Saving Water a Natural Resource

We have been facing a Water crisis inspite of the huge capacities being created for storing water.
As they say a Penny Saved is a Penny Earned.

I have noticed in households, every time residents visit the wash room for nature's call, flush the tank, thus draining 5/10 ltrs of water, when maybe 0.5 / 1 ltr would have been good enough.

Maybe we need to ask the manufacturers to create a Flush Tank with an inner partition, 

so that for the first call, they only need to press the button that will flush 0.5 / 1 ltr.
It is only when they empty their bowels, they need to activate the lever to flush 5 / 10 ltrs.

Normally a family of 4 will have used the wash room 20 times a day * 2 Million habitants in Mumbai , would be the amount of water saved per day * 365 and the amount saved per year, which could be huge.

Trust we learn to conserve this most important resource