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Water Resources
By Shimon C. Anisfeld ISLAND PRESS
Copyright © 2010 Shimon C. Anisfeld
All rights reserved.
ISBN: 978-1-59726-973-5
CHAPTER 1
Past, Present, and Future: Introduction to the Water Crisis
Take a moment to imagine water, to bring a picture of this vital substance to your mind's eye.
What do you think of? A favorite lake or river? A glass of drinking water? A refreshing shower? An irrigation sprinkler? A baptismal font?
People and water are deeply interlinked. We humans are mostly water, as is the surface of the planet we live on. We use water in so many ways: drinking; cleaning ourselves and our belongings; growing our food; making the products we use; producing energy; enjoying ourselves while swimming or boating; fishing; transporting people and goods; sustaining our spirits. Equally important to our survival, but less obvious, is the fact that water plays a critical role in maintaining the health of the earth by controlling the planet's heat and energy balances, cycling nutrients and other elements, allowing the growth of the plants and algae on which all life depends, and maintaining the biodiversity of aquatic and terrestrial ecosystems.
This book is an introduction to water resources, in which we explore the many interactions between people and water. It emphasizes two contrasting—but complementary—ideas: (1) we are facing serious water problems, and (2) there is much that we can do to manage this resource better and alleviate those problems. This chapter provides a brief history of past water management, a summary of the present crisis, and some thoughts on possible paths toward a better future.
1.1. The Past: A Brief History of Water Resource Management
Humans have always needed water, and early civilizations developed where water sources were available to support their populations. Over time, different regions developed their own approaches to managing water, displaying a rich diversity of technologies. A few examples: The ancient Egyptians were heavily dependent on the Nile for irrigation water, which they obtained both through natural flooding and through active water management such as the digging of irrigation canals and the utilization of water-lifting devices such as the shadouf. The Egyptians also developed a system for monitoring and recording river water levels. In Persia, tens of thousands of gently sloping underground tunnels called qanats were dug to deliver groundwater to cities and fields; similar technologies with different names have been used around the world (karez in Afghanistan, laoumia in Cyprus, surangam in India). The Romans built pipelines and large raised aqueducts to transport water, and constructed buried sewer pipes to remove wastewater. The Chinese constructed irrigation canals to bring water from rivers to fields, dug the 1600-km-long Grand Canal to transport goods and people, and built levees along the Huang He (Yellow River) to protect land from flooding. The Spanish developed a system of irrigation canals called acequias, which they later introduced to the areas that they colonized in the New World. In England and elsewhere, water was used to power mills, often by impounding water behind a small dam.
Along with these technologies came cultures and governance systems for managing water. The historian Karl Wittfogel famously argued that water had a strong influence on the development of despotic civilizations ("hydraulic empires") in the Middle East and Asia, due to the need to harness large amounts of manpower to build and maintain water delivery systems in arid regions with large rivers (Wittfogel 1957). Wittfogel's thesis is now considered overly simplistic, but it points to the ways that water—as arguably the most important natural resource of all—can influence the development of civilizations.
The Twentieth Century
The twentieth century saw global population increase dramatically from about 1.6 billion to 6.1 billion. This population explosion, together with the development of new technologies, led to significant changes in water management. In turn, these changes in water management were crucial in allowing the expansion in population, which would not have been possible without new water supplies for cities and for agriculture.
Water management in the twentieth century was dominated by what has been referred to as the "hard path." Three technologies played crucial roles in defining this path.
Dams
For centuries, small dams have powered mills and impounded water for storage and delivery. But the twentieth century saw an explosion in dam-building, especially of large dams—those over 15 meters high—and major dams—those over 150 meters high. The real era of dam-building began in the mid-twentieth century, first in the United States and then in other countries. By the year 2000, there were approximately 48,000 large dams worldwide, an astonishing number. Although North America and Europe have largely stopped building dams, dam construction in Asia continues apace, especially in China and India. China now has about half of all the large dams in the world (WCD 2000).
