Idaho Drought and Surface Water Supply Index (SWSI)

• SWSI Explanation
• SWSI Calculation Procedure

The following documents require Adobe Acrobat.

2010 Snowpack & Streamflow Needed for Adequate Irrigation Supply as of 10/14/2009 (36KB)
2009 Snowpack & Streamflow Needed for Adequate Irrigation Supply as of 10/15/2008 (66KB)

• US Drought Monitor - Map of Current Drought Status -Updated weekly
• NRCS Snowpack/Drought Monitor Weekly Update Reports -Updated weekly
• US Seasonal Drought Outlook - Map -Updated monthly

Individual Basin Products - SWSI Tables and Graphs

Panhandle Region

• The following document requires Adobe Acrobat.
  
   Panhandle SWSI

Clearwater River Basin

• Monthly Graph of Snow, Reservoir and Streamflow for Recent Years -Updated monthly

  SWSI Tables 1971-present require Adobe Acrobat.

  Jan

  Feb

  Mar

  Apr

  May

  Jun

  Jul

  Aug

  Sep

  Oct-Sep

• Graphs - Reservoir and Streamflow - 1971 to present, and Historic

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

• Dworshak Reservoir Inflow Forecast Graphs, 2002 - Present
• Annual Streamflow - Historic Data - 1, 2, 3, 4, 6, 8, 10 Year Total

1yr

2yr

3yr

4yr

6yr

8yr

10yr

Salmon River Basin

• Monthly Graph of Snow, Reservoir and Streamflow for Recent Years -Updated monthly

  SWSI Tables 1971-present require Adobe Acrobat.

  Jan

  Feb

  Mar

  Apr

  May

  Jun

  Jul

  Aug

  Sep

  Oct-Sep

• Graphs - Reservoir and Streamflow - 1971 to present, and Historic

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

• Streamflow Forecast Graphs, 2002 - Present
• Annual Streamflow - Historic Data - 1, 2, 3, 4, 6, 8, 10 Year Total

1yr

2yr

3yr

4yr

6yr

8yr

10yr

• Moose Creek Precipitation   Monthly
• Mill Creek Summit Precipitaton   Monthly  

Weiser, Payette, Boise River Basins

• Weiser Basin

  • Monthly Graph of Snow and Streamflow for Recent Years -Updated monthly

    SWSI Tables 1971-present require Adobe Acrobat.

    Jan

    Feb

    Mar

    Apr

    May

    Jun

    Jul

    Aug

    Sep

    Oct-Sep

  • Graphs - Streamflow - 1971 to present, and Historic

  Jan

  Feb

  Mar

  Apr

  May

  Jun

  Jul

  Aug

  Sep

• Streamflow Forecast Graphs, 2002 - Present
• Annual Streamflow - Historic Data - 1, 2, 3, 4, 6, 8, 10 Year Total

1yr

2yr

3yr

4yr

6yr

8yr

10yr

• Payette Basin

  • Monthly Graph of Snow, Reservoir and Streamflow for Recent Years -Updated monthly

    SWSI Tables 1971-present require Adobe Acrobat.

    Jan

    Feb

    Mar

    Apr

    May

    Jun

    Jul

    Aug

    Sep

    Oct-Sep

  • Graphs - Reservoir and Streamflow - 1971 to present, and Historic

  Jan

  Feb

  Mar

  Apr

  May

  Jun

  Jul

  Aug

  Sep

• Streamflow Forecast Graphs, 2002 - Present
• Annual Streamflow - Historic Data - 1, 2, 3, 4, 6, 8, 10 Year Total

1yr

2yr

3yr

4yr

6yr

8yr

10yr

• Deadwood Summit Precipitation   Monthly   Annual Departure



• Boise Basin

  • Monthly Graph of Snow, Reservoir and Streamflow for Recent Years -Updated monthly

    SWSI Tables 1971-present require Adobe Acrobat.

    Jan

    Feb

    Mar

    Apr

    May

    Jun

    Jul

    Aug

    Sep

    Oct-Sep

    2010 Amount Needed

  • Graphs - Reservoir and Streamflow - 1971 to present, and Historic

  Jan

  Feb

  Mar

  Apr

  May

  Jun

  Jul

  Aug

  Sep

• Streamflow Forecast Graphs, 2002 - Present
• Annual Streamflow - Historic Data - 1, 2, 3, 4, 6, 8, 10 Year Total

1yr

2yr

3yr

4yr

6yr

8yr

10yr

• Prairie Precipitation   Monthly
• Trinity Mountain Precipitation   Monthly

Wood and Lost River Basins

• Big Wood Basin

  • Monthly Graph of Snow, Reservoir and Streamflow for Recent Years -Updated monthly

    SWSI Tables 1971-present require Adobe Acrobat.

