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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...courses of the western prairie. By midsummer the grasses are fading toward the golden brown color they will hold through the remainder of the year, and only the wildflowers and the trees along the streams provide more vivid hues. Patches of pale gray or brown reveal exposed soil or outcrops of soft, crumbling bed-rock. Subtle shadings across the landscape come with changes in the angle of ...
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...the dry lowlands, and tributaries heading on the prairie DOI: 10.5876/9781607322313.c01contribute little to the mainstem. This is one of the paradoxes of rivers of the western prairie: flowing for hundreds of kilometers across some of the conti-nentâs driest and most open country, the rivers begin in, and are sustained by, abundant winter snows falling in deep, narrow valleys of the topographic excla-...
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...mountain front. The horizons are not yet endless, however, for the rivers flow Metaphors to the contrary, the Rockies are not eternal. They have, however, been repeatedly re-created through multiple episodes of mountain building dur-ing the past 1,700 million years. A mountain range represents a tug of war between the internal forces of the planet that shift tectonic plates and fold and fault rocks ...
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...wastes, which stream flows were sufficient to dilute. Contemporary knowledge of historical plant and animal distributions comes mainly from this period, when scientists made the first systematic surveys of species present along streams of the foothills and plains. These distributions were already changing, however, in response to flow regulation and consumptive uses. Sauger (Sander canadensis) had ...
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...brought water into the South Platte system, where 1,000 reservoirs and 500 irri-gation ditches stored and distributed the water. Despite all these imports, water levels in the major bedrock aquifer underlying the Denver Basin dropped as much as 240 meters during the last twenty years of the twentieth century, and some domestic wells in the southern part of the metropolitan area went dry. Xeriscap-...
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...of velvet herbage, the sky for its boundary upon every side; the whole clothed with a radiant efflorescence of every brilliant hue. We rode thus through a perfect wilderness of sweets, sending forth perfume, and animated with myriads of glittering birds and butterflies . . . You will scarcely credit the profusion of flowers .Â .Â . We passed whole acres of blossoms all bearing one hue . . . and then again a ...
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...people were hunting, fishing, and gathering from a variety of food sources and living in small, dispersed bands. Archaeologists know the most about people of the Woodland Period (600 BCâAD 1050), however, for which 7,800 sites have been The climate of the Illinois River basin was slightly cooler and wetter during the period of Woodland culture, but the vegetation remained similar to earlier ...
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...back towards the river we pass through the heavy timber where the still brown water, cool and clear, overlies the decaying leaves and vegetation of last seasonâs This description of a seemingly idyllic landscape is offset by Kofoidâs mention in his account of huge masses of cattle-yard refuse, agricultural erosion creating âa turbid yellow flood pouring out from the Spoon River,â and sewage.2...
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...tions. âCâ streams are in fair condition, with reduced fish Biological characterization of Illinois streams, showing stream segments in each of the primary categories highlighted as darker lines. Segments that appear to be disconnected from the drainage network are along streams too small to be included in these maps. After Critical Trends inventory for the state, represent an improvement over a similar survey in 1972, ...
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...per year (out of a total 12.6 billion metric tons), for example, yet they have reduced the flux of sediment reaching the ocean by 1.4 billion metric tons per year as a result of trapping sediment in reservoirs. Simultaneously, diverse evidence contin-ues to accumulate that humans are significantly altering atmospheric chemistry and global climate. In recognition of these so-called anthropogenic effects (from ...
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Page Count: 408
Publication Year: 2013