Skip to main content

Attention hunters: Visit our FAQ page for information about the use of centerfire, single-shot rifles for deer hunting in Illinois. 

Water Supply


Adequate and reliable supplies of clean water are critical to all Illinois residents, Illinois Business and Industry, and to Illinois’ aquatic ecosystems. The Illinois Department of Natural Resources, Office of Water Resources is charged “to study and investigate ways and means by which the various water uses may be coordinated to the end that the water resources of the State be put to their maximum beneficial use and, in connection therewith, to request any department or agency of the State to make surveys, studies, investigations, prepare plans, reports and furnish such data and information as may be necessary.” (20 ILCS 801/5-10(a))

Permits for water withdrawal

Permits are not required for the sole activity of withdrawing water from a ground or surface water source. If the withdrawal involves construction of a permanent intake structure in a public body of water or in the floodway of a stream regulated under IDNR/OWR’s floodway construction rules, a permit will be required per the Rivers, Lakes, & Streams Act (615 ILCS 5). Permits authorizing construction of intake structures in public bodies of water will generally be subject to special conditions restricting the withdrawal of water during periods of low flow to prevent adverse effects on navigation, natural resources or other public interests in the public body of water.

Annual reporting of withdrawals is mandatory in Illinois that pump at a rate of 70 gallons per minute or greater (100,000 gallons per day) per the Water Use Act of 1983 (525 ILCS 45). For more information, please see the Illinois Water Inventory Program webpage.


The State of Illinois is guiding regional efforts to properly plan for the adequate quantity and quality of water for all users by creating, maintaining and implementing Regional Water Supply Planning Committees (RWSPC). The RWSPCs consists of water supply representative of public water supply, power generation, industrial, commercial, irrigation, livestock, and environmental interests. The Illinois State Water Survey (ISWS) develops water demand and water supply reports for each region. The RWSPC reviews and provides input on the reports and then develops a regional water supply planning report addressing the shortages, conflicts, conservation measures and other recommendations. Following the report publication, the RWSPC implements the recommendations listed in their report.

Current Status:

Three RWSPCs, Northeastern, East-Central and Kaskaskia, have completed their regional water supply plan. The Illinois State Water Survey has developed water demand reports for the Middle Illinois region, the Rock River region and the Kankakee sub-region. These documents are more can be found on the ISWS water supply planning website .

Lake Michigan Allocation Program

The Illinois Lake Michigan Water Allocation Program (Program) was developed to manage Illinois’ diversion of water from Lake Michigan in response to a 1967 Supreme Court Decree amended in 1980. This Decree limits Illinois’ diversion to 3,200 cfs based on a 40-year running average. The program is authorized by the “LEVEL OF LAKE MICHIGAN ACT” [615 ILCS 50] and is implemented by the IDNR/OWR’s Lake Michigan Management Section using its Part 3730 Rules “ALLOCATION OF WATER FROM LAKE MICHIGAN”. These rules were updated in November 2014.

The objectives, or goals, of Illinois' allocation program can be summarized as follows:

  • To make the greatest amount of Lake Michigan water available for domestic water supply.
  • To use Lake Michigan water allocations as a tool to preserve groundwater resources for communities in northeastern Illinois who will not have access to a Lake Michigan water supply.
  • To make long-term allocations so that communities receiving an allocation for the first time can secure the needed financing to construct regional water distribution systems.
  • To carefully consider the competing needs of all water users in the region so that allocations promote the efficient development of water supplies in the region in light of long-range needs and objectives.
  • To require all users of Lake Michigan water to conserve and manage this resource.

Additional information on the Lake Michigan Water Allocation Program can be found in the Department’s Part 3730 Rules.


Lake Michigan

Russell G. Flinchum
Lake Michigan Management Section
160 N. LaSalle Street, Suite S-703, Chicago, IL 60601
(312) 814-9694 (312) 793-5968 fax

Other Water Supply Issues

Wes Cattoor, P.E., CFM
Water Supply Engineer
One Natural Resources Way, Springfield, IL 62702-1271
(217) 782-4847 FAX (217) 785-5014

Water Supply Resources