    Jan

    Feb

    Mar

    Apr

    May

    Jun

    Jul

    Aug

    Sep

    Oct-Sep

    2010 Amount Needed

  • Graphs - Reservoir and Streamflow - 1971 to present, and Historic

  Jan

  Feb

  Mar

  Apr

  May

  Jun

  Jul

  Aug

  Sep

• Streamflow Forecast Graph, 2002 - Present
• Annual Streamflow - Historic Data - 1, 2, 3, 4, 6, 8, 10 Year Total

1yr

2yr

3yr

4yr

6yr

8yr

10yr

• Hyndman Precipitation   Monthly



• Little Wood Basin

  • Monthly Graph of Snow and Streamflow for Recent Years -Updated monthly

    SWSI Tables 1971-present require Adobe Acrobat.

    Jan

    Feb

    Mar

    Apr

    May

    Jun

    Jul

    Aug

    Sep

    Oct-Sep

    2010 Amount Needed

  • Graphs - Streamflow - 1971 to present, and Historic

  Jan

  Feb

  Mar

  Apr

  May

  Jun

  Jul

  Aug

  Sep

• Streamflow Forecast Graphs, 2002 - Present
• Annual Streamflow - Historic Data - 1, 2, 3, 4, 6, 8, 10 Year Total

1yr

2yr

3yr

4yr

6yr

8yr

10yr




• Big Lost Basin

  • Monthly Graph of Snow, Reservoir and Streamflow for Recent Years -Updated monthly

    SWSI Tables 1971-present require Adobe Acrobat.

    Jan

    Feb

    Mar

    Apr

    May

    Jun

    Jul

    Aug

    Sep

    Oct-Sep

    2010 Amount Needed

  • Graphs - Reservoir and Streamflow - 1971 to present, and Historic

  Jan

  Feb

  Mar

  Apr

  May

  Jun

  Jul

  Aug

  Sep

• Streamflow Forecast Graphs, 2002 - Present
• Annual Streamflow - Historic Data - 1, 2, 3, 4, 6, 8, 10 Year Total

1yr

2yr

3yr

4yr

6yr

8yr

10yr




• Little Lost Basin

  • Monthly Graph of Snow, Reservoir and Streamflow for Recent Years -Updated monthly

    SWSI Tables 1971-present require Adobe Acrobat.

    Jan

    Feb

    Mar

    Apr

    May

    Jun

    Jul

    Aug

    Sep

    Oct-Sep

    2010 Amount Needed

  • Graphs - Reservoir and Streamflow - 1971 to present, and Historic

  Jan

  Feb

  Mar

  Apr

  May

  Jun

  Jul

  Aug

  Sep

• Streamflow Forecast Graphs, 2002 - Present
• Annual Streamflow - Historic Data - 1, 2, 3, 4, 6, 8, 10 Year Total

1yr

2yr

3yr

4yr

6yr

8yr

10yr

• Moonshine Precipitation   Monthly

Upper Snake River Basins

•   Henrys Fork

  • SWSI Tables 1971-present require Adobe Acrobat.

    Jan

    Feb

    Mar

    Apr

    May

    Jun

    
    

  • Streamflow Forecast Graph, 2006 - Present
  
  

    Teton River

  • Monthly Graph of Snow, Reservoir and Streamflow for Recent Years -Updated monthly

    SWSI Tables 1971-present require Adobe Acrobat.

    Jan

    Feb

    Mar

    Apr

    May

    Jun

    Jul

    Aug

    Sep

    Oct-Sep

  • Graphs - Reservoir and Streamflow - 1971 to present, and Historic

  Jan

  Feb

  Mar

  Apr

  May

  Jun

  Jul

  Aug

  Sep

• Streamflow Forecast Graph, 2002 - Present
• Annual Streamflow - Historic Data - 1, 2, 3, 4 Year Total

1yr

2yr

3yr

4yr




• Snake River near Heise

  • Monthly Graph of Snow, Reservoir and Streamflow for Recent Years -Updated monthly

    SWSI Tables 1971-present require Adobe Acrobat.

