Why does Joliet need a new water source?   

Joliet’s current water source, the deep sandstone aquifer, is not sustainable and will no longer be able to meet the City’s Maximum Day Demands by 2030. Knowing this, the City of Joliet evaluated multiple new alternative water sources over the course of 2018 and 2019 as part of the Phase I and Phase II Alternative Water Source Studies. The City explored the potential use of the Illinois, Kankakee, Des Plaines, and Fox Rivers as well as Lake Michigan to identify which had the potential for use as a sustainable, reliable water source for the City and region. Options were ruled out due to the inability to provide sufficient and consistent quantities of water and potential challenges in meeting future water quality requirements. Based on the results of those studies and significant public input, the Joliet City Council selected Lake Michigan as their new water source in January 2020.  The efforts in 2020 have been focused on refining the two remaining alternatives (Lake Michigan Water – Chicago Department of Water Management and Lake Michigan Water – New Indiana Intake) to allow for City Council selection of a new water source alternative in January 2021.

Is it possible for Joliet to avoid the need for an alternative water source by conserving water?

No. While Joliet is taking major steps to conserve water now and over the next decade, no amount of conservation will make the deep ground aquifer sustainable. A new water source will still be necessary.

Why doesn’t the City of Joliet use the Des Plaines River for their new water source? 

Or the Kankakee or Illinois Rivers?

The Des Plaines River was evaluated as a raw water source in the Phase I Study. The analysis determined that significant testing and piloting would be required by the Illinois Environmental Protection Agency to prove that the river could be a viable water source and prove that it could be reliably treated to drinking water standards.  Given the potential influence of upstream wastewater and stormwater discharges and its relatively low raw water quality, the Des Plaines River was not evaluated further.

The Kankakee River was evaluated as a raw water source in the Phase I and Phase II Studies.  Given minimum low flow requirements restricting use of the river during periods of drought, which became more stringent between the Phase I and Phase II Studies, it was determined that reliance on the Kankakee River would limit the future growth potential of the City of Joliet and could not supply the demands of the region; therefore, the Kankakee River was not recommended as a viable raw water source.

The Illinois River was evaluated as a raw water source in the Phase I and Phase II Studies.  Through the Phase II Study, it was determined that the quantity of water in the river could be sufficient for Joliet, future growth, and the region.  Given the seasonal variability of the raw water quality and concerns by some residents about potential contaminant discharges into the river, the City Council decided not to select the Illinois River but instead selected Lake Michigan water.


How does Joliet get approval to use Lake Michigan water? Would this include water for the surrounding region or just Joliet? Does this application impact other Great Lakes states or involve the Great Lakes Compact?

All users of Lake Michigan water in Illinois must obtain a permit from the Illinois Department of Natural Resources (IDNR) for an allocation of Lake Michigan water.  Joliet has applied for a permit in Class 1B, which is for users who will provide relief to the Cambrian-Ordovician aquifer located below northeastern Illinois.  Joliet’s permit would only apply to Joliet’s needs. Other municipalities looking to switch to Lake Michigan water must apply for their own permits from the IDNR. Communities currently utilizing Lake Michigan water – either directly or through purchases from the City of Chicago Department of Water Management – could continue to do so without further permitting.

Because Joliet is requesting use of a portion of Illinois’ existing authorized diversion of water within Illinois, the requirements of the Great Lakes Compact do not apply in this situation. Regardless of where the intake is for Joliet to access water, the water will be treated and used in Illinois. For this reason, only the rules of Illinois’ diversion program apply.


How will this affect my water bill and when will water rate increases begin?

Joliet has a combined utility bill which includes water, sewer and garbage services.  Assuming an average residential water usage of 700 cubic feet, the current average monthly utility bill in 2020 is approximately $100.  In the current average monthly utility bill, the portion for water is approximately $34. 




















In order to support the water program implementation as well as general water system improvements, in 2030 the average monthly water bill is projected to increase to between $90 and $93 if Joliet proceeds independently and between $75 and $79 dollars under a regional option.  The anticipated monthly average water bill between 2020 and 2040 for the implementation of the 30 MGD Scenario is shown on the following graph.


























Note that the City Council has already approved water rate increases in the amount of 10.5% annually on November 1, 2020 and November 1, 2021.  Additional annual water rate increases vary depending on alternative selected and whether Joliet proceeds independently or under a regional option.  The rate increases below are based on anticipated funding requirements for each alternatives and will be subject to further refinement and City Council approval. The anticipated annual water rate increases between 2020 and 2040 for the implementation of the 30 MGD Scenario are shown on the following graph.


chart 1.png
chart 2.png
City of Joliet.jpg