Need rationale for selection of 135 litres per day per capita as domestic consumption level in urban India

What is the basis of taking 135 liters per capita per day as the water required for domestic consumption in urban India? Do we have a document / basis / survey which will tells us the average water used per capita per day for bathing, washing clothes, drinking, toilet flush, cooking ?

Aruna Ramani Grover
arunshok@gmail.com