1400 ‎(2)‎

• UCREFRP Catalog Number: 1400
• Author: Simons, D. B., et al., ed.
• Title: Proceedings
• USFW Year: 1980.
• USFW - Doc Type: Workshop on Downstream River Channel Changes Resulting From Diversions or Reservoir Construction.
• Copyright Material: NO

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with sand and gravel depending upon the extent of backwater from the
Little Snake River.

Far Reach No.3, significant changes could occur. The construction
of earns on the Yampa River will result in reduced bed material transport
capacity. Because the supply of bed load from the Little Snake will not
change, the Yampa may aggrade at the confl uence. Also, if the peak
flows on the Yampa are reduced significantly, then upstream progressing
degradation will occur on the Little Snake during corresponding high
flows (Figure 3). Therefore, it is probable that the Yampa River will
aggrade in Reach No.3, this would create backwater effects up the Yampa
a~d drown out the r1ffles. With this flow situation, sands and gravels
moved into the pools will probably stay there, at least until high flows
are released from the reservoi rs. In regard to channel confi gurat ion
and meander pattern in Reach No.3, it is difficult to predict changes
that may occur. The maps are inadequate to clearly ascertain historical
shifting of the ~hannel. Air photos over a time span are essential to
evaluate the lateral stability of the river. Also, the magnitude,
frequency and duration of releases from the reservoirs must be known in
order to attempt to predict future channel configuration. In qual ita-
t1vs terms, it appears that the channel pattern is controlled by
bQulders along the river banks and reduced flows will produce relatively
l1ttle change. However, if aggradation takes place at the confluence,
then the build-up of channel bars will deflect currents into the banks
resulting in some change to the channel pattern. The pattern below the
confluence is likely to have several distinct channels flowing adjacent
to bars and islands.

In order to carry out further detailed analysis, however, more data
are required.

ADDITIONAL DATA REQUIREMENTS

The fo 11 owi ng data are required in order to ana lyze the vari QUS
river reaches and tQ predict river changes.

Little Snake River

x
X

x

x

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