Which one among the following industries is the maximum consumer of water in India?

Answer: (d) Thermal power

Coal power plants use huge volumes for cooling and ash handling — the large majority of all industrial water use in India.

The idea

Total water use depends on both water needed per unit and the scale of an industry. A thermal power station must remove large amounts of waste heat after steam passes through its turbine. This cooling need explains the thermal-power answer in the 2013 comparison; visible river pollution is a different measure.

Fuel heats water into steam → Steam turns a turbine → Generator produces electricity → Exhaust steam enters a condenser → Cooling water carries away waste heat → Water is recirculated or discharged according to the cooling system

Why the others are wrong

(a) Engineering uses water, but far less.

(b) Paper is very water-hungry per tonne, but the sector is much smaller.

(c) Textile dyeing uses a lot per unit, but not the most in total.

The trap

Paper and textiles are famous for polluting rivers, so they come to mind first. The question is about CONSUMPTION, where coal power dominates.

Also know

Withdrawal is water taken from a source; consumption is the part not returned, for example through evaporation. Once-through cooling and cooling towers have different withdrawal and consumption patterns. Coastal plants may use seawater for cooling, and nuclear stations also need cooling water even though they do not burn coal.