California water resources


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An Overview and History of California

Water Resources Development
“The history of California in the twentieth century is the story of a state inventing itself with water. The principal centers of urban settlement and industrial and agricultural production in California today were in large part arid wastelands and malarial bogs in their natural condition. The modern prosperity of the state has consequently been founded upon a massive rearrangement of the natural environment through public water development.”
William L. Kahrl, Water and Power (1982)
“California's water system might have been invented by a Soviet bureaucrat on an LSD trip.”
Peter Passell, Economic Scene: Greening California,

New York Times, Feb. 27, 1991

1. To provide an overview of the development of water resources in California and the American West, I will lecture and answer your questions (rather than the other way around).

We start with a brief discussion of western water resources development and then turn to a more detailed look at California. The story begins with the native landscape and waterscape of the west and continues with the history of the development of water resources. We will consider both aboriginal water use and the creation of pueblo and rancho water rights under Spanish and Mexican law. The California portion of the story proceeds with the local use of water by the miners and early farmers in the Sacramento Valley and leads to regional water development by irrigation districts in the San Joaquin Valley and the Imperial Valley at the end of the 19th Century. The first large transbasin developments were the City of Los Angeles' Owens Valley project, the City of San Francisco's Hetch Hetchy project, and the East Bay's Mokelumne River project, all of which were constructed in the early 20th Century.

The history then turns to the great conflicts between riparians and appropriators during the late-19th and early 20th Centuries that led to the constitutional amendment of 1928 that added what is now Article X, Section 2 to the California Constitution, Article X, Section 2, which contains both the reasonable use and beneficial use doctrines, is the foundation of modern California water law. The middle part of the 20th Century is dominated by the construction of the two largest water projects—the federal Central Valley Project and the State Water Project—that supply water to about two-thirds of the California’s population. These projects are the hallmarks of what Norris Hundley has called the “hydraulic society.” They have made modern California (both for better and for worse) possible.
Since the late 1960s, the history of California water policy is largely the story of efforts to restore and protect the environment from further degradation caused by the large water projects. The focal points of the environmental response have been the Owens Valley and Mono Basin on the east side of the Sierra Nevada, the Klamath River and the other wild and scenic rivers of the north coast, the federal reclamation program, and (most importantly) the Sacramento-San Joaquin River Delta and San Francisco Bay estuary. The modern era of California water law has seen Congress, the California Legislature, and the courts significantly limit and modify the water rights system through laws such as the Clean Water Act, the Endangered Species Act, their state law counterparts, the Central Valley Project Improvement Act, the public trust doctrine, water efficiency regulations, water transfer laws, and other incentives to conservation and reallocation.

We also will study California's water supply and demand balance, the existing water allocation, current shortages and projected changes in supply and demand, points of conflict between instream and consumptive uses, and other sources of stress on the system. These stress points are the result of overuse of the state’s rivers, estuaries, and groundwater basins where existing demands exceed the sustainable carrying capacity of the ecosystem that is the source of supply. All of California’s water controversies—from the Klamath River endangered species crisis, to the court-imposed limits on exports of water from the Delta, to the on-going groundwater adjudications in central and southern California—share this feature. As described more fully below, these problems will be exacerbated by global climate change as we move into the middle part of the 21st Century.

2. As you read through the assignment, please try to learn the following ways of measuring water and water flows, as we will refer to them throughout the course:
Acre Feet (af) This is the most common way of measuring standing water. An acre foot is the quantity of water that would cover one acre to a depth of one foot. One acre foot is 325,851 gallons. A family of four or five uses approximately one acre foot of water per year.
Acre feet annually This is the most common way of measuring the quantity of water

(afa) present in a river system, or diverted and used for consumptive purposes, each year. For example, we will learn that the average annual runoff in the Sacramento River basin is approximately 22.4 million afa; and the average annual water use by State Water Project contractors is approximately 2.2 million afa.
Cubic feet per This is the most common way of measuring the flow of water in a

second (cfs) river or aqueduct. One cubic foot of water is 7.48 gallons. One cfs is 448.8 gallons per minute, or 646,317 gallons per day, or 1.98 acre feet per day.
Source: California Department of Water Resources, Conversion Factors for Water.
3. Another view of commonly used terms may be found is offered by Ed Quillen, What Size Shoe Does an Acre-Foot Wear?, in High Country News, Western Water Made Simple 190-92 (Island Press 1987):

Acre Foot The amount of water required to cover one acre, which is about the size of a football field, or 0.40468564 hectare, to a depth of one foot, about the length of a football shoe, or 30.48 centimeters--that is, about 325,848.882718339 gallons or 1,233.43773084702 steres. Most popularly explained as the amount of water an average family of four uses in one year, but this definition is too fluid, only in desert regions is it appropriate.

