Colorado Surface Water Supply Index by Hydrologic Unit

Colorado's Surface Water Supply Index (SWSI) compares current basin water volumes against historical data for the same month. The dataset provides sub-basin-level calculations including streamflow, forecasts, and reservoir storage components. It is published by data.colorado.gov and was last updated in April 2026.

Use Cases

• Forecast drought severity by training models on Component Volume and Component NEP against historical Report Month and Report Year data.
• Analyze seasonal water availability trends by correlating Component Type (streamflow, forecast, storage) with Basin and Report Month.
• Compare water supply conditions across HUC8 sub-basins using Component Volume and HUC8 Name as spatial grouping keys.
• Assess reservoir storage contribution to the overall index by filtering Component Type and analyzing time-series data.

Strengths

• Provides sub-basin-level granularity via HUC8 and HUC8 Name identifiers.
• Includes multiple calculation components (Component Type) such as streamflow, forecast, and reservoir storage.
• Data is regularly maintained, with a last update in April 2026.

Limitations

• Unknown total row count and dataset size limits assessment of statistical power.
• Geographic scope is restricted solely to Colorado's river basins.
• Sample data is unavailable to preview data quality and distributions.

Provenance

Source

data.colorado.gov

Collection Method

Calculated from components including streamflow, streamflow forecasts, and reservoir storage volumes.

Freshness

Updated April 2026.

Geography

Colorado river basins and sub-basins.