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<br />length from 282 feet at 1,028 cfs to 224 feet at 1,687 cfs. Average
<br />depth of this backwater ranged from 15 inches at 1,383 cfs to 21
<br />inches at 1,978 cfs.
<br />
<br />Ouray - Two backwaters were studied at the Ouray site. Reference
<br />backwater A (river mile 251) was present for four flows, from 1,683
<br />cfs to 1,031 cfs, and reference backwater B (river mile 261.5) was
<br />present for six flows, from 2,635 cfs to 1,031 cfs. Backwater A was
<br />a relatively long backwater, ranging from 423 feet at 1,374 cfs to
<br />297 feet at 1,031 cfs. Average depth ranged from 15 inches at 1,374
<br />cfs to 25 inches at 1,683 cfs. Backwater B remained relatively
<br />constant in length, ranging from 375 feet at 1,031 cfs to 350 feet
<br />at 1,683 cfs. Backwater B was the deepest backwater measured, with
<br />an average depth ranging from 52 inches at 1,877 cfs to 32 inches
<br />at 1,031 cfs.
<br />
<br />Sand Wash - Three reference backwaters were selected for study at
<br />the Sand Wash site. However, because of inclement weather, these
<br />backwaters were only visited for two flows. Reference backwater A
<br />(river mile 224.3) increased in length from 103 feet (2,370 cfs) to
<br />300 feet (1,698 cfs) while it's average depth was stable, averaging
<br />27 inches at 2,370 cfs and 1,698 cfs. Backwater B (river mile
<br />224.7) decreased from 512 feet in length at 2,370 cfs to 340 feet
<br />at 1,698 cfs. Average depth for the two flows was 26 and 24 inches.
<br />Backwater C was 235 feet at 2,370 cfs and 220 feet in length at
<br />1,698 cfs. The average depth for these two flows was 20 and 16
<br />inches.
<br />
<br />Conclusions
<br />
<br />Optimum flows for maximizing backwater area varied among sites. At
<br />the Island Park and Jensen sites backwater area was maximized at
<br />the lowest flows studied (1,381 and 1,101 cfs). Backwater area
<br />produced at these flows was greater than 60 percent more than that
<br />produced at the 1,687 cfs flow.
<br />
<br />Optimum flows for producing backwater area at the Ouray site were
<br />1,687 and 1,773 cfs. All flows from 2,423 to 1,101 cfs produced
<br />greater than 60 percent more backwater area than the 5,260 cfs
<br />flow. The Sand Wash site behaved in a similar manner and an
<br />optimum flow range of 1,773 to 1,101 was indicated.
<br />
<br />The optimum flow for maximizing backwater area at the Mineral
<br />Bottom site was 3,261 (at the Green River gauge). Backwater area
<br />at this flow was nearly twice as much as that produced at the other
<br />flows studied.
<br />
<br />The optimum flow for maximizing backwater area for
<br />four upper sites was 1,101 cfs, and an optimum range
<br />1,101 cfs was indicated.
<br />
<br />the combined
<br />of 1,773 to
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