Surface Water Supply Index (SWSI)
A Surface Water Supply Index (SWSI) is a predictive indicator of the surface water available in a basin compared to historic supply. The SWSI is calculated by summing the two major sources of irrigation water supply; reservoir carryover and spring and summer streamflow runoff. These two sources are analyzed together when determining the total surface water supply available for the season.
Drought Related Links
- US Drought Monitor - Map of Current Drought Status (Updated weekly)
- Snowpack/Drought Monitor Weekly Update Reports (Updated weekly)
- US Seasonal Drought Outlook - Map (Updated monthly)