In response to water restrictions and the prospect that all watering of gardens might soon be banned, we investigated putting in a grey water system. Such systems take water used in showers, baths and washing machines and water your garden with it. It sounds like a good idea.
Anyhow, apart from the fact that to replumb the house would be a major renovation, it turns out that we wouldn’t generate much water this way. Why? Well, we have a super-water efficient front loading washing machine. It maybe uses a third or less of the water of top loaders. So in order to make a grey water system viable we would have to get rid of that and buy a high water using machine! Yet another reason why pricing rather than restrictions is the way to go.