The Lake Michigan Service Area: Drinking Water Provision

As part of the  Water Rate Setting Study , the  Government Finance Research Center (GFRC)  examined the production and provision of drinking water in Northeast Illinois. Whether a municipality produces, i.e., pumps and treats, its own water, or purchases its water wholesale from another utility is key to understanding the rate-setting process. Specifically, although Lake Michigan is the dominant source of drinking water in the region, most communities have limited direct access to its resources. As a result, Lake Michigan's waters are distributed to municipalities through various wholesale supply chains across the Lake Michigan Service Area (LMSA). Thus, the complex dynamics of these supply chains and purchasing relationships shape the rate-setting process in the region.

At the bottom of the page, you can download data, learn about data sources, and access the data dictionary.

Notably, as defined in our study, Northeast Illinois includes seven counties (Cook, DuPage, Lake, McHenry, Kane, Kendall, and Will) and 284 municipalities. Of those 284 municipalities:

• Only 12 municipalities directly pump water from the lake, while 160 municipalities purchase Lake Michigan water
• 7 out of 12 municipalities that directly pump Lake Michigan water also sell water wholesale to other communities
• 18 municipalities that purchase Lake Michigan water also resell Lake Michigan water to other communities
• The majority of communities on groundwater (101 of 108) self-produce and do not engage in wholesale with neighbors

To better understand the provision and production of drinking water in the LMSA, the GFRC researchers created variables based on the  2012 Illinois State Water Survey  provided by the Prairie Research Institute at the University of Illinois Urbana-Champaign, which the GFRC researchers updated to reflect source and network changes, as of 2022, using an extensive review of news articles and various online sources.

All maps on this page allow you to click on a municipality to learn more about its characteristics.

There are two approaches to water provision in the region:

• 117 municipalities in Northeast Illinois get their water by producing it themselves - pumping it from wells, Lake Michigan, or other surface water such as the Fox River.
• A larger share - 161 municipalities - purchase their water from another municipality or utility.

In addition, six communities in the seven-county region do not fit within this categorization. Aurora, unlike other communities, self-produces a majority of its water but still purchases additional water from neighboring North Aurora. Five communities - Bolingbrook, Homer Glen, University Park, Holiday Hills, and Orland Park - have fully privatized systems, regulated by the Illinois Commerce Commission. In these cases, the municipality does not engage in the provision of water to residents. Every step of water delivery including water production or purchasing, distribution, billing, water quality monitoring, and maintenance is handled by a private company.

In general, there are two ways water purchase agreements can be set up:

To the left is an illustration of a series of individual purchasing agreements. Wilmette draws directly from Lake Michigan, treats the water, and sells wholesale to Glenview, who in turn sells to a private utility, who in turn sells to Prospect Heights.

Several communities in the region purchase wholesale water from private producers, but the municipality delivers water to residents (i.e., Plainfield and Prospect Heights).

To the left is an illustration of cooperative purchasing agreements. Evanston draws directly from Lake Michigan, treats the water, and sells wholesale to the Northwest Water Commission (NWC). NWC distributes water amongst its members, which include Buffalo Grove, Wheeling, Palatine, and Arlington Heights. In addition, Des Plaines, a non-member, purchases water from NWC, at a surcharge.

Note that Joliet and its surrounding communities are in the process of transitioning from groundwater to Lake Michigan water due to diminishing aquifers. This will further change the dynamics of the region.

 Download data , learn about  data sources , and access the  data dictionary . For questions, please email  gfrc@uic.edu  .