Water Use Data
Effective water supply research, planning, and decision-making require accurate data on how much water is withdrawn, where withdrawals occur, and how water is used. The Illinois Water Inventory Program (IWIP) centralizes this information in a database of high-capacity water wells and intakes. To date, IWIP’s database includes more than 16,000 active and inactive withdrawal points from over 5,600 facilities across Illinois.
IWIP Water Use Reports
IWIP has released several reports summarizing program data. The most recent Water Withdrawals in Illinois report analyzes withdrawals from 2018–2022, with a focus on 2022. The report’s water withdrawal data is presented in gallons and can be accessed in the following spreadsheets:
- Illinois withdrawals by county, 2018–2022
- Illinois Public Water Supply (PWS) withdrawals by county, 2018–2022
- Illinois Self-Supplied Industry (SSI) withdrawals by county, 2018–2022
- Illinois Agricultural Irrigation (IRR) withdrawals by county, 2018–2022
For questions about the latest IWIP report or its data, please contact Cora Wessman, IWIP coordinator.
Applications of IWIP Data
IWIP data support a range of scientific, planning, and regulatory efforts, including:
| Data Use | Description |
|---|---|
| Tracking, Mapping, and Assessing Water Use | IWIP monitors and maps water use by Illinois community water systems, industrial facilities, and irrigators over time. IWIP records are used in tools such as the Illinois EPA’s Source Water Assessment Program tool, which helps visualize water use and vulnerability across the state. |
| Assessing Groundwater Trends and Aquifer Sustainability | IWIP aquifer withdrawal data are used alongside groundwater level observations and estimated recharge (use-to-yield mapping) to assess the health of major aquifers. (See: An Analysis of Groundwater Use to Aquifer Potential Yield in Illinois) For example, comparisons between pumpage and potentiometric surface maps help assess stress on the Cambrian-Ordovician aquifer system. |
| Federal Reporting | Groundwater use data contribute to the U.S. Army Corps of Engineers’ Lake Michigan Diversion Accounting Program. |
| Forecasting Water Demand for Regional Water Supply Planning Efforts | IWIP data support complex models that project future water use — information communities need to plan for long-term sustainability. (See: Kane County Water Resources Investigations) |
| Environmental Response and Risk Assessment | IWIP water use records help assess the impact of environmental hazards, such as toxic spills or contamination events, on both groundwater and surface water sources. |
| Well Impact Assessments | IWIP data inform reviews of how new or existing high-capacity wells may affect nearby users. |
Requesting Data
IWIP water withdrawal data is separated into three categories: public water supply, industrial/commercial, and irrigation. We can provide facility-level or source-level data on public water supply use. Industrial/commercial and irrigation data are considered private data. This data is only available in aggregated county- or watershed-level pumpage totals due to privacy agreements, unless the reporting entity gives us written permission.
Data from 1978 through 2023 are currently available.
If you are interested in using IWIP data, email Cora Wessman, IWIP coordinator, or call 217-333-5838 with a description of the data you are interested in and the purpose of the data request.
For requests specific to wells or intakes and their attribute/location data, contact Bill Saylor at 217-333-9043 or email gwinfo@isws.illinois.edu.