For example, in a wet state like Minnesota, the average family of four consumes only 0.44 acre-feet of treated water in a year, and in Oregon it's all of 0.34 acre-feet. But in dry Colorado, it's 0.93 acre-feet; arid Wyoming, 0.96 acre feet; thirsty Arizona, 0.99; desert Nevada, 1.12; and parched Utah, 2.46. These dull figures (given the topic, they can't be dry statistics) demonstrate that treated water is unlike other commodities: The less gasoline there is available, the less people consume, but the less water there is, the more people consume.
Beneficial Use Any use of water which (1) takes water out of a natural channel, and (2) benefits a bank account. Thus courts have held that keeping water in rivers so that fish might swim in it is not a beneficial use, whereas using water to carry silt into collection impoundments (often called reservoirs) is a beneficial use.
CFS Colorado writer Lewis Newell once discovered an interesting similarity between the CFS and the UFO; many people believe in both, but no reliable witness has ever seen either.
Diversion An entertainment. For instance, a popular metropolitan diversion is to dry up high mountain valleys by piping water to the cities below. Then the metropolis invites immigrants by promoting both its ample water supply and its proximity to pristine mountain valleys with sparkling fishing streams.
Reclamation In standard English, "reclamation" means to return something to a former use. In water English, "reclamation" means converting land that has always been desert into farmland, a use it never had.
Uphill The natural direction that Western water flows, providing there is money uphill.

Water Right A property right to certain quantities of water in certain locations, depending upon the use of the water and the priority of the water right. Water rights are either very valuable, because men have given their lives in battles over water rights, or else of little value, because, unlike other forms of real and personal property, water rights are not taxed.

4. Perhaps the most important characteristic of California water policy is hydrologic variability. The variations in water supply take three forms:

  1. Geographic Disparities. More than 70 percent of California’s water supply originates north of San Francisco, principally in the Sacramento River basin and in the North Coast. Yet, approximately 75 percent of the demand for water is to the south of this hydrologic divide. As we will see, much of the water supply engineering is designed to move water from the north, where it is abundant, to the south, where it is scarce.

  1. Seasonal Variations. On average, 75 percent of California’s annual precipitation falls between November and March, with approximately 50 percent occurring between November and February. Yet, urban and agricultural demand for water is relatively low during this period and peaks in the summer and late fall months when precipitation is usually nonexistent.

  1. Annual Variability. Finally, water supplies vary dramatically from year-to-year. For example, annual water run-off in the state is approximately 71 million acre feet. This average includes a record low of 15 million acre feet in 1977, which was the second year of the worst acute drought on record, and the historic high of 135 million acre feet in 1983, which was part of the El Niño phenomenon. During the 20th Century, California has suffered serious droughts in 1912-13, 1918-20, 1922-24, 1929-34, 1947-50, 1959-61, 1976-77, 1987-92, and 2007-2010.

All of these variations render water resources management highly uncertain.

Source: California Department of Water Resources, California Water Plan Update 2009 (Bulletin 160-09), Chapter 3.

5. These contemporary hydrologic uncertainties pale in comparison to recent estimates of the worst droughts in California’s geologic history:
William K. Stevens, Severe Ancient Droughts: A Warning to California

N.Y. Times, July 19, 1994

Beginning about 1,100 years ago, what is now California baked in two droughts, the first lasting 220 years and the second 140 years. Each was much more intense than the mere six-year dry spells that afflict modern California from time to time, new studies of past climates show. The findings suggest, in fact, that relatively wet periods like the 20th century have been the exception rather than the rule in California for at least the last 3,500 years, and that mega-droughts are likely to recur.

The evidence for the big droughts comes from an analysis of the trunks of trees that grew in the dry beds of lakes, swamps and rivers in and adjacent to the Sierra Nevada, but died when the droughts ended and the water levels rose. Immersion in water has preserved the trunks over the centuries. Dr. Scott Stine, a paleoclimatologist at California State University at Hayward, used radiocarbon dating techniques to determine the age of the trees' outermost annual growth rings, thereby establishing the ends of drought periods. He then calculated the lengths of the preceding dry spells by counting the rings in each stump.

This method identified droughts lasting from A.D. 892 to A.D. 1112 and from A.D. 1209 to A.D. 1350. Judging by how far the water levels dropped during these periods--as much as 50 feet in some cases--Dr. Stine concluded that the droughts were not only much longer, they were far more severe than either the drought of 1928 to 1934, California's worst in modern times, or the more recent severe dry spell of 1987 to 1992. In medieval times the California droughts coincided roughly with a warmer climate in Europe, which allowed the Vikings to colonize Greenland and vineyards to grow in England, and with a severe dry period in South America, which caused the collapse of that continent's most advanced pre-Inca empire, the rich and powerful state of Tiwanaku, other recent studies have found.

