How to Avoid Utilities When Digging in Your Yard

Trench-digging. Monty Rakusen / Getty Images

Missing utilities that run through your yard is a difficult task. As a home ages, services are added to the house, trenches are dug, and earth or sod laid over the top. The trench location is quickly forgotten. When a home passes from one owner to another, utility locations are typically not transmitted to the new owner. 

Fortunately, you can often find the location of major utilities—water, power, sewer, and gas—by means of a locating company that offers its services for free.

Common Scenarios Where You Might Hit Utility Lines

Who Do You Call?

In a perfect world, there would be one nationwide number you could call to order marking services. At this time, though, it is still a patchwork of local and companies that provide this service.

In some areas there are aggregated services similar to the nationwide one—but on a smaller, regional scale. A few of the larger services:

There is a nationwide initiative, Call 811, that aims to coordinate these local and regional services. At this point, though, it only acts as a conduit to help you find your service.

What Those Pavement Markings Mean

Plan for the locator service to show up at least two days before you intend to dig, but no more than 28-30 days before. 

The two days' lead is required to give the locator company time to show up. The 28 to 30 expiration date is put in place because pavement markings will eventually wear or wash off. Also, new utilities may be added between the time of location and the time of digging.

  • White - Proposed excavation
  • Pink - Survey markings
  • Red - Electric
  • Yellow - Gas, oil, steam
  • Orange - Communications, alarms
  • Blue - Potable water
  • Purple - Reclaimed water, irrigation
  • Green - Sewer

Service Lines You Might Still Miss

Yards may contain many other lines that are considered buried services. They cannot be called utilities because they do not come from or lead to the utility company's larger service.

These smaller services may include:

  1. Irrigation pipes
  2. Low-voltage landscape light wiring
  3. Line-voltage conduit or cable feeding exterior lights
  4. Electric cable for outside spas and pools or lights

In these cases, proceed with caution and call a company that serves the relevant trade for help. For example, electricians may help you figure out the path of wiring that feeds from the service panel to a detached electrified workshop.