How to Fix an Ineffective Curtain Drain

Dig into the trench containing the curtain drain with one of the sanitary tees or wye fittings. Sanitary tees should be located on each corner of the curtain drain, while wye fittings are on the long length of pipe on the sides. Locating wye fittings can be difficult if you don't know exactly where they are. The only functional difference between a wye fitting and sanitary tee is that the third pipe is perpendicular in a sanitary tee but at an angle on a wye fitting.

Remove the plug blocking the third pipe in the fitting. Don't disconnect the fitting from the curtain drain.

Insert the power snake into the third pipe of the fitting and push it through the pipe. Use the foot pedal to rotate the power snake clockwise as you push it through the pipe. Continue until you feel the power snake resisting.

Pull the power snake back a few feet while rotating it counterclockwise with the foot pedal. After moving a few feet, reverse the snake with the foot pedal turning it clockwise and push it back into the pipe until you feel resistance again. Repeat this back-and-forth motion until you no longer feel a clog in that section of pipe.

Repeat these steps for each fitting in the curtain drain until it resumes draining properly. Fill in the holes in the trench when you are finished.