Using clean drinkable water to flush isn’t making much sense economically and environmentally. Yet this is the most practical one. (I don’t really see how people living in huge cities could all use dry or composting toilets)
This is why I believe that each and everyone of us should install dual flush toilets to minimize the quantity required to do so. Using the low flow flush does the trick in the vast majority of cases.
This will enable you to save huge quantities of water and thus lower your bills and environmental impact. So why not installing such a system this week and start saving money ?
Here is some little research I did. According to Toilets A, B, C :
If all U.S. households installed water-saving features, water use would decrease by 30%.
This would save an estimated 5.4 billion gallons of water per day, resulting in daily dollar-volume savings of $11.3 million or more than $4 billion per year.
Water-efficient fixtures installed in U.S. households in 1998 alone saved 44 million gallons of water every day, resulting in total annual dollar-value savings of more than $33.6 million.
(…) The largest daily user of water in the home is the toilet. By replacing this one product with a high-efficiency toilet (HET) you can greatly affect your total water usage.
I guess similar figures could be found in France and in Europe as a whole…