Cheyenne, Wyoming Water Outage Today

Cheyenne tap water system, by the numbers

Federal records name Cheyenne Board of Public Utilities as the public water system for Cheyenne, with about 64,165 people on its mains.

Where Cheyenne's tap water comes from

Tap water in Cheyenne starts as surface water. Cheyenne Board of Public Utilities takes it from the Granite Springs Reservoir, the New North Crow Diversion Reservoir, and the Rob Roy Reservoir and runs it through treatment before it reaches the mains. Treatment points named in EPA's facility list include Sherard WTP. After treatment the water is held in 6 storage tanks and reservoirs and pushed uphill by 7 pump facilities; that storage is the buffer that keeps taps running for a few hours after a pump or main fails.

What this means in an outage. Surface water needs a treatment plant running around the clock, so a plant shutdown, a raw-water pump failure or a long power cut at the plant can lower pressure across the whole service area, not just on one street. Boil water notices are more likely to be citywide after that kind of failure than after a single main break.

Why the water goes out in Cheyenne

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

• Freezing weather. Cheyenne sees about 165 days a year with a low at or below 32°F, and 58 days at or below 20°F. The coldest morning in the 2015 through 2025 record came on February 14, 2021. The longest stretch with highs that never rose above freezing ran 9 days, ending December 31, 2015. Frozen service lines and meters cause single-address outages, while ground frost and thaw cycles crack older mains and produce the street-wide breaks.
• Storm-driven power loss. Thunderstorm wind, hail and tornado reports in Laramie County number 553 since 2015. Pump stations and treatment plants that depend on Black Hills Energy 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. 41.5% of occupied homes in Cheyenne 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.
• Flooding and heavy rain. NOAA logged 41 flood, flash flood and heavy rain reports in Laramie County from 2015 through 2026. 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.
• 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.
• Scheduled work, or a fault inside your own home. Utilities warn customers before a planned shutoff. If nothing was announced and the neighbors are fine, the cause is probably your shutoff valve, meter or pressure regulator.

Freeze, heat and rain: the Cheyenne weather record

Main break season in Cheyenne 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 Cheyenne sees each kind of weather, not what any one thermometer read on a given day.

Boil water advisories and the federal violation record for Cheyenne

EPA lists no health-based violations for Cheyenne Board of Public Utilities since 2015.

When Cheyenne loses pressure after a break or a failed test, Cheyenne Board of Public Utilities 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 U.S. EPA Region 8 (Wyoming public water systems are overseen federally) supervises the process.

Lead, older pipes and water quality in Cheyenne

The most recent 90th-percentile lead result filed for Cheyenne Board of Public Utilities is 15 ppb (2025). The federal action level is 15 ppb, so that result is under it, but not by much.

The age of the housing matters more than the utility's test average: 41.5% of occupied homes in Cheyenne predate 1970 and 1986 was the year lead pipe and solder were banned. Flush the cold tap after an outage and ask Cheyenne Board of Public Utilities whether your service line is on its lead inventory.

Restoration times for water outages in Cheyenne

Most repairs of an ordinary main break in Cheyenne take half a day once the crew is on site. Bigger mains, deep bury and busy roads stretch that to a day or more.

Cheyenne Board of Public Utilities will post an estimated restoration time for a break that affects many customers; ask for the repair crew's estimate when you call.

Preparing for a long water outage in Cheyenne

Census figures put the typical Cheyenne household at about 2.2 people. At one gallon per person per day that is 7 gallons for three days or 31 gallons for a two-week supply.

• A standard water heater is a ready-made 40-gallon reserve. Shut off its power or gas, open a hot tap somewhere in the house, and draw from the drain valve.
• Fill the bathtub and a few large pots as soon as you hear a break is likely; that water is for flushing and washing, not drinking.

Water systems near Cheyenne, side by side

Water outage pages for nearby cities

Fort Collins, CO · Laramie, WY · Denver, CO · Aurora, CO