September 05, 2018

It is such a nice feature when a home’s gutters and downspouts enter the  ground so that rain water exits the property underground. The benefit of such an in ground drainage system, is that the water does not flow across the top of the landscaping, which could be messy, muddy or cause damaging erosion.  In colder climates, over-the-soil drainage can cause additional problems; for example when the flow of rain water crosses a walkway or driveway and freezes into a sheet of ice. The risk of a “slip and fall” accident can be enough to motivate a homeowner to pursue an expensive in-ground drainage project.


When you see a home’s downspouts (also known as leader pipes) entering the ground, the rain water will flow to meet one of the following conditions.


  • Underground pipe, slightly sloped clear (not clogged) system drains down hill and exists on top of the ground somewhere further away from the building.
  • Underground large drainage pit, hopefully large enough to capture the water.  These pits are usually initially filled with drainage stone so the water can fill the air space in between the stones.
  • Either of the above scenarios, however years of drainage has carried debris but the system is clogged and water can no longer enter.

Many homes have gutters and downspouts that are unprotected.  These unprotected gutters allow debris, small and large, to enter the gutter, travel down the downspout and into the in ground drainage.   While the in-ground drainage system might allow a certain amount of debris to enter and continue to flow, allowing such debris into the system will eventually cause the system to reach capacity and will eventually clog.   Clearing such clogs can be very expensive and can sometimes even be impossible. A drainage pit filled with stone may receive just enough debris that the rate of water flowing down the downspout will exceed the rate of water that the pit can accept,  causing back pressure and overflow. For this reason, it is a good idea to have a loose or wide-open fitting between the downspout and the drainage pipe so that when the in-ground drainage system can no longer accept 100% of the water, that water can overflow at the loose fitting down near the ground.   Such a loose fitting keeps the water from backing up the leader pipe all the way to the gutter. Water will take the path of least resistance, so it makes sense for that path to allow out-flow down near the ground rather than up at the fascia and soffit.


While a home may be getting away with allowing debris to enter the pipe or pit for now, eventually the system will reach it’ capacity, so it makes logical and financial sense to stop the debris from entering the drainage system.   Rain barrel technology uses screens and filters to keep the debris from entering the rain barrel, however these screens and filters need to constantly and consistently be cleaned and maintained or else the system will clog quickly.

Early in my career, I had a customer complain that none of her in-ground drainage pipes were flowing. We cleared the pipes with an expensive roto-rooter-type of service, and of course she then asked, “how do I keep this from happening again”?    Our solution was to put a small wire strainer, which is in the shape of a lightbulb, into each gutter outlet tube. These wire strainers worked well to keep the debris from entering the leader pipe, but unfortunately they caused her gutters to overflow every 2 to 3 weeks.    We had solved one problem but we had created a maintenance nightmare because the wire strainers had only a small amount of surface area to trap the debris. Within a very short amount of time, leaves and tree seeds would pile up surrounding the wire strainer, completely stopping the water flow and causing the rain water to pour over the side of the gutter.    I remember back then wishing that there were a full length gutter strainer on the market. The greater the amount of surface area encompassed by the gutter strainer, the more debris the strainer will accept while continuing to flow freely, and thus less maintenance would be required to keep the entire system functioning. Since that time, a gutter guard has come onto the market which acts as a full length gutter strainer and is incredibly easy to clean and maintain while keeping the debris out of the storm drains..  Click here to see a full length gutter strainer  .


Covers, screens and other helmet-type devices exist, but they do not all operate in a manner that will keep your storm drains clear.   The helmet-type devices, also known as covers, have a slot at the outermost edge, which is supposed to allow water into the gutter while also keeping debris out.   The issues with these devices are the fact that when it rains heavily, the cover can cause the fast water to skip right past the gutter and cascade over the side such that the water is not even entering the gutter.   Additionally, while the slot is thin, the size of the slot is long so that long thin debris such as twigs, leaves and any thin item can flow with the water and fit into the slot so it really does not keep debris out of the downspouts or out of the storm drains.   When these items require maintenance, there is the added difficulty of requiring tools, skill and fasteners to disassemble and reinstall for cleaning. The gutter screens that have large openings to accept the water, continue to also accept debris because the debris which is in the lengthwise position can still fit through the screen apertures.  Thus lengthwise and small debris will continue to enter your storm drains if you use a screen with large enough openings. Conversely, the screens with the smallest openings will keep your gutters and storm drains clear, however the microscreen openings are so small that they clog up in no time and they also cause the fast water in heavy rains to skip past the gutter.   When leaves lay on the screens, they create a flat mat of sticky debris which also aids to stop the water from entering the gutter and cause it to bypass the gutters altogether.


In order to avoid the high cost of having to clean out your in-ground storm drainage system,  some sort of strainer or filter device will be required and some degree of maintenance will also be required in order to both keep the drainage clear but also simultaneously keep the gutters, downspouts, and drainage flowing.   Small strainer devices can be used solely over the outlets and downspouts, but those small-surface-area devices require very frequent maintenance because they do not have enough surface area to accept a volume of debris while also continuing to flow.  The small wire strainers will keep debris out of the downspout but they will clog frequently and cause the gutter to overflow when clogged. The greater the surface area of the strainer, the less maintenance that will be required. A full length gutter strainer that keeps the debris out, will keep your storm drains clear and also decrease the amount of maintenance required to keep the entire system flowing.


Alex O’Hanley


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