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<br />e <br /> <br />e <br /> <br />e <br /> <br />recommendation is for 1. 75 cfs for April through July and 0.5 cfs for the remainder of the <br />year. <br /> <br />CUB CREEK <br /> <br />Cub Creek is a small tributary of Bear Creek which flows into Bear Creek from the south at <br />the base of the dam at Evergreen Lake. Cub Creek is one of the few perennial tributaries of <br />Bear Creek below Evergreen Lake. Electrofishing (from 9/21/87) shows that Cub Creek holds <br />reproducing populations of three species of trout - brook, brown, and rainbow. This fact <br />makes this stream somewhat unique for front range streams and the Division of Wildlife is <br />very interested in seeing that this fishery is protected with instream flow appropriations. The <br />Division conducted stream cross section measurements at the same time as the above described <br />fishery investigations. The Division's original flow recommendations based on the R2CROSS <br />output were 5 cfs summer and 2 cfs winter; these were based on the standard application of the <br />hydraulic criteria. Water availability analyses conducted by the CWCB staff showed that this low <br />elevation stream did not have sufficient water available during the winter months to meet the 2 cfs <br />recommendation; only 0.75 cfs was available in this stream during the low flow period. Due to <br />the magnitude of the difference between the summer flow recommendation (5 cfs) and the winter <br />low flows, the Division revised the summer flow recommendation to be more in line with the <br />winter flows by using the winter flow rationale for a suminer flow recommendation of 2 cfs <br />(meets two of three criteria) and 0.75 cfs as a water availability limiting winter flow <br />recommendation. At 0.75 cfs the 50% wetted perimeter criterion is met and only 0.06 feet is <br />sacrificed to the average depth criterion. This, in the Division's opinion is mitigated by the fact <br />that the maximum depth in this representative critical riffle is still maintained at an adequate level <br />of 0.24 feet which should provide adequate low flow habitat for fish. The flow recommendation <br />is for 2 cfs April 15 though June and 0.75 cfs for the remainder of the year. <br /> <br />BLUE CREEK <br /> <br />Blue Creek is a tributary of Cub Creek which drains the 8.5 square miles south of the town of <br />Evergreen. The fishery of Blue Creek is very similar to that of Cub Creek except that no brown <br />trout were sampled; nonetheless, reproduction of both brook trout and rainbow trout appears to <br />occur in Blue Creek also. Due to the hydraulic characteristics of the cross section in this very <br />small stream (a bankfull top width ofless than 9 feet), the 1 foot per second average velocity <br />criterion is never met and the 0.2 foot minimum average depth criterion is met at near bank full <br />conditions. It was therefore necessary to use some professional judgement in recommending an <br />instream flow for this small stream. Instead of using average depth it was necessary to look at the <br />maximum depth keeping in mind the assumption that this cross section is both representative and <br />critical. At 0.75 cfs, approximately 95% of the bankfull wetted perimeter is wet and even though <br />the average depth is only 0.17 fee~ the maximum depth is over 0.50 feet thus providing adequate <br />depth for fish passage at times oflow flow and adequate wetted perimeter for food production <br />and spawning. Average velocity is still adequate at 0.75 cfs - it is maintained at approximately <br />0.65 fps. So even though only one criterion is met, the Division believes that the fishery will be <br />protected during the months of April through July with a flow of 0.75 cfs. As for the winter <br />months, 0.25 should provide adequate flow protection for over-wintering fish in that average <br />