Drought Vulnerability of Illinois' Community Surface Water Systems, Illinois State Water Survey

Illinois Drought

Drought Vulnerability of Illinois' Community Surface Water Systems

The following contains an assessment of the potential impact of severe drought conditions on Illinois community water supplies, primarily based on the estimation of the water yield provided by each community’s surface water supply sources. Potential uncertainties in the estimation of each system’s yield have been analyzed to the extent where confidence limits are placed on yield values. The ISWS has designated that, to be considered adequate, a system should with 90% confidence be able to fulfill the community’s water demand through a severe drought similar to the historical drought of record. In contrast, previous ISWS yield studies for surface water supplies were characterized by a single estimate of the firm or safe yield, which essentially established roughly a 50% level of confidence. ISWS Contract Report 2007-08 provides a description of the various data uncertainties considered in determining the confidence of a yield estimate. Information describing the water sources of each surface-water supplied system was taken from ISWS Contract Report 2008-02 with selected updates. These studies were supported in part by funding from the Illinois Department of Natural Resources, Office of Water Resources.


Links with a community name (Altamont) will provide system information. The associated vulnerability link will provide that system's drought vulnerability classification.

Altamont   [vulnerability]
Alto Pass Water District   [vulnerability]
Ashland   [vulnerability]
Aurora   [vulnerability]
Blandinsville   [vulnerability]
Bloomington   [vulnerability]
Breese   [vulnerability]
Canton   [vulnerability]
Carbondale   [vulnerability]
Carlinville   [vulnerability]
Carlyle   [vulnerability]
Carthage   [vulnerability]
Centralia   [vulnerability]
Charleston   [vulnerability]
Coulterville   [vulnerability]
Danville (Aqua Illinois)   [vulnerability]
Decatur   [vulnerability]   [detailed analysis]
Effingham   [vulnerability]
Elgin   [vulnerability]
Evansville   [vulnerability]
Fairfield   [vulnerability]
Farina   [vulnerability]
Flora   [vulnerability]
Gateway Regional Water Supply   [vulnerability]
Gillespie   [vulnerability]
Greenfield   [vulnerability]
Greenville   [vulnerability]
Highland   [vulnerability]
Hillsboro   [vulnerability]
Holiday Shores   [vulnerability]
Holland Regional Water Supply   [vulnerability]
Jacksonville   [vulnerability]
Kankakee (Aqua Illinois)   [vulnerability]
Kaskaskia Water District   [vulnerability]
Kinkaid Area Water System   [vulnerability]
Kinmundy   [vulnerability]
La Harpe   [vulnerability]
Lake of Egypt Public Water District   [vulnerability]
Lake Shannon, Inc.   [vulnerability]
Litchfield   [vulnerability]
Macomb   [vulnerability]
Marion   [vulnerability]
Mattoon   [vulnerability]
Mount Olive   [vulnerability]
Nashville   [vulnerability]
Neoga   [vulnerability]
New Berlin   [vulnerability]
Oakwood   [vulnerability]
Olney   [vulnerability]
Otter Lake Water Commission   [vulnerability]
Palmyra-Modesto   [vulnerability]
Pana   [vulnerability]
Paris   [vulnerability]
Peoria (Illinois-American)   [vulnerability]
Pinckneyville   [vulnerability]
Pittsfield   [vulnerability]
Pontiac (Illinois-American)   [vulnerability]
Rend Lake Intercity Water System   [vulnerability]
Salem   [vulnerability]
SLM Water Commission   [vulnerability]
Sparta   [vulnerability]
Springfield   [vulnerability]
Staunton   [vulnerability]
Streator (Illinois-American)   [vulnerability]
Taylorville   [vulnerability]
Vandalia   [vulnerability]
Vermont   [vulnerability]
Vienna   [vulnerability]
Vienna Correctional Center   [vulnerability]
Waverly   [vulnerability]
Wayne City   [vulnerability]
Wilmington   [vulnerability]

Notes and Terminology

Illinois State Water Survey

2204 Griffith Dr., MC-674
Champaign, IL 61820-7463
Email us with questions or comments.


© 2022 University of Illinois Board of Trustees. All rights reserved.
For permissions information, contact the Illinois State Water Survey.
Terms of use | Privacy Policy | Web Administrator.