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. From April 15 through August 31 the R2CROSS analysis indicates a flow appropriation of 4.5 cfs is re~uired to maintain the three principal criteria of average depth, average veloctty and percent wetted perimeter; I . From September 1 to April 14, the R2CROSS indicates an instream flow appropriation of 1.9 cfs to mJintain two of the three principal criteria, specifically percent wetted pJrimeter and average depth; I Water Availability. The USGS maintained a gage (USGS gage 09016500) on Arapaho Creek between October, 1945 and Octo~er, 1971. This gage was located downstream of the confluence of Arapaho Creek and Buchanan Creek, below the outlet of Monarch Lake. Trout Unlimited recommends usihg the aerial apportionment method to estimate daily flows on Arapaho Creek. This apptoach assumes that discharge past any point on a , stream is proportional to the basin area draining to that point. Thus discharge past any , point upstream of a gage is equal to the discharge passing the gage multiplied by the ratio , of the watershed area above the ungaged point to the watershed area above the gaged point. Although the watershed area abo~e USGS gage 09016500 is approximately 46.9 square miles, Arapaho Creek above Buchanan Creek drains only 17.4 square miles. Thus, flows in Arapaho Creek above Buchana~ Creek are expected to be 0.37 that of those measured at the USGS gage. This aerial!apportionment approach was used to estimate the flow above Buchanan Creek for the period between 10/1/44 and 9/30/71. These dates assume a water year starting on 10/1. I . Although the lake likely dampened the ~ows from further up in the basin, the reservoir is owned by the Forest Service who manages the lake to support a "high quality non- motorized experience". As such they attempt to maintain constant levels in the lake. According to the Forest Service, the darlI is akin to a spillway and the discharge of water from the lake is approximately equal to the discharge into the lake minus losses to seepage and evaporation. Thus, flows p~st the USGS gage, as adjusted to for area, are likely a conservative estimate of flows ih the proposed instream flow reach. I , . This analysis showed that the estimatedlaverage daily flow above the Arapaho Creek Diversion between 10/1/44 and 9/30/71Iexceeded the recommended flows. Additionally, 50% of monthly flows were greater thaq the recommended flows throughout the year. In an attempt to produce a more robust analysis of water availability, average monthly flows through the reach were also estimkted using the Colorado StreamS tats webpage I maintained by the United States Geological Survey: I http://water. USgs. gov /osw/stFeamstats/colorado. html , StreamS tats uses regression equations t9 provide estimates of discharge for ungaged sites. This analysis also indicated that througl1out the year typical flows through the proposed instream flow reach would exceed the r~commended flows. , .