Indian urban water supply practice: In which of the following cities is raw water commonly conveyed from source to treatment plant predominantly under gravity (classic scheme)?

Introduction / Context:
Large Indian metro systems use diverse conveyance arrangements—gravity aqueducts from upland reservoirs where topography permits, and pumped raw water mains where head is insufficient. Recognizing a gravity-fed legacy scheme helps in exam questions about design approaches and energy costs.

Given Data / Assumptions:

• Classic arrangements from well-known reservoirs and treatment plants.
• Generalized knowledge used in standard civil engineering exams.

Concept / Approach:

Mumbai’s historic systems (e.g., Tansa, Vaitarna, Bhatsa supplies) include long gravity conveyances to large treatment plants (e.g., Bhandup complex). In contrast, cities like Delhi and Chennai typically have substantial pumping components due to flatter terrain or distant sources.

Step-by-Step Solution:

Verification / Alternative check:

Municipal histories and design documents describe gravity aqueducts feeding Mumbai’s treatment works; the scheme is often cited in textbooks as a gravity conveyance example.

Why Other Options Are Wrong:

• Kolkata/Delhi/Chennai often require pumping due to terrain and source locations.
• Hyderabad also uses pumping from river sources and reservoirs.

Common Pitfalls:

• Assuming all metros use the same conveyance strategy.
• Confusing gravity distribution within a city with gravity conveyance from the distant source to plant.

Final Answer:

Mumbai (Bombay).