Does Tiwanaku's Fate Await Modern California?
Dr. Stine, who reported his findings last month in the British journal Nature, says that California, like Tiwanaku, presents "a classic case of people building themselves beyond the carrying capacity of the land," which is determined not by wet times but by dry ones. "What we've done in California is fail to recognize that there are lean times ahead," said Dr. Stine, "and they are a lot leaner than anything we've come up against" in the modern era.
How far ahead that reckoning might lie is, of course, uncertain. But one ominous sign may be that the earth's climate as a whole is now warming up, whether from natural causes or because of heat-trapping atmospheric gases emitted by industrial society. Any significant global warming would probably cause changes in atmospheric circulation and precipitation patterns, and the new findings suggest that "during much of medieval time the planetary ocean-atmosphere system operated in a mode unlike that of modern time," Dr. Stine wrote in Nature. This alteration of the system could well have been caused by a natural global warming, he said. He believes that one long-term effect was to steer storm tracks and rainfall away from California. If this pattern was indeed brought about by a medieval global warming, he said, a future global warming--whether natural or human-induced--might bring back the decades-long droughts of yore.

Dr. Stine's findings, combined with similar evidence he turned up in Patagonia, strengthen the case of those who believe that the earth experienced a general warming at the time of the Middle Ages, Dr. F. Alayne Street-Perrott, a paleoclimatologist at Oxford University in England, wrote in a commentary accompanying Dr. Stine's report in Nature. Other experts maintain that the medieval warming was not global but instead affected only some parts of the world. "I'm not prepared to believe that the whole world was warmer," said Dr. Malcolm K. Hughes, a paleoclimatologist who directs the Laboratory of Tree Ring Research at the University of Arizona in Tucson. Nor is it possible to say for sure that future global warming would bring back the large-scale droughts of the past. "We've not done the work on the actual mechanisms," he said. But he said that Dr. Stine's findings, coupled with similar conclusions that can be drawn from other tree-ring studies by scientists in his laboratory, are a "serious cause for concern." There appears to be little doubt that the epic dry spells of the past did occur, he said, adding that "what has happened can happen."

The findings also emphasize the importance of precipitation changes, rather than simply changes in temperature, when weighing the potential impact of future global climate change, Dr. Stine wrote in Nature.

Periods of “Epic Drought”
The Sierra Nevada, where Dr. Stine conducted his study, is California's most important area for the collection of water. Runoff from the Sierras provides two-thirds of the state's surface-water supply for cities and farms. The study involved trees at four places: Mono Lake, Tenaya Lake, the West Walker River and Osgood Swamp. Dr. Stine's tree-ring analysis found that live trees had covered dry beds of lakes, streams and swamps for overlapping periods of 50, 100, 141 and 220 years and that these "lowstand" periods were clustered in two major dry spells separated by a century-long wet period. "Epic drought," he wrote in Nature, is "the only plausible explanation for the site-to-site contemporaneity of the stumps." In the period separating the two long droughts, Dr. Stine said, the water in Mono Lake rose to a level higher than any in the last 150 years, suggesting that the California climate was even wetter then than it is today. The last century and a half, Dr. Stine found, has been the third wettest period in the last three millenniums. But, he said, "the vast majority of years during the past 3,500 years have been much drier than what we've come to expect to be normal in California."

The evidence for the medieval drought periods is especially strong, Dr. Hughes said, because the lake basins are closed, with no natural outlets; consequently, their water levels are influenced only by inflow and evaporation, making them ideal gauges of drought. And even though radiocarbon dating is somewhat imprecise, he said, it is good enough "to show two major phases of tree growth and lowstands; there's no doubt about that." This, he said, shows that "often, for sure, there have been periods of 100 years or more" that have been "markedly drier" than the 20th century. The 10th to the 14th centuries, encompassing the prolonged droughts reported by Dr. Stine, saw "dramatic changes" in Western Hemisphere civilizations, Dr. Street-Perrott wrote in Nature, and some have been attributed by archeologists to changes in rainfall. One example is the sudden decline of the Anasazi cliff-dwellers in the American southwest at about the year 1300. Another, even more striking, is the collapse of Tiwanaku.

