Mitigation for the Construction and Operation of Libby Dam

Table A4. Libby Creek depletion population estimates for fish > 75 mm per 1,000 feet using 95
% confidence intervals. Upper confidence intervals are in parenthesis.
Year 1998 1999 A 2000 A 2001 2002 2003
Section 1 – below
Hwy 2
Rainbow Trout 81 26 125 46 (51.09) 117 84 (95.5)
(126.80)
(129.56)
Brook Trout 6 (8.27) 6 13 10 (12.33) 16 (24.29) 5
Bull Trout ----- ----- ----- ----- 3 0
Mountain Whitefish ----- ----- ----- ----- 3 1
Total Population B 90
(115.89)
32 138 57 (63.79) 138
(152.67)
Water Temp. 0 C 9 ----- 16 15 14 ------
Discharge (cfs) 6.9 ----- ----- ----- ----- ------
Section 2 –above Hwy
2
Rainbow Trout 203
----- ----- 148 ----- 100
(225.20)
(192.77)
(107.5)
Brook Trout 7 ----- ----- 2 ----- 2
Bull Trout 5 (6.26) ----- ----- ----- ----- 2.08
Total Population B 208 ----- ----- 160 -----
(228.39)
(213.40)
Water Temp. 0 C 5 ----- ----- 20 ----- ------
Discharge (cfs) 6.9 ----- ----- ----- ----- ------
Section 3 – upper
Cleveland
Rainbow Trout ----- ----- 170
(193.73)
172
(182.26)
163
(183.16)
112.3
(126.9)
Brook Trout ----- ----- ----- ----- ----- ------
Bull Trout ----- ----- 3 8 (11.15) 7 10.8 (13.7)
Mountain Whitefish ----- ----- ----- ----- 1 -----
Total Population B ----- ----- 170
(193.73)
172
(182.26)
163
(183.16)
A) Section 1 population estimates in 1999 and 2000 were single pass catch–per-unit-effort
estimates due to high escapement rates. Actual population is higher than reported.
B). Includes rainbow, rainbow x cutthroat hybrids, and brook trout. Bull trout were not
included in the total population estimate.
152