Surface Water Supply Index Report

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:

ID	Basin Name	SWSI
1	Marias River above Tiber Reservoir	0.4
2	Tobacco River	0.9
3	Kootenai Ft. Steele to Libby Dam	0.9
4	Kootenai River below Libby Dam	1.8
5	Fisher River	0
6	Yaak River	0.5
7	North Fk. Flathead River	1
8	Middle Fk. Flathead River	0.5
9	South Fk. Flathead River	3.1
10	Flathead River at Columbia Falls	1.6
11	Stillwater/Whitefish Rivers
12	Swan River	-0.4
13	Flathead River at Polson	0.9
14	Mission Valley
15	Little Bitterroot River
16	Clark Fork River above Milltown	0.7
17	Blackfoot River	0
18	Clark Fork River above Missoula	0
19	Bitterroot River	0.4
20	Clark Fork River below Bitterroot River	0.1
21	Clark Fork River below Flathead River	0.6
22	Beaverhead River	0.2
23	Ruby River	-0.7
24	Big Hole River	0.2
25	Boulder River (Jefferson)	-0.4
26	Jefferson River	0.6
27	Madison River	1
28	Gallatin River	-0.7
29	Missouri River above Canyon Ferry	0
30	Missouri River below Canyon Ferry	0
31	Smith River	0
32	Sun River	0.4
33	Teton River	1
34	Birch/Dupuyer Creeks	-1.9
35	Marias River below Tiber Reservoir	1.7
36	Musselshell River	-1.6
37	Missouri River above Fort Peck	0.4
38	Missouri River below Fort Peck	0.9
39	Milk River
40	Dearborn River near Craig
41	Yellowstone River above Livingston	3.1
42	Shields River	-0.6
43	Boulder River (Yellowstone)	0.4
44	Stillwater River	0.7
45	Rock/Red Lodge Creeks	-0.4
46	Clarks Fork River	3.3
47	Yellowstone River above Bighorn River	2.4
48	Bighorn River below Bighorn Lake	3.8
49	Little Bighorn River	-1
50	Yellowstone River below Bighorn River	3
51	Tongue River	0.4
52	Powder River	0.2
53	Upper Judith Basin	-0.4
54	St. Mary River	1.7

March 2017
Surface Water Supply Index Report

Provided by the US Natural Resources Conservation Service
Bozeman, Montana

March 2017 Surface Water Supply Index Report

Provided by the US Natural Resources Conservation Service Bozeman, Montana

March 2017
Surface Water Supply Index Report

Provided by the US Natural Resources Conservation Service
Bozeman, Montana