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" c' . . . - 3 - crest and continues to drain until a new lower water surface elevation equal to the height of the new board is established. For purposes of administrating the proposed plan for augmentation, Copper proposes to fabricate a new series of boards allowing the lake's water elevation to drop in one inch increments. A release of water from West Lake equal to 1 inch of depth is equivalent to 0.075 acre feet, assuming the lake is full at the start of release. Using an equation for rectangular weirs, the release of that amount is calculated to occur over a 55.5 hour period. The release rate would vary from approximately 30 gpm at the beginning of release to less than 2.0 gpm near the end. The average release would equal 7.3 gpm over the 55.5 hour period. This flow release exceeds the 1.6 gpm augmentation requirement; however, it represents the lowest practical release rate that can be achieved under this structure. At this rate of release, it would take approximately 17.8 days to release all 0.58 acre feet of augmentation water. Consequently, while the amount released is greater than the amount of depletions, there will be a number of days each month when no release is being made and the 0.0025 cfs of depletions are not being replaced. This situation is similar to other existing plans for augmentations for which the CWCB has agreed to "slug releases" of augmentation water due to the small amount of depletions and other physical constraints. However, due to the unique nature of this proposal, the stipulation would contain a provision stating that the CWCB's acceptance of the terms and condition as in this case are based upon the specific facts and circumstances of this application and shall establish no precedent applicable to any other water court proceeding. Historical Flows on West Tenmile Creek According to a letter from Copper's consultant Scott Fifer, dated April 26, 2007, streamflows in the upper reach of West Tenmile Creek (above West Lake) are most often well above the CWCB's instream flow water rights. The potential shortages to CWCB water rights occur in the lower reach of West Tenmile Creek (below West Lake) due to various downstream diversion structures and to a losing stream channel in the lower most segment of the reach. Therefore, the proposed augmentation sources, including West Lake and the West Tenmile Ditch, appear to be properly positioned to augment depletions from Copper Mountain's CB-2 Well. A review of data collected at the gage indicates that flows in West Tenmile Creek generally exceed the instream flow amounts. Average monthly flows for the gaged period of record (1973 - 1979) always exceeded the amounts decreed to in stream flow water right. Furthermore, average monthly flows during 1977, an extremely dry year, were also above the minimum flow. Although flows in West Tenmile Creek generally appear to satisfy the instream flow water right, there were two instances (April 1975 and April 1976) when average monthly discharge measured at the West Tenmile Creek at Copper Mountain gage was slightly below the instream flow amount. However, these instances, seem to be driven by later than average spring snowmelt, rather than a lack of available water. Also, the USGS streamflow measurements do not include tributary inflow from Roundabout Creek and Union Creek. Both tributaries originate from the ski mountain and enter West Tenmile Creek upstream of West Lake. These sources would further enhance streamflows and reduce in duration the limited amount of time that streamflows might fall below the decreed ISF amounts. In summary, stream flows in West Tenmile Creek above the proposed augmentation sources generally remains above the decreed ISF amounts, even during drought year conditions. Even if Flood Protection. Water Project Planning and finance. Stream and Lake Protection Water Supply Protection. Conservation Planning