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U00720 · The identification of spilled water would be based on an Aspinall "hydrologic triggering criteria" · The timing, magnitude and duration would be suggested by the NPS (as long as the total "event" was limited to the acre feet at risk of spill) · the "risk of spill" criteria could be slightly "liberalized" to allow for' a greater frequency of bypasses and spills 3) Shoulder flows would be eliminated from further consideration · these are the "costly" part of NPS' water claim · there is less scientific evidence for the efficacy of these flows · other NPS actions could be undertaken (such as mechanical removal of river--side vegetation) Possible Related Actions The NPS is interested in making the peak flows do as much "scouring" of riparian vegetation as possible. The larger the magnitude of the peak flow, the greater the scouring effect. At the same time, the NPS is committed to minimizing flooding at Delta,Colorado, downstream from the Aspinall Units. If the NPS was willing to settle for base flows plus producing peak flows only with "spilled" water, the State of Colorado and other water and power user groups may be supportive of actions which would allow for higher peak flows. These might include: · Requesting that the Corps of engineers design flood protection for the town of Delta Requesting Congressional appropriations for this purpose Requesting appropriated monies to modify dam structure modifications which would safely handle more frequent spills . . Park Service Benefits from Settlement · Quick settlement of its water right · Non-litigious agreement on its water right with water and power users · The ability to "manage" the peak flows, when they occur. [This point deserves some elaboration. The NPSjustifies the peak and shoulder flow portions of its claim on the idea that naturally occurringfloods used to remove riverside vegetation and create naturallamtfor11}ssuchCJ~ beaches andsandbars, In poif!Lofiact, it is the peqkflows that does this work. Peakflows scour vegetation and alter/he morphological condition of the river bed in hours, not days or weeks. The question is merely a matter of frequency: how often do these floods need to occur to accomplish their assigned tasks? If the current management of the reservoir produces floods that are notfrequent enough, a slightly altered management could produce floods which are more frequent. It is likely that a solution could be devised that produces sufficient frequency of flooding to satisfy the needs of the NPS which also satisfying a reasonable "hydrologic triggering criteria".] · The ability to have higher flows through the canyon without causing flood damage at Delta