Dams are built for several purposes:
• Water supply and irrigation: Dams allow for the delivery of water to urban ("water supply") and agricultural users, through two mechanisms. First, dams simplify the process of capturing and delivering water from a river by creating an impoundment from which to draw water and by increasing the elevation of the water so that it can be delivered more easily by gravity. Second, dams capture water during wet periods and store it for delivery during dry periods. This is particularly important in seasonal or drought-prone climates.
• Flood control: Dams can capture large floods and release them slowly to minimize flooding damage downstream.
• Hydropower: The power of falling water can be used to run watermills or, as is done today, drive turbines that generate electricity.
• Navigation: Dams convert flowing, shallow water to still, deep water, which can allow ships and barges to more easily move up and down river systems.
• Recreation: A secondary purpose for many large dams is water-based recreation on the reservoir that develops behind the dam.
• Fishing: Usually a secondary purpose, some reservoirs are used for capture fisheries or aquaculture.
Many of the largest dams serve multiple purposes, though managing for these different purposes may require divergent approaches. For example, managing for flood control involves keeping the reservoir as low as possible between storm events, while managing for water supply involves storing as much water as possible.
Beyond these specific purposes, large dams are symbols of development, technology, and "the control of nature." The Hoover Dam, for example, symbolized technological optimism to an America struggling to emerge from the Great Depression. The awe inspired by the Hoover Dam is captured in President Franklin Delano Roosevelt's response to seeing the immensity of the structure: "I came, I saw, I was conquered." Likewise, the ability to successfully pull off a large dam project has been a rite of passage and point of pride for many developing nations.
To many people, however, dams symbolize exactly what is wrong with the hard path: the brutal attempt to control nature with raw force; the lack of respect for free-flowing rivers and healthy ecosystems; the disregard for the lives of local citizens displaced by the reservoir and dam workers injured or killed during construction; the disease of "gigantism" that tries to build its way out of every problem.
In the US, two federal agencies have been particularly responsible for building and operating large dams: the Bureau of Reclamation, established by the Reclamation Act of 1902 and given the mission of helping settle the arid West by supplying irrigation water to farmers (and, later, hydroelectric power to cities); and the Army Corps of Engineers, which has responsibility for flood control, navigation, and sometimes water supply in much of the eastern half of the country.
Canals
Two types of artificial waterways have played key roles in the hard path of water management: conveyance canals and navigation canals.
If dams gave us the ability to store water, conveyance canals(along with pipes and tunnels) gave us the ability to deliver it over large distances to cities and farms that have sprung up far from any natural sources of water. Examples that stand out include the Central Arizona Project (540 km), which delivers water from the Colorado River to Phoenix and Tucson and to farmers in central Arizona; the All-American Canal (130 km), which transports water from the Colorado to the Imperial Irrigation District in California; and the plan under way in China to move massive amounts of water from south to north. In many cases, conveyance canals are used to move water from one river basin to another (interbasin water transfer), which can lead to high environmental, economic, and social costs. One source (Thatte 2007) estimates that there are currently 134 interbasin transfers worldwide, representing about 14% of the world's water use; proposed projects (including the Chinese project mentioned above) would increase the volume of water moved by a factor of 3.
Navigation canals allow the inexpensive movement of people and goods over large distances. Whereas navigation on rivers involves adjusting our mobility to the vagaries of the natural river network, the construction of navigation canals allows us to adjust the water network to our transportation needs.
Wells
The third member of the hard path's technology trio—the well—is perhaps the least obvious, because it is the smallest and most widely distributed. Hand-dug wells have been used for millennia as a way to obtain water, but our use of wells and boreholes (narrow drilled wells) grew tremendously during the twentieth century, due to advances in drilling technology and the availability of electric and diesel-powered pumps. Untold millions of wells are now used to extract water at high rates from great depths. This has allowed us to tap into groundwater in a way that was previously impossible. In many places, we are now using groundwater much more quickly than it is being replenished—meeting today's water needs at the expense of future generations.
1.2. The Present: A Water Crisis
Despite the tremendous technological advances of the twentieth century, most water experts agree that we are now facing an unprecedented global water crisis. This crisis can be broken into 10 interrelated components, each of which will be covered in a chapter of this book.
Flooding (Ch. 4). Despite our efforts to protect ourselves from flooding, large floods still do extensive—even increasing—damage to property and people.
