Electric lines are buried between 18 inches and 4 feet deep, depending on the type of line and what's above it

Residential service lines — the wires bringing power to your house — are typically buried 18 to 24 inches below the surface. Distribution lines, which carry power between neighborhoods, go down 24 to 36 inches. Transmission lines, the high-voltage lines that move power across regions, are often buried 3 to 4 feet deep or deeper, though many are still on poles above ground because burying them costs significantly more.

The depth depends on local building codes, soil type, frost line depth in your region, and what's above the line. A line under a driveway or road needs to be deeper than one under a yard. Frost line — the depth soil freezes in winter — varies from near zero in warm climates to 4 feet or more in cold ones. Lines must go below the frost line so freezing and thawing don't shift them and damage the insulation.

Depth also depends on whether the line is in a conduit (a protective pipe) or direct burial cable. Direct burial cable can go shallower because the cable itself is armored. Lines in conduit need more protection and often sit deeper.

Key Takeaways

  • Residential power lines to your house are buried 18 to 24 inches deep; distribution lines serving neighborhoods are 24 to 36 inches deep.
  • Local frost line depth — how far soil freezes in winter — determines the minimum burial depth in your area.
  • Lines under driveways, roads, or other structures are buried deeper than lines under open ground.
  • Before digging anywhere on your property, call 811 or your local utility to have lines marked, because hitting a buried line can cause electrocution, fire, or service loss.

Why frost line matters for burial depth

Soil expands when it freezes and contracts when it thaws. If a power line sits above the frost line, this movement can bend, crack, or shift the cable, damaging the insulation and creating a hazard. Building codes require lines to be buried below the frost line so they stay stable year-round.

Frost line depth varies dramatically by region. In Florida or southern Texas, it may be only 6 to 12 inches. In Minnesota, Wisconsin, or upstate New York, it can be 4 feet or deeper. Your local building department or utility company can tell you the frost line depth for your address. If you're planning any digging project — installing a fence, planting trees, adding a deck — knowing this depth helps you avoid hitting utilities.

The difference between direct burial cable and conduit

Direct burial cable has a thick, armor-like outer layer that protects it from soil, moisture, and small punctures. Because the cable itself is tough, it can be buried at the minimum depth — often 18 inches for residential service. The armor also makes it less likely that a shovel or garden tool will pierce it.

Conduit is a plastic or metal pipe that holds the wire inside. The wire itself is thinner and more vulnerable, so the whole assembly needs to be buried deeper — typically 24 to 36 inches — to reduce the risk of damage from digging, roots, or settling soil. Conduit also protects against rodents chewing through the wire.

What happens if you dig near a buried line

Hitting a buried power line can cause electrocution, fire, or a gas explosion if the line is near a gas pipe. It can also knock out power to your home or your neighborhood. Even if you don't hit the line directly, digging near it can loosen soil around it, exposing it or shifting it into a position where it's easier to damage later.

Before any digging — for a fence post, a tree, a deck foundation, or a utility line of your own — call 811 (in the United States) or your local utility locating service. They will send someone to mark all buried utilities with paint or flags, at no cost. This takes a few days, but it's the only safe way to know where lines are. Some utilities also offer a free app or online map showing approximate line locations, but the physical marking is more accurate.

Why some power lines stay above ground

High-voltage transmission lines — the big ones strung between tall metal towers — are usually above ground because burying them costs 5 to 10 times more than poles and wires. The cables are thicker, the conduit or trenching is more extensive, and maintenance becomes harder if something fails underground. For lines carrying power across states or regions, the cost difference is too large to justify burying them.

Distribution lines in some neighborhoods are also on poles for the same reason. However, many cities and suburbs are moving toward underground distribution lines for safety, aesthetics, and to reduce outages from storms and fallen trees. This is a long-term project because it requires replacing poles, rewiring, and burying lines block by block.

How to find out the burial depth in your area

Your local utility company or building department can tell you the standard burial depth for your region. You can also check your area's building code — most municipalities have it online. Search "[your city or county] building code" and look for the section on electrical installation or underground utilities.

If you're planning a project that involves digging, the safest approach is to call 811 before you start. They will mark all utilities, and the locator can also tell you the depth of each line. This information is useful if you're digging a foundation, installing a pool, or planting large trees whose roots might eventually reach a line.

Frequently Asked Questions

Can I dig in my yard without calling 811 if I stay shallow?

No. Even shallow digging can hit a line, especially if the line is at the minimum depth or if soil has shifted. Calling 811 takes a few days and costs nothing. It's the only way to know for certain where lines are buried on your property.

What should I do if I hit a power line while digging?

Stop digging when ready and move away from the area. Do not touch the line or the shovel. Call 911 and your utility company. If the line is energized, touching it or the wet soil around it can cause electrocution. Stay at least 10 feet away until help arrives.

Are all power lines to my house buried?

Not always. Some homes have overhead service lines on poles. If your power comes from a pole near your house, those lines are above ground. If you don't see poles near your home, your service line is likely buried. Your utility bill or a call to your utility company can confirm which you have.

Do I need a permit to dig near a marked utility line?

Yes, in most places. Even after 811 marks the lines, you usually need a permit from your local building department before digging near them. The permit ensures the work is inspected and done safely. Check with your city or county before starting any project.

How often do buried power lines need maintenance?

Buried lines need less frequent maintenance than overhead lines because they're protected from weather and falling trees. However, they can fail due to soil movement, water damage, or rodent damage. Your utility company monitors them regularly and repairs them when needed, usually after a failure is reported.