ALP 3

Contents
Table 5. Handling and holding mortality and survival of 0 -plus largemouth bass (70 mm mean
TL), fathead minnow (55 mm mean TL), and RBT eggs.
During June 2010, the Ridges Basin Dam control house began to complete the electronic system
used to control the sleeve and butterfly valve. With the new system, both valves could be
opened or closed in approximately 1 minute and were also equipped with electronic
measurements of the percent open position of the sleeve valve attd the discharge in cubic feet per
second (cfs). To reach the 10 percent open position, the sleeve:yalve `open' button was held
down until the 10 percent mark was approached and then the button was released in effort to land
on the 10 percent mark. This new method was much faster and likely more precise than the
visual estimation used to read the dial above the sleeve valve. However, the sleeve valve was
slowly re- pressurized over a 1 -2 hour period aftec,the fish were inserted For the 10 trials
performed at the 6828 ft reservoir elevation, the. sleeve valve averaged 10.Q4'percent open and
23 cfs from the available discharge measurements (table 6).
1 10:14
2 9.90
3 °10.10
7
$;
9.77
23.0
10.45
23.0
10
10.04
23.0
Mean
10.04
23.0
Table 6. Percent opeh positio6 bf the sleeve valve and the resulting discharge (cfs) at a reservoir
elevation of 6828 ft.
Largemouth Bass (70 mm mean TL)
At the reservoir elevation of 6828 ft, a total of 10 trials were performed using 100 live 1 -plus
largemouth bass (mean TL 70 mm, mean height 14.7 mm) per trial. Total length LMB
measurements ranged from 55 to 80 mm. No LMB escaped the injection process. Each replicate
was injected into the discharge pipe upstream of the sleeve valve immediately after the FHM to
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