That the world needs a new 'water ethic' was first suggested by Sandra Postel, in her 1992 environmental best-seller The Last Oasis. This is a great little book. Despite minor technical reservations, I have to say it is head and shoulders above anything else that has been written on the world water situation recently. If you are interested enough in the subject to have persisted this far, you really need to buy it, or get it from your local library, and read it carefully.

The central notion is that we should attempt to develop, in ouselves, and instill in future generations, an idealistic, essentially moral, sense of 'respect' for water, based on its unique place in ourselves and our world. It would serve as "a guide to right action in the face of complex decisions about natural systems we do not and cannot fully understand".

The issues are well laid out and discussed in this reference from the the Harvard Seminar on Environmental Values 1997-1998.