Underground Rainwater Drainage Explained

Once the rain runs off the roof and has been captured by the gutters and funneled to the ground, everything is great, right? Well, maybe not.

There are three main components of a rain gutter system: the gutter itself, the downspout/extension and the underground drain pipe. This last portion is what guarantees you are not swamping your basement and creating problems. Where does your drain pipe end? Typically, they mosey out to the street, in urban areas.

The average roof surface area is around 2,000 square feet. During a rain shower of one inch, the gutter system of this average roof size will catch well over a thousand gallons of water. 


Needless to say, if the drain pipe is non-existent or clogged, it could raise havoc on your home.

  • Your basement or ground floor and foundation will be severely weakened.
  • Your yard will become a lake and ruin your lawn.
  • The basement and ground floor will be overrun with mold and mildew. They cause health issues, especially for young children, the elderly, and those afflicted with a respiratory disease.
  • If you have an HVAC system with the fan unit located outside, near a wall of the house, as they usually are, the unit may experience problems, costing you a great deal of money for repair.

Quick Check

If you know where the drain pipe funnels the rain, grab a friend or family member and perform a quick check. While you stand at the end, have your partner pour water onto the roof using a hose so it runs to the gutters. If you do not see any water coming out after a couple of minutes, then clearly there is a problem.

Underground Rainwater Drainage Solutions

There are various types of ditches you can build, to drain away from the house. You can also move the water further from your foundation with downspout extensions. Some families catch the water by having the downspout empty into barrels or a cistern.  Plus, you can ask your local home center store for other ideas to solve the problem or recommendations on professional drainage services.


FLEX-Drain - the underground rainwater drainage solution


Amerimax Provides a superior offering with its FLEX-DRAIN line of products. Visit your nearest home center store and ask for Amerimax.