Water efficiency is reducing water wastage by measuring the amount of water you actually require for a particular purpose versus the amount of water used or delivered.
Water efficiency differs from water conservation. In that it focuses on reducing waste, not restricting use.
Taking a Bath
Bathing with a bucket of water uses 25-30 litres of water
Using a low flow shower uses around 95 litres of water
Bathing in a bathtub uses 132-189 litres of water