Naperville, Illinois Water Outage Today

Naperville water system at a glance

Federal records name Naperville's water system as the public water system for Naperville, with about 156,406 people on its mains. Customers know it as Naperville Department of Public Utilities – Water; the name on your bill is the one to call.

Where Naperville's tap water comes from

Naperville does not collect its own raw water. Naperville's water system buys surface water from Du Page Water Commission and distributes it through its own mains. After treatment the water is held in 14 storage tanks and reservoirs, which is the buffer that keeps taps running for a few hours after a pump or main fails.

The outage angle. Problems can start outside the city: if Du Page Water Commission has to shut a main or its plant, Naperville can run short even though nothing is wrong with the local pipes. Follow alerts from the supplier and from Naperville Department of Public Utilities – Water.

Why the water goes out in Naperville

Water outages are local, so the likely cause depends on weather, pipe age and the grid. For Naperville, these stand out.

• Freezing weather. Naperville sees about 136 days a year with a low at or below 32°F, and 48 days at or below 20°F. The coldest morning in the 2015 through 2025 record came on January 31, 2019. The longest stretch with highs that never rose above freezing ran 19 days, ending March 2, 2015. Frost pushes into shallow service lines first. Mains follow when the ground heaves and thaws, which is why break counts climb a day or two after the temperature swings.
• Flooding and heavy rain. NOAA logged 91 flood, flash flood and heavy rain reports in DuPage County from 2015 through 2026, and 5 days a year bring an inch of rain or more. Floodwater can undercut pipe crossings, swamp pump stations and overload treatment plants, and a notice to boil water often follows when it enters the system.
• Storm-driven power loss. Thunderstorm wind, hail and tornado reports in DuPage County number 323 since 2015. Pump stations and treatment plants that depend on Naperville Electric Utility run on the electric grid, so a storm that downs power lines can lower water pressure even when no pipe is damaged.
• Younger pipe, different risks. Only 10.9% of occupied homes in Naperville predate 1970 (US 35.5%), so more of the network is newer plastic or ductile iron. Breaks tend to come from construction damage, pressure surges and weather rather than age.
• Digging and utility work. Street projects, fiber installation and excavation near buried pipe regularly cut mains in Naperville with no warning, usually on a day with perfectly ordinary weather.
• Planned shutoffs and a problem at one address. Valve replacements and new connections are announced ahead, often with door hangers. If neighbors have water, check your own shutoff valve, meter and pressure regulator before calling.

Naperville weather and water-main stress, 2015–2025

Main break season in Naperville runs from late fall into early spring, with the coldest stretch around December through February.

Because this is gridded reanalysis data, individual hot and cold days can read a few degrees off what the airport recorded. The day counts and yearly patterns are the useful part.

Naperville boil water notices and EPA compliance record

EPA lists no health-based violations for Naperville's water system since 2015. It also lists 17 monitoring or reporting entries that are about paperwork rather than water quality, such as a missed sample or a late report.

Most recent entries, all monitoring or reporting:

• April 2023: A missed or late disinfection byproduct monitoring sample It is marked resolved.
• January 2023: A missed or late monitoring or reporting requirement (chemical and radiological contaminants)

A boil water notice in Naperville is a separate thing from a violation. Naperville Department of Public Utilities – Water issues one when pressure falls low enough for contamination to enter the pipes, after a main break is repaired, or when a routine test comes back positive. The Illinois Environmental Protection Agency (Illinois EPA) oversees the process, and the notice stays until clean samples come back, usually a day or two after pressure returns.

What the lead tests and housing age say about Naperville

The most recent 90th-percentile lead result filed for Naperville's water system is 7.1 ppb (2025). The federal action level is 15 ppb, so that result is comfortably below it.

The age of the housing matters more than the utility's test average: 10.9% of occupied homes in Naperville predate 1970 and 1986 was the year lead pipe and solder were banned. Flush the cold tap after an outage and ask Naperville Department of Public Utilities – Water whether your service line is on its lead inventory.

When will the water come back on in Naperville?

A crew that arrives at an ordinary main break in Naperville usually needs 4 to 8 hours to isolate the pipe, dig, repair, flush and restore pressure. Large transmission mains, deep pipes and breaks under busy streets can take a day or more.

Ask Naperville Department of Public Utilities – Water for a restoration estimate when you report the outage; for large breaks it is normally posted and updated as the repair progresses.

Preparing for a long water outage in Naperville

Census figures put the typical Naperville household at about 2.7 people. At one gallon per person per day that is 8 gallons for three days or 38 gallons for a two-week supply.

• Your water heater tank holds 30 to 50 gallons of clean water. Turn off the power or gas to it first, then drain from the valve at the bottom.
• Fill a tub or large containers early for toilets, cleaning and handwashing, and store drinking water separately in clean bottles.

Water systems near Naperville, side by side

Water outage pages for nearby cities

Aurora, IL · Joliet, IL · Elgin, IL · Chicago, IL