Where are major western reservoirs showing the strongest combined
storage and drought stress?
This screening map combines daily Bureau of Reclamation storage for
six operationally significant reservoirs with current U.S. Drought
Monitor intensity and state population/social-vulnerability context.
It does not estimate legal water allocations, municipal
days-of-supply, or downstream service areas.
Data health
Reclamation RISE storageLoading
U.S. Drought MonitorLoading
CDC population / SVILoading
Loading primary signal…
Shortage attention score
Seasonal storage stress = 50 × (1 − seasonal percentile / 100)
30-day
decline stress = 15 × clamp(−Δ30d% / 10, 0, 1)
Drought stress =
20 × D / 4, where D = 0…4
Exposure context = 10 ×
clamp((log10(pop) − 5) / 2, 0, 1)
Vulnerability = 5 ×
population-weighted SVI
Attention score = sum, capped at 100
The seasonal percentile compares the latest storage with
observations within ±21 calendar days of the same date during the
prior 10 years. The score is a MitchellCo screening metric, not an
official Reclamation or drought-shortage designation.
