Drought Risk Analysis Tool

The Drought Risk Analysis Tool can be used to assess the potential impact of severe drought on Illinois community water supplies, primarily by estimating water yield from each community’s surface water sources.

Potential uncertainties in the estimation of each system’s yield have been analyzed to the extent that confidence limits are placed on yield values. ISWS has designated that, to be considered adequate, a system with 90% confidence must meet the community’s water demand during a severe drought, such as 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.

Information describing the water sources of each surface-water supplied system was originally assembled in ISWS Contract Report 2008-02 and is being updated periodically by ISWS. These studies were supported in part by funding from the Illinois Department of Natural Resources, Office of Water Resources.

Questions?

For questions or comments, please email Wei Dang.