Guide · Water lines
How deep does a water line need to be in Colorado?
Updated Oct 17, 2026
The plumbing code (IPC Section 305.4) says outdoor water pipe must be buried below the frost line and a minimum depth below grade. Frost depth and water service depth are set locally, and 13 of the jurisdictions in CodeCheck Colorado set their own water service depth.
What does the plumbing code require for water line depth?
The model rule is about freezing. Water pipe outside the building has to be buried below the local frost line and at least a minimum depth below grade. Pipe in attics, crawl spaces, outside walls or anywhere it can freeze must be protected.
What is the frost line depth in Colorado cities?
There is no single state frost depth. Each building department publishes its own. Some cities also set a water service depth that is deeper than their published frost depth, so the city’s water service rule is the number to dig to.
Does my water utility have its own depth?
Often, yes. Water providers can set their own service line standards on top of the plumbing code, so check the provider’s standards along with the city’s rule.
Which Colorado cities set their own water service depth?
13 jurisdictions in the app have a local water service rule. Free samples already public on city pages are shown.
| City or county | Code | Local rule | Adopted by |
|---|---|---|---|
| Adams County | 2024 IPC | Free sample Adams County: exterior water lines go at least 48 in. below grade; protect pipes in cold spots with insulation or heat (IPC 305.4). | Ordinance No. 12 |
| Arvada | 2024 IPC | Sign in to see Arvada’s water line rule | Ord. No. 4921 |
| Aurora | 2021 IPC | Sign in to see Aurora’s water line rule | Ord. No. 2021-65, Ord. 2015-44 |
| Boulder | 2024 IPC | Sign in to see Boulder’s water line rule | Ordinance No. 8684, Ordinance No. 8720 |
| Commerce City | 2021 IPC | Sign in to see Commerce City’s water line rule | Ord. No. 2484, Ord. No. 2486 |
| Denver | 2024 IPC | Sign in to see Denver’s water line rule | Ord. No. 735-25, Ord. No. 1634-25 |
| Fort Collins | 2024 IPC | Sign in to see Fort Collins’s water line rule | Ord. 218 |
| Greenwood Village | 2018 IPC | Sign in to see Greenwood Village’s water line rule | Ord. 23, Ord. 13 |
| Lafayette | 2024 IPC | Sign in to see Lafayette’s water line rule | Ord. No. 12, Ord. No. 2026-12 |
| Lakewood | 2021 IPC | Sign in to see Lakewood’s water line rule | Ord. O-2022-17, Ord. O-2023-16 |
| Northglenn | 2024 IPC | Sign in to see Northglenn’s water line rule | CB-2039 |
| Superior | 2024 IPC | Sign in to see Superior’s water line rule | Ord. O-9 |
| Thornton | 2024 IPC | Sign in to see Thornton’s water line rule | Ord. No. 3731 |
What about lines to a garage, shed or yard hydrant?
The same freeze rule applies: any water pipe that can freeze has to be buried deep enough or protected.
Call 811 before you dig
Colorado law requires a locate request before you dig. Call 811.