When you say french drain are you talking perforated lines or catch basins with PVC pipe? If it is PVC pipe then i would look into Hydro Jetting the pipe from basin to basin. This is what I have at my house and every couple years I hydro jet the pipes.

 

Sorry it is a catch Basin but has corrugated pipe.

 

That black corrugated pipe should be against the law to use. Tree roots love it.
Your drains are filled with tree roots.
Seen it too many times

 

I'm guessing Gofish2day is probably spot on. Might as well dig it all up and start over.

 

if it's corrugated pipe, that's the problem. Rip it out and start over and go with solid pvc.

 

Would have to agree corrugated pipe is not the best way to go. Maybe running a camera trough to see how bad it is from section to section. May be only a certain section that is bad.

 

Sounds more like a drain than a French drain. If it's the black polypropalene ADS pipe it may be full of tree roots. If it is of sufficient diameter, relatively round, on grade, with reasonable alignment throughout and has an open outfall end you may be able to push a smaller diameter pipe into it and then make the re-connections. Good luck.

 

Seems to me you need to talk to your neighbors who share the line. Won't do any good for you to spend money replacing a line if they do not and the obstruction (assumed) is on their property, or in the easement behind their property.