Climatologists define drought as a period of abnormally dry and/or unusually hot weather sufficiently prolonged for the corresponding deficiency of water to cause a "serious hydrologic imbalance". More simply put, too dry and/or too hot for too long. Interpreting what is "too dry" or what is "too long" is difficult. What is known is that when a serious hydrologic imbalance occurs in Minnesota, soil moisture reserves, groundwater supplies, lake levels and stream flows are negatively influenced. Water-dependent industries including agriculture, public utilities, forestry, and tourism are profoundly affected. Although droughts are not as sudden as floods, the economic aspects of droughts can be just as significant.
Because long-term (months/years) climate variations are unpredictable, drought is largely unpredictable. Once a drought commences, it is not known whether it is the sixth month of an eight-month drought or the sixth month of an eight-year drought.
Monitoring drought conditions
Because of the unpredictable character of drought, water resource conditions are monitored (stream flow and lake level for example) and water use is tracked. DNR Waters follows emerging patterns, relying heavily on precipitation departure and precipitation ranking maps and the U. S. Drought Monitor map.
For more information concerning drought monitoring, see our Drought Information Resources page.
DNR Waters Drought Procedures
Although DNR Waters continuously monitors climate and water resources, its "watch" is heightened when key climate and water resource conditions warrant. As stated in the Minnesota Statewide Drought Plan , State, Federal and water users/suppliers begin to act when a significant portion of a watershed is abnormally dry or in a moderate drought, as defined by the U.S. Drought Monitor. The Statewide Drought Plan identifies key resource triggers, agency coordination and mitigation measures, and provides a framework for preparing for and responding to droughts to minimize conflicts and negative impacts on Minnesota's natural resources and economy.
The original Minnesota Statewide Drought Plan was submitted to the Legislature in October of 1990. Learn more about the history of the development of the current plan.
Should conditions warrant, DNR Waters may be required to suspend surface water appropriation permits as dictated by its Surface Water Appropriation Permit Issuance and Suspension Procedures . The DNR Division of Waters may also be involved in well interference resolution.
DNR Waters has played an important role in the development of a Mississippi River Low-Flow Management Plan .
- Protected Flow defined
- Water conservation links
- Drought Planning for Small Community Water Systems (3.3 Mb)
- Protecting Public Health During Drought Conditions
- National Drought Mitigation Center
• What is Drought?
- NOAA's Drought Information Center
- Minnesota's Drought of 1988
- Climate's impact upon water availability in Minnesota