Wide Rivers Crossed
The South Platte and the Illinois of the American Prairie
Publication Year: 2013
During the past two centuries, these rivers changed dramatically, mostly due to human interaction. Crops replaced native vegetation; excess snowmelt and rainfall carried fertilizers and pesticides into streams; and levees, dams, and drainage altered distribution. These changes cascaded through networks, starting in small headwater tributaries, and reduced the ability of rivers to supply the clean water, fertile soil, and natural habitats they had provided for centuries. Understanding how these rivers, and rivers in general, function and how these functions have been altered over time will allow us to find innovative approaches to restoring river ecosystems.
The environmental changes in the South Platte and the Illinois reflect the relentless efforts by humans to control the distribution of water: to enhance surface water in the arid western prairie and to limit the spread of floods and drain the wetlands along the rivers in the water-abundant east. Wide Rivers Crossed looks at these historical changes and discusses opportunities for much needed protection and restoration for the future.
Published by: University Press of Colorado
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The North American prairie—the portion of the continent bounded on the east by forest and on the west by forested mountains—is a landscape of distances. When one is traveling across the western prairie, the periodic mountain ranges rimming the grasslands seem unnatural, as though Earth’s interior had been extruded and exposed for reasons not apparent. ...
Part 1: Streams of the Shortgrass Prairie: The South Platte River Basin
1. At the Headwaters
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In much of the world, a flowing river represents the excess water that cannot be held by the plants and soil along the river’s course. The adjacent landscape overflows into the river, each tributary swelling the flow of the mainstem. In contrast, the stream flow that sustains the largest rivers of the western prairie begins far from the dry lowlands, ...
2. Onto the Plains
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Forty years later, Horace Greeley described a June crossing of the South Platte’s tributary, the Poudre River, where it flowed from the mountain front, as “at least three feet deep for about a hundred yards, the bottom broken by the bowlders, and the current very strong.”2 ...
3. River Metamorphosis
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Some characteristics of streams in the South Platte basin circa 1800 persisted a century later. Cities were growing rapidly along the base of the mountains, and irrigated farm fields spread across the plains east of the mountains. All of these people and crops consumed water from the rivers, ...
4. What the Future Holds
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Two and a half million people lived within the South Platte River basin, mostly along the foothills between Denver and Fort Collins, in 1999. The population of the Denver area was projected to increase by an additional 1 million over the next twenty years as an estimated 36,400 hectares of farmland and ranchland ...
Part 2: Streams of the Tallgrass Prairie: The Illinois River Basin
5. Natural History of the Illinois River
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Illinois is known as the Prairie State, and much of its land was once covered in tallgrass prairie. Grasses spreading to the distant horizons, swaying in the prairie winds like waves on the ocean, was one of the memorable sights for people moving west from the great forests of the eastern United States. ...
6. Native Americans and the First European Settlers
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The seventeenth-century river described in chapter 5 is based on what scientists have been able to glean from recent fossils and from historical records prior to European settlement. This natural river the first Europeans encountered had been influenced for millennia by indigenous peoples who burned the grasslands, ...
7. Twentieth-Century River Metamorphosis
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In describing the Illinois River circa 1900 during high water, Dr. Charles Kofoid of the Illinois Natural History Survey wrote of traveling by boat across the flooded bottomlands: ...
8. What the Future Holds
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Several state governmental agencies set out to inventory the condition of streams in Illinois toward the end of the twentieth century. Scientists developed a Biological Stream Characterization to categorize streams based mostly on the diversity, abundance, and condition of aquatic insects and fish. ...
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Intervals of geologic time are named to record either some particular place where rocks of that age were first described, as in the Jurassic Period, named for rocks first described in the mountainous Jura region between France and Switzerland, or to indicate their relative position in the timescale, ...
English-Metric Unit Conversions
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Page Count: 408
Publication Year: 2013