This figure represents the Hierarchy of Water Requirements based on Maslow's hierarchy of needs.

There is a growing demand on the existing water resources which includes River Water Sources, Precipitation and Ground Water Sources. Thus the primary objective of a planned development is to provide adequate, reliable and good quality potable water. For this purpose, standards of water requirements were developed by national agencies.

It is very important to calculate the water requirements accurately to avoid failure in water planning, management and conservation. Standard Water Requirements are calculated per person per day. The basic factors that influence these requirements are:

Human Consumption

Bathing

Flushing

Washing

Miscellaneous Activities

Other factors that also affect the requirements are: