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I I I I I I I I I I I I I I I I I I I 6.3 DOWNSTREAM WATER RELEASES During the time the outlet is plugged, approximately 9 cfs must be provided downstream of the dam, based on Durango's water right of 8.9 cfs. This amount will probably not be required in October because the City water demand is usually lower at this time. The CDOW recommends that 8 cfs be maintained to the Durango diversion point and 4 cfs below that point. Tributary inflows below the dam and above the diversion point will contribute to the river flows but will vary from year to year. The available streamflow data does not allow an estimate to be made of the intervening flows. The worst possible scenario would require 9 cfs for Durango and 4 cfs for the fishery for a total of 13 cfs; this situation has not occured in actual practice. A release of 9 cfs has been the actual minimum release and is more likely during construction. The fabricated plug would provide releases of up to 14 cfs at water elevation 8070 feet, which is 30 feet below the anticipated level. This more than satisfies the requirements. The butterfly valve can be adjusted to release about 8 cfs which is the desired release to keep the area around the gates as dryas possible while crews are repairing the gates. The releases will be increased if necessary to meet downstream requirements. Releases would be interrupted for up to one hour after the crews finish the gate on one barrel and begin work on the other. The bulkhead to divert water to the other barrel requires that the crews have access upstream of the gates and that the outlet be closed while they are moving the bulkhead. 6.4 RESERVOIR DRAWDOWN The reservoir water level maintained while the outlet is plugged will be decided by a combination of several factors which include: 1) the spring runoff into the reservoir, 2) the amount of 6.0-6