January 2006
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-1.8
1Marias Above Tiber Reservoir-1.8
2Tobacco-1.3
2Tobacco-1.3
3Kootenai to Libby Dam-0.8
3Kootenai to Libby Dam-0.8
4Kootenai River below Libby Dam0.8
4Kootenai River below Libby Dam0.8
5Fisher River-0.9
5Fisher River-0.9
6Yaak River-1.7
6Yaak River-1.7
7North FK. Flathead River-1.5
7North FK. Flathead River-1.5
8Middle FK. Flathead River-1.7
8Middle FK. Flathead River-1.7
9South FK. Flathead River0.6
9South FK. Flathead River0.6
10Flathead at Columbia Falls-0.1
10Flathead at Columbia Falls-0.1
11Stillwater/Whitefish Rivers-0.8
11Stillwater/Whitefish Rivers-0.8
12Swan River0.3
12Swan River0.3
13Flathead River at Polson-1.6
13Flathead River at Polson-1.6
14Mission Valley-0.5
14Mission Valley-0.5
15Little Bitterroot River-3
15Little Bitterroot River-3
16Clark above Missoula1.1
16Clark above Missoula1.1
17Blackfoot River-0.1
17Blackfoot River-0.1
18Clark Fork above Missoula0.4
18Clark Fork above Missoula0.4
19Bitterroot River0.6
19Bitterroot River0.6
20Clark Fork River below Bitterroot River0.5
20Clark Fork River below Bitterroot River0.5
21Clark Fork River below Flathead River-0.8
21Clark Fork River below Flathead River-0.8
22Beaverhead River-2.1
22Beaverhead River-2.1
23Ruby River1.1
23Ruby River1.1
24Big Hole River0.4
24Big Hole River0.4
25Boulder River (Jefferson)0.8
25Boulder River (Jefferson)0.8
26Jefferson River1.2
26Jefferson River1.2
27Madison River2.1
27Madison River2.1
28Gallatin River2.1
28Gallatin River2.1
29Missouri River above Canyon Ferry0.2
29Missouri River above Canyon Ferry0.2
30Missouri River below Canyon Ferry-0.3
30Missouri River below Canyon Ferry-0.3
31Smith River0.8
31Smith River0.8
32Sun River-1.7
32Sun River-1.7
33Teton River-1.5
33Teton River-1.5
34Birch/Dupuyer-2.9
34Birch/Dupuyer-2.9
35Marias Below Tiber Reservoir-2
35Marias Below Tiber Reservoir-2
36Musselshell River1.6
36Musselshell River1.6
37Missouri River above Fort Peck-1.4
37Missouri River above Fort Peck-1.4
38Missouri River below Fort Peck-3.5
38Missouri River below Fort Peck-3.5
39Milk River0.2
39Milk River0.2
40Dearborn-1.1
40Dearborn-1.1
41Yellowstone River above Livingston1.4
41Yellowstone River above Livingston1.4
42Shields River2.9
42Shields River2.9
43Boulder River (Yellowstone)2.5
43Boulder River (Yellowstone)2.5
44Stillwater River1.1
44Stillwater River1.1
45Rock/Red Lodge Creeks0.5
45Rock/Red Lodge Creeks0.5
46Clarks Fork River1.3
46Clarks Fork River1.3
47Yellowstone River above Bighorn River1.4
47Yellowstone River above Bighorn River1.4
48Bighorn River below Bighorn Lake-0.2
48Bighorn River below Bighorn Lake-0.2
49Little Bighorn River0.4
49Little Bighorn River0.4
50Yellowstone River below Bighorn River0.7
50Yellowstone River below Bighorn River0.7
51Tongue River0
51Tongue River0
52Powder River1
52Powder River1