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I I I I I I I I I I I I I I I I I I I Colorado River -15-lIJile Reach The IS-Mile Reach of the Colorado River extends from Palisade, Colorado (RM 185) downstream to the confluence of the Gunnison River at about RM 170 (Figure 2), Two major upstream diversions divert flow from the river during the irrigation season (April Ito November I) and instream flows can be impacted in some years. The Government Highline diversion is located in lower Debeque Canyon (RM 193,7) and the Highline canal has a capacity of 1,620 cfs. The Grand Valley diversion dam is at RM 185.4 and the Grand VaHey canal has a capacity of 640 cfs. Flows at the Palisade Gage are typically 1,200 to 1,600 cfs less than above the diversion structures in Spring and Summer. Winter (November to March) flows in the IS-Mile Reach do not appear to create fishery concerns, There were two study sites in the IS-Mile Reach. Corn Lake was from RM 177.5 downstream to RM 175,3 (Figure 2) and was 3,9- km in length. This site was electro-fished in 1999,2000,2001 and 2003, The river in this section includes five small backwaters, Flow was generally confined within the main channel, as opposed to a braided channel (Anderson and Stewart 2003), The other study site, named the Clifton Site, was added in 2000. The Clifton Site was just upstream, only a short section (about 300 m) from the Corn Lake site, The Clifton site is from RM 177.7 to 180.4 and has a total length of 4,2 km, In this section, the river has two large sections where flow is split by islands. There is an old diversion structure located at RM 179.7. An old diversion structure backs water along the north shoreline making a large backwater. Because the two sites are adjacent, it is possible and desirable to combine data into one site to serve as a single station to represent the IS-Mile Reach, 3