Fluctuations in Demand:

Although this average daily demand is supplied at uniform rate throughout day and night. It will not be sufficient because the demand or requirement varies hourly, daily, weekly and monthly. The variations are known as fluctuations in demand.

Monthly Variations:

The rate of consumption reaches a maximum in the summer. This high rate usually extends over two to four months depending upon location of the place. In cold countries, a secondary maximum often occurs in the winter owing to the wastage of water to prevent freezing.