Where there is a potamus, riparian rights become a source of intome for lawyers.

riparian
adj.
5< L riparius < ripa, river bank < IE *reipa, steep edge < base *rei3, to slit, cut > RIVE, REAP6
1 of, adjacent to, or living on, the bank of a river or, sometimes, of a lake, pond, etc.
2 designating any right enjoyed by the owner of riparian land