Over the past century, humans have molded the Colorado River to serve their own needs, resulting in significant impacts to the river and its ecosystems. Today, many scientists, public officials, and citizens hope to restore some of the lresources in portions of the river and its surrounding lands. Environmental restoration on the scale of the Colorado River basin is immensely challenging; in addition to an almoverwhelming array of technical difficulties, it is fraught with perplexing questions about the appropriate goals of restoration and the extto which environmental restoration must be balanced against environmental changes designed to promote and sustain human economic development. Restoring Colorado River Ecosystems explores the many questions and challenges surrounding the issue of large-scale restoration of the Colorado River basin, and of large-scale restoration in general. Robert W. Adler evaluates the relationships among the laws, policies, and institutions governing use and managemof the Colorado River for human benefit and those designed to protect and restore the river and its environment. He examines and critiques the often challenging interactions among law, science, economics, and politics within which restoration efforts must operate. Ultimately, he suggests that a broad concept of “restoration” is needed to navigate those uncertain waters, and to strike an appropriate balance between human and environmental needs. While the book is primarily about restoration of Colorado River ecosystems, it is also about uncertainty, conflict, competing values, and the nature, pace, and implications of environmental change. It is about our place in the natural environment, and whether there are limits to that presence we ought to respect. And it is about our responsibility to the ecosystems we live in and use.
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About the Author
Robert W. Alderis associate dean for academic affairs and the James I. Farr Chair and Professor of Law at the S.J. Quinney College of Law, University of Utah. He studies and writes about protection and restoration of aquatic ecosystems.
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Restoring Colorado River Ecosystems
A Troubled Sense of Immensity
By Robert W. Adler
ISLAND PRESSCopyright © 2007 Robert W. Adler
All rights reserved.
Introduction: Retaking Old Ground
With the power of modern engineering, we increased dramatically our ability to change the natural world. Especially in the European tradition, and in some interpretations of Judeo-Christian liturgy, some believe it to be our very obligation to mold nature to our benefit. Those of us who are wealthy enough to enjoy modern conveniences protect ourselves from the elements in climate-controlled buildings. We do not feel the effects of famine and drought because of mass-produced and chemically preserved food delivered by truck and train, and stored water piped through indoor plumbing. We blast through mountains to route our highways, fill in swamps to grow our food and to build our cities, and even change the course of mighty rivers and the destiny of colossal canyons.
Thus, it was with supreme confidence that late 19th century engineer Robert Brewster Stanton promoted his proposed railroad along the Colorado River through the length of the Grand Canyon: "That the proposed road is feasible and practicable, and at a reasonable amount of cost, is beyond question." He was probably correct, given that railroads had been built in even more challenging locations by that time, although the railroad through the Grand Canyon was never built. But other, even more profound engineered changes were not too far distant.
The massive Glen Canyon Dam seems almost more permanent than the sandstone cliffs into which it is anchored. Engineers designed the dam with massive blocks of concrete, cured with refrigerated coils to ensure its strength. The natural canyon consists largely of more fragile rock, sandstone whose very aesthetic fame is caused by erosion. The dam, however, is only as strong as its host canyon. As the walls erode, so goes the dam. Regardless of whether it lasts another decade, another century, or another millennium, it cannot last forever. After all, the hydrological power it restrains helped to cut the Grand Canyon out of the Colorado Plateau in the space of just several million years, a "flicker of a nod" in geological time.
More long-lasting than the dam itself may be the changes it has brought to the Colorado River, especially combined with the effects of the dozens of other dams, water diversions, dikes, levees, and other artificial changes to the river, its channel, its banks, its tributaries, and its biota. We molded (or more accurately, remolded) the river to serve the needs of human communities, but with significant impacts to the river and its ecosystems. Now, many scientists, public officials, and citizens hope to reshape nature in a different way, to restore portions of the river and its ecosystems. Environmental restoration on the scale of the Colorado River basin, or even significant portions of the basin, is an immensely challenging endeavor. In addition to an almost overwhelming array of technical difficulties, it is fraught with perplexing questions about the appropriate goals of restoration and the extent to which environmental restoration must be balanced against environmental changes designed to sustain the human economy.
