Can You Reroute a Downspout That’s Overwhelming a Buried Drain?

Yes, in most cases you can reroute a downspout that’s sending too much water into a buried drain. The solution usually involves adding new downspout drops, redirecting water flow to other areas of the building, or running the gutter line in a new direction so runoff is distributed more evenly rather than all funneling to one overwhelmed exit point.

A commercial property manager in Kearney, MO recently called us with exactly this problem. A previous contractor had routed a downspout directly into a buried pit drain, and the drain simply could not handle the volume of water coming off the roof. Water was pooling, the drain was backing up, and they needed a better solution before things got worse.

This is more common than you might think. When a building’s drainage system is designed without accounting for actual roof runoff volume, buried drains take on more than they can handle. The good news is that gutters and downspouts can usually be reconfigured to spread that load. We offer rain gutter services that include exactly this kind of drainage rerouting work, and we always start with a free on-site assessment so we can see what we are actually dealing with before making any recommendations.

Why Would a Buried Drain Get Overwhelmed by a Single Downspout?

A buried drain gets overwhelmed when the volume of water funneled into it exceeds what it was designed to handle, which often happens when too many downspouts feed into one exit point or when the original drain was undersized.

Most buried drains are sized for a specific flow rate. When a building has a large roof area draining toward one low point, and all of that water exits through a single downspout into one buried drain, the system gets flooded fast. Heavy rain events in the Kansas City metro can dump a lot of water in a short window. One drain just cannot keep up.

It is also worth noting that older commercial buildings were sometimes retrofitted with drainage solutions that were not engineered with the full roof surface in mind. The original gutter layout may have never been revisited, even as water problems got worse over time.

What Are the Signs That Your Downspout and Buried Drain Setup Is Failing?

The most obvious sign is standing water near the drain outlet or at the base of your building after rain, but there are several other warning signs worth watching for.

• Water overflowing from the gutter even when it is not clogged
• Soggy or eroded ground around the buried drain access point
• Water seeping toward your foundation or into the building
• Gurgling sounds from the buried drain during or after rain
• Visible pooling on the roof or at a single low spot
• Only one or two downspouts handling a long stretch of roofline

That last point is a big one. If you have a long building with only two downspouts, you are relying on a very small exit capacity for a very large roof. Adding downspout locations is often one of the most cost-effective fixes available.

How Can You Reroute a Downspout to Relieve Pressure on a Buried Drain?

The most practical approaches involve adding new downspout drops along the gutter run, redirecting the existing gutter line around the building, or diverting water to a surface outlet in a location where it can discharge safely without causing damage.

Adding More Downspout Locations

Instead of sending all the roof runoff to one point, we can cut into the existing gutter and add additional downspouts at intervals along the building. This splits the water load and dramatically reduces what any single buried drain has to handle. For a long single-story building, this is often the simplest and most affordable fix.

Rerouting the Gutter Around the Building

If the current gutter layout channels water toward one problem corner, we can sometimes run new gutter sections along a different wall. This redirects flow to a location where it can be discharged more safely, whether that means a surface outlet on a graded area, a different drain, or simply a splash block away from the structure.

Disconnecting From the Buried Drain Entirely

In some cases, the best move is to stop using the buried drain altogether for that downspout. If there is a graded area nearby where water can discharge onto the surface and flow away from the building naturally, a simple downspout extension or elbow can do the job without any buried infrastructure involved.

Frequently Asked Questions

Can you add downspouts to an existing gutter system without replacing the whole thing?

In most cases, yes. We can cut into an existing gutter run and add a new outlet and downspout without replacing the entire system. This depends on the condition and type of the existing gutter, which is why we always look before we commit to a specific scope of work.

What if my commercial building has a non-standard gutter style?

Some older commercial buildings have built-in box gutters or specialty profiles that require different equipment and techniques. If that is the case, we will tell you honestly during the assessment. We would rather give you accurate information than take on work that is outside our wheelhouse.

How do I know if my buried drain is undersized or just clogged?

A clogged drain will usually back up suddenly and clear up again once the clog is removed. An undersized drain will consistently struggle during any significant rainfall, even when clean. If cleaning the drain does not solve the problem, the issue is almost certainly capacity, not debris.

Is this the kind of work Jet Stream Guttering handles?

Yes. We handle gutter rerouting, downspout additions, and drainage reconfiguration for both residential and commercial properties. Visit the Jet Stream Guttering homepage to get an overview of what we offer, or reach out directly to talk through your specific situation.

Ready to Stop Fighting Your Drainage System?

If your buried drain is getting overwhelmed every time it rains, the fix is usually simpler than you think. Adding a downspout, rerouting a gutter section, or redirecting flow to a better discharge point can take the pressure off a system that was never designed for the load it is carrying.

We offer free on-site assessments for commercial and residential properties in Kearney, MO and the surrounding area. We will come out, look at what you have, and give you an honest answer about what can be done and what it will take to do it. No pressure, no upsell, just a straight conversation about your roof drainage.

Contact us today to schedule your free assessment. We are local, we are responsive, and we would rather solve your problem the right way than patch it and send you a bill.