Thanks King and I appreciate that water itself is highly subject to political ownership. My view isn't to look for ownership of water per se or even delivery utilities which are often regulated.
My thoughts are that finding, pumping, and transferring water from one place to another provide the best investing keyhole. That requires equipment and expertise, which is likely to come from the private sector, even if governments own and control the actual water itself. Desalination is an obvious technology.
Fresh water is important but is only a very small part of total water demand. Essentially every organism on Earth needs water and we in turn need the plants, creatures etc, not to mention washing, industrial uses. Water can be filtered at the point of consumption as it is in many homes today and of course there is a market for such filters. However it is competitive and I just don't find it quite so interesting.