| | An extended period of below-normal precipitation that results in uncommonly low levels of streamflow, shallow groundwater, and/or reservoir storage. Hydrologic drought usually infers some adverse impact, or the threat thereof, to the availability of water for instream and/or offstream uses. For Illinois, a hydrologic drought is typically considered to represent infrequent conditions that may recur on average no more than once in roughly 8-10 years, and, like other types of drought, affects large regions within the State. |
