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

Air photos

Site inspection or ground photos

River cross sections

Hydrologic information

For the Vampa River problem, topographic maps were supplied and air
photos of the Lily Park. Reach were obtained duri ng the work.shop. A
general appraisal of the two reaches follows.

Box Elder Reach

The river channel may be described as having an irregular meander
pattern, deeply entrenched in a 1000 foot deep canyon, with a thin layer
of alluvium on the bed. The bank.s are essentially bedrock. There are
no air photos, consequently it is difficult to assess the river
processes, but it appears that the river is stable and is not expected
to change its pattern.

Lily Park Reach

As noted from the topographic maps and the air photos, the Vampa
River changes character several times as it emerges from the Cross
Mountain Canyon; in fact this reach can be further subdivided into three
distinct reaches as follows (see Figure 1 for details of reaches as
traced from air photos).

Reach No.1. The Vampa River is confined within stable steep
bank.s, has a pool and riffle sequence with some midchannel bars
composed of gravel and boulders. The channel pattern is irregular with
some bends and straight reaches. It appears that the sediment load
brought into this reach from the Cross Mountain Canyon would be
transported through the Reach and that the channel is relatively stable
(s~e Figure 2 for river profile).

Reach No.2. The Vampa River becomes wider with a regular meander
pattern. The bank.s consist of a high terrace on the left which appears
stable and a low floodplain on the right which is susceptible to
erosion. This reach has several point bars and could be aggrading due
to the confluence at the bottom end of the reach.

Reach No.3. The Vampa River widens significantly and flows within
low unstable banks. The bed has large midchannel bars as well as wide
point bars indicating that material is depositing throughout the reach
and trat the bed is aggrading.

With the various reaches described, we can now discuss the scope of
the problem to be studied.

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