Water Service Outages in Montana by City
96% of Montana's 803 community water systems serve 3,300 people or fewer, so many outages and boil water notices affect a single small town or subdivision.
Montana drinking water record
Busiest year: 2019 (80 violations). Counted by the year the violation period began. Source: EPA SDWIS.
- Community water systems: 803 active systems serve about 790,601 people. 769 of them (96%) serve 3,300 people or fewer; 683 draw mainly on groundwater and 117 on surface water.
- Health-based violations since 2015: 689, at 147 systems (18% of all systems). That share is 9th of 50 states (1 = lowest).
- Most common problems: contaminant averages over the limit (331); surface water treatment (143); contaminant readings over the limit (84). Source: EPA SDWIS
- Largest system: Billings City Of, about 114,000 people, with 0 health-based violations since 2015. Source: EPA SDWIS
- Housing age: the median Montana home was built in 1981 (US 1980). Source: US Census Bureau, ACS 2020–2024 (table B25035)
- Storm damage to water service: NOAA storm narratives mention water mains, boil water notices or lost water service in 3 episodes in Montana since 2015. Source: NOAA Storm Events Database
- December 11, 2025, Lincoln (flood): “The Lower Flower Creek Diversion Dam was nearly compromised by debris and high sediment, resulting in a long-term boil water advisory for the City of Libby.” Source: NOAA Storm Events Database
- April 10, 2023, Blaine (flood): “Chinook water plant was surrounded by water.” Source: NOAA Storm Events Database
| System | People served | Main source | Health violations since 2015 |
|---|---|---|---|
| Billings City Of | 114,000 | Surface water | 0 |
| Missoula Water | 68,200 | Groundwater | 0 |
| Great Falls City Of | 60,000 | Surface water | 5 |
| Bozeman City Of | 56,000 | Surface water | 0 |
| Butte Silverbow Water Dept | 33,000 | Surface water | 0 |
| Helena Water System | 32,091 | Surface water | 3 |
Source: EPA SDWIS.
Montana is 2nd of 5 (1 = lowest share). Source: EPA SDWIS.
Checked September 2026.
Who to call in Montana, city by city
4 Montana cities on this site and the water utility for each. What to do while you wait is in our water service outage guide.
- Billings City of Billings Public Works
- Missoula Missoula Water
- Great Falls City of Great Falls Public Works
- Bozeman City of Bozeman Water
Frequently asked questions
Is there a water service outage in Montana right now?
Not on this site: no reports from Montana in the last 24 hours.
How many public water systems are in Montana?
EPA records list 803 active community water systems in Montana, serving about 790,601 people. 96% serve 3,300 people or fewer.
How common are drinking water violations in Montana?
Since 2015, 147 of 803 community water systems in Montana (18%) have had at least one health-based violation, 689 in total.
What is the largest water system in Montana?
Billings City Of, which EPA records list as serving about 114,000 people.
Report counts are user-submitted; other figures name their official source. How our data works
Cities in Montana with Water Service Outages Information
Billings
no reports in the last 24 hours · pop. 117,116
City of Billings Public Works
Bozeman
no reports in the last 24 hours · pop. 53,693
City of Bozeman Water
Great Falls
no reports in the last 24 hours · pop. 59,478
City of Great Falls Public Works