August 1999
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 Reservoir0.7
1Marias Above Tiber Reservoir0.7
2Tobacco1.9
2Tobacco1.9
3Kootenai to Libby Dam3.2
3Kootenai to Libby Dam3.2
4Kootenai River below Libby Dam1.9
4Kootenai River below Libby Dam1.9
5Fisher River2.8
5Fisher River2.8
6Yaak River3.1
6Yaak River3.1
7North FK. Flathead River1.2
7North FK. Flathead River1.2
8Middle FK. Flathead River0.9
8Middle FK. Flathead River0.9
9South FK. Flathead River0.6
9South FK. Flathead River0.6
10Flathead at Columbia Falls0.9
10Flathead at Columbia Falls0.9
11Stillwater/Whitefish Rivers0.1
11Stillwater/Whitefish Rivers0.1
12Swan River0.1
12Swan River0.1
13Flathead River at Polson0.8
13Flathead River at Polson0.8
14Mission Valley-2.2
14Mission Valley-2.2
15Little Bitterroot River2.8
15Little Bitterroot River2.8
16Clark above Missoula-0.5
16Clark above Missoula-0.5
17Blackfoot River1
17Blackfoot River1
18Clark Fork above Missoula0.3
18Clark Fork above Missoula0.3
19Bitterroot River0.7
19Bitterroot River0.7
20Clark Fork River below Bitterroot River0.4
20Clark Fork River below Bitterroot River0.4
21Clark Fork River below Flathead River0.7
21Clark Fork River below Flathead River0.7
22Beaverhead River0.4
22Beaverhead River0.4
23Ruby River-0.3
23Ruby River-0.3
24Big Hole River-1.5
24Big Hole River-1.5
25Boulder River (Jefferson)-1.2
25Boulder River (Jefferson)-1.2
26Jefferson River-0.4
26Jefferson River-0.4
27Madison River0.4
27Madison River0.4
28Gallatin River-2
28Gallatin River-2
29Missouri River above Canyon Ferry-0.3
29Missouri River above Canyon Ferry-0.3
30Missouri River below Canyon Ferry-0.6
30Missouri River below Canyon Ferry-0.6
31Smith River-1.9
31Smith River-1.9
32Sun River-1.4
32Sun River-1.4
33Teton River-3
33Teton River-3
34Birch/Dupuyer-2.9
34Birch/Dupuyer-2.9
36Musselshell River0.2
36Musselshell River0.2
37Missouri River above Fort Peck1
37Missouri River above Fort Peck1
38Missouri River below Fort Peck0.1
38Missouri River below Fort Peck0.1
39Milk River0.1
39Milk River0.1
41Yellowstone River above Livingston0.7
41Yellowstone River above Livingston0.7
42Shields River-2.7
42Shields River-2.7
43Boulder River (Yellowstone)0.1
43Boulder River (Yellowstone)0.1
44Stillwater River-0.6
44Stillwater River-0.6
45Rock/Red Lodge Creeks0.2
45Rock/Red Lodge Creeks0.2
46Clarks Fork River-0.1
46Clarks Fork River-0.1
47Yellowstone River above Bighorn River0.4
47Yellowstone River above Bighorn River0.4
48Bighorn River below Bighorn Lake1.3
48Bighorn River below Bighorn Lake1.3
49Little Bighorn River0.1
49Little Bighorn River0.1
50Yellowstone River below Bighorn River1.1
50Yellowstone River below Bighorn River1.1
51Tongue River0.9
51Tongue River0.9
52Powder River0.7
52Powder River0.7
999Kootenai at Ft. Steele0
999Kootenai at Ft. Steele0