January 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
2Tobacco-2.3
2Tobacco-2.3
3Kootenai to Libby Dam-1
3Kootenai to Libby Dam-1
4Kootenai River below Libby Dam-0.2
4Kootenai River below Libby Dam-0.2
5Fisher River-1.2
5Fisher River-1.2
6Yaak River-0.6
6Yaak River-0.6
7North FK. Flathead River-2
7North FK. Flathead River-2
8Middle FK. Flathead River-0.9
8Middle FK. Flathead River-0.9
9South FK. Flathead River0.4
9South FK. Flathead River0.4
10Flathead at Columbia Falls-0.6
10Flathead at Columbia Falls-0.6
11Stillwater/Whitefish Rivers0
11Stillwater/Whitefish Rivers0
12Swan River-1.7
12Swan River-1.7
13Flathead River at Polson-1.8
13Flathead River at Polson-1.8
14Mission Valley-2.8
14Mission Valley-2.8
15Little Bitterroot River1.6
15Little Bitterroot River1.6
16Clark above Missoula-0.3
16Clark above Missoula-0.3
17Blackfoot River-0.6
17Blackfoot River-0.6
18Clark Fork above Missoula-1.6
18Clark Fork above Missoula-1.6
19Bitterroot River0
19Bitterroot River0
20Clark Fork River below Bitterroot River-1.1
20Clark Fork River below Bitterroot River-1.1
21Clark Fork River below Flathead River-1.6
21Clark Fork River below Flathead River-1.6
22Beaverhead River0.4
22Beaverhead River0.4
23Ruby River-0.6
23Ruby River-0.6
24Big Hole River-1
24Big Hole River-1
25Boulder River (Jefferson)0.2
25Boulder River (Jefferson)0.2
26Jefferson River0.6
26Jefferson River0.6
27Madison River-0.5
27Madison River-0.5
28Gallatin River-0.8
28Gallatin River-0.8
29Missouri River above Canyon Ferry0.1
29Missouri River above Canyon Ferry0.1
30Missouri River below Canyon Ferry-0.1
30Missouri River below Canyon Ferry-0.1
31Smith River2.7
31Smith River2.7
32Sun River0
32Sun River0
33Teton River1.2
33Teton River1.2
34Birch/Dupuyer1.2
34Birch/Dupuyer1.2
35Marias Below Tiber Reservoir2.1
35Marias Below Tiber Reservoir2.1
36Musselshell River0.6
36Musselshell River0.6
37Missouri River above Fort Peck0.6
37Missouri River above Fort Peck0.6
38Missouri River below Fort Peck-0.2
38Missouri River below Fort Peck-0.2
39Milk River1.6
39Milk River1.6
40Dearborn-0.3
40Dearborn-0.3
41Yellowstone River above Livingston0.1
41Yellowstone River above Livingston0.1
42Shields River-2.3
42Shields River-2.3
43Boulder River (Yellowstone)-1.1
43Boulder River (Yellowstone)-1.1
44Stillwater River-0.8
44Stillwater River-0.8
45Rock/Red Lodge Creeks1.7
45Rock/Red Lodge Creeks1.7
46Clarks Fork River0.5
46Clarks Fork River0.5
47Yellowstone River above Bighorn River-0.1
47Yellowstone River above Bighorn River-0.1
48Bighorn River below Bighorn Lake0.2
48Bighorn River below Bighorn Lake0.2
49Little Bighorn River2
49Little Bighorn River2
50Yellowstone River below Bighorn River0
50Yellowstone River below Bighorn River0
51Tongue River2.8
51Tongue River2.8
52Powder River1.7
52Powder River1.7
53Upper Judith River1.7
53Upper Judith River1.7
54Saint Mary River1.3
54Saint Mary River1.3