January 2013
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-1.3
1Marias Above Tiber Reservoir-1.3
2Tobacco0.8
2Tobacco0.8
3Kootenai to Libby Dam0.6
3Kootenai to Libby Dam0.6
4Kootenai River below Libby Dam1.3
4Kootenai River below Libby Dam1.3
5Fisher River1
5Fisher River1
6Yaak River2.7
6Yaak River2.7
7North FK. Flathead River1.3
7North FK. Flathead River1.3
8Middle FK. Flathead River1.6
8Middle FK. Flathead River1.6
9South FK. Flathead River3.1
9South FK. Flathead River3.1
10Flathead at Columbia Falls1.7
10Flathead at Columbia Falls1.7
11Stillwater/Whitefish Rivers0
11Stillwater/Whitefish Rivers0
12Swan River-0.4
12Swan River-0.4
13Flathead River at Polson1.2
13Flathead River at Polson1.2
14Mission Valley-1.6
14Mission Valley-1.6
15Little Bitterroot River1.7
15Little Bitterroot River1.7
16Clark above Missoula0
16Clark above Missoula0
17Blackfoot River0
17Blackfoot River0
18Clark Fork above Missoula0.2
18Clark Fork above Missoula0.2
19Bitterroot River0.1
19Bitterroot River0.1
20Clark Fork River below Bitterroot River0.2
20Clark Fork River below Bitterroot River0.2
21Clark Fork River below Flathead River0.8
21Clark Fork River below Flathead River0.8
22Beaverhead River-0.3
22Beaverhead River-0.3
23Ruby River-0.7
23Ruby River-0.7
24Big Hole River-0.9
24Big Hole River-0.9
25Boulder River (Jefferson)-1.2
25Boulder River (Jefferson)-1.2
26Jefferson River0.5
26Jefferson River0.5
27Madison River0.2
27Madison River0.2
28Gallatin River-0.8
28Gallatin River-0.8
29Missouri River above Canyon Ferry0.2
29Missouri River above Canyon Ferry0.2
30Missouri River below Canyon Ferry0.1
30Missouri River below Canyon Ferry0.1
31Smith River1.3
31Smith River1.3
32Sun River-0.4
32Sun River-0.4
33Teton River0.4
33Teton River0.4
34Birch/Dupuyer-2.4
34Birch/Dupuyer-2.4
35Marias Below Tiber Reservoir1.3
35Marias Below Tiber Reservoir1.3
36Musselshell River0.7
36Musselshell River0.7
37Missouri River above Fort Peck0.6
37Missouri River above Fort Peck0.6
38Missouri River below Fort Peck-1.1
38Missouri River below Fort Peck-1.1
39Milk River0
39Milk River0
40Dearborn-1
40Dearborn-1
41Yellowstone River above Livingston0.4
41Yellowstone River above Livingston0.4
42Shields River-1.1
42Shields River-1.1
43Boulder River (Yellowstone)0.1
43Boulder River (Yellowstone)0.1
44Stillwater River-0.9
44Stillwater River-0.9
45Rock/Red Lodge Creeks0
45Rock/Red Lodge Creeks0
46Clarks Fork River-0.2
46Clarks Fork River-0.2
47Yellowstone River above Bighorn River0.1
47Yellowstone River above Bighorn River0.1
48Bighorn River below Bighorn Lake-0.3
48Bighorn River below Bighorn Lake-0.3
49Little Bighorn River-3.1
49Little Bighorn River-3.1
50Yellowstone River below Bighorn River-0.1
50Yellowstone River below Bighorn River-0.1
51Tongue River-2
51Tongue River-2
52Powder River-0.5
52Powder River-0.5
53Upper Judith River1.5
53Upper Judith River1.5
54Saint Mary River1.8
54Saint Mary River1.8