Skip to Content

5 Way to Unclog a Clogged Downspout Underground

5 Way to Unclog a Clogged Downspout Underground

Share this post:

This post may contain affiliate links. If you click one of these links and make a purchase, I may earn a commission at no additional cost to you. In addition, as an Amazon Associate I earn from qualifying purchases.

Having an underground downspout is an excellent solution for accumulating rainwater. However, when the drain pipes get clogged, it can turn into a nightmare.

So, if you have an underground downspout, keep reading. In this article, I’ll tell you everything you need to know about a clogged downspout underground and how to fix it.

What Is an Underground Downspout?

An underground downspout is a system that contractors install under your lawn through trenches. It redirects rainwater and melting snow away from the house’s foundation.

Sometimes, the pipes of the underground downspout connect between the gutter coming down from the house ceiling and the public sewer system.

Other times, depending on the design, those pipes redirect the water from the gutter to the street or the far area of your lawn.

How To Unclog an Underground Gutter Drain Pipe

There are a few methods that can help unclog your underground gutter drain pipe. But first, you’ll need to locate the clog.

Locating the clog can be tricky, as the majority of the pipes are underground. However, clogs are usually located at transitional points, like elbows and tees.

You can use a garden hose to determine the location of the clog by shoving it down the pipe and marking the spot where it stops.

Measure the distance you marked on the hose to pinpoint the exact clogging location.

There are a few methods to try that can help unclog underground Gutter drain pipes, which are:

Method #1: Using a Garden Hose

Sometimes the clog might be so simple that an ordinary garden hose can unclog it. So, you might want to try simpler methods first.

First, you need to disconnect the downspout from where it connects to the gutter drain pipe. Then, insert a garden hose into the pipe and turn it on to its most powerful setting.

Finally, check to see if the water is coming out of the drain pipe’s other end.

Method #2: Using a Plumber’s Snake

You don’t have to purchase a plumber’s snake for this method. Home improvement stores or hardware stores rent out these tools and it comes in various lengths.

Insert the plumber’s snake as far as you can into the drainage pipes or until it hits the clogged spot. Then, rotate the handle and pull the plumber’s snake out interchangeably.

The plumber’s snake should catch whatever is jammed inside the pipes, or at least poke and break up the blockage.

Run a water hose down the pipes to check if the flow is running smoothly.

Method #3: Using a Hydro Jet

A hydro jet is a tool that ejects water at high pressure. It’s similar to power washing but for the inside of the pipes.

It works by inserting a high-pressure hose inside the clogged drain pipe and blasting the water through it. The pressure helps break down clogs and remove any solid debris stuck in there.

Method #4: Using a Flush Bag

A flush bag, also known as a drain bladder, is a type of instrument made from strong rubber, and it looks like a deflated balloon.

All you need to do is attach it to a water source, shove it down the clogged drain pipe, and turn on the water.

Then, the water inflates the balloon causing it to release a huge gush of water that would clear up the blockage.

There are some precautions for using a flush bag as it could damage your pipes. It can also cause the water to rush back in your direction, which might cause harm.

So, always make sure to use safety gear and be careful when using any kind of tools or machines.

Method #5: Using a Milling Machine

There are different models of milling machines that are highly effective for stubborn blockages like hard build-ups or ingrown tree roots.

A milling machine uses the same approach as the plumber’s snake but with different head attachments and higher power.

Milling machines break up all kinds of clogs and clean the inside of your gutter drain pipes.

Signs Your Underground Gutter Drain Pipe Has a Clog

A clogged underground gutter drain pipe is a serious problem that you should address immediately to avoid any further damage.

Unfortunately, it’s not easy to spot the problem unless it rains. So, here are 5 signs your underground gutter drain pipe has a clog:

1 – Rainwater Isn’t Draining

One of the most obvious signs your rainwater drain pipes are clogged is that you notice it’s not draining at the exit point during a rainy day.

Most types of those pipes drain the water onto the sidewalk. That’s why you need to check the end of the pipes at your sidewalk and make sure it’s flowing seamlessly.

2 – Gutters Are Overflowing

Another major sign your drain pipes have a clog is that the gutter will start to fill up with water and overflow at the top. The excess water will pour out of the gutter and onto the ground beneath them creating erosions.

3 – Leaking Water at the Seams

This sign you can spot during the storm. When the rainwater drain pipes have a clog, you’ll notice leakage at the joints of your downspout or gutter.

4 – Water Stains or Pools on the Ground

When the rainwater drain pipe has a clog, you’ll notice water pooling in your backyard or front lawn around the area where the pipes are buried.

You might also notice water stains on your driveway if the pipes are close by, or even signs of moisture on the floors of your home.

5 – Water Damages in the Basement

One of the most serious signs you notice when there’s a clog inside your rainwater drain pipes is water damage. It can happen in the basement or crawl space of your house.

Water damage in the basement can mean that there’s a clog somewhere in the pipes. It also can be a sign that those drain pipes are emptying the rainwater too close to the house.

How Do Underground Downspouts Get Clogged

Several reasons can cause your underground downspout to get clogged, which are:

Pipe Damage

If the pipes weren’t buried deep enough, heavy equipment or vehicles can damage them.

