Effects of flow diversion on downstream channel form in mountain streams
Date
1993
Authors
Ryan, Sandra, author
Caine, Nel, author
Colorado Water Resources Research Institute, publisher
Journal Title
Journal ISSN
Volume Title
Abstract
This paper reports on a study of regime, bedload transport, and channel morphology in diverted and free-flowing segments of mountain streams in Colorado where flow has been diverted, in some cases, for up to one hundred years. The goal of the project was to determine whether differences in channel form and processes could be detected and linked to changes in flow regime from diversion. The effect of diversion on flow fegime can very considerably between individual steams. Typically, the total annual water yield is drastically reduced by diversion, though, where storage is limited, occasional high flows, with a five-to-ten year return frequency, move thought the natural channel. These larger events have the potential to reset changes in morphology incurred during the intervening dry years, such as channel narrowing and fining of bed size distribution. In general, changes in channel capacity were quite subtle, and the most apparent change was a decrease in channel width due to vegetation and the development of low bank beneath a former cut bank. No change in morphology was apparent in constrained channels. The results here are preliminary as of December 1993. Final results will be presented in subsequent publications.
Description
December 1993.
Rights Access
Subject
Water diversion -- Environmental aspects -- Colorado
Streamflow -- Colorado
Geomorphology -- Colorado