June 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 Reservoir0.2
1Marias Above Tiber Reservoir0.2
2Tobacco2.7
2Tobacco2.7
3Kootenai to Libby Dam2.5
3Kootenai to Libby Dam2.5
4Kootenai River below Libby Dam3.7
4Kootenai River below Libby Dam3.7
5Fisher River2.4
5Fisher River2.4
6Yaak River3.1
6Yaak River3.1
7North FK. Flathead River1.3
7North FK. Flathead River1.3
8Middle FK. Flathead River1.7
8Middle FK. Flathead River1.7
9South FK. Flathead River3.1
9South FK. Flathead River3.1
10Flathead at Columbia Falls2
10Flathead at Columbia Falls2
11Stillwater/Whitefish Rivers0
11Stillwater/Whitefish Rivers0
12Swan River2.9
12Swan River2.9
13Flathead River at Polson1.4
13Flathead River at Polson1.4
14Mission Valley1.6
14Mission Valley1.6
15Little Bitterroot River2.3
15Little Bitterroot River2.3
16Clark above Missoula1.1
16Clark above Missoula1.1
17Blackfoot River2.4
17Blackfoot River2.4
18Clark Fork above Missoula1.5
18Clark Fork above Missoula1.5
19Bitterroot River1.9
19Bitterroot River1.9
20Clark Fork River below Bitterroot River1.6
20Clark Fork River below Bitterroot River1.6
21Clark Fork River below Flathead River1.5
21Clark Fork River below Flathead River1.5
22Beaverhead River-0.7
22Beaverhead River-0.7
23Ruby River-1
23Ruby River-1
24Big Hole River0.6
24Big Hole River0.6
25Boulder River (Jefferson)-0.1
25Boulder River (Jefferson)-0.1
26Jefferson River0.4
26Jefferson River0.4
27Madison River1.4
27Madison River1.4
28Gallatin River-0.3
28Gallatin River-0.3
29Missouri River above Canyon Ferry0.2
29Missouri River above Canyon Ferry0.2
30Missouri River below Canyon Ferry0.3
30Missouri River below Canyon Ferry0.3
31Smith River2.8
31Smith River2.8
32Sun River1
32Sun River1
33Teton River0.1
33Teton River0.1
34Birch/Dupuyer0.1
34Birch/Dupuyer0.1
35Marias Below Tiber Reservoir0.9
35Marias Below Tiber Reservoir0.9
36Musselshell River0.9
36Musselshell River0.9
37Missouri River above Fort Peck0.4
37Missouri River above Fort Peck0.4
38Missouri River below Fort Peck0.3
38Missouri River below Fort Peck0.3
39Milk River1.2
39Milk River1.2
40Dearborn-1.6
40Dearborn-1.6
41Yellowstone River above Livingston1
41Yellowstone River above Livingston1
42Shields River0.1
42Shields River0.1
43Boulder River (Yellowstone)-1
43Boulder River (Yellowstone)-1
44Stillwater River-0.4
44Stillwater River-0.4
45Rock/Red Lodge Creeks-3.4
45Rock/Red Lodge Creeks-3.4
46Clarks Fork River2.2
46Clarks Fork River2.2
47Yellowstone River above Bighorn River0.8
47Yellowstone River above Bighorn River0.8
48Bighorn River below Bighorn Lake-1.4
48Bighorn River below Bighorn Lake-1.4
49Little Bighorn River-0.8
49Little Bighorn River-0.8
50Yellowstone River below Bighorn River-0.2
50Yellowstone River below Bighorn River-0.2
51Tongue River-1
51Tongue River-1
52Powder River-0.9
52Powder River-0.9
53Upper Judith River1.6
53Upper Judith River1.6
54Saint Mary River2.4
54Saint Mary River2.4
999Kootenai at Ft. Steele0
999Kootenai at Ft. Steele0