How Deep Are Water, Sewer, and Gas Lines Buried?

At RX Plumbing & Drain, we handle underground plumbing every day. That means we spend a lot of time thinking about what’s buried below your property, especially water and sewer lines. These lines, along with gas, electrical, and communication cables, sit at different depths depending on your region and code requirements.

The depth of these lines isn’t just fun trivia fodder. It matters when you’re digging, installing, or repairing anything underground. And if you get it wrong, the consequences can be serious, from burst water mains to severed gas lines.

In today’s article, we’ll go over the following:

• How deep each utility line is usually buried

• Why that depth matters

• How to locate your own utility lines safely

• When to call 811

• Common mistakes and examples

We’ll also wrap up with FAQs at the end.

How Deep Are Water Lines Buried?

Most residential water lines are buried between 18 and 24 inches deep. But that’s not a guarantee. Local codes, climate conditions, and soil type can all affect this number.

The International Residential Code (IRC) recommends burying water lines at least 6 inches below the frost line. So in colder states, lines may need to be 30 inches deep or more to avoid freezing. In warmer climates like here in Georgia, you can expect water lines closer to that 18-inch mark.

But here’s the catch: installers don’t always follow the rules. We recently helped a homeowner in North Georgia who had a leaking water main. After digging, we found the pipe buried only 3 inches deep. Clearly not up to code. It had been that way since the home was built so we weren’t surprised to see that it was leaking.

Key Takeaway

Never assume your water line is buried as deep as it should be. Always call 811 before you dig.

How Deep Are Sewer Lines Buried?

Sewer lines rely on gravity to move waste. That means they need to slope steadily downhill. To make that happen, sewer lines are buried deeper than water lines.

In most homes, residential sewer lines are between 18 and 30 inches deep. In colder regions not named Georgia, they may go down 5 to 6 feet to stay below the frost line.

City sewer mains usually sit even lower, often starting at 4 feet and sloping down deeper from there.

Something to Consider

If you’re connecting to the city main, your residential line has to slope to match its depth. That’s why carefully planning the trench properly is so important.

How Deep Are Gas Lines Buried?

Natural gas lines are also commonly buried 18 to 24 inches deep. But local codes can vary. Denser cities may allow for shallower installs in certain zones. Again, it depends on your specific city or county.

Gas lines are dangerous. Striking one with a shovel can cause leaks, fires, or worse. That’s why calling 811 is so important. It’s the law in most states, and for good reason. Georgia doesn’t enforce calling 811 before digging small, non-mechanized projects, but it’s a free service that you should take advantage of regardless.

Code Note

Most jurisdictions require gas lines to be buried in yellow polyethylene (PE) piping with tracer wire. That wire helps locators find the line before digging.

How Deep Are Electrical Lines Buried?

Electrical line depth depends on the type of power and what it supplies.

• Low-voltage (like landscape lighting): often 12 inches deep

• Standard residential electric (120/240V): usually 18 to 24 inches

• High-voltage lines: may go 36 inches or deeper

Conduits for power lines should be buried with warning tape placed several inches above the line in the trench. But as always, not everyone follows the rules.

We’ve uncovered lines buried too shallow, missing tracer wire, or tangled with other utilities. These things should never happen, but they sadly do.

How Deep Are Communication Lines Buried?

TV, internet, and phone cables are generally the shallowest utility lines.

• Coaxial cables and fiber optics: often sit just 12 inches below the surface

These can be easy to nick if you’re planting shrubs, installing fences, or doing basic landscape work. If you sever one, you might knock out your entire street’s internet service. You don’t want to get on your neighbors’ bad side, do you?

Why You Should Call 811 Before Digging

Tools like ground-penetrating radar and electromagnetic locators exist, but they’re expensive and can be tricky to use if you’re not experienced. Even then, they might not detect every line.

That’s why calling 811 is the best first step.

811 is the national “Call Before You Dig” hotline. When you call, local utility locators come to your property, usually within 48 hours, and mark out all known underground lines using color-coded paint:

• Blue: Water

• Green: Sewer

• Red: Electric

• Yellow: Gas

• Orange: Communications

Important Note

Once marked, don’t dig within 2 feet of the line in any direction. You may see advice online saying 18 inches, but we personally recommend the 2-foot rule for safety. Here’s an easy way to remember it: “2 feet 2 be safe.”

What Can Go Wrong When You Dig Alone?

Some homeowners think a “small project” doesn’t need 811. But even planting a mailbox can hit a line if you’re unlucky.

We’ve seen it all:

• A gas line punctured by a homeowner planting a hedge.

• A cable line cut during mailbox installation.

• A sewer line cracked during fence post digging.

And again, this is because many of those lines weren’t originally buried as deep as they should’ve been.

We Take Underground Plumbing Seriously

RX Plumbing & Drain specializes in underground repairs. That means we often repair the damage other crews cause or are unwilling or unable to fix.

We’ve replaced water lines that were too shallow, rerouted sewer lines laid with the wrong slope, and dug up gas lines that had been poorly marked. We have the right team and tools to tackle any underground plumbing project you need.

FAQs: Utility Line Depth and Digging Safety

How do I know how deep my water or gas line is?

You can’t know for sure just by guessing. Call 811 or your local building department. They can often provide details, and 811 will mark the exact path.

Can I trust that lines are always buried to code?

No. We’ve found many lines buried too shallow. Builders sometimes cut corners and that’s why inspections matter.

What happens if I hit a utility line?

You could face property damage, service loss, or injury. Some utility strikes carry fines or liability for repair costs.

Can I rent a locator device myself instead of calling 811?

You can, but 811 is free. It’s also more thorough and carries legal weight

How long do I have to wait after calling 811?

Usually about 48 hours. Don’t start digging until all the lines have been marked.

Is it illegal to dig without calling 811?

In most states, yes. Georgia law doesn’t require it for small, non-mechanized projects, but it’s highly recommended in every situation.

What’s the safest digging distance from a marked line?

Stay at least 2 feet from each side of the marking and try to use hand tools when digging close.

Can I rely on utility depth charts for my zip code?

Not entirely. Charts help, but actual conditions vary. Always confirm with a locator.

Georgia’s Trusted Underground Plumbing Experts

Utility lines don’t always sit where you expect. Local codes set the rules, but human error, corner-cutting, and older construction all affect the actual depth.

Calling 811 is fast, free, and could save you thousands. So whether you’re planting a tree, digging a trench, or just curious about what’s underground, do it the right way.

If you need underground plumbing repairs, call RX Plumbing. We know how to work around these lines and how to fix them if something’s already gone wrong. You can trust our team to cut costs, not corners.