Yard flooding mitigation project
I have an issue that I'm having a problem with dealing with due to the large scale nature of the project. Apparently about five years ago, the neighbor across the road did a massive manipulation of the terrain to create a flooding disaster for this person. The water seems to be coming from a 12" culvert pipe nearby that drains into a different neighbor's roadside ditch. Looking at satellite imagery from different years, you can clearly see how changes in the landscape have created this "seasonal raging river" that is literally washing away this persons lawn. I would guess that about 120+ cubic yards of terrain has been washed away by looking at historical photos and seeing the massive depression in the landscape.
With that said, and just short of "blowing up" the culvert (as that would be illegal), what do you think would be the best way to mitigate this problem? The home owner doesn't want an above ground water feature as I suggested. Maybe we could "control" but not block the output of the culvert with a device and then just trench some rigid 4" or 6" tubing down - french drain style?
Right now I'm considering raising the property level behind the easement with low berm and install the drainage tubing.
What do ya'll think?