How to Know if Your Underground Drain is Clogged (And How To Fix It!)

By Gutter Expert Henry Gerbin
Updated On

Are you wondering if your underground drain is clogged (and how to unclog it if it is)?

You’ve come to the right place!

In this Regional Gutter Repair guide, you’ll learn:

  • How underground drains work
  • The signs your underground gutter drainage system has a clog
  • How to prevent underground drain clogs

And much more!

Picture of an underground drain grate

So, if you’re looking for answers on if your underground drain is clogged, keep reading our detailed guide below to get answers to all of your questions!

How Do Underground Drains Work (And Why Are They Important)?

Put simply, underground drains connect to your home’s gutter downspouts to funnel water away from your home – and, more importantly, your home’s roof and foundation – toward the storm drains on your street. Sometimes these drains even connect directly to your sewer line or your french drain system for added certainty that the water goes where it should.

So why does that matter?

Well, when water pools too close to your house (which can happen frequently if you don’t have underground drains and/or your house is at a low elevation) it can cause water damage, mold growth, and tons of other problems.


This not only creates wear and tear on your foundation, but it can kill your grass (hello, overwatering!) and erode your foundation’s stability over time, too.

Underground drains work by creating a closed funnel system that connects to your gutters on your roof and moves the water through the downspouts and away from your home.

Close up of an underground drain system being installed

What Are The Signs Your Underground Drain is Clogged?

So let’s say you’re noticing some water pooling around your home, or you’re seeing signs of moisture seeping into your basement. Does that mean your underground drain is clogged?

It could be!

There are a few surefire ways to determine if your underground drain system is clogged and needs attention. These can range from super obvious signs to signs that are more subtle. The best way to check for a clog, however, is actually to wait for the rainy season! This might sound counterintuitive (most of the time, you want to preemptively fix problem areas of the home before they enter their busy season, right?), but it actually makes sense.

When the rainy season hits, it makes it very easy to examine your entire gutter system for areas where there are clogs, leaking, or broken parts. The same goes for your underground drains. 

That rain and water flow will help you see where the water is going and whether or not it’s being drained properly. 

So, if you’re noticing some of the key issues below once the rain hits, it might be time to have one of our gutter pros come out and check your system for clogs.

Water Pooling or Overflowing from the Downspout Connection

In most cases, your downspout is connected to your underground drains with different types, sizes, and shapes of adapters.

All adapters provide the same function: they allow for the seamless and quick transition of water flow from one pipe to the other. 

These high-quality adapters ensure water doesn’t start leaking out of the downspout extensions or joints while allowing your system to take twists and turns that help the water move to where it should go.

Water spewing out of an overflowing gutter connection

Therefore, an excellent way to identify drainage problems is by checking the seams around these adapters as well as the bottom of the downspouts around your house. 

If your underground drain line is clogged, you’ll see water gushing back outside the drainage pipe and spilling outside the adapter seams. 

This happens because the water can’t flow down and out. Instead, it fills the downspout pipe with water, forcing it to seep from the joints so it can escape the pressure. 

Of course, as we mentioned before, the only way to see this is when it’s actually raining!

So, if you’re concerned about a clog in your system, you’ll have to be around to examine your downspouts the next time it rains to truly identify the issue. 

If you notice water coming back outside the pipe or water pooling up around the drain, that’s a dead giveaway that your drain is clogged.

Don’t want to wait until it rains to solve the mystery? Check for water stains around your underground drain systems (particularly if the drains are near your driveway) or soil that is mushy even though it hasn’t rained for a while. 

That’s a key indicator that something is amiss!

Plus, if you notice water stains around your underground drain systems, it’s a sign of clogging. 

Water Damage in Your Basement

Another surefire sign that you may have a clogged underground drain is water damage in your crawl space or basement. This can happen when your downspouts are improperly placed or if they get clogged and cause water to pool around the foundation.

