Millions of people in India's southern city of Chennai are struggling as taps run dry.
Trains and trucks have been bringing water in for residents, but it comes at a cost.
Environmentalists are warning this is a problem which could soon affect many other countries.
1. How big is the problem of water scarcity in India?
2. Do you believe there will be wars for water in future? Justify your views.
3. How can we prevent global water shortage?