I think the best idea for an event would be to demonstrate how much water is available to the developing countries compared to the Third World.
This would be in the form of a 15ft-high ice sculpture of
a drop of water emerging from a hand pump – the purpose of the experiment would show how quickly the amount of water that the sculpture was made of was consumed by people at the exhibition. At the start of the day this sculpture would form part of a photo shoot, before it is shattered, melted down and made as part of a reservoir of water for visitors. Then over the course of the day it would be monitored as people returned to the makeshift “watering h***” for refreshment.
A tally would be kept throughout to see the level of
water there was in the morning to the evening. Finally, a video presentation of how much water people have access to would be shown to people to demonstrate the drastic shift in adequate, clean water... the overall goal is to provide an emotional reaction to how well people like me live with water every day, opposed to over a billion people worldwide suffering from a severe lack of supply.