Planning

Underground Utilities: What to Do Before Fence-Post Digging

Fence posts can intersect gas, electricity, communications, water, sewer, irrigation and private services. Depth cannot be safely guessed from the surface.

Reviewed July 2026By Elliot R. Wainford
Key point: A shallow post hole is still excavation. Contact the correct local service before every project.

Use the service for your location

In Canada, Click Before You Dig connects users with provincial or regional notification systems. In the United States, 811 routes requests to the appropriate state centre. The United Kingdom’s HSE guidance describes planning, locating services and safe excavation as the core elements of work near buried utilities.

Waiting periods, mark validity and responsibilities differ. Submit accurate work limits and do not begin until the required responses are complete.

  • Mark the proposed fence route before requesting locates.
  • Keep ticket numbers and maps.
  • Confirm who is responsible when a contractor is hired.

Public locates may not show private lines

Lines installed after a utility meter—such as private lighting, irrigation, propane, septic, outbuilding or pool services—may require records or a private locator. Ask what the public service does and does not cover.

Treat markings as a warning zone

Paint and flags show an approximate location, not permission to excavate carelessly. Follow the local instructions for tolerance zones, hand exposure, expiry and re-marking.

Check the decision before committing

Before ordering or approving work, explain in plain language how the proposal handles use the service for your location, public locates may not show private lines and treat markings as a warning zone. When the explanation depends on phrases such as “it should be fine,” identify what measurement, document or product specification would replace the guess.

Review the plan from both sides of the fence and through every season. Access, drainage, snow, vegetation and future repairs often reveal problems that are not visible in a front-elevation drawing.

Questions to settle

  • What site fact or local rule confirms the approach to use the service for your location?
  • What trade-off created by public locates may not show private lines is acceptable, and who accepted it?
  • How will treat markings as a warning zone be inspected or maintained after the fence is complete?
  • Which part of the decision depends on a manufacturer, local authority, utility service, surveyor, contractor or engineer?
  • What changed condition—soil, grade, use, neighbour access, climate or damage—would require the plan to be reviewed?

Records worth keeping

Keep the site sketch, measurements, approvals, survey or boundary evidence, locate ticket, neighbour notes, quote scope and final photographs together.

When to pause and get local help

Pause the project when the boundary, permission, utility response or site access remains uncertain. A small delay before ordering is usually cheaper than relocating a finished fence.

Safety and compliance boundary: Confirm current local rules, product instructions, utility-locate requirements and site-specific structural needs before work begins.