Massive drainage abuts yard

[serenedi]

What is the name of your state? Pennsylvania
There is new construction going on next to my property. Due to heavy construction above us these two properties now flood during rain and thaw. The township is allowing the adjacent lot to build a massive drainage which is approximately 8 feet wide by 100 feet long with a large pool at the end of the drain to direct run-off water. This drain consists of large rocks. It starts out against the two property lines at the front meeting point and proceeds down and eventually gets about 10 feet away from my property line. I have complained to the town that if anyone were to be injured in this drain they could fall onto my property and I would have liability. They told me to let the courts figure that out. Don't setback regulations restrict the construction of this type of "structure". Aren't setback reg's around to protect both property owners. Please advise.What is the name of your state?