Water School

What are drought classifications?

Every year since 1999, the U.S. Drought Monitor has created maps that include levels of dryness and drought severity.

These maps note different classes of drought severity by colors.

The drought levels include:

  • Yellow - D0, abnormally dry
    • Impacts going into drought - short-term dryness slowing planting, growth of crops or pastures
    • Impacts of coming out of drought - some lingering water deficits and pastures or crops not fully recovering
  • Light Orange – D1, moderate drought
    • Impacts include:
      • Some damage to crops, pastures
      • Streams, reservoirs, or wells low, some water shortages developing or imminent
      • Voluntary water-use restrictions requested
  • Dark Orange – D2, severe drought
    • Impacts include:
      • Crop or pasture losses are likely
      • Water shortages common
      • Water restrictions imposed
  • Red – D3, extreme drought
    • Impacts include:
      • Major crop/pasture losses
      • Widespread water shortages or restrictions
  • Maroon - D4, exceptionally dry
    • Impacts include:
      • Exceptional and widespread crop/pasture losses
      • Shortages of water in reservoirs, streams, and wells creating water emergencies

These maps are used, in particular, by the Brazos River Authority to help determine and assess the drought conditions within the Brazos River basin. They also help determine when, or if, part of a drought contingency plan should be implemented.

Drought classifications and other drought data are tools often used to understand droughts' economic, environmental and social impacts.

Historically, the higher the classification of a drought, the worse the long-term impact it has on an area's environment, people and economy.'

For more information on drought classification and severity, view the video below.


Return to Water School to learn more about water!




The information provided on this site is intended as background on water within the Brazos River basin. There should be no expectation that this information is all encompassing, complete or in any way examines every aspect of this very complex natural resource.

If you have questions about a post or would like additional information, please contact us or call 888-922-6272.

mgd algae sewage bottled water bay hydrology agriculture electric companies habitat TCEQ dam supply use sediment minerals E coli spillway quality precipitation subsidence district flood pool pollutants water planning water code USGS kayak map water plants conservation turbidity storage aerobic solids water quality wildlife farming basin Board hydrilla mission ground water dock insurance fish kill chlorine anaerobic main stem authority brackish lake level taste legislation rain streamflow camping acre-feet hunting boating beneficial use acre-foot reservoir landscaping PAM limestone surface water septic system jobs pharmaceuticals stream smell inundated calcium salt canoeing meta tag speaker mitigation biosolids filter indirect re-use hydropower subsidence gulf aquifer rights medicine gate hydrologic cycle electricity monitor watershed system reservoirs drilling costs corps of engineers chlorides soil treatment channel tributary sludge mainstem well effluent flood control lake industrial sanitation emergency use possum kingdom fertilizer corps environmental allens creek reservoir lake levels employment marsh golden algea riparian inland lawn volume xeriscape golden algae infection septic drinking water organic cfs appropriation gage maps evaporation water treatment canoe lake dissolved solids recreation releases climate gas lakes drought fishing municipal governance wastewater depth water rights fork riverine flood estuary environment impound runoff permit planning wetland oxygen bed and banks agricultural measure contract invasive plants classification streamflow granbury contaminants subwatershed potable salinity groundwater clarity water cycle wetlands river water clarity watercourse water supply E. coli industry spring direct re-use water use water parasite consumption