This book explores those questions and challenges. It evaluates the relationships among the laws, policies, and institutions governing use and management of the Colorado River for human benefit, and those designed to protect and restore the river and its environment. It examines and critiques the challenging interactions among law, science, economics, and politics within which restoration efforts must operate, often in the face of tremendous scientific uncertainty. Ultimately, this book proposes that the concept of "restoration" must include more than efforts to rehabilitate individual patches of habitat or specific features of the river. Restoration should include changes in how we use and manage the resources of the river, or ways to replace those resources, to strike an appropriate balance between human and environmental needs (to the extent that those goals can be separated), for the Colorado River and elsewhere.
This chapter introduces the major challenges inherent in an undertaking as complex as restoring the ecosystems of the Colorado River. First, however, although these issues will be explored in more detail in chapters 2–4, we need some background on how we have changed the river, and why.
Taming the Colorado—How We Changed the River to Meet Human Needs
The Colorado River plummets from its headwaters more than 14,000 feet above sea level through the magnificent canyons of Utah and Arizona (figure 1.1). It continues through the deserts of Arizona, California, Baja California, and Sonora to its languid end in the Colorado River delta and the Sea of Cortéz (Gulf of California). Wild, volatile, and unpredictable, the natural river varied dramatically from its headwaters to the delta, from year to year, and from season to season. The river once raged through its canyons every spring, sending hundreds of thousands of cubic feet per second of snowmelt from the Rockies to the sea, only to subside to a comparative trickle during the fall and winter. Each summer, after the snowmelt receded, sand and gravel bars emerged and formed habitats used by native fish. Those unique conditions supported a system with one of the world's largest percentages of endemic fish, species found nowhere else on the planet. In its lower reaches, the river often spilled out over a broad floodplain, nourishing thousands of acres of wetlands that hosted lush vegetation and a bounty of waterfowl and other wildlife. The river also carved the sublime, rugged, and remote canyons for which the Colorado Plateau earned its scenic fame.
But while the wild Colorado was bountiful and beautiful, it was hardly friendly to human users. Hohokam Indians built dams and irrigation canals similar in concept, although not in size and impact, to those built by European settlers centuries later. The Hohokam structures were relatively easy to build, but also easy for the river to wash away during a spring surge. Some early southwestern explorers and traders traveled the waters of the lower Colorado in sternwheeler steamboats, but at times they ran their craft in reverse so the wheel could plow rather than ply through the river's frequently shifting sandbars. Upriver, brave (or foolish) trappers and explorers plummeted through roaring whitewater canyons in flimsy boats and canoes. Farmers and ranchers found plenty of water during the spring runoff, but only a silt-laden trickle during summer and fall when they needed it most for crops and pastures.
That once volatile Colorado is now relatively tamed by what has been called a massive system of plumbing, designed to provide more reliable water supplies to farmers and urban users, to control flooding, and to generate hydroelectric power. Dams include Glen Canyon, Hoover, Davis, Parker, Imperial, Laguna, and Morelos on the main stem down to the Mexican border; Fontanelle and Flaming Gorge on the Green; the Aspinell Project on the Gunnison; Navajo on the San Juan; Coolidge on the Gila; and Saguaro, Canyon, Apache, and Theodore Roosevelt on the Salt. These monuments—and hundreds of smaller dams and diversions throughout the system—leveled the river's natural volatility and transformed it into a step-series of placid lakes joined by remnants of flowing river. By storing the region's spring runoff behind dams, communities could divert for human use waters that once flowed to the sea. Farms and communities now could use the river's liquid gold when and where it was needed, not when and where it happened to flow. Storing water behind dams also protected communities from the annual floods that once discouraged extensive settlement along the river's broad floodplains.
