Drains and Names

Posted by & filed under Blog.

I want to clear a big misconception in the home/garden/yard/average homeowner community. Before I get high and mighty or come across as sounding like “I can’t believe you made such an amateur mistake. How did you not know the difference,” I want to come forth by saying: “I had no idea what-so-ever.”

Prepare yourself. If you didn’t know this already, this is not a French drain.


Let me clarify that again. This is NOT a French drain.

stormdrain cross section

Yes, those little green squares in the ground. Those are not French.

Now maybe you already know what a French drain is, and maybe I’m the only one in the world who thought that those little green grates in the ground were called “French drains,” but I’d like to think that everybody (save for the few elite) refers to them in the same ignorant manor. From here on out I will assume that you were as confused and surprised as I was. (Which I realize you probably can’t contain your excitement right now)

If that isn’t a French drain what is? Well before we get into that let me enlighten you as to what you’ve been (undoubtedly) been mistakenly calling French drains.

Behold the beauty of the Surface Drain

long surface drain

Now any of the above pictures can be called a surface drain. Why? I bet it has something to do with them being a drain… near the surface. Yes, everything from a small green square to a long grey rectangle is called a surface drain. Now this non-French drain is mainly used for collecting (I’m sure you can guess) SURFACE water. Sometimes in an area of heavy rain or low soil percolation (to filter or trickle) you might need to use a surface drain for that excess of water. These should move water away from the surface quickly and efficiently, but doesn’t do much for groundwater.

Doesn’t do much for ground water you say? What about…

French Drain

That’s right. Beneath those rocks is our French drain you’ve been so curious about.

Let’s get a better look at what it actually looks like, and maybe also a nice diagram.


And now for the diagram.


Not what you thought is it?

A French drain is basically a trench filled in with gravel and rock that has a perforated pipe to redirect both surface and groundwater away from an area. The main goal here is to prevent ground and surface water from penetrating or damaging building foundations, but French drains are also used behind retaining walls sometimes to relieve ground water pressure. The reason the pipes are perforated is that when water seeps through the rocks, the pipe will collect the water and be redirected away from your foundation.

Now my mom used to call those little green squares in the backyard (and probably still does) French drains. Whether that’s because she was misinformed or just wanted to sound more sophisticated, I don’t know. Because she called it that, I only knew it as such. This might not be life changing information, but now you too can correct people at dinner parties and social gatherings when someone foolishly throws the term “French drain” out without being civilized enough to know what one actually is.