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RESULTS 2003 A total of 282 fish in 117 hours of netting was captured leaving the spillway of Elkhead Reservoir in 2003 (Table 2). Depth over the spillway was estimated at less than one foot. The escapement per hour per net ranged from zero to 12.5 fish/hr with an average of 2.41 fish/hr. The net captured 0.91 m of the 41 m total spillway width (Table 2). The per net captures were multiplied to estimate the range of escapement per hour and per day for the total spillway width. Eight fish species were captured during the 2003 sampling. The most abundant fish were black crappie and bluegill, which comprised 78% and 16% of the escapement respectively (Table 3). Largemouth bass (n=1 273 mm TL), smallmouth bass (n=1 230 mm TL) and rainbow trout (n=1 346 TL) escapement was less than 1% of the total. Fish total lengths ranged from 50 mm to 350 mm (Figure 9). The majority of the black crappie was approximately 125 mm total length. The majority of the bluegill was 75 mm total length. The smallest fish captured were sand shiner and speckled dace. No fish bearing finclips or Floy tags were recaptured. No fish were captured in 112 hours of netting on the outlet (Table 2). Total release capacity of the outlet is 180 cfs. The outlet release during the sampling was estimated at less than 5 cfs. The highest hourly escapement rate occurred just after sunset (Figure 10), while the highest weekly escapement rates occurred during weeks of higher discharge (Figures 11-12, Table 4). The stream flow was approximately 600 cfs the week of April 28th, 2003, peaked at approximately 1000 cfs during the week of May 19th, 2003 and dropped to approximately 350 cfs the week of June 2, 2003. Highest diel escapement rates in all weeks sampled occurred between 8:00 pm to 10:00 pm in the evening. 2004 Lower snow pack resulted in lower flows in Elkhead Creek during May and June of 2004. It is likely that the lower volume of water passing over the spillway contributed to a lower catch rate. A total of 60 fish were captured moving through the spillway (249.5 hours of netting). The per net captures were multiplied (based on two nets during 2004) to estimate the range of escapement per hour and per day for the-total spillway width (Table 2). The estimated total hourly escapement estimates assumed an equal rate of escapement for the entire spillway width. This may over or under estimate the escapement if the rate of escapement varies across the spillway. Conditions at the spillway precluded safe sampling at locations other than the east and west ends. Based on the data from 2004, the rate of escapement varies and is higher on the east side than the west side. Five fish species were captured during the 2004 sampling. The most abundant fish were bluegill and black crappie, which comprised 47.6% and 45.9% of the escapement respectively (Table 3). Smallmouth bass, rainbow trout and fathead minnow were also collected in low numbers during the 2004 season. One fish, a 55 mm TL smallmouth bass, was captured at the outlet structure (118.17 hours of netting). The outlet release in 2004 was similar to 2003. Depth of the water over the outlet in the reservoir at the time of capture was 10 meters. FINAL REPORT - Elkhead Reservoir Escapement, Project No.: 118 Page 8 Miller Ecological Consultants, Inc. May 20, 2005