August 2014
Surface Water Supply Index Report

Provided by the US Natural Resources Conservation Service
Bozeman, Montana

The SWSI is designed for areas that rely primarily on snowmelt runoff as the primary source of surface water. The SWSI accounts for snowpack, mountain precipitation, streamflow, reservoir contents, and soil moisture conditions. The SWSI can be used by irrigators, fisheries personnel, recreationists, and others who utilize surface waters. SWSI values are categorized as follows:

IDBasin NameValue
1Marias River above Tiber Reservoir1
1Marias River above Tiber Reservoir1
2Tobacco River0.6
2Tobacco River0.6
3Kootenai Ft. Steele to Libby Dam1
3Kootenai Ft. Steele to Libby Dam1
4Kootenai River below Libby Dam0.9
4Kootenai River below Libby Dam0.9
5Fisher River0.5
5Fisher River0.5
6Yaak River-0.5
6Yaak River-0.5
7North Fk. Flathead River2
7North Fk. Flathead River2
8Middle Fk. Flathead River3.5
8Middle Fk. Flathead River3.5
9South Fk. Flathead River2.5
9South Fk. Flathead River2.5
10Flathead River at Columbia Falls2.1
10Flathead River at Columbia Falls2.1
12Swan River2.9
12Swan River2.9
13Flathead River at Polson3.2
13Flathead River at Polson3.2
14Mission Valley2.3
14Mission Valley2.3
15Little Bitterroot River1.9
15Little Bitterroot River1.9
16Clark Fork River above Milltown0.5
16Clark Fork River above Milltown0.5
17Blackfoot River1.1
17Blackfoot River1.1
18Clark Fork River above Missoula1.2
18Clark Fork River above Missoula1.2
19Bitterroot River2.3
19Bitterroot River2.3
20Clark Fork River below Bitterroot River1.5
20Clark Fork River below Bitterroot River1.5
21Clark Fork River below Flathead River2.6
21Clark Fork River below Flathead River2.6
22Beaverhead River-2.7
22Beaverhead River-2.7
23Ruby River0.1
23Ruby River0.1
24Big Hole River0.2
24Big Hole River0.2
25Boulder River (Jefferson)0.6
25Boulder River (Jefferson)0.6
26Jefferson River0.2
26Jefferson River0.2
27Madison River-0.1
27Madison River-0.1
28Gallatin River0.4
28Gallatin River0.4
29Missouri River above Canyon Ferry0.2
29Missouri River above Canyon Ferry0.2
30Missouri River below Canyon Ferry0.6
30Missouri River below Canyon Ferry0.6
31Smith River2.1
31Smith River2.1
32Sun River0.5
32Sun River0.5
33Teton River0.6
33Teton River0.6
34Birch/Dupuyer Creeks0.1
34Birch/Dupuyer Creeks0.1
35Marias River below Tiber Reservoir2.3
35Marias River below Tiber Reservoir2.3
36Musselshell River1.6
36Musselshell River1.6
37Missouri River above Fort Peck1.1
37Missouri River above Fort Peck1.1
38Missouri River below Fort Peck-0.2
38Missouri River below Fort Peck-0.2
40Dearborn River near Craig-1.2
40Dearborn River near Craig-1.2
41Yellowstone River above Livingston1.7
41Yellowstone River above Livingston1.7
42Shields River2.1
42Shields River2.1
43Boulder River (Yellowstone)3.1
43Boulder River (Yellowstone)3.1
44Stillwater River2.5
44Stillwater River2.5
45Rock/Red Lodge Creeks2
45Rock/Red Lodge Creeks2
46Clarks Fork River3.6
46Clarks Fork River3.6
47Yellowstone River above Bighorn River2.3
47Yellowstone River above Bighorn River2.3
48Bighorn River below Bighorn Lake1.2
48Bighorn River below Bighorn Lake1.2
49Little Bighorn River2.7
49Little Bighorn River2.7
50Yellowstone River below Bighorn River1.8
50Yellowstone River below Bighorn River1.8
51Tongue River3.1
51Tongue River3.1
52Powder River2.3
52Powder River2.3
53Upper Judith Basin-0.9
53Upper Judith Basin-0.9
54St. Mary River3.4
54St. Mary River3.4