Utility locates
Utility locates and markings
In Louisville, Colorado, utility locate flags or paint marks are placed in yards or along streets to indicate the location of buried underground utilities. These markings are part of a required safety process to prevent damage to utilities during digging or construction.
Why they’re there
A contractor, utility company, or the City of Louisville may have requested a locate through Colorado 811 before any digging began. This is required by Colorado law to avoid service disruptions and hazards.
Who requested them
You can find out by calling Colorado 811 at 811 or visiting Colorado811.org and providing details from the flags.
How long they last
Locate markings typically remain for about 30 days. If work is delayed, a new locate is required.
Why you might see them even if you’re not digging
Utilities may be marking lines for a neighbor’s project, maintenance, upgrades, or City work like water or sewer improvements.
Can you refuse them?
No — state law requires marking utilities to protect public safety and service continuity.
What do the different colors mean?
| Color | What it is marking |
| Red | Electric |
| Yellow | Gas |
| Blue | Water |
| Green | Sewer |
| Orange | Communications |
| Purple | Reclaimed water |
| White | Proposed excavation area |
Questions?
Contact City of Louisville Public Works at 303‑335‑4608 or Colorado 811 at 811 for more information.