DroughtWatch | Drought & Water-Supply Stress

Where are drought conditions translating into water-supply stress for people and agriculture?

Data health

Waiting for live sources…

How to read this map

Hazard / signal: Meteorological / hydrological drought
Exposure: Population and water demand
Consequence / vulnerability: Water-supply / agricultural stress

Official/source values remain distinct from MitchellCo derived screening scores or estimates. Derived values are for prioritization and interpretation, not official warnings or predictions.

Official weekly drought intensity + current USGS streamflow + county population/social vulnerability. The map separates meteorological/agricultural drought classification from hydrologic observations and from the non-official vulnerability screen.

U.S. Drought Monitorloading…

USGS streamflowloading…

CDC county contextloading…

Region load: waiting…

Three drought lenses

Meteorological/agricultural: USDM D0–D4 is the official broad-scale weekly synthesis and incorporates many indicators and impacts.

Hydrological: USGS points show current discharge in ft³/s. They are operational observations, not labeled low-flow without a historical percentile comparison.

Exposure/vulnerability: CDC SVI and population show where drought coincides with communities potentially less able to absorb disruption.

Layers Official USDM drought polygons USGS current streamflow gauges Derived county vulnerability screen

Highest drought + vulnerability screen

#	County	USDM	Score
Waiting for regional layers…

Derived score, 0–100
USDM: D0=15, D1=30, D2=50, D3=70, D4=85
SVI: +10 × overall SVI percentile rank
population: +min(5, log10(population))
cap at 100.

USGS discharge is deliberately not added to this score because raw ft³/s is not comparable across watersheds. A later version could add a historical flow percentile when a stable nationwide percentile service is verified.

Sources & cadence

U.S. Drought Monitor current FeatureServer: NDMC/USDA/NOAA current D0–D4 polygons. Weekly product; loaded once per selected region. The service exposes release/map dates.

USGS Instantaneous Values Service: parameter 00060, discharge in ft³/s. Browser CORS is supported by USGS. Checked every 30 minutes while visible/online, spatially split into ≤5°×5° cells because USGS limits bounding-box requests to 25 square degrees.

CDC/ATSDR SVI 2022 county layer: county geometry, ACS-derived population, overall SVI percentile rank. Static 2022 vintage; loaded once per selected region.

Omitted: reservoir storage, groundwater percentile, snowpack/SWE and precipitation anomaly are not included in this version because a single nationwide browser-safe/keyless source with comparable current values was not verified during this build. Their absence is shown rather than replaced with synthetic data.

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Map tiles © OpenStreetMap contributors. USDM/NDMC, USDA, NOAA, USGS and CDC/ATSDR data retain their own attribution and terms.