How deep are wires buried in yard?

The depth at which electrical wires are buried in yards varies depending on the type of wire and its purpose. However, there are general guidelines for how deep different kinds of wires should be buried underground.

Power Lines

Power lines that deliver electricity to homes and businesses are typically buried 18-36 inches underground. According to the National Electrical Code (NEC), service-entrance wires that run from the street to a home should be buried at least 18 inches deep. Meanwhile, feeder wires that run from the service entrance to subpanels and circuits should be buried at least 24 inches deep.

Burying power lines deeper than the minimum recommendations provides additional protection from being damaged by digging or erosion. Power companies and electricians often bury lines closer to 36 inches deep to prevent accidents and service interruptions.

Electrical Wiring for Outdoor Fixtures

For electrical wiring that connects outdoor fixtures like lights, pumps, or outlets, the NEC requires a burial depth of at least 6 inches. This minimum depth prevents damage from garden tools or lawn equipment. Deeper burial depths may be recommended in areas where excavation work frequently occurs.

Low-Voltage Landscape Lighting

Low-voltage lighting systems used for landscape lighting are typically buried only 2-6 inches underground. These shallow depths are suitable since the wires carry only 12V or 24V compared to the 120V or 240V in power lines. At just 2 inches deep, landscape lighting can still be covered by grass or soil while avoiding damage from aeration or edging equipment.

Sprinkler System Piping

For underground PVC pipes that supply water for irrigation sprinkler systems, a burial depth of 6-12 inches is common. At this depth, the pipes are protected from freezing temperatures in northern climates. Sprinkler system main lines are sometimes buried 12-18 inches deep for additional freeze protection.

Cable and Phone Lines

Telecommunications cables including cable TV, phone, and fiber optic lines are often buried about 12-18 inches underground. Local codes may dictate specific depths, especially near roads or other utilities. Like power lines, deeper burial provides more protection for undisrupted service.

Conclusion

In summary, the recommended burial depths for various wires and pipes in yards are:

• Power lines – 18-36 inches
• Outdoor electrical wiring – 6 inches minimum
• Low-voltage lighting – 2-6 inches
• Sprinkler systems – 6-18 inches
• Communications cables – 12-18 inches

Digging deeper than the minimums provides extra protection. When installing systems or digging in a yard, check with your utility companies to locate existing underground wires and pipes first. Knowing what is below ground at what depths prevents accidents. Careful burial of all systems also saves on repairs and replacements over time.

Typical Burial Depths for Wires and Pipes

Here is a table summarizing the typical burial depths discussed:

System	Typical Burial Depth
Power lines	18-36 inches
Outdoor electrical wiring	6 inches minimum
Low-voltage lighting	2-6 inches
Sprinkler system piping	6-18 inches
Telecommunications cables	12-18 inches

Factors That Determine Burial Depth

There are several factors that influence how deep wires and piping need to be buried:

Local building codes

Most jurisdictions have electrical codes and plumbing codes that specify minimum burial depths within that locality. These codes must be followed.

Frost line

In colder climates, systems must be buried below the frost line to prevent freezing. This can mean burial depths of 3-4 feet or more.

Soil/terrain

Areas with a high water table or loose soil may require deeper burial. Likewise, rocky areas may mandate shallower depths.

Other existing utilities

New lines and pipes must maintain safe distances from existing underground infrastructure, which affects depth.

Frequency of digging/excavation

Systems buried where digging occurs often, like in a garden or construction area, should be deeper.

Voltage/current

Higher voltage power lines require more earth cover than low-voltage lighting cables, for example.

Locating Buried Wires and Pipes

Since most wires and pipes are buried underground, special techniques are used to determine their locations:

• Call 811 – This free national “Call Before You Dig” number arranges for utilities to mark their buried lines.
• Use wire/pipe locators – Specialized electromagnetic tools can detect many buried systems.
• Look for above-ground clues – Surface-level boxes, manhole covers, and faucets often indicate underground utilities.
• Check installation records – Installers document measurements of buried systems.
• Enlist a professional – Underground utility locating services use advanced subsurface detection.

Carefully locating wires, pipes, and other equipment before any digging protects buried systems and prevents dangerous accidents.

Working Around Buried Utilities

When excavating or trenching in areas with underground wires or piping:

• Dig by hand within 2 feet of markings.
• Avoid using mechanical equipment near markings.
• Follow all safe dig practices.
• Exercise extreme caution when working around high-voltage lines.
• Confirm locates before backfilling trenches.

Maintaining a safe working distance from buried utilities guards against disruptions, injuries, and costly repairs.

Depth Variations

While standard burial guidelines exist, depths can vary on a case-by-case basis. Some reasons include:

• Improper installation at shallower depths
• Settling of covering soil over time
• Erosion exposing buried systems
• Previous excavations affecting depth
• Undocumented repairs or modifications

As such, appropriate depths should be verified through locate services before any digging. Assumptions about how deep systems are buried can be dangerous.

Conclusion

Knowing standard burial depths provides a useful starting point when working around underground utilities. However, appropriate depths should always be confirmed through locate services before excavating. Careful digging and adherence to safe practices are vital anytime working around potentially shallow wires or pipes. With proper precautions, buried systems can be avoided to ensure safe digging.