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<br />SUMMARY
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<br />mRIGATION
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<br />Operation of the development alternatives would not affect the
<br />amount of water diverted for irrigation use within the study
<br />area, including private irrigation diversions as well as the
<br />UVRP, The Montro,se and Delta Canal (M&D) and the LOutzenhizer
<br />Canal would receive the majority of their water supply from the
<br />Uncompahgre River with development, Under the no-action
<br />alternative, about 59 percent of the water supplies delivered to
<br />these canals would be derived from the Gunnison River, Under any
<br />of the development alternatives, about 35 percent would be
<br />derived from the Gunnison. Conversely, the Selig, East,
<br />Ironstone, and Garnet canals would receive higher percentages of
<br />Gunnison River water. Senior water rights for private irrigation
<br />diversions along the Gunnison and Uncompahgre Rivers would
<br />continue to be honored, '
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<br />RIVER MORPHOLOGY
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<br />Without development, the Gunnison River between the North Fork
<br />confluence and Delta would be expected to become narrower and
<br />more stable due to the effects of existing upstream water storage
<br />projects, Changes being caused by the Aspinall Unit on the
<br />Gunnison River upstream from the North Fork would continue,
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<br />With development, more of the riverbed would be exposed. The
<br />principal time that this would occur is in the nongrowing season.
<br />This would limit encroachment of' riparian vegetation and wetlands
<br />during periods of low and intermediate flows, Scouring during
<br />high flow periods would maintain the channel.
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<br />Without dev,elopment, the Uncompahgre River upstream of the study
<br />area would become a narrower and more stable river under the
<br />influence oj Ridgway Reservoir. Within the study area
<br />(downstream ftom the South Canal), the bank erosion that now
<br />occurs would continue, and bank stabilization by individuals and
<br />local governments would continue.
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<br />With development, bank erosion in the Uncompahgre River between
<br />the South Canal and the proposed tailrace wou,ld decrease together
<br />with the river's potential to scour encroaching vegetation.
<br />Between the proposed tailrace and Delta, the river would become
<br />more unstable and significant additional bank erosion would occur
<br />unless bank protection was initiated, To reduce this erosion,
<br />bank stabilization would be performed by the Spons9rs before
<br />development in areas found to be most susceptible to erosion_
<br />Changes in erosion would be monitored during operations, and
<br />further bank stabilization would be completed where necessary,
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