How do I clean a french drain/yard drain on a slope that may be clogged with dirt/rocks?

Question

I live on a slope, with drain holes in retaining walls at the bottom of my property to drain the upslope portion of the property. When it rains, water does not flow out, leading me to believe that they are clogged. What is the best way to clean out these drain holes to allow my property to drain water properly.

Answer 1

Well, after I paid a company to come out and clean mine out, I learned the DIY trick. I, too, live on a slope with a drainage system that is intended to drain off the slope. The company I called charged me $250 to basically blow out the lines. I found you can do the same thing with a pressure washer. It is a wet and messy job and I found shoving PVC pipe down the drain helps push the clogged dirt and debris through the line, but it works.

Answer 2

Understand a french drain is supposed to be made up of rocks that allow the draining of the water out of the retained area. What should have happened is a layer of filter material should be placed above the drainage rocks to keep silt out of the rocks.
Now for the bad news, the only way to clear the french drain is to dig it up and relay the drain. So if it is not causing you any problems, I wouldn't mess with it. The water may be finding it's own natural way out of the ground, especially if you live in an area that has been dry.