There are many good reasons to reduce the water consumption as much as possible.
First of all, because the world's population is growing dramatically (by about 80.000.000 persons per. year) without the available fresh water increasing.
Second, because the pattern of rain is changing so more places will experience drought.
Third, because some of the sources (the big glaciers) are shrinking.
And fourth, using less water is the same as using less energy=Less CO2. We all know that we have to reduce the emissions of CO2 to slow down the climate change as much as possible – and by using less energy you also save money.