The Colorado River's artificial plumbing system contributes immensely to the human economy and lifestyle in the arid Southwest. It provides water and electricity for the economies of seven U.S. states and two in Mexico. Water stored behind dams within the basin and diverted to users both in and out of the watershed now serves population centers with more than 30 million people, and irrigates more than 3 million acres of land. That same water drives turbines that generate 11.5 billion kilowatt-hours of hydroelectric power a year, enough to supply about 13 million households. (Average annual household consumption in the United States is 908 kilowatt-hours. Hydroelectric plants are particularly suited to generate power during periods of peak demand, such as hot summer days in the Southwest when air conditioners run almost constantly. This is power that comes without the need to dig for coal or drill for oil, without the smoke that fouls human lungs, and without the greenhouse gases that transform the global climate. Hydroelectric power is sustainable in that it will continue so long as the river flows.
If those benefits were not enough, the massive reservoirs behind the dams built to fuel the region's economic growth are also playgrounds for millions of visitors who come to boat, camp, fish, and enjoy the splendor of the Colorado's canyons, and who pour buckets of money into local and regional economies. Land once subject to flooding is now protected behind dikes and levees because the dams hold back and release water gradually, except during exceptionally wet periods when storage capacity is insufficient. Colorado River reservoirs can store an impressive 60 million acre-feet (maf) of water, four times the average annual flow of the river. (An acre-foot, intuitively enough, is the volume of water necessary to cover an acre of land to a depth of one foot [approximately 326,000 gallons]). The vast majority of that capacity is in Lake Mead and Lake Powell, the two largest reservoirs in the United States, with a combined maximum storage of more than 50 maf.
But those benefits come with a serious price. From its headwaters in the mountains of Wyoming and Colorado to its delta in the Sea of Cortéz—where the river flows at a tiny fraction of its former majesty—human change has taken its toll on the biological and aesthetic resources of the Colorado River. Hundreds of miles of formerly flowing river now lie below artificial reservoirs, and the dams fragment the river both physically and biologically. With a few exceptions in the headwaters, upstream of any dams, even those stretches that remain "river" have been changed significantly. In most places, spring flood flows are significantly smaller and flows from the dams are much higher and more uniform during other parts of the year. Especially below the Hoover Dam, hundreds of miles of river channel are imprisoned within levees or constrained by artificially "armored" rock banks. Water released from the dams is typically much colder and more uniform in temperature than in the natural river, and is starved of the sediment and nutrients that used to flow downstream. This loss of sediment changed the former patterns of bars and eddies that provide habitat for native fish. It also robbed sand from beaches formerly used by river runners, other recreationists, and wildlife. Water quality has deteriorated due to direct releases of sewage and industrial waste, and polluted runoff from farms, roads, mines, mining wastes, and other sources adds salts and other contaminants.
On top of all that, we have introduced dozens of nonnative ("exotic" or "alien") species, some intentionally and others by accident, which can prey on or outcompete native species. Once-thriving populations of endemic fish are now gone from parts of their former range, replaced and outcompeted by artificially introduced trout and other species. The U.S. Fish and Wildlife Service has listed four Colorado River fish species—the humpback chub, bonytail chub, razorback sucker, and Colorado pikeminnow—as endangered. (Ichthyologists changed the popular name of the last to pikeminnow from Colorado squawfish, which was an offensive slur to Native Americans. The new name will be used in this book, except in quotations from earlier sources.) Riparian communities once dominated by cottonwood, willow, and other native plants are now overrun by tamarisk. (This plant is often known as salt cedar, although this name is technically correct for only one species of tamarisk. For convenience I will refer to all species collectively via the singular "tamarisk.") For hundreds of miles, levees and other structures separate the river from its natural floodplain, and reduced flows have eliminated the river's natural spring overflows. Birds and other species that once thrived in those habitats, like the southwestern willow flycatcher and the Yuma clapper rail, are endangered due to the loss of riparian habitat. Many of the canyons that once contributed to the majesty and mystery of the region are drowned below hundreds of feet of water and silt. Among the affected portions of the ecosystem is the Grand Canyon, that towering symbol of American conservation and undisputed international treasure.
