Property Related

My neighbor has recently broken his boundary wall and moved it backward on his own side, creating a narrow open space between his wall and mine. In that newly created space, he is now constructing a drain (nali) that carries dirty bathroom and urine water. The problem is that this drain is very close to my house wall, and the flow of dirty water is entering or touching my property, creating health and hygiene problems for my family. When I objected, he claimed that he is building the drain within his own land and that I have “encroached on the lane area.” However, I have all the land ownership documents (patta/registry) clearly showing that the area up to my wall belongs to me. Despite being informed, he continues the construction and even threatened me, saying that if I stop him, he will “deal with me in any way.”