Tiwanaku was a flourishing empire that lasted seven centuries and reached its zenith near the end of the first millennium A.D. It commanded an area about the size of California, extending from the Andean plateau around Lake Titicaca to the Pacific Coast and covering parts of present-day Bolivia, Chile and Peru. The empire's economy was based on intensive agriculture carried out on raised fields: acres of end-to-end rectangular platforms created by digging the dirt from areas between them. The dug-out areas became canals from which silt was taken to provide fertilizer. This highly productive and environmentally sound system dominated Latin American agriculture for centuries.
Death of a Civilization

But several lines of evidence, including analyses of fossilized pollen grains and isotopes of oxygen in lake sediments, make it clear that an extended drought afflicted the region starting between A.D. 950 and A.D. 1000 and continuing, with fluctuations, until 1410, concluded a study last year by Charles R. Ortloff, a fluid-mechanics specialist at the FMC Corporate Technology Center at Santa Clara, Calif., and Dr. Alan L. Kolata, an archeologist at the University of Chicago. That period mostly overlaps the one in which the California mega-droughts occurred. The South American drought was of "horrendous proportions," said Dr. Kolata, and it destroyed Tiwanaku's agricultural base. The empire's cities were abandoned by about 1000. Dr. Kolata believes that the raised fields could no longer support the cities, and archeological evidence shows that the fields were abandoned between 1000 and 1100. The political state collapsed, the population dispersed and, with agriculture no longer possible, the people relied on raising alpacas and llamas. Tiwanaku's agricultural system had been able to adjust to the less drastic cycles of drought and inundation that were thought to be normal, but "Tiwanaku agro-engineers were incapable of responding to a drought of unprecedented duration and severity," Mr. Ortloff and Dr. Kolata wrote in a 1993 paper in The Journal of Archeological Science.

Like Tiwanaku's engineers, those who draw up California's water-management plans do so on the basis of what are believed to be normal droughts but in fact are not nearly as severe as what has occurred in the past and can occur again, said Dr. Stine. "The assumption they've made for a long time--that California is subject to droughts of a maximum of seven years--could be harmful in the long run," he said, because "they have doled out water on that assumption. "This could be destructive if you get hit with a 9th or a 10th or a 15th year of severe drought."
In gauging the length and frequency of droughts for planning purposes, California officials rely on a tree-ring study extending back to about 1560. Over that period, the 1928-1934 drought was the longest and worst. The problem, said Dr. Stine, is that the study period includes not only the wet 19th and 20th centuries, but also the even wetter 16th and 17th centuries. "They're using the wettest period of the last 3,000 years to define the duration and severity of the droughts we can expect in the future," he said.

Maurice Roos, the chief hydrologist of the California Department of Water Resources, said he had not read Dr. Stine's report in Nature. But he did acknowledge that a mega-drought of the kind described in the report would probably cause much of the state's lush irrigated cropland to cease producing. The cities would probably have the money and political power to appropriate enough water to get by, he said, adding, "There will always be some water; there is not going to be no water." He said he would not expect farming to cease altogether, or cities to be deserted. Modern California has at least one coping weapon that Tiwanaku did not: the ability to turn sea water into fresh water. The 1987-92 drought did, in fact, prompt Santa Barbara to build a desalinization plant, Mr. Roos said, though he was quick to point out that this solution at present would be "enormously expensive."

At the very least, Dr. Stine wrote in Nature, a recurrence of the medieval droughts "would be highly disruptive environmentally and economically." Planning for a mega-drought now, while heads are a little cooler, would help, he says. The planning might include, for example, deciding which crops are to be taken out of production first, what restrictions to place on the pumping of groundwater and how cities are to obtain water. But in the end, he said, a reprise of the medieval droughts would simply overwhelm California's efforts to cope. And he said: "We don't need 200 years of drought to bring us down. At some point, in the 9th year, or the 15th year or the 19th year, the damage is done and it doesn't matter any more."
Glen M. MacDonald, A La Niña on Steroids:

It Happened Before, It Could Be Happening Again.

L.A. Times, July 13, 2007

If you like it hot and dry and live in Southern California, you could be in luck. Our combination of an arid winter, scorching summer and host of wildfires may not be a short-term aberration. Consider the possibility of decades of dry, hot weather, stretching from Southern California to the headwaters of the Sacramento and Colorado river systems—the lifelines that allow us to flourish in our arid to semi-arid landscape. That is the nature of a "perfect drought," and new research regarding a past episode of climate warming tells us we could be on the brink of a new one.

Historical climate records show that such prolonged droughts can and do occur. The last one began in the late 1980s and ended in the early 1990s. California dried at the same time that the flow of the Colorado River declined by almost 40%. Oceanic and atmospheric measurements tell us that this blast of hyper-aridity was associated with depressed temperatures in the eastern Pacific, sort of a persistent La Niña condition. In 1992, the rain and snow returned. However, during 1990 and 1991 alone, the drought cost California an estimated $2 billion in agriculture losses, increased energy costs and damage to the environment. What if that drought had spanned decades?

Two interlinked phenomena are looming that could provide the ingredients needed to produce droughts lasting decades. A recent study led by Rich Seager of Columbia University examined the results of 19 climate models and found one very consistent and alarming result: Warmer temperatures are producing increased uplift of air masses in the tropics. As the air rises, it cools, the water vapor condenses and produces more tropical precipitation. Eventually, though, that air descends, warms and becomes drier.

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