems and cost. Right?
Faith. According to Reisner, the first anglos to do serious irrigated agriculture in the west were the Mormons, who pioneered digging ditches starting in Utah and then throughout the region (even as far as Riverside, CA, although they later retrenched in Utah). Their hard work diverting the streams flowing into the Great Salt Lake made many people think that it was possible to turn the desert into farmland, and the land-rush was on. For the non-Mormons, it was faith in science and engineering, from the debunked theory that “rain follows the plow” to the faith in the prowess of the Bureau of Reclamation and Army Corps of Engineers, that led them to continue moving to the Southwest and trying their hand at irrigating the deserts.
There’s also a large element of political power involved, because especially after WWII, eastern farmers were getting paid to not plant crops when prices were low, while western farmers received massively subsidized water to plant those same crops. That’s how California and Arizona cotton could compete with cotton from Alabama and Mississippi, for example.
The men running the relevant congressional committees were westerners, and the example of the New Deal had made the politicians think that, so long as the economy grew, they could make dams and other waterworks with abandon, help their constituents, and push the costs off onto the future when growth would cover them, as it had covered Hoover Dam when it was built in the depths of the Depression. Reisner calls water projects “wampum” for congressmen all over the US, and planting a water project in someone’s district was a standard way to pay for a political favor elsewhere. This was a big element of the pork barrel politics that inflated our national debt to the levels we see to day. To a large extent, that debt is welfare money, but it’s welfare for western farmers and ranchers (many of them now industrial farms owned by multinationals), not for poor, inner city minorities. There’s a deep irony that so many small government rural Republicans would become dispossessed migrants if the government stopped subsidizing their way of life, but that’s what we’ve got in the US.
It’s even worse with the southwestern cities. LA gets a lot of water pumped uphill from the Sacramento Delta and over the Tehachapi Mountains, in part because the late Gov. Pat Brown (Jerry Brown’s father) thought that he’d rather see all the development messing up southern California, rather than up in his native northern California, and he got some interesting political deals to make it “pay” for all the players involved, including the oil companies. I could go on, but the political chicanery and very human personalities of the people involved are the best part of Reisner’s book.
Yes, our western water system is unsustainable. Eventually, the Oglalla Aquifer under the Dust Bowl will run dry, the area will perforce switch back to grazing and dryland farming, and there likely will be another Dust Bowl. Yes, the loss of western agriculture means that a lot of cheap food that has been feeding the world and keeping it “peaceful” will disappear, world food prices will go up (China, Russia, and Australia have areas with the same problems as the American West), and that will cause or exacerbate famine and civil unrest all over the globe.
One thing that’s not clear is when all the bad things start happening. Reisner figured it would happen by 2000, but he’s demonstrably wrong by now. He thought that San Joaquin groundwater would be exhausted by now, even though others thought it would be exhausted decades before, and so far everyone’s been wrong. Partly they keep finding more groundwater, partly they keep getting more water pumped south, and partly the land’s getting too salty for many crops, so that less is getting pumped. Gov. Jerry Brown is still trying to complete his father’s Peripheral Canal (it has a different name now), and so forth.
The reason the whole thing hasn’t yet crashed is that when there are tens of millions of people depending on a project, no politician will cut them off, especially in the name of something as ill-defined as long-term sustainability. The pols will find a way to patch things together, even if the cost is passed onto the future. The West’s water systems are, for the most part, rationally designed on the individual level, but the designs and locations are based on fundamentally insane and short-sighted, even stupid, politics. According to Reisner, all the best sites for dams were dammed by the 1940s, and the western dams proposed now (many are designs 50 years old) are stupid places to dams. Worse, the projects were designed to last 50-100 years, they were all built at least 50 years ago, and now they’re going to be maintained and upgraded well beyond their design life, except in cases where they’re so stupid that it’s better to take them apart, as we’re seeing with dam removal projects.
Still, the upshot is that it’s even harder than I thought to predict when our water system will fall apart. The key factor isn’t design life, it’s maintenance, political will, and economic growth. We’re willing to pay for maintenance so long as we can convince ourselves that future growth will cover the costs. When the growth really and truly stops, the whole thing will start to fall apart, but I don’t think we’ll be able to see that coming more than a few years in advance.
The “good” news is that, if we can find ways to keep PV solar panels clean without using water (as they do with the Mars Rovers), we can increasingly grow solar farms in old irrigated fields. In the decades to come, the West may become an exporter of power rather than food, with the cities as manufacturing hubs and food imported from elsewhere. It’s not a great solution, and I suspect that a lot of people will leave the West, but it’s what we’ve got.
The flip side to that is that where the solar and wind plants go is a matter of politics as much as rational economics. We saw that with Ivanpah, and we’ll see it many more times. Just as some of the old dams were irrational designs that delivered, at best, ten cents on every dollar invested, but were built anyway, I suspect we’ll see a huge proliferation of solar and wind farms that don’t make a lot of sense economically, but which bring home the bacon to some politician or other.
What did I miss?
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