    Jan

    Feb

    Mar

    Apr

    May

    Jun

    Jul

    Aug

    Sep

    Oct-Sep

    2010 Amount Needed

  • Graphs - Reservoir and Streamflow - 1971 to present, and Historic

  Jan

  Feb

  Mar

  Apr

  May

  Jun

  Jul

  Aug

  Sep

• Streamflow Forecast Graphs, 2002 - Present
• Annual Streamflow - Historic Data - 1, 2, 3, 4, 6, 8, 10 Year Total

1yr

2yr

3yr

4yr

6yr

8yr

10yr

• Sheep Mountain Precipitation   Monthly   Annual Departure
• Lewis Lake Divide Precipitation   Monthly

Southside Snake River Basins

• Oakley Basin

  • Monthly Graph of Snow, Reservoir and Streamflow for Recent Years -Updated monthly

    SWSI Tables 1971-present require Adobe Acrobat.

    Jan

    Feb

    Mar

    Apr

    May

    Jun

    Jul

    Aug

    Sep

    Oct-Sep

    2010 Amount Needed

  • Graphs - Reservoir and Streamflow - 1971 to present, and Historic

  Jan

  Feb

  Mar

  Apr

  May

  Jun

  Jul

  Aug

  Sep

• Streamflow Forecast Graphs, 2002 - Present
• Annual Streamflow - Historic Data - 1, 2, 3, 4, 6, 8, 10 Year Total

1yr

2yr

3yr

4yr

6yr

8yr

10yr

• Howell Canyon Precipitation   Monthly
• Magic Mountain Precipitation   Monthly   Annual Departure



• Salmon Falls Basin

  • Monthly Graph of Snow, Reservoir and Streamflow for Recent Years -Updated monthly

  • SWSI Tables 1971-present require Adobe Acrobat.

    Jan

    Feb

    Mar

    Apr

    May

    Jun

    Jul

    Aug

    Sep

    Oct-Sep

    2010 Amount Needed

  • Graphs - Reservoir and Streamflow - 1971 to present, and Historic

  Jan

  Feb

  Mar

  Apr

  May

  Jun

  Jul

  Aug

  Sep

  • Streamflow Forecast Graphs, 2002 - Present
  • Annual Streamflow - Historic Data - 1, 2, 3, 4, 6, 8, 10 Year Total

  1yr

  2yr

  3yr

  4yr

  6yr

  8yr

  10yr

  • Salmon Falls Allotment 2008 - Requires Adobe Acrobat.

    Apr (25 KB)

    May (26 KB)

  
  

• Bruneau Basin

  • Monthly Graph of Snow and Streamflow for Recent Years -Updated monthly

    SWSI Tables 1971-present require Adobe Acrobat.

    Jan

    Feb

    Mar

    Apr

    May

    Jun

    Jul

    Aug

    Sep

    Oct-Sep

  • Graphs - Streamflow - 1971 to present, and Historic

  Jan

  Feb

  Mar

  Apr

  May

  Jun

  Jul

  Aug

  Sep

  • Streamflow Forecast Graphs, 2002 - Present
  • Annual Streamflow - Historic Data - 1, 2, 3, 4, 6, 8, 10 Year Total

  1yr

  2yr

  3yr

  4yr

  6yr

  8yr

  10yr

  Owyhee Basin

  • Monthly Graph of Snow and Streamflow for Recent Years -Updated monthly

    SWSI Tables 1971-present require Adobe Acrobat.

    Jan

    Feb

    Mar

    Apr

    May

    Jun

    Jul

    Aug

    Sep

    Oct-Sep

  • Graphs - Streamflow - 1971 to present, and Historic

  Jan

  Feb

  Mar

  Apr

  May

  Jun

  Jul

  Aug

  Sep

  • Streamflow Forecast Graphs, 2009 - Present

Bear River Basin


• Monthly Graph of Snow, Reservoir and Streamflow for Recent Years -Updated monthly

  SWSI Tables 1971-present require Adobe Acrobat.

  Jan

  Feb

  Mar

  Apr

  May

  Jun

  Jul

  Aug

  Sep

  Oct-Sep

  2010 Amount Needed

• Graphs - Reservoir and Streamflow - 1971 to present, and Historic

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

• Streamflow Forecast Graphs, 2002 - Present
• Annual Streamflow - Historic Data - 1, 2, 3, 4, 6, 8, 10 Year Totals

1yr

2yr

3yr

4yr

6yr

8yr

10yr

• Oxford Summit Precipitation   Monthly

Last Modified: 02/05/2010