Western Reservoir Conditions - Daily Data for Teacup Visualization

This resource contains daily CSV files of reservoir storage conditions across the western United States, generated for the Bureau of Reclamation reservoir teacup visualization dashboard. Each file provides current storage values alongside historical statistical benchmarks for 213 reservoirs.

Data Sources

Current storage values are fetched daily from multiple authoritative sources:

Historical statistics are derived from a 30-water-year baseline period: October 1, 1990 through September 30, 2020.

File Naming Convention

droughtData{YYYYMMDD}.csv where the date is the target observation date.

Example: droughtData20260203.csv contains conditions for February 3, 2026.

File Structure

Each CSV contains one row per reservoir location (213 total) with the following columns:

Empty fields indicate data is not available for that location (e.g., reservoirs without historical statistics or without a current reading within the 7-day lookback window).

Update Frequency

Daily. The generating script targets yesterday's date by default and looks back up to 7 days to find the most recent valid measurement for each reservoir.

Processing Workflow

Data is generated by rezviz_data_generator.R in the teacup-generator repository, which:

1. Loads location metadata for all 213 reservoirs from locations.geojson
2. Loads pre-computed historical day-of-year statistics from a Parquet file
3. Queries each reservoir's data source API for the most recent storage value
4. Joins current values with historical percentiles for the target calendar day
5. Computes derived metrics (percent of median, average, and capacity)
6. Writes the output CSV and uploads it to this HydroShare resource

The script is containerized via Docker for reproducible daily runs:

bash docker build -t rezviz . docker run --env-file .env rezviz # yesterday (default) docker run --env-file .env rezviz 2026-01-15 # arbitrary date

Data Quality Notes

• Current values may lag the target date by up to 7 days if recent data is unavailable from the source API.
• Historical statistics are based on the 1990-2020 baseline period. Not all 213 reservoirs have historical data; those without will have empty statistical columns.
• Reservoirs sourced from USACE return sub-daily data; the most recent value for the target date is used.
• CDEC and USGS sources provide daily values.
• The DataUrl column contains the exact API call used, enabling verification of any individual value.

Contact

Kyle Onda, Center for Geospatial Solutions, Lincoln Institute of Land Policy