The distribution system in water supplies is an essential component for ensuring that clean water is delivered to consumers. It is designed based on various factors that determine the demand for water. The correct answer to this question is option D - greater of (b) and (c).

Factors considered in designing water distribution system:

1. Average daily demand: It is the average amount of water required by consumers on a typical day. This value is calculated based on the population served by the water supply system, the size of households, and the types of businesses in the area.

2. Peak hourly demand: It is the maximum amount of water required by consumers during a specific hour of the day. This value is calculated based on the peak usage hours, such as early morning and late evening when people are using water for personal hygiene and household chores.

3. Coincident of draft: It is the maximum amount of water that can be drawn from the water supply system at any given time. This value is calculated based on the number of consumers using water simultaneously and the types of activities they are engaged in.

Designing the water distribution system:

The water distribution system is designed based on the maximum demand for water. The design considers the following factors:

1. Storage capacity: The water supply system must have enough storage capacity to meet the peak demand for water. This ensures that there is always enough water available during periods of high usage.

2. Pipe size: The size of pipes used in the water distribution system is determined based on the maximum demand for water. Larger pipes are used in areas with high peak demand to ensure that water pressure is maintained.

3. Pump capacity: The water supply system must have sufficient pump capacity to meet the maximum demand for water. This ensures that water is delivered to consumers at the required pressure.

4. Distribution network: The distribution network is designed based on the location of consumers and the demand for water in different areas. The network must be able to deliver water to every consumer at the required pressure.

Conclusion:

In conclusion, the design of the water distribution system is critical to ensuring that clean water is delivered to consumers. The system is designed based on the maximum demand for water, which is determined based on factors such as peak hourly demand and coincident of draft. The design considers factors such as storage capacity, pipe size, pump capacity, and distribution network to ensure that water is delivered to consumers at the required pressure.