Chicago, Illinois Water Outage Today

Who runs the water in Chicago: system profile

The city runs its own public water system, which EPA records show serving roughly 2,721,308 people. Customers know it as Chicago Department of Water Management; the name on your bill is the one to call.

Source water and treatment in Chicago

Chicago drinks surface water. Chicago draws it from rivers, lakes or reservoirs and treats it before it goes into the distribution system. Treatment points named in EPA's facility list include Tp 01-Jardine Plant and Tp 02-Sawyer Plant. After treatment the water is held in 4 storage tanks and reservoirs and pushed uphill by 12 pump facilities; that storage is the buffer that keeps taps running for a few hours after a pump or main fails.

The outage angle. A surface-water system depends on its plant staying online. If the plant, the raw-water pumps or the power feeding them fails, pressure can fall across the entire service area at once, and a precautionary boil notice tends to cover whole zones rather than the single street of a main break.

What causes water outages and low pressure in Chicago

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

• Freezing weather. Chicago sees about 88 days a year with a low at or below 32°F, and 23 days at or below 20°F. The coldest morning in the 2015 through 2025 record came on January 30, 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 286 flood, flash flood and heavy rain reports in Cook County from 2015 through 2026, and 5 days a year bring an inch of rain or more. Flooding is hard on water systems in three ways: it erodes soil around pipe crossings, drowns pumps and electrical equipment, and can let contaminated runoff into the mains, which triggers precautionary boil notices.
• Storm-driven power loss. Thunderstorm wind, hail and tornado reports in Cook County number 1,013 since 2015. Pump stations and treatment plants that depend on ComEd run on the electric grid, so a storm that downs power lines can lower water pressure even when no pipe is damaged.
• Older neighborhoods and pipe. 67.5% of occupied homes in Chicago were built before 1970, against 35.5% nationally. Streets of that age tend to sit on cast iron and early steel mains that are near or past their design life, which is where most breaks start.
• Construction and third-party damage. A backhoe or boring crew that hits a main is among the most common reasons a single block goes dry without warning. Utilities handle those the same way as any break: isolate, repair, flush.
• 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.

Freeze, heat and rain: the Chicago weather record

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

A note on the numbers: they are modeled for the city center and averaged over eleven years, so they show how often Chicago sees each kind of weather, not what any one thermometer read on a given day.

Is Chicago water safe? Boil notices and EPA record

EPA lists no health-based violations for Chicago since 2015. It also lists 47 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:

• July 2025: A lead and copper violation It is marked resolved.
• May 2025: A missed or late monitoring or reporting requirement (surface water treatment and turbidity) It is marked resolved.

When Chicago loses pressure after a break or a failed test, Chicago Department of Water Management asks affected customers to boil water for drinking and cooking. The notice ends only after samples come back clean, which usually takes one to two days after service returns, and the Illinois Environmental Protection Agency (Illinois EPA) supervises the process.

Lead service lines and old plumbing in Chicago

The most recent 90th-percentile lead result filed for Chicago is 7 ppb (2026). The federal action level is 15 ppb, so that result is far from the limit.

The age of the housing matters more than the utility's test average: 67.5% of occupied homes in Chicago predate 1970 and 1986 was the year lead pipe and solder were banned. Flush the cold tap after an outage and ask Chicago Department of Water Management whether your service line is on its lead inventory.

How long a water outage lasts in Chicago

A crew that arrives at an ordinary main break in Chicago 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. With 2,721,308 people on the system, a break on a main that feeds a whole district can leave thousands of homes dry at once, and crews may close valves several blocks away to isolate it.

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

How much water to keep on hand in Chicago

With about 2.3 people in the typical Chicago home, FEMA's one-gallon-per-person-per-day rule means 7 gallons covers three days and 33 gallons covers two weeks.

• 27% of homes are in buildings with 20 or more units. Upper floors lose pressure first, and rooftop tanks and booster pumps depend on building power.
• 54% of households rent. Tell your landlord or property manager about a leak or outage right away, since the shutoff valve may be theirs.
• 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.
• If a planned shutoff or storm is coming, fill the tub and some buckets for flushing toilets and washing; keep drinking water in clean sealed containers.

Water systems near Chicago, side by side

Water outage pages for nearby cities

Naperville, IL · Joliet, IL · Elgin, IL · Aurora, IL