Feel it yet? That dire sense of déjà vu? It probably depends on your livelihood or interests. If you’re a Bay Area boulevardier or the type once described in singles ads as a lover of long walks on the beach, you’re no doubt delighted by the unceasing blue skies and unseasonably pleasant temperatures. But it’s another matter if you’re a farmer, salmon fisherman, water agency manager, skier or whitewater kayaker. Your income—or at least, your sense of well-being— is directly determined by what falls from the sky.
Or doesn’t fall. Which has been pretty much the case this year, just as it was in the all too recent drought of 2013 – 2016. Sure, last winter’s precipitation was a record breaker, dumping gigatons of snow in the Sierra Nevada and sluicing so much water downstream that we almost lost Oroville Dam. But now the perfect weather is making us recall our recent parched past, when we watched our lawns wither, irrigated the roses with salvaged gray water, and made do with five minute showers. So, are we about to teeter back into the bad old days?
Maybe. Climatologists researching California’s rainfall records have determined that it’s statistically impossible to predict precipitation from one month to the next. But longer trends may well be detected, or at least handicapped. The Climate Prediction Center of the National Weather Service recently observed that much of the West is experiencing the “persistent ridging” (i.e., presence of strong, storm-rebuffing high-pressure systems) that characterized the recent drought. Moreover, say federal meteorologists, California’s rainy season seems unable to get off the blocks, despite early and promising precipitation across the northernmost part of the state. The Center predicts drought development across much of the Southwest; still, government meteorologists anticipate that areas north of the Bay Area will experience “greater potential for precipitation” by the time the wet season winds up.
And even if that bothersome high-pressure ridge stays anchored over California, we should be in pretty good shape for a while.
When viewed from the geologic time scale, the recent drought, as well as the other devastating droughts of 1987 and 1976, could well be the norm.
“I’m not extraordinarily worried about the near term,” says Peter Gleick, the president of the Pacific Institute. “We had an extremely wet winter last year and our reservoirs are full, so we’ll start out [the dry season] in pretty good shape. Also, our responses over the last five years [such as water restrictions on urban users] show that we can handle shortages to some degree.”
Unhappily, what really saved us during the recent drought was overpumping of groundwater, says Gleick, who earned his Doctorate and Master’s in energy and resources at Berkeley. Such pumping, he says, is unsustainable, resulting in the permanent overdraft of state aquifers. Moreover, overdrafting has resulted in massive ground subsidence throughout much of the San Joaquin Valley, causing billions of dollars in damaged infrastructure. It’s possible, even likely, that future droughts won’t be mitigated by groundwater simply because it may not be there.
Such ongoing and long-term effects of the last drought are particularly worrisome because 2013 -2016 wasn’t necessarily an anomaly; it could be a signal that the state is returning to an arid baseline that characterized conditions for many thousands of years prior to Euro-American settlement. B. Lynn Ingram, a professor emerita at UC Berkeley’s Department of Earth and Planetary Science who has studied the West’s paleo-climatic record, has observed that the recent drought—as well as the devastating droughts of 1987 – 1992 and 1976 – 1977—aren’t outliers. When viewed from the geologic time scale, she says, they could well be the norm.
“The past 150 years, which we have used as our baseline for assumptions about rainfall patterns, water availability for agriculture, water laws, and infrastructure planning, may in fact be an unusually wet period,” Ingram wrote in Origins, a journal on the connections on between current events and history published by Ohio State University and Miami University.
Some of the first evidence that California periodically endures droughts lasting years, decades or longer was confirmed in the mid-1930s by Samuel Harding, a Cal engineering professor. California had been affected by the same drought that was causing the Dust bowl in the Great Plains, resulting in a significant shrinking of Lake Tahoe. While visiting the diminished lake, Harding noticed a bunch of large tree trunks poking up from the surface along the lake’s south shore. Given their size, he figured that the trees indicated the lake had once been much lower than its 1930s level, and for a considerable period of time; otherwise they’d never have achieved trunk diameters of three feet. He took core samples of the stumps, and identified as many as 150 growth rings. That meant that the lake had been at a reduced level for at least a century and a half—a situation that could only have been induced by prolonged drought. Later, radiocarbon analyses of Harding’s trees indicated they had died about 4,800 years ago in the Mid-Holocene epoch (our current geologic epoch, though some scientists have begun referring to the present as the Anthropocene, the geologic epoch shaped by human activity).
Subsequent work by other researchers confirmed that California’s geologic history is marked by such “megadroughts.” As noted by Ingram, archaeologist Susan Lindstrom dove on another batch of submerged Lake Tahoe tree stumps, some of them three and a half feet in diameter. Analyses extended the duration of the responsible drought from 4,840 years ago to 6,290 years; in other words, California endured a drought lasting 1,420 years at a time when Amerindians inhabited the continent.
“As global temperatures increase, things just keep getting drier and more burnable. California gets hit particularly hard by that as we’ve just seen, but that feedback works at the global level.”
