January 2007
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-0.4
1Marias Above Tiber Reservoir-0.4
2Tobacco-0.1
2Tobacco-0.1
3Kootenai to Libby Dam1.5
3Kootenai to Libby Dam1.5
4Kootenai River below Libby Dam1.8
4Kootenai River below Libby Dam1.8
5Fisher River0.5
5Fisher River0.5
6Yaak River2.7
6Yaak River2.7
7North FK. Flathead River0.6
7North FK. Flathead River0.6
8Middle FK. Flathead River0.4
8Middle FK. Flathead River0.4
9South FK. Flathead River1.8
9South FK. Flathead River1.8
10Flathead at Columbia Falls1.2
10Flathead at Columbia Falls1.2
11Stillwater/Whitefish Rivers0.7
11Stillwater/Whitefish Rivers0.7
12Swan River-1.4
12Swan River-1.4
13Flathead River at Polson1
13Flathead River at Polson1
14Mission Valley1.4
14Mission Valley1.4
15Little Bitterroot River0.2
15Little Bitterroot River0.2
16Clark above Missoula1
16Clark above Missoula1
17Blackfoot River0.2
17Blackfoot River0.2
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 River0.8
21Clark Fork River below Flathead River0.8
22Beaverhead River-1.1
22Beaverhead River-1.1
23Ruby River-9.9
23Ruby River-9.9
24Big Hole River-0.1
24Big Hole River-0.1
25Boulder River (Jefferson)0.4
25Boulder River (Jefferson)0.4
26Jefferson River-9.9
26Jefferson River-9.9
27Madison River-0.5
27Madison River-0.5
28Gallatin River-0.7
28Gallatin River-0.7
29Missouri River above Canyon Ferry-9.9
29Missouri River above Canyon Ferry-9.9
30Missouri River below Canyon Ferry-9.9
30Missouri River below Canyon Ferry-9.9
31Smith River0.9
31Smith River0.9
32Sun River0.3
32Sun River0.3
33Teton River0.4
33Teton River0.4
34Birch/Dupuyer-2.6
34Birch/Dupuyer-2.6
35Marias Below Tiber Reservoir0.9
35Marias Below Tiber Reservoir0.9
36Musselshell River-9.9
36Musselshell River-9.9
37Missouri River above Fort Peck-9.9
37Missouri River above Fort Peck-9.9
38Missouri River below Fort Peck-3.8
38Missouri River below Fort Peck-3.8
39Milk River0.1
39Milk River0.1
40Dearborn-0.1
40Dearborn-0.1
41Yellowstone River above Livingston0.4
41Yellowstone River above Livingston0.4
42Shields River-1.2
42Shields River-1.2
43Boulder River (Yellowstone)0.2
43Boulder River (Yellowstone)0.2
44Stillwater River-0.8
44Stillwater River-0.8
45Rock/Red Lodge Creeks-9.9
45Rock/Red Lodge Creeks-9.9
46Clarks Fork River-1.2
46Clarks Fork River-1.2
47Yellowstone River above Bighorn River-0.1
47Yellowstone River above Bighorn River-0.1
48Bighorn River below Bighorn Lake-2.1
48Bighorn River below Bighorn Lake-2.1
49Little Bighorn River-0.3
49Little Bighorn River-0.3
50Yellowstone River below Bighorn River-1
50Yellowstone River below Bighorn River-1
51Tongue River-9.9
51Tongue River-9.9
52Powder River-2
52Powder River-2
53Upper Judith River-9.9
53Upper Judith River-9.9
54Saint Mary River1
54Saint Mary River1