As we all know, animals can drain many resources when managed in a conventional style. In a 'duckponics' system, however, water is continously pumped and recirculated through gravel filtration beds, leaving it clean and free of dirt and grime.
Resenting having to replace hundreds of gallons of water per day for her ducks, Aleece Landis, at the time of filming claims not to have replaced her duck's water in weeks.
The gravel beds also double up as a bed for the banana trees, thus simultaneously watering and providing them with essential nutrients, but you can of course substitute plants according to your climate.
If you are thinking of looking after ducks, see 'Starting with Ducks' by Katie Thear
For more lateral, intelligent ways of designing permaculture systems, see Aranya's indispensable 'Permaculture Design: a step-by-step guide' (eBook available)