Water distribution networks — preferred layout in well-planned cities: Which distribution network layout is generally adopted in a well-planned city to ensure redundancy, circulation, and pressure uniformity?

Introduction / Context:
A city’s pipe network layout influences reliability, pressure maintenance, water age, and fire-fighting performance. In modern, well-planned urban areas with regular street patterns, looped networks are preferred over branched dead-ends.

Given Data / Assumptions:

• City with planned blocks and intersecting streets.
• Objective: redundancy, uniform pressures, and ease of isolation without widespread outages.

Concept / Approach:
The grid-iron system forms loops so that water can reach any node from multiple directions, limiting stagnation and allowing sections to be shut off for maintenance while maintaining service via alternate paths. Terms like interlaced or reticulation are often used synonymously with looped networks, but “grid-iron system” is the classic designation for well-planned cities laid out on a rectangular pattern.

Step-by-Step Solution:

Verification / Alternative check:
Hydraulic modeling shows looped networks maintain pressures better under peak and fire flows and exhibit lower water age compared to dead-ends.

Why Other Options Are Wrong:

• Interlaced/reticulation often mean looped too, but the canonical choice taught is “grid-iron system”.
• Dead-end systems suit unplanned growth and are prone to stagnation.
• Pure radial systems are more typical around large reservoirs or zones, not whole-city coverage.

Common Pitfalls:
Confusing terminology; assuming any loop suffices without considering valve placement and sectorization.

Final Answer:
Grid-iron system