March 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 Reservoir0.1
1Marias Above Tiber Reservoir0.1
2Tobacco0
2Tobacco0
3Kootenai to Libby Dam0.8
3Kootenai to Libby Dam0.8
4Kootenai River below Libby Dam3.2
4Kootenai River below Libby Dam3.2
5Fisher River-0.4
5Fisher River-0.4
6Yaak River-0.1
6Yaak River-0.1
7North FK. Flathead River0.6
7North FK. Flathead River0.6
8Middle FK. Flathead River0.5
8Middle FK. Flathead River0.5
9South FK. Flathead River1.8
9South FK. Flathead River1.8
10Flathead at Columbia Falls0.8
10Flathead at Columbia Falls0.8
11Stillwater/Whitefish Rivers0
11Stillwater/Whitefish Rivers0
12Swan River0.2
12Swan River0.2
13Flathead River at Polson0.6
13Flathead River at Polson0.6
14Mission Valley0.7
14Mission Valley0.7
15Little Bitterroot River2.1
15Little Bitterroot River2.1
16Clark above Missoula0.9
16Clark above Missoula0.9
17Blackfoot River0.4
17Blackfoot River0.4
18Clark Fork above Missoula0.6
18Clark Fork above Missoula0.6
19Bitterroot River0.7
19Bitterroot River0.7
20Clark Fork River below Bitterroot River0.6
20Clark Fork River below Bitterroot River0.6
21Clark Fork River below Flathead River0.6
21Clark Fork River below Flathead River0.6
22Beaverhead River0.3
22Beaverhead River0.3
23Ruby River-0.6
23Ruby River-0.6
24Big Hole River-0.8
24Big Hole River-0.8
25Boulder River (Jefferson)0.4
25Boulder River (Jefferson)0.4
26Jefferson River0.7
26Jefferson River0.7
27Madison River-0.8
27Madison River-0.8
28Gallatin River-0.8
28Gallatin River-0.8
29Missouri River above Canyon Ferry0.1
29Missouri River above Canyon Ferry0.1
30Missouri River below Canyon Ferry0.2
30Missouri River below Canyon Ferry0.2
31Smith River3.2
31Smith River3.2
32Sun River0.4
32Sun River0.4
33Teton River1.7
33Teton River1.7
34Birch/Dupuyer1.4
34Birch/Dupuyer1.4
35Marias Below Tiber Reservoir2
35Marias Below Tiber Reservoir2
36Musselshell River1.4
36Musselshell River1.4
37Missouri River above Fort Peck1
37Missouri River above Fort Peck1
38Missouri River below Fort Peck0.2
38Missouri River below Fort Peck0.2
39Milk River1.6
39Milk River1.6
40Dearborn0.5
40Dearborn0.5
41Yellowstone River above Livingston0.3
41Yellowstone River above Livingston0.3
42Shields River-0.2
42Shields River-0.2
43Boulder River (Yellowstone)0.1
43Boulder River (Yellowstone)0.1
44Stillwater River-0.8
44Stillwater River-0.8
45Rock/Red Lodge Creeks0.2
45Rock/Red Lodge Creeks0.2
46Clarks Fork River1.2
46Clarks Fork River1.2
47Yellowstone River above Bighorn River0.2
47Yellowstone River above Bighorn River0.2
48Bighorn River below Bighorn Lake0.8
48Bighorn River below Bighorn Lake0.8
49Little Bighorn River2.4
49Little Bighorn River2.4
50Yellowstone River below Bighorn River0.5
50Yellowstone River below Bighorn River0.5
51Tongue River2.9
51Tongue River2.9
52Powder River2.3
52Powder River2.3
53Upper Judith River4
53Upper Judith River4
54Saint Mary River0.7
54Saint Mary River0.7
999Kootenai at Ft. Steele0
999Kootenai at Ft. Steele0