Most homeowners know what a gutter cleaning looks like. Someone cleans out the debris, flushes the downspouts, and the water flows freely again. That covers the vast majority of gutter systems. But for homes with underground downspout drains, the picture is a little different.
When your downspouts connect to pipes that run underground, the water from your gutters has to travel through that buried system before it exits at the street, a dry well, or a drainage point in the yard. That underground section is out of sight and, for most homeowners, completely out of mind. Until it backs up.
Underground gutter jetting is the service that clears those buried lines when a standard gutter cleaning is not enough to solve the problem. At Sunset Hill Window Cleaning, we offer this service to homeowners across the Denver area who are dealing with drainage issues that go deeper than the gutter itself. Here is everything you need to know about it.
1. What Is Underground Gutter Jetting?
Underground gutter jetting is a professional drain-clearing method that uses high-pressure water to blast through blockages inside buried downspout pipes. A flexible hose is fed into the underground line through the downspout opening, and water is forced through at high pressure to break up and flush out whatever is causing the clog.
The process is thorough in a way that snaking or manual clearing cannot match. The pressurized water does not just poke a hole through the blockage and leave debris behind. It scours the interior walls of the pipe and pushes everything out completely, restoring the drain to its full capacity.
It is also safe for the pipe when done correctly by someone who knows what they are doing. The pressure is controlled and the hose is sized to the pipe, so the process clears the line without damaging the underground infrastructure.
2. How Underground Downspout Drains Get Clogged
Underground drains clog gradually, and the process usually starts at the surface and works its way down over time.
Debris from the Gutters
Leaves, seed pods, shingle grit, and organic material that make it past the gutter outlet and into the downspout can accumulate at bends and low points in the underground pipe. In Denver, cottonwood seeds are a particularly common culprit. They compact into a dense, fibrous mat that water cannot push through.
Tree Root Intrusion
This is one of the more serious causes. Tree roots naturally seek out water sources, and an underground drain carrying runoff from your gutters is exactly the kind of consistent moisture source roots are drawn to. Over time, roots work their way into joints and cracks in the pipe and grow to the point where they restrict or completely block the flow of water.
Soil Settling and Pipe Displacement
Colorado’s clay-heavy soil expands and contracts with moisture changes throughout the year. Over time, this movement can shift the underground pipes out of alignment, creating low spots where debris collects and water pools instead of draining. These low spots become natural blockage points.
Sediment and Mineral Buildup
In areas with hard water, mineral deposits can coat the interior walls of underground pipes over years of use, gradually reducing the diameter of the pipe and slowing drainage. Combined with other debris, even a partially narrowed pipe can back up completely during a heavy rain.
3. Signs Your Underground Drain May Be Clogged
Because the problem is underground and out of sight, homeowners often do not catch it until a heavy rain makes the symptoms impossible to ignore. Here is what to watch for:
- Water overflowing from the gutters even though the gutters themselves appear clear of debris
- Water backing up at the base of the downspout or pooling around the foundation during or after rain
- The downspout outlet at the street, yard, or curb is not releasing water during or after a storm
- Soggy or waterlogged areas in the yard that follow the path of the underground pipe
- A gurgling sound coming from the downspout area when water is trying to drain
Any one of these on its own is worth investigating. More than one showing up at the same time is a strong signal that the underground line needs to be cleared.
4. Why This Matters More in Denver Than You Might Think
Denver’s climate creates a few conditions that make underground drain problems more common here than in many other parts of the country.
Heavy Rainfall in Short Bursts
The Front Range is known for afternoon thunderstorms that dump significant rainfall in a short window of time. A partially clogged underground drain might handle light rain without any visible symptoms, but when a storm pushes a large volume of water through the system quickly, a compromised drain will back up fast and the overflow has nowhere to go but around your foundation.
Cottonwood Season
Late May through June, cottonwood trees shed their seeds in volume across the Denver metro area. The fluffy white seeds get into gutters, compress in downspouts, and make their way into underground drains. Homeowners who do not clear their gutters during or after cottonwood season are often setting themselves up for underground drain problems by late summer or fall.
Active Tree Canopy in Older Neighborhoods
Many of Denver’s established neighborhoods, including those in Lakewood, Arvada, Wheat Ridge, and older parts of the city, have mature tree canopies with root systems that have been spreading for decades. Homes in these areas are more vulnerable to root intrusion in underground drain lines than newer construction in areas without established trees.
5. Underground Gutter Jetting vs. Snaking: What Is the Difference?
Homeowners sometimes ask whether snaking the drain would accomplish the same thing. The short answer is that snaking and jetting are different tools for different situations.
A drain snake is a rotating auger that drills through a blockage and creates a channel for water to pass through. It is effective for certain types of clogs, particularly solid obstructions. But it does not clean the pipe walls, and it can leave debris behind that will re-accumulate quickly.
Jetting uses pressurized water to blast the blockage apart and flush everything out of the line completely. It also cleans the interior of the pipe as it goes, removing the sediment and buildup that snaking leaves behind. For underground gutter drains dealing with compacted organic debris, mineral buildup, or root intrusion, jetting is the more thorough and longer-lasting solution.
6. How Often Should Underground Drains Be Serviced?
For most homes with underground downspout drains, having the lines inspected and cleared every one to two years is a reasonable maintenance schedule. Homes surrounded by mature trees, particularly cottonwoods or elms, or homes where root intrusion has been an issue in the past may benefit from annual service.
The best time to schedule it is in late fall after the leaves have dropped and the gutters have been cleaned for the season. That way you are going into winter with a clear system, which matters in Colorado where freeze and thaw cycles can turn a partially blocked pipe into a fully blocked one.
If you have never had your underground drains serviced and your home has a buried downspout system, it is worth scheduling an inspection. Most homeowners are surprised to find out how much has accumulated down there over the years. Pairing it with your regular gutter cleaning is the most efficient way to handle both at once.
Dealing with a Backed-Up Underground Drain? We Can Help. Sunset Hill Window Cleaning provides underground gutter jetting and gutter cleaning services throughout the greater Denver area, including Lakewood, Arvada, Littleton, Wheat Ridge, Highlands Ranch, and surrounding communities. If your gutters are overflowing and the downspouts look clear, the problem may be underground. Contact us today for a free assessment. We will find the problem and clear it out.