The Colorado River is just one example of what we have done to almost all rivers in the United States since European settlement. And no wonder, given the degree to which waterways fueled economic activity. Virtually from the beginning of recorded history, people have settled at the water's edge. Waterfront areas were among the first to be developed, because proximity to water was useful for navigation, irrigation, industry, defense, and household use. Flat, fertile floodplains were easy to build on and productive to farm. From before the earliest days of the American republic, waterways were critical for transportation and trade, settlement, fishing, and defense.
This use and development of U.S. rivers and other waterways produced some of the most dramatic ecological change in human history. Most people know that we have dumped immense amounts of chemical pollution into our waters, but do not consider the many other ways we have changed the face and the shape of the aquatic environment. Experts are virtually unanimous that the biggest problem facing aquatic ecosystems is not pollution, but the destruction and alteration of aquatic habitats. The banks of most rivers and streams no longer support their natural riparian plants, with a loss of as much as ninety-five percent of natural vegetation in some areas. Floodplain development destroyed about half of the natural woody riparian habitat in the contiguous states. We filled or otherwise destroyed more than half of the wetlands in those states, and although the rate of wetlands destruction has slowed, we continue to lose about 60,000 acres a year, despite a stated national goal of "no net loss" of wetlands. More than six hundred thousand stream miles are inundated by reservoirs, and diversions from those structures seriously alter natural stream flows and habitats. Many more waters are levied, diked, armored, rip-rapped, and channelized, largely to aid or protect development at the water's edge. We justify this massive hydraulic machine by arguing that economic progress is needed if not inevitable, change is essential to foster that growth, and we must accept a highly modified environment as the price of our modern lifestyle.
The growing environmental restoration movement, however, openly defies such concepts of futility in the name of utility. Although restoration as a strategy for environmental protection is not new, it is becoming more prominent and more ambitious. In fact, it can be viewed as the third major strategy of the modern environmental era (beginning in the 1960s). Let's take a moment first to explore briefly the way in which restoration fits within the overall suite of environmental management strategies, issues to which we will return in more detail in chapters 5–9.
Restoration and the Environmental Movement
In the second half of the 20th century, environmental management involved two main strategies. First, we tried to mitigate the increasingly severe environmental damage caused by our accelerating industrial economy and our thirst for more and bigger things. Asthmatics choked on smoky air; rivers caught fire; and solitude dwindled as millions of Americans sought the great outdoors in their cars and trailers. Mitigation is somewhat like a paramedic treating an accident victim. The immediate task is to stop the bleeding and to minimize the resulting harm. We built fish ladders, for example, to reduce the effects of dams on migratory fish, although often with questionable success. The dams were designed to accommodate water development with as little harm to fish as possible. We set treatment requirements for polluted effluent from factory pipes and public sewage systems, but continued to release somewhat cleaner residues into the nation's rivers. With this treatment strategy, we aimed to reduce impacts while allowing the growth of American industry, population, and quality of life.
Excerpted from Restoring Colorado River Ecosystems by Robert W. Adler. Copyright © 2007 Robert W. Adler. Excerpted by permission of ISLAND PRESS.
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Table of Contents
ContentsABOUT ISLAND PRESS,
CHAPTER ONE - Introduction: Retaking Old Ground,
CHAPTER TWO - The Living Artery: Disruptions to the River's Linear Connections,
CHAPTER THREE - Only the Hills Will Know: Changes in the Watershed,
CHAPTER FOUR - Tree of the People: Tree of Life,
CHAPTER FIVE - Down the Great Unknown: Environmental Restoration in the Face of Scientific Uncertainty,
CHAPTER SIX - Casting of the Lots: Conflicting Methods and Goals in Environmental Restoration,
CHAPTER SEVEN - Ownership of Unownable Things: Property Rights and Environmental Restoration at the Water's Edge,
CHAPTER EIGHT - An Elusive and Indefinable Boundary: Restoration and Political Borders,
CHAPTER NINE - The Lovely and the Usable: Toward a More Holistic Approach to Restoration,
CODA - Into New Dimensions,
About the Author,
Island Press Board of Directors,