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The Traditional River
<br />Platte
<br />"Platte" is the French word for flat-an honest translation by French explorers of
<br />"nebraska", the Omaha Indian name for the broad shallow braided river (Matter 1969, : 6). The
<br />North Fork of the Platte is 618 milf:s long, while the South Fork extends 424 miles before the
<br />two combine just west of North Platte Nebraska to form the 310-mile main stem. Measured by
<br />volume at the mouth, the Platte River delivers an average of 5,980 cubic feet per second (cfs) to
<br />the Missouri, a pittance compared t:o rivers such as the Ohio (281,000 cfs), or the Missouri
<br />(76,200). Approximately 90,000 s(luare miles in Colorado, Wyoming, and Nebraska contribute
<br />surface runoff and groundwater to the Platte River, yielding an average annual flow of 1.3
<br />million acre feet to the Missouri (Platte River EIS Team 2000).
<br />Near the continental divide Colorado and Wyoming mountain snowpack thaws into
<br />rivulets gathering into plunging streams that flow through rough canyons and then abruptly run
<br />out on flat prairie where water settles into wide beds, which, well before the Nebraska borders,
<br />drop only at an average rate of 7 foet per mile (Ring 1999, : 13). Plains channels are typically
<br />broad, braided, and sandy, with lovr banks, sparse woody vegetation and high sediment loads
<br />(Wohl, McConnell, Skinner, and Stenzel 1998); Eschner, 1981 #10], Average annual rainfall
<br />slowly increases as one travels fror.n west to east, from about 12 inches to 20 at the 98`' meridian
<br />two thirds across Nebraska. Aridity dictated a river bounded by a short-grass plains landscape of
<br />buffalo and blue grama grasses.
<br />Prior to European settlemerit, the natural flow pattern consisted of a spring rise
<br />(beginning in March), extending to a peak in late May or June, and then a sharp decline in late
<br />June into summer, fall, and winter months. Spring and early summer floods cleared vegetation
<br />from sandbars, islands, and river banks, and distributed sediment across a wide path. Channels
<br />had only small and infrequently distributed clumps of green ash, plains cottonwood, box-elder,
<br />and willows growing along the banks. A mile wide in some places, the river was described as a
<br />burlesque of rivers, braided with islands, studded with sandbars. Early travelers complained that
<br />the Platte could not be ferried for lack of water, and could not be bridged for lack of timber
<br />(Matter 1969: 239). When FremonLt descended the North Platte in early September 1845, he
<br />attempted to float a bull boat with a draft of four inches and, after dragging it on the sands for
<br />three to four miles, abandoned the 'boat entirely (Simons and Associates Inc. 2000).
<br />Characteristics and Value of Ecosystem Services
<br />Rivers in open flat country typically support more complex ecological communities than
<br />smaller woodland streams. More sunlight, more algae and zooplankton provide a broader base
<br />for the food chain. In addition rivers with small gradients meander, demonstrating a dynamic
<br />equilibrium between erosion and deposition of sediment). Faster moving water scours out earth
<br />from the outside curves of channel;s and deposits this load when the velocity slows at inside
<br />curves. Stretches of maximum velocity and the deepest part of a channel lie close to the outer
<br />side of each bend and then cross over near the inflection between the banks, resulting in zones of
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