Moisture seeping into a basement due to overflowing underground drains


If you notice your downspouts draining water really close to your house, it’s probably clogged somewhere down the line and draining from the downspouts to compensate for that. 

Usually when this happens you’ll see water bubbling close to the foundation wall if your drainage system is clogged or broken. 

Now, obviously, the whole point of having these drains in the first place is to prevent that water from pooling by your foundation and wreaking all sorts of havoc, so you’ll want to make sure you do regular inspections like this in the rainy season and call in a pro at the first sign of a clogged drain to maintain your foundation’s health!

Overflowing Gutters

If your underground drain is clogged, you may notice your gutters overflowing too. When your clogged underground drain system doesn’t let any water pass through it, the rainwater has to come out…somewhere.

Initially, the downspout will start filling with water. But eventually, the entire downspout will fill with that water, and once that happens it’ll resort to filling up the gutters along your roofline (not good!).

At first, you’ll notice water pouring from the downspout adapter, but if the seal is strong, you may not notice water spilling at all. Water might also end up leaking out of other elbows or seams on the downspout higher up in the system.

Overflowing gutter downspout

When the downspout clogs, the gutters will fill with water and once that happens, you may see water leaking from each gutter seams. 

Last but not least, once the underground drain, downspout, and gutters are full of water, the rainwater will pour over the top of the gutter like a waterfall. 

Which, if we’re being honest, sounds kind of cool. But we promise, this waterfall is a lot less fun than a visit to Niagara Falls.

How a Gutter Expert Will Fix Underground Drain Clogs

Ok great, so you’ve got a clogged underground drain. Now what?

Well, first thing’s first you should probably call a professional to come and unclog it. This isn’t usually something the average homeowner should take on as you can end up doing more harm than good.

To unclog an underground drain, here are a few key practices gutter professionals use to get your gutter system back in working order. 

Repairing Visible Ends

First and foremost, they conduct a visible repair. They typically do these types of repairs at the ends of your underground downspout pipe. They repair the drains near the foundation entrance, the adapters, or places that allow water to exit.

Gutter pros can easily spot gutter damage to the drainage system. When they conduct a visible inspection, they might notice different cuts or areas of the pipe damaged and in need of repair. 

The gutter expert will usually cut off the damaged section and replace it with a new section using their professional tools and techniques. 

If the pipe near the foundation requires repair, they’ll have to work near the bottom of your downspout. They will usually have to detach the bottom strap that keeps the downspout in place. It’s important to repair this quickly as it can cause foundation damage. 

Sometimes this requires a full re-installation of your gutter drainage system, which means the gutter expert will have to remove the old downspout and replace it. This is a cumbersome job, particularly because of the heights involved. 

Give our team of gutter service professionals a call if you need assistance. 

Dig Up the Problem Pipe

If your downspout has water backing up, the chances are that the pipe itself is crushed or buckled. This restricts or completely stops the water from flowing. Tree roots, vehicles driving over the lines, and even shifting earth can compromise the pipe’s structure and construction.

If the pipe is broken or damaged, the gutter expert’s first step is locating the problem area. Experts typically use a metal snake or a metal detector to do this. They will use a wire with metal attached to it and run it across your underground drainage system.

When the wire hits the clogged area, that means they have reached the damaged part of your pipe. Next, the gutter pro will use the metal detector to find out where the clog blocks the metal attachment. This way, they’ll know where to dig.

The gutter repair expert will carefully dig up the ground around the area that requires reconstruction. They might have a survey performed on your property first to ensure they do not dig into an electrical or gas line. Once they pinpoint the problem area, they will replace the broken pipe with a brand new section. 

Digging and replacing underground drain pipes is a lot of work. And to get it done right, you will want professional assistance. Our gutter service experts are just a call away. We can locate the damaged pipe swiftly and replace it within a few hours— all with minimal damage to your landscaping. 

How Do They Unclog an Underground Drain?

There are several ways to unclog an underground drain pipe, including blow bag, hydro jetting, and cable rodding. 