Additionally, any utility work that requires digging, like fencing or electrical work, might damage the pipes during the process.

So, make sure to inform the handyman you hired about the trail your drain pipes go through. That way you could avoid any accidental damages.

Pipe Screws

One of the main reasons is screws holding the downspout to the underground drain pipes.

If those screws are too long, they might block the path for some fallen debris and potentially cause clogging. So, make sure to always use smaller screws.

Some ‌things that could get caught up inside the drain pipes include but are not limited to:

  • Leaves, debris, small twigs
  • Small animals, rodents, or snakes
  • Children’s toys or balls
  • Birds’ nests

Tree Roots

Tree roots can cause problems, especially for perforated pipes.

Naturally, tree roots follow the water source, and that causes the roots to enter through these little holes. Gradually, the roots will grow larger causing blockage and damage to the pipes.

Pipe Installing Angle

If the underground gutter drainage system wasn’t installed sloping at a proper angle of at least 1%, this will cause slow water flow.

Consequently, over time, the debris carried by the water will accumulate and cause blockage to the pipes.

How To Prevent Future Clogging

There’re a few precautions to prevent any future clogging which are:

  • Check for leakage: Make sure to regularly check for any of the leakage signs mentioned previously.
  • Clean and maintain: It’s important to habitually maintain and clean your underground gutter drainage system before the wet season starts.
  • Install gutter guards: Gutter guards keep the leaves, debris, and branches out, which helps maintain the water flow.
  • Install a downspout strainer: Downspout strainers also make sure that no debris gets into your downspout.
  • Install a downspout filter box: A downspout filter box catches any hard matter that manages to get through your downspout.

Pros and Cons of Having Underground Downspouts

Underground downspouts are one of the most effective ways to keep water from damaging your house, especially if you’re living in an area with high precipitation levels.

Pros of Having Underground Downspouts

Here are the pros of having underground downspouts:

They’re Perfect for uneven Terrains

The above-ground gutter drain system is not effective and hard to install when it comes to uneven terrains.

Unlike the underground gutter drainage system, which is perfect in these kinds of situations because the terrains are easier to adjust in this case.

They Protect the Foundation

An underground downspout drainage system helps keep the water away from your house and protects your house’s foundation.

Additionally, it protects your and your family’s health by keeping the moisture levels low, which prevents the growth of mold and mildew.

They Maintain the Property’s Aesthetic

For gutter drain pipes to be effective, they have to transfer the water about 7–10 feet away from the property’s foundation.

Imagine that length of pipes going through your front lawn ruining the beautiful landscaping. That’s why underground gutter drain systems are great for maintaining the property’s aesthetic.

They’re Excellent for High-risk Homes

High-risk homes are those located in areas that experience heavy rain or snowfall, which aren’t simple to handle with an above-ground drainage system alone.

In these areas, underground gutter drainage systems work perfectly alongside other waterproofing solutions to better protect high-risk homes.

Those solutions include hydrophobic insulations, sump pumps, sealants, interior french drains, vapor barriers, and dehumidifiers.

Cons of Having Underground Downspouts

Although there are many advantages to underground downspouts, the downsides of having them are worth considering.

Here are the cons of having underground downspouts:

They Get Clogged

Of course one of the main concerns about having an underground rainwater drainage system is that it can get clogged.

Additionally, it can be really challenging to pinpoint the exact location where the clog is.

They’re Hard to Clean

Underground downspouts draining pipes are hard to service and maintain. That’s because of poor accessibility. Unlike above-ground downspouts, which are easy to access and clean.

They’re Prone to Freezing

During extreme temperatures, the underground downspout pipes can freeze. This makes them vulnerable to breaking under the pressure of solidifying water.

Additionally, the frozen water inside the underground pipes takes longer to melt than above ground pipes.

They’re Expensive

The cost of installing a well-designed underground downspout drainage system can be much more expensive than a traditional above-ground downspout.

However, nothing is worth more than your family’s health and well-being.

How Are Underground Downspouts Installed

The process of designing and installing an underground gutter drainage system can take anywhere from 1 to 3 days.

It can be a bit costly to install, however, the advantages of such a system outweigh the disadvantages.

There’s one important thing to do before you start the process, which is to call 811. It’s the national call-before-you-dig number.

They provide you with the location of any buried utility line that you might damage during the digging process.

Here are the steps for installing an underground downspout drainage system:

  1. Determining the path of the pipes that will run through your lawn
  2. Digging the trench about 12–48 inches deep underground with a 1% slope
  3. Laying down the pipes into the trenches
  4. Installing tees where the pipes intersect
  5. Directing the pipes towards the sewer system or the street
  6. Installing reducers and adapters where applicable
  7. Hooking your downspout to the drainage pipes
  8. Filling the trenches up and leveling them back with the ground

Final Thoughts

Gutter drainage systems are really practical, especially in high-risk areas. It helps protect your house and redirects water away from its foundations.

However, a clogged downspout underground can be extremely annoying because it’s not always easy to locate the clog’s location.

Thankfully, there are a few methods that will help you unclog your underground drain pipes, like a hydro jet, a flush bag, a milling machine, or a plumber’s snake.

If none of those methods work, you can always call your local plumber or hire a professional service to do the task.

Share this post: