Here you can see the exit point for the french drain in the front yard. The pipe itself is perforated to allow water to enter the pipe (instead of being drawn into the house). There is also a sleeve – also called a sock – surrounding the drain. This sleeve allows water to pass through, but won’t allow dirt or sediment to get into the pipe. Without a sleeve, sediment could build up restricting or even stopping the flow of water in the pipe.
The exit point itself is carefully designed. You can see there is a green dome on top which will pops up gently to release water, and then it goes back into its housing. Since only water pressure can lift the dome, this ensures that no rocks, dirt – or even small animals – can gain entry into the french drain.
Drainage grates are also sometimes used in french drains and can be placed anywhere along the length of the pipe. As in this case, it is generally best to install grates at the lowest points in the yard where water is likely to pool and cause problems. Use of a drainage grate like this allows an easy path for water to quickly be whisked away from the area where it can’t cause damage.