Greetings!

I live along Difficult Run and over the past 20 years there has been significant erosion along the eastern side into our property in such a way that we theoretically own land on the OTHER side of the stream.  Recently, there has also been a large amount of trash and tree debris collecting where trees have fallen into the stream.  Who is responsible for the clogging of the stream and the collection of debris?  Since we have substantial land in the valley, it does not impose any risk to our house but I am concerned about the appearance, possible damage to the sewage system (man hole in our back yard) and the health of the stream itself.  Also, the pipe in the photo might be from the construction on Route 7?  Please advise...