Water and Wastewater Rates

What Makes Up Your Water and Wastewater Bill

Fixed User Charges

The following fixed water/wastewater user charges are in effect for Naperville Water Utility customers in 2023:

Water Capital Charge

In 2022, a water capital charge appeared for the first time on water customers’ bills. This charge will provide a stable revenue source not based on usage variables, such as weather or conservation trends, for maintenance and capital improvements to the equipment and facilities that deliver water.

For a standard residential 5/8-inch X ¾-inch meter, the flat monthly water capital charges are as follows:


Monthly Charge

2023 $1.02
2024 $1.09

Phosphorus Charge

A graduated phosphorus charge was introduced in 2017 for wastewater customers. These funds will be utilized to fund 50% of the Illinois Environmental Protection Agency-mandated Springbrook Water Reclamation Center improvements to reduce the amount of phosphorus discharged from the facility. Work on the improvements is anticipated to begin in the mid-2020s. The phosphorus surcharge will expire once funds collected are equal to 50% of the cost of improvements.

DuPage Water Commission/City of Chicago Costs

The wholesale water rate on customer bills is a direct pass-through of the water rate charged by the DuPage Water Commission (DWC), the City of Naperville’s water supplier. The wholesale water rate component is determined by the DWC based on the City of Chicago’s water rates.

The DWC sets its wholesale water rate each year in April, to go into effect May 1. The current rate is $3.87 per 100 cubic feet and will remain at this amount through April 30, 2023. 

Unincorporated Customer Surcharge

Unincorporated Naperville water customers pay a 10% surcharge on water rates. These customers' bills will have wholesale, retail and monthly customer service charge rates 10% higher than the rates in the above PDFs, which apply to incorporated Naperville customers.

2023 Water and Wastewater Rates 

Maintaining our Infrastructure

The Naperville Water Utilities periodically conducts rate studies to help plan for upcoming financial needs. The most recent study, conducted in 2021, provided guidance on customer rates through 2024.

Before the rate study, the Water Utilities conducted an asset evaluation to determine if any of its assets required additional funding to meet regulations, reverse undesirable service trends, or proactively replace capital assets to minimize potential customer inconvenience. The asset evaluation showed additional needs in the water main replacement program and Springbrook Water Reclamation Center to maintain service levels and regulatory compliance moving forward.

To address these needs, the 2021 rate study looked at the appropriate level of funding and rate structures to support that funding. Average residential water and wastewater customers will see a 4.7% increase on their bills each year from 2022 to 2024. In 2023, average residential water and wastewater customers will see a $4.61 increase on their combined monthly water and wastewater utility bill. Average commercial customers will see a 4.5% increase in 2023 and 4.6% increase in 2024.

This increase allows the utility to proactively expand its water main replacement to three miles per year to help prevent main breaks. The increase will also support the start of improvements at Springbrook to maintain regulatory compliance. The revenue model developed uses a blended pay-as-you-go (rates) and financing plan, which ultimately keeps rates and charges lower for the customer. Additional support for Springbrook and an associated financial plan will be discussed more in 2023.

2023 and 2024 Residential Rates

An average residential water/wastewater customer uses 750 cubic feet of water per month. A customer with this usage will see the following average monthly utility bills. 

Year Average monthly bill 
2023 $90.79
2024 $95.03