August 2012
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-2
1Marias Above Tiber Reservoir-2
2Tobacco4
2Tobacco4
3Kootenai to Libby Dam4
3Kootenai to Libby Dam4
4Kootenai River below Libby Dam4
4Kootenai River below Libby Dam4
5Fisher River2.6
5Fisher River2.6
6Yaak River4
6Yaak River4
7North FK. Flathead River3.8
7North FK. Flathead River3.8
8Middle FK. Flathead River2.2
8Middle FK. Flathead River2.2
9South FK. Flathead River1.1
9South FK. Flathead River1.1
10Flathead at Columbia Falls2
10Flathead at Columbia Falls2
11Stillwater/Whitefish Rivers0
11Stillwater/Whitefish Rivers0
12Swan River2.9
12Swan River2.9
13Flathead River at Polson3.3
13Flathead River at Polson3.3
14Mission Valley2.3
14Mission Valley2.3
15Little Bitterroot River3.4
15Little Bitterroot River3.4
16Clark above Missoula-0.4
16Clark above Missoula-0.4
17Blackfoot River0
17Blackfoot River0
18Clark Fork above Missoula-0.6
18Clark Fork above Missoula-0.6
19Bitterroot River0.5
19Bitterroot River0.5
20Clark Fork River below Bitterroot River-0.3
20Clark Fork River below Bitterroot River-0.3
21Clark Fork River below Flathead River2
21Clark Fork River below Flathead River2
22Beaverhead River-0.6
22Beaverhead River-0.6
23Ruby River-1.3
23Ruby River-1.3
24Big Hole River-1.1
24Big Hole River-1.1
25Boulder River (Jefferson)-1.1
25Boulder River (Jefferson)-1.1
26Jefferson River0.1
26Jefferson River0.1
27Madison River-1
27Madison River-1
28Gallatin River-3.2
28Gallatin River-3.2
29Missouri River above Canyon Ferry-1
29Missouri River above Canyon Ferry-1
30Missouri River below Canyon Ferry-0.5
30Missouri River below Canyon Ferry-0.5
31Smith River0
31Smith River0
32Sun River-0.2
32Sun River-0.2
33Teton River-1.3
33Teton River-1.3
34Birch/Dupuyer-0.7
34Birch/Dupuyer-0.7
35Marias Below Tiber Reservoir0.8
35Marias Below Tiber Reservoir0.8
36Musselshell River-1.5
36Musselshell River-1.5
37Missouri River above Fort Peck-0.3
37Missouri River above Fort Peck-0.3
38Missouri River below Fort Peck0.2
38Missouri River below Fort Peck0.2
39Milk River2.2
39Milk River2.2
40Dearborn-3.5
40Dearborn-3.5
41Yellowstone River above Livingston-1.6
41Yellowstone River above Livingston-1.6
42Shields River-3.4
42Shields River-3.4
43Boulder River (Yellowstone)-0.4
43Boulder River (Yellowstone)-0.4
44Stillwater River-2
44Stillwater River-2
45Rock/Red Lodge Creeks-2.9
45Rock/Red Lodge Creeks-2.9
46Clarks Fork River0.5
46Clarks Fork River0.5
47Yellowstone River above Bighorn River-1.2
47Yellowstone River above Bighorn River-1.2
48Bighorn River below Bighorn Lake-1.6
48Bighorn River below Bighorn Lake-1.6
49Little Bighorn River-2.6
49Little Bighorn River-2.6
50Yellowstone River below Bighorn River-1.4
50Yellowstone River below Bighorn River-1.4
51Tongue River-0.8
51Tongue River-0.8
52Powder River-2.7
52Powder River-2.7
53Upper Judith River-1.7
53Upper Judith River-1.7
54Saint Mary River3.1
54Saint Mary River3.1
999Kootenai at Ft. Steele0
999Kootenai at Ft. Steele0