Before starting any digging project, Colorado state law requires homeowners and contractors to contact Colorado 811 at least three days in advance to have underground utilities located. This applies to any project that disturbs the ground, including installing fences, mailboxes, or planting trees and shrubs.
Underground utility lines can be difficult to predict, and digging without proper markings can lead to serious injury, service disruptions or fines. Always request a locate before you dig to stay safe and compliant.
- Comply with One Call Law (C.R.S. § 9-1.5-103) by:
- Maintaining an active membership with Colorado 811.
- Maintaining accurate records of underground infrastructure.
- Responding to locate requests within two full business days of the request (unless a documented agreement between the excavator and the locator exists to extend the due date) to accurately locate and mark underground infrastructure.
- Responding to emergency requests within one hour during business hours and two hours after business hours.
- Contact 811 at least three business days before excavating.
- Review and keep Positive Response information onsite for the duration of your project and compare it with the markings. If markings are missing, unclear, or the utility is not found under the mark, stop work in that area and submit an excavator renotification request.
- The use of hand tools or “soft digging” is required in the tolerance zone, which is 18 inches from exterior sides of the marked utility.
- Maintain the marks — use diligence to protect the locate marks. If marks are lost or destroyed, the excavator must contact 811 to have the marks refreshed.
- If using trenchless technology or the excavation crosses a marked utility, the excavator must expose and visually verify the utility.
- The excavator must maintain vertical and horizontal clearance standards when installing utilities near underground infrastructure.
- It is preferred to pre-mark specific area of excavation with white paint, stakes or flags.
Helpful Resources
Frequently Asked Questions
Any time a project involves moving or disturbing the ground, a locate request is required by Colorado law. This includes activities such as digging, trenching, boring, backfilling, ditching, grading, plowing-in, pulling-in, ripping, scraping, grading or even minor projects like installing posts or planting.
Locate marks are valid for 30 days from the ticket’s due date or until they are no longer visible — whichever comes first. If the marks are damaged or fade, you must stop digging and contact Colorado 811 for re-marks. If your project continues beyond 30 days, request an update or new ticket at least two business days before the marks expire.
If your locate marks get destroyed during your project, you must cease all digging and contact Colorado 811 to request re-marks.
You do not need to be home for your locate request to be completed. However, please ensure we have access to the front lot and that any animals are properly contained. If access is an issue, you may arrange a specific meeting date and time when submitting your request through Colorado 811.
There is no charge to have utility locates done.
The person doing the digging must be the one to request locates. If you have hired a company or contractor, it is their responsibility to issue the request.
Each color indicates a different type of utility line, as follows:
Our locators take care to place markings responsibly. The paint used is solvent-based and designed for temporary use. It will not harm grass or most landscaping surfaces. The markings will naturally fade or wash away over time.
Please leave them as is to prevent damaging underground utilities. In addition, removing a locate flag that’s still in use is a misdemeanor under Colorado law.
Utility lines are within 18 inches of either side of the marks. Exercise caution when digging in this area by hand-digging and exposing utility lines so that you are aware of their actual location and depth.
Our locators will mark all underground infrastructure that is owned, operated and maintained by Denver Water. We will mark up to the meter as a courtesy. We do not mark privately-owned utilities. Visit Colorado 811 for a list of companies who provide private locating services.
It is possible that no water lines are present in your specified dig area. Once the “locate by” date on the ticket has passed, you are required to review your Positive Response information before beginning any excavation. This information will include the status of the request and can be found in the Positive Response email sent by Colorado 811, or on the Positive Response page at Colorado 811.