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Introduction How Rivers Run Stories Value Of A River What We Can Do
Flow of a River - Hydrology
Factors of flow: Example (pg 7 of 11)

For thousands of years, the Colorado River flooded through the Grand Canyon, its muddy waters scouring banks, depositing sediment in terraces, sorting gravel, cobble, and boulders into patterns throughout the stream bed. Melting of the Rocky Mountain snowpack often caused floods greater than 100,000 cubic feet per second (cfs) during spring and early summer. By late summer and fall, flows would fall to as low as 3,000 cfs. Water temperatures ranged from more than 80° F in the summer to near freezing in winter.

Construction of the Glen Canyon dam in 1963 eliminated the natural variability and pattern of streamflow. The river's flow exceeded 30,000 cfs only 3 percent of the time and rarely reached the normal late-summer low flows. Meanwhile, daily flows fluctuated sharply to meet the daily change in demand for power generation. Water flowed from the base of the dam at a nearly constant 46-48° F and was exceedingly clear because the sediment remained trapped in Lake Powell.


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Introduction
Flow
Description
Water cycle
Watersheds
Stream order
Factors of flow
Consequences
Stories
Shape
Connections
Quality
Life
Summary
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