Scarcity (Ch. 5). More and more regions are starting to run out of water as population grows, per-capita water use increases, and pollution renders water sources unusable.
Change (Ch. 6). Several interacting dynamics—population growth, climate change, and land use change—are altering both the supply of water and the demand for it, and are posing serious challenges to water management methods that are based on the patterns of the past.
Technology (Ch. 7). While appropriate technologies are an important part of the solution, the indiscriminate construction of large water infrastructure projects is part of the problem, causing serious environmental and social impacts.
Ecosystem degradation (Ch. 8). Aquatic ecosystems have paid a heavy price for our water management, and we are in danger of losing the natural foundation that underlies our physical, economic, and spiritual well-being.
Human health (Ch. 9). Billions of people in developing countries lack access to safe water and adequate sanitation, and suffer from serious health consequences as a result; even in rich countries, drinking water can contain toxics and pathogens.
Agriculture (Ch. 10). Our ability to grow enough food for the whole world is threatened by lack of water; at the same time, agricultural land is being degraded by salinization and pollution.
Industry (Ch. 11). Energy use and industrial activity require large volumes of water and contribute to the pollution and degradation of water resources.
Inefficiency and inequity (Ch. 12). Current water policies often allocate water inefficiently and inequitably, with some users being granted excessive volumes of cheap water, while others lack sufficient water for vital needs.
Conflict (Ch. 13). Throughout the world, scarce water is leading to tensions among different sectors, states, and countries; these tensions, in turn, get in the way of more efficient, cooperative water management.
1.3. The Future: An Emerging Approach to Water Management
We are now at a crucial juncture in water management. The challenges of the twenty-first century demand a new approach that builds on the lessons of the past and incorporates innovative philosophies and technologies. This emerging approach to water management is finding expression in three related philosophies: the "soft path," Integrated Water Resource Management, and the Watershed Approach.
The soft path approach—in contrast to the "hard path" of building large, centralized infrastructure to meet ever-growing demands for water—focuses on water management that accommodates both human and ecosystem needs through a combination of conservation, decentralized technologies, and integrated management. The term soft path was originally used in the context of energy choices by Amory Lovins (1977) and was first used in the water context by Brooks (1993). However, it was popularized and more fully developed for water by Peter Gleick (Gleick 2002, Wolff and Gleick 2002).
Integrated Water Resource Management (IWRM) originates from a sustainable development context, which emphasizes meeting current development needs without impairing the integrity of natural systems and their ability to meet future needs. The term IWRM was first articulated internationally in the 1992 Dublin Statement on Water and Sustainable Development, which came out of a preparatory meeting for the United Nations Conference on Environment and Development (UNCED) in Rio de Janeiro. IWRM is currently a key component of international water discourse, although it seems to mean somewhat different things to different people.
The Watershed Approach is essentially the US Environmental Protection Agency's version of IWRM. The Watershed Approach was initiated in 1996, with further guidance published in 2001 and 2008. States throughout the US are currently creating and implementing watershed plans based on this approach.
Below I outline the key features of the emerging approach to water management, drawing on what I believe to be the most important contributions of each of the philosophies mentioned above.
Balancing Different Demands. As noted in section 1.1, humans rely on water resources for a variety of different uses—uses that often exert conflicting demands on these resources. In the past, water development has often proceeded in a single-sector fashion, with each group of users implementing their own plans without coordination with others, resulting in both conflict and inefficiency. The key challenge of water management is figuring out how to best balance all the different demands on a water resource, from drinking water to navigation to ecosystem protection. Integrated planning that considers all users is very difficult to do but can lead to much better outcomes.
Efficiency and Equity. The values to be considered in balancing different demands can be summed up by the "two Es": efficiency—obtaining the maximum total benefits from the water resource; and equity—distributing those benefits in a fair way.
Sustainability. In evaluating the demands on a water resource, it is important to include two key "users" that are often ignored:
• Future users: The principles of sustainable development demand that today's water uses not compromise the needs of future generations.
(Continues...)
Excerpted from Water Resources by Shimon C. Anisfeld. Copyright © 2010 Shimon C. Anisfeld. Excerpted by permission of ISLAND PRESS.
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