I like water gardens because the are tranquil and a small bubbler can be all that is needed to make any garden a center of attraction (a Zen moment please).

But we do sustainable here on the farm and it must have a purpose to add support to the farm life or income so here's how we plan to use water gardening:

Spring, Summer and Fall rain water fill a small 200 gallon pond (sides are built out of recycled materials and the pond is lined), for open animal water with a solar bubbler and a few gold fish. This pond grows algea and duck weed (which is high in protein and the chickens love it).

A pond for rice production fed by rain water from a bulding. Like the animal water pond but much bigger and it is drainable so it can be dried out to work in it. Mother Earth News had a pond/swimming pool designed like this.

A smaller pond closer to the house and veggie gardens holds our Chinese water chessnuts and another tier holds cattails (which are suppose to taste like cucumbers) but become wild bird feed over the long winters here. The heads also make get torches for summer evenings outside, just soak them a few hours in home-made fuel and stick them in a deep pail of sand to light. They burn a few hours and keep bugs away. If you find the flame to un-managable - wrap tin-foil around part of the cattail before lighting. If you want light from the flame you will need to add some pine sap to give the flame some color (since pure alcohol burns so clean it often has no visible flame).

These projects are major undertakings so they will most likely be left for last but important for the integration of the farm life.