Here, we talk in detail about some of the top ways our gutter experts use to unclog an underground drain:

Water Jet Stream

The fact is that most clogs are either at a transition point or elbows. This means gutter repair specialists can usually unclog the gutter by hand and with a simple process, like a water jet. 

We recommend that you reach no more than two feet into the drain before resorting to tools to assist you in clearing your clogged drain system. One of the most common tools gutter experts use to clean clogged pipes is a jet stream from a hose.

They will disconnect your underground drain system by removing the downspout pipe. They will usually wear rubber gloves to remove the clogs near the opening first since there could be mold, insects, snakes, leaves, renegade frogs, and other harmful items in your gutters. Then they’ll use a water jet to clear out the remaining clog. 

Man using a hydrojet to clean out clogged underground drain

A water jet is a practical yet simple way to fix clogging, as well as clean your drainage pipe. The high-pressure water helps push water towards the clogged line and resolves all your clogged pipes and slow water flow problems by forcing the clog out of the pipe.

If you’re doing maintenance and repairs to your gutters yourself, always wear proper protection to avoid hurting yourself. 

Blow Bag

Otherwise referred to as a drain bladder, a blow bag is another excellent way to unclog drains. A blow bag uses a sudden high pressure of air to eject your clog. It’s the Heimlich Maneuver of the gutter world. 

These devices resemble a deflated balloon and are typically manufactured from high-quality rubber. This balloon-shaped blow bag is attached to a continuous water source, as well as the clogged drain pipe.

After the blow bag fills with water, it releases a sudden and intense rush of water to eliminate the blockage in the pipe.

However, homeowners should make sure they’re careful when using a blow bag since excessive pressure can cause damage to your pipes, especially if your tube has weak joints. Otherwise, leave this task to gutter pros so nothing accidentally breaks. 

Cable Rodding

Cable rodding is also known as rooting, augering, and snaking. In this process, your gutter expert will push a heavy-duty metal cable through your drainage pipe system.

This technique aims to poke around the blockage and break it so water can start flowing through it again.

Hydro Jetting

Hydro jetting refers to an innovative way of cleaning your drainage pipe. This method is pretty similar to power-washing your pipes and involves a hydro jet.

During this process, a gutter clog removal expert will insert and snake a high-pressure hose through the downspout pipe. Then, they’ll send a powerful blast of water to remove existing solid and greasy debris from your drainage pipe while slowly pulling it out.

Pictoe Milling Machine

Last but not least, a great way gutter experts use to remove stubborn clogs like hard sediment build-up or ingrown tree roots from your pipes is with the help of a Picote Milling Machine.

This system imitates the approach of a cable rodding; however, it includes specialty heads to the cable ends. These heads let the Picote machine break blockages, remove debris, and perform in-depth wall-to-wall pipe cleaning. 

When Should You Call A Professional Gutter and DownSpout Specialist?

While identifying and removing blockages in an outdoor, concealed downpipe system is not impossible, it can be challenging.

Consider reaching out to our professional gutter and downspout specialists if you notice slow drainage, water back up, or complete clogs. 

Here are a couple of signs that indicate you need to contact our local gutter and downspout specialists right away:

  • Mildew or moss is starting to accumulate near the drainage system
  • The seams of your pipes are experiencing stress
  • Your gutters are overflowing
  • Your downspouts are leaking at the joints
  • The area around the drainage system is rotting, becoming oversaturated, or swampy
  • The drainage system is cracking or buckling

Our gutter installation and repair team loves fixing drainage issues and getting homeowners’ gutter systems working properly. If you have a clog or other gutter issues, fill out the form below to get in touch with our gutter technicians today!

Meet Your Gutter Expert

Henry Gerbin


Whether your gutters are leaking, broken, or you're just someone considering the purchase of your first set of gutters Henry is here to help. He regularly contributes his thoughts and knowledge with the RegionalGutterRepair readers publishing guides and studies on the latest in gutters.

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