Stream and Station

Most
Probable
Forecast
(1000 AF)

Most
Probable
Forecast
(% of Avg)

Reasonable
Maximum
(% of Avg)

Reasonable
Minimum
(% of Avg)

30 Year
(1961-1990)
Avg Runoff
(1000 AF)

COLUMBIA RIVER
Mica Reservoir Inflow, BC

Arrow Lakes Inflow, BC

Birchbank, BC (1)
International Boundary, BC (1)
Grand Coulee, WA (1)

Rock Island Dam blo, WA (1)
The Dalles nr, OR (1)

FEB-SEP
APR-SEP
FEB-SEP
APR-SEP
APR-SEP
APR-SEP
JAN-JUL
APR-SEP
APR-SEP
JAN-JUL
APR-SEP

13400
12900
28800
27400
46800
64300
68700
70400
78400
116000
108000

102
101
107
107
107
108
109
109
111
110
109

121
122
119
119
131
132
137
137
140
138
139

82
81
96
95
83
83
80
81
82
82
79

13170
12730
26800
25540
43800
59730
63280
64850
70480
105900
98980

KOOTENAI RIVER
Libby Reservoir Inflow, MT (1)

Libby, MT (1)
Leonia, ID (1)
Kootenay Lake Inflow, BC

JAN-JUL
APR-SEP
APR-SEP
APR-SEP
APR-SEP

6530
6910
7330
8580
17400

102
102
102
104
105

137
135
132
137
127

67
69
71
71
82

6396
6772
7207
8275
16650

DUNCAN LAKE INFLOW, BC

FEB-SEP
APR-SEP

2280
2200

98
98

117
118

79
78

2319
2238

CLARK FORK RIVER
Missoula abv, MT
Missoula blo, MT
St. Regis, MT (1)
Plains nr, MT (1)
Whitehorse Rapids, ID (1)

APR-SEP
APR-SEP
APR-SEP
APR-SEP
APR-SEP

2100
3860
3040
13000
14400

125
125
123
113
112

170
165
173
155
153

80
84
73
72
69

1681
3099
4095
11470
12910

BLACKFOOT RIVER
Bonner nr, MT

APR-SEP

1150

124

171

78

926

BITTERROOT RIVER
Darby nr, MT
at Mouth, MT

APR-SEP
APR-SEP

675
1760

125
124

158
170

92
78

540
1419

N. FORK FLATHEAD RIVER
Columbia Falls nr, MT

APR-SEP

1970

107

145

70

1836

S. FORK FLATHEAD RIVER
Hungry Horse Res in, MT (1)

JAN-JUL
APR-SEP

2420
2330

107
107

143
144

71
69

2269
2184

M. FORK FLATHEAD RIVER
West Glacier nr, MT

APR-SEP

1960

110

154

65

1788

FLATHEAD RIVER
Columbia Falls, MT
Flathead Lake Inflow, MT (1)

APR-SEP
APR-SEP

6420
7600

108
110

143
149

73
71

5960
6926