Which is the smallest mains in a water distribution system?

• A. Indicating feeders
• B. Secondary feeders
• C. Primary feeders
• D. Distributors

Answer: (D)

In a water distribution system, mains are arranged by size and function: large trunk lines bring water from treatment to broad areas, intermediate lines branch off to reach neighborhoods, and the smallest mains deliver water to a localized area and its hydrants and service connections. The smallest mains are called distributors because they take water from the larger feeders and distribute it into the local streets with enough pressure for nearby service lines and hydrants. Primary feeders are the largest lines, carrying high flow to wide areas, while secondary feeders are intermediate. Indicating feeders aren’t the end of the chain in this hierarchy, so they aren’t the smallest.