While underground downspouts are less of an eye-sore than other lawn draining options, it can be tricky tracing the pipe’s end if you weren’t there when it was installed. So, where do underground downspouts go?
In most cases, buried downspouts systems resurface to drain up ground somewhere away (1-3 feet) from the house foundations. It could also connect to city drains and collect the running water from entire neighborhoods at once.
In this post, we’ll go over the possible routes that your downspout could follow, how to locate the end, and what problems to expect. Let’s jump right in!
The main goal with underground downspouts is to redirect the gutter rainwater away from the house itself. This could mean releasing the water off to vents, pop-emitters, culverts, storm sewers, dry wells, or many other options.
Let’s break down the likely places for an underground downspout to drain into two main categories:
One of the easiest routes for an underground downspout to take is to simply resurface back on your property to drain. While this might sound alarming, it’s usually a safe system, provided that you don’t live somewhere with heavy rain.
In some cases, there will be a connected pop-up emitter that spreads the water over a larger surface area. This can be a nifty little trick to avoid pooling in your yard.
Meanwhile, other pipes will simply drain onto a nearby gravel pit that allows the rainwater to naturally flow back into the water table.
It’s crucial with this type of downspout to make sure that you never redirect the water into someone else’s house foundations.
Plus, if the buried pipe isn’t installed on a slope, you’ll risk backlogging, creating a pooling belly, and mildew accumulation. Ideally, the pipes should flow downhill from the downspout to the exit site.
In some neighborhoods, the underground downspout will lead to a city drainage system to keep the water off properties entirely.
This means that your pipes could connect to:
- Gutters on the side of the road
- Main culverts
- Remote storm sewers
The main issue with city drainage is that any minor problem in one house’s pipes could cause problems for the entire neighborhood.
For instance, if someone drills a hole into the main storm pipe without professional consultation, the system could leak or get blocked for the whole street.
While it’s not impossible to find houses where the downspout connects to floor drains, it’s not the ideal setup.
Although the downflow helps flush the debris down by the force of gravity, any clog along the vertical pipe poses a huge risk to the basement foundation. Meanwhile, if the under-floor section gets clogged, you’ll have water back flowing into the basement or even the crawl space.
Keep in mind that roots, leaves, and other gutter fallout can easily clog the floor pipes. That’s why in-building drains aren’t really a good drainage option to consider for your underground downspout.
In some homes, the downspout is connected to the sump pump system with French drains to hit two birds with one stone. If you know where the buried pipes drain, this could be a valid option.
However, you generally want to avoid mixing greywater lines with downspouts.
Depending on where you live, it might be illegal to dispose of greywater with your underground downspouts that flow into soil, storm pipes, sewer drainages, or nearby water bodies.
The main problem with moving into a previously-owned house is that you never really know all the nitty-gritty details right off the bat.
That’s mainly why it can be quite puzzling to try and figure out where that buried pipe goes from the downspout.
Here are a few methods to help you trace the underground pipe’s path:
Before you jump into expensive and drastic solutions, try to look for the exit site on your property first.
Whether it’s hooked up to a pop-up emitter or released right before the curb and into the street, it should be fairly easy to identify.
You’ll just need to take a walk around your property while hosing water down the main downspout and look for an exit site on your lawn.
While the first step is convenient and mostly hassle-free, you can’t always spot the exit site on your lawn, especially with a clog somewhere along the line. This means that you can just hose water down the pipe and wait for it to pop at the other end.
In cases like this one, you’ll have to resort to machinery to map out the pipe’s path underground.
The most commonly used option here is a pipe drain cleaner. Those have long hose-like attachments (usually less than an inch wide) that you push into the downspout’s input.
Once the cleaner is in, it starts rotating and hitting the pipe underground, making a very loud clacking noise that you can follow. With a can of spray paint, you can trace the sound from start to end.
However, you’ll only be able to go as far as the path is clear ahead. If there’s a clog somewhere there, you’ll have to snake it out first before completing the mapping step to reach the exit site.
To take the guesswork (and actual physical work) out of the equation, you can always just leave it to the professional.
Odds are, they’ll also start with mapping using a pipe drain cleaning machine. However, if that fails, they’ll have some tricks up their sleeves to locate the existing site.
If you end up needing major dig-ups and pipe replacements, you’ll probably be glad you had the professional handle it. In most cases, it’ll be way cleaner and more efficient than a regular DIY job.
One other option to consider is to just ask around. If you’re still in contact with the previous owner, they could have a better idea about the downspout system.
Sometimes, even the neighbors could point to possible drainage sites if the setup is similar along the neighborhoods. This is particularly true with pipes that drain to city lines, culverts, or storm drains.
It’s not always a productive solution, but who knows? You might just get lucky with a neighbor who knows his stuff!
If that doesn’t work out for you, you might have to get in touch with your local public works department for help.
Mapping out where the downspout goes once it dips below the ground level could sound like pure guesswork, but it can be fairly simple if you know the common routes.
So, where do underground downspouts go?
Usually, the pipe could drain onto your lawn through pop-up emitters, or it might just flow onto gravel pits. Alternately, some systems lead to city facilities like sidewalk gutters, culverts, storm sewers, or dry wells.
If you’re not sure which setup is used in your house, try looking around your yard for exit sites or get a piper cleaner machine to trace the path through the noise.
I have a bachelor’s degree in Computer Information Systems and over 10 years of experience working in IT. As a homeowner, I love working on projects around the house, and as a father, I love investigating various ways to keep my family safe (whether or not this involves tech). I’ve also played guitar for almost 20 years and love writing music, although it’s hard to find the time these days.