Work by Ingram on San Francisco Bay sediments that contain precipitation information on the Sacramento and San Joaquin River watersheds determined that the great Mid-Holocene drought was anything but an aberration. As described in her Origins article, her studies “….showed that droughts lasting over a decade occurred regularly over the past two millennia at intervals of 50 to 90 years. The [sediment] cores also revealed a period of high salinity [linked to reduced freshwater flows] that began about 1,700 years ago and ending about 700 years ago, suggesting another prolonged drought.”
Richard Walker, professor emeritus of geography and the author of The Conquest of Bread: 150 Years of Agribusiness in California, is deeply familiar with the studies on California’s megadroughts, and observes they contain a message we can ignore only at our peril.
“The last drought was serious, but in the two thousand-year record, it’s not close to being the most severe,” Walker says. “It’s not just about precipitation; it’s about transpiration. As global temperatures increase, things just keep getting drier and more burnable. California gets hit particularly hard by that as we’ve just seen, but that feedback works at the global level. Stephen Pyne [of Arizona State University] wrote a book on global wildfires, and he noted that to a degree, the world is always on fire—that’s part of normal wildland ecology. But the feedback element is worrisome. We’re now getting severe tundra fires regularly, and that’s not good.”
California supports a massive water storage and transfer complex, and some may feel that provides insurance against extended drought. That isn’t the case, says Walker. The system is maxed out. With the exception of a couple of large North Coast river systems—the Klamath and the Eel Rivers, specifically—all of the state’s major drainages have been tapped. Though both the Klamath and the Eel are off limits for major diversions to the south state under existing policies, Central Valley agribusiness has long been determined to develop them, says Walker. That goal seems to be shared at least obliquely by Governor Jerry Brown, who has always pushed for a water transfer project around the Sacramento/San Joaquin Delta—first during his initial gubernatorial term in the 1980s with the Peripheral Canal, and more recently with a reprise effort, the twin Delta Tunnels. The tunnels project has been widely pilloried because of expense, negative environmental impacts and the fact that it would provide no new water, only expedite deliveries from north to south of existing water.
“It’s asinine because there’s no more available water,” says Walker. “The only way to make [the tunnels] work is by tapping the Eel and the Klamath.”
“Now we’re just rearranging the deck chairs on the Titanic instead of looking for icebergs. We need a different course.”
There are plans on the drawing boards for other storage projects, including Sites reservoir, an off-stream reservoir in the hills west of the Sacramento Valley; a new dam on the upper San Joaquin River at Temperance Flat; and raising Shasta Dam. Collectively, these projects could store an additional 3.6 million acre feet of water under optimum (i.e., very wet) scenarios at a cost of almost $8 billion.
But optimum storage can be hard to achieve, especially during the deep droughts that are sure to be part of our future. Besides, says Walker, heat and aridity will cause tremendous evaporation at Sites.
“You’d likely lose almost as much as you store at Sites,” Walker said, “and the total yield from raising Shasta Dam would be around 500 thousand acre feet. That’s a drop in the bucket. And the environmental and archeological impacts at Shasta [raising the dam would flood lands sacred to the Winnemem Wintu people] would be extreme, so I think it’d be difficult to get it through.”
In sum, says Walker, “We’ve already developed all the good storage sites, and now we’re just rearranging the deck chairs on the Titanic instead of looking for icebergs. We need a different course.”
And that course, he continues, is water conservation: permanent urban and agricultural requirements for saving water, better technology to achieve those ends, fitting canals and aqueducts with impermeable linings, retrofitting delivery systems to stop leaks, and better monitoring to insure compliance.
The state could also increase its water supply dramatically simply by taking marginal agricultural lands out of production, particularly in the selenium-contaminated holdings of the western San Joaquin Valley, says Walker.
A USDA analysis in 2002 determined that more than 9 million acres of San Joaquin Valley land were used for all agricultural purposes, including grazing. Cultivated land – cropland – currently accounts for about five million acres. According to the Pacific Institute, about 1.3 million acres of this total is drainage-impaired land in the western part of the Valley. When extra water is used to flush accumulated salt from such croplands, selenium is carried from the soils into waterways, poisoning fish and wildlife and threatening human health.
“It really has to stop,” says Walker. “The Westside is basically crappy land with little natural rainfall. It all depends on water from the Central Valley Project and the State Water Project (respectively, California’s primary federal and state water delivery systems). At current land values, we could buy out Westlands [the largest irrigation district in the western San Joaquin] for between $10 to $15 billion and solve most of the problem.”
Much of California relies on groundwater, and we continue to overdraft those supplies at a truly alarming rate.
A couple of hundred thousand acres of impaired lands already have been retired, but the program needs to be expanded, say environmentalists and water conservation advocates. Indeed, a study by the Environmental Water Caucus based on data collected from recent state water plans, the Pacific Institute and the Planning and Conservation League, concluded that two million acre feet of water a year could be saved by retiring impaired agricultural lands. Other measures, including improving agricultural and urban use efficiency and recycling, could kick that figure up to 13 million acre feet.
But surface deliveries are only part of the issue. As Gleick noted, much of California relies on groundwater, and we continue to overdraft those supplies at a truly alarming rate. The 2014 state Sustainable Groundwater Management Act is a necessary step in correcting such excesses, says Gleick, but many of the strictures don’t go into full effect for decades, “and we can’t afford to wait until 2020 or 2030.”
Along with determining how to use water in a wise and equitable fashion, we need to figure out how to pay for it, says Michael Hanemann, a professor at Cal’s department of agricultural and resource economics.
“Water is a massively expensive resource, far more capital intensive than electricity, natural gas, or communications,” says Hanemann. “Fully 85 to 90 percent of the cost of water is capital required for infrastructure. And that infrastructure has to be fully in place before you get a single drop coming out of your tap.”
That’s an even bigger problem these days than in the past because the current proposals for state water infrastructure upgrades, such as the Delta Tunnels, don’t enjoy wide support, Hanemann says. While Southern California water users were willing to finance the State Water Project sixty years ago, they are not showing similar enthusiasm for the Delta Tunnels.
“You can make the argument that the all citizens have a compelling interest in the tunnels as insurance,” says Hanemann, “but that’s not the way they’ve been sold. And the essence of the problem is that they’re very expensive, and they were proposed at a time when Southern California has been moving toward local supplies [including recycling, new local reservoirs and desalinization]. When you pay for insurance, you’re determining your risk aversion, including how much of a premium you’re willing to pay to avoid that risk. It’s only when your house burns —or in this case, if a prolonged and catastrophic drought hits—that you can determine whether insurance was a good idea.”
A crucial step in getting our water rights in shape is measuring the water that exists. The holders of those rights can take as much as they want, as long as they don’t inconvenience other rights holders.
Nor are our problems with water limited to supplies and infrastructure costs. Water rights issues in California are a legal mare’s nest, leading to an unending procession of suits and counter-suits with no resolution in sight. Indeed, state water claims outstrip supplies by a significant degree, a situation blandly described by water wonks as “oversubscription.” A full examination of the various rights and their applications would require a book, or two or three. Suffice it to say the end result is highly unsatisfactory to most parties involved. And while this mishmash of conflicting claims creaks along during years of plenty, the likelihood that everything will break down terminally during a decade-long drought seems assured. So getting our water rights in order is essential, says Hanemann, as important as reliable infrastructure and effective conservation programs.
“A crucial step in getting our water rights in shape is measuring the water that exists,” he says. “Many riparian rights are not yet quantified, so the holders of those rights are like tenants in common. They can take as much as they want, as long as they don’t ‘inconvenience’ other riparian rights holders. Obviously, real problems occur when shortages exist. So we need to straighten out water rights in a way that makes real enforcement possible.”
Further, while the 2014 Sustainable Groundwater Management Act was important and seminal legislation, it also contains multiple weaknesses, says Hanemann.
“Without those flaws, however, it wouldn’t have passed,” he says. “It had to be set up as a semi-crippled piece of legislation to get the political support it needed. The biggest problem is that it allows groundwater users to define the range of their aquifers independent of reality. From a scientific point of view, that’s ridiculous. The only sensible way to manage groundwater is through an independent agency that is charged with accurately mapping the extent and capacity of individual aquifers.”
Matt Kondolf, a professor of landscape architecture and environmental planning at Berkeley’s department of environmental design, largely agrees with Hanemann that institutional causes are driving many of California’s water problems.
“Our system of water rights [and] subsidies results in inefficient, outdated and suboptimal use of water, driven by many perverse incentives,” Kondolf emailed in response to questions from CALIFORNIA. “We actually have a lot of water in the state, and with our existing storage and [better management], we could get ourselves through most short droughts, though not long droughts such as [those between] 850 – 1090 CE and 1140 – 1320 CE.”
But things can still be done to optimize water storage, says Kondolf. For one thing, many of California’s reservoirs are unable to store water to full capacity due to sedimentation. By removing the mud, silt, and sand that has washed into them over the years, a significant degree of “new” storage can be realized at a fraction of the cost of building additional reservoirs or raising dams.
“Assessing options for removing sediment and preventing additional sedimentation certainly makes sense,” writes Kondolf, though he cautions some investments made today may not pay off for years. “It’s generally best to let gravity do the work [e.g., through flushing by strategic water releases]. Mechanical removal tends to be very expensive and you wind up with lots of material to dispose of during times of the year when you can’t put it in the rivers. However, compared to the costs of building new storage, mechanical removal can still be favorable.”
In sum, then, it seems that California has the water and infrastructure necessary to weather short to moderately long droughts. Still, it will take profound political will to implement and enforce more effective policies. And when it comes to megadrought, all bets are off. That’s terra, or rather aqua, incognita. Meanwhile, the clock keeps ticking.
“Even apart from climate change, tree ring records show that precipitation is highly variable in California,” says Walker. “And with climate change, conditions are likely to get more variable and hotter. We have to expect it.”
Posted on January 3, 2018 - 5:31pm