In India, natural ponds, tanks, and lakes—even if inside private land—are generally considered common property resources.
Courts (including the Supreme Court) have repeatedly held that natural waterbodies cannot be filled, diverted, or destroyed, even by the landowner. They are protected under the Environment Protection Act, Wetlands (Conservation and Management) Rules, 2017, and municipal/state laws.
If the pond is man-made for personal use (like a farm pond, fishery tank, or irrigation tank):
If it is fully artificial and not classified as a public/common water resource, the owner may fill it, but only after getting approval from the local authority (panchayat/municipality/revenue department), especially if land use is recorded as "wetland" or "waterbody" in revenue records.