8188

• UCREFRP Catalog Number: 8188
• Author: Muth, R. T., et al.
• Title: Flow and Temperature Recommendations for Endangered Fishes in the Green River Downstream of Flaming Forge Dam.
• USFW Year: 2000.
• USFW - Doc Type: \
• Copyright Material: NO

Final Report

3-52

September 2000

Table 3.14.-Continued.

Flow Condition by Reach3
Process Reach 1 Reach 2 Reach 3
Floodplain Processes
Inundate floodplain with Not applicable because Significant flooding is From White River to
levees in place. of life-history needs of initiated in the Ouray Pariette Draw, 265 ha of
fishes in reach. area at 527 m3/s floodplain becomes
(514 ha); 1,457 ha inundated at 623 m3/s;
becomes inundated at 425 ha at 680 m3/s; and
575 m3/s; 3,238 ha 767 ha at 920 m3/s.
becomes inundated at Flooding is initiated in
643 m3/s; 3,561 ha Canyonlands National
becomes inundated at Park between RK 41 and
748 m3/s. In the Island 56 at 1,104 m3/s; the
Park area, 98 ha of highest level of
floodplain becomes inundation is estimated at
inundated at 1,090 m3/s. 200 ha at 1,500 m3/s. At
flows of 509-1,924 m3/s,
the amount of inundated
floodplain increases
linearly from about 3 to
about 130 ha between RK
61 and 69.
Inundate floodplain with Not applicable because Flooding would be 23 ha would be flooded at
levees removed. of life history of fishes initiated at 368 to 453 509 m3/s in Canyonlands
in reach. m3/s in the Ouray area. National Park between
RK 61 and 69.

a River reaches: (1) Flaming Gorge Dam to Yampa River confluence, (2) Yampa River confluence to White River
confluence, and (3) White River confluence to Colorado River confluence.

Peak flows scour and rearrange sediment deposits within the channel. An important factor
in maintaining sediment-transport and depositional dynamics (and therefore preventing vegetation
encroachment, channel narrowing, and vertical accretion of deposits and banks) is maintaining some
degree of variability in annual peak flows as occurred prior to regulation. This can be achieved by
linking peak releases to hydrologic conditions within the basin for any given year.

Providing suitable spawning substrates within the channel requires maintenance of dynamic
sediment processes as well. Cobble and gravel deposits that are used for spawning are formed at very
high flows. Lower peak flows result in deposition of fine sediments on these spawning areas, which
are subsequently flushed as the flow level drops. Variability in peak flows whose timing coincides
with the natural runoff cycle is needed to ensure suitable sites are available during the spawning
period.