July 1993
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 Above Tiber Reservoir-1.1
1Marias Above Tiber Reservoir-1.1
2Tobacco-2
2Tobacco-2
3Kootenai to Libby Dam-1.2
3Kootenai to Libby Dam-1.2
4Kootenai River below Libby Dam-1.3
4Kootenai River below Libby Dam-1.3
5Fisher River-1.3
5Fisher River-1.3
6Yaak River-2.2
6Yaak River-2.2
7North FK. Flathead River-2
7North FK. Flathead River-2
8Middle FK. Flathead River-2
8Middle FK. Flathead River-2
9South FK. Flathead River-2
9South FK. Flathead River-2
10Flathead at Columbia Falls-2
10Flathead at Columbia Falls-2
11Stillwater/Whitefish Rivers-0.7
11Stillwater/Whitefish Rivers-0.7
12Swan River0
12Swan River0
13Flathead River at Polson-0.2
13Flathead River at Polson-0.2
14Mission Valley1.3
14Mission Valley1.3
15Little Bitterroot River-2.9
15Little Bitterroot River-2.9
16Clark above Missoula-2
16Clark above Missoula-2
17Blackfoot River-2.1
17Blackfoot River-2.1
18Clark Fork above Missoula-2
18Clark Fork above Missoula-2
19Bitterroot River-1.6
19Bitterroot River-1.6
20Clark Fork River below Bitterroot River-1.9
20Clark Fork River below Bitterroot River-1.9
21Clark Fork River below Flathead River-0.7
21Clark Fork River below Flathead River-0.7
22Beaverhead River-2
22Beaverhead River-2
23Ruby River2.2
23Ruby River2.2
24Big Hole River-2.5
24Big Hole River-2.5
25Boulder River (Jefferson)-1.4
25Boulder River (Jefferson)-1.4
26Jefferson River-1.4
26Jefferson River-1.4
27Madison River2
27Madison River2
28Gallatin River0.7
28Gallatin River0.7
29Missouri River above Canyon Ferry0.5
29Missouri River above Canyon Ferry0.5
30Missouri River below Canyon Ferry0.9
30Missouri River below Canyon Ferry0.9
31Smith River-1
31Smith River-1
32Sun River-1.5
32Sun River-1.5
33Teton River-2.4
33Teton River-2.4
34Birch/Dupuyer-1.4
34Birch/Dupuyer-1.4
36Musselshell River2.9
36Musselshell River2.9
37Missouri River above Fort Peck1.5
37Missouri River above Fort Peck1.5
38Missouri River below Fort Peck-1.6
38Missouri River below Fort Peck-1.6
39Milk River-1.5
39Milk River-1.5
41Yellowstone River above Livingston0
41Yellowstone River above Livingston0
42Shields River2.7
42Shields River2.7
43Boulder River (Yellowstone)-0.3
43Boulder River (Yellowstone)-0.3
44Stillwater River-0.1
44Stillwater River-0.1
45Rock/Red Lodge Creeks0.4
45Rock/Red Lodge Creeks0.4
46Clarks Fork River0.2
46Clarks Fork River0.2
47Yellowstone River above Bighorn River0
47Yellowstone River above Bighorn River0
48Bighorn River below Bighorn Lake1.1
48Bighorn River below Bighorn Lake1.1
49Little Bighorn River0.6
49Little Bighorn River0.6
50Yellowstone River below Bighorn River0.9
50Yellowstone River below Bighorn River0.9
51Tongue River-0.9
51Tongue River-0.9
52Powder River1.7
52Powder River1.7
999Kootenai at Ft. Steele-2
999Kootenai at Ft. Steele-2