How to Unclog Drain Pipe from Underground Rainwater Drain

A drainpipe of rain is usually installed to carry water away from your house. Many of these pipes are placed underground to avoid the ugliness of the pipes supported on the floor next to the house. An underground drainage pipe can clog in a variety of forms, including leaf accumulation or damage to the pipe itself. The methods used to clear a drainage pipe, range from something simple to ask the help of a professional.


  1. Check where the water drains out of the pipe. Many times this end of the pipe has a sheet guard or metal screen. Take off your guard and remove any debris you can find. Light a flashlight in the opening to see if you can detect the lock.
  2. Disconnect drain from where it connects to drain pipe. Remove the guard at the other end of the drain pipe, if any. Turn on a garden hose in its most powerful configuration and run the water through the drain spout. Check to see if water and debris are coming out of the other end of the spout.
  3. Rent a plumber’s snake at the hardware store or home improvement store. Pass the snake as far as you can through the drain spout. Remove the viper and run water through the pipe with a hose. Check to see if the water comes out of the other end of the pipe.
  4. The viper passes through the opposite end of the drain, if it was not long enough to pass through the entire pipe at the other end. Pass the snake as far down the spout as you can. Remove it from the spout. Water flows at the opposite end of the pipe.
  5. Put a hose at one end of the pipe. Check to see how far it goes before it crashes. Draw a mark on the hose with a boom and remove the hose. Put this long mark on the underground drainage pipe. Dig the floor at the blocking point and inspect the pipe. It is possible that it has been damaged by the roots. A damaged pipe will probably have to be replaced.
  6. Call a professional plumber. He probably has a broader and longer snake.

Tips & Warnings

  • Some underground drainage pipes are installed in sophisticated systems that include log covers above where the pipes change direction. Remove the registration caps and disconnect the pipe where it changes direction. Try to pass a viper in both directions at these points in the pipe.
  • Stop running water in the pipe if it goes back.