Young people are increasingly becoming involved in the water debate.

In Mexico City, Cesar Cruz Rojas and his friends from Oikos-Mexico (a youth-led environmental organization) go door-to-door telling their neighbours about water conservation and proper waste disposal in the home. They've even written a script called 'Saving Our Water', which has been broadcast on the local radio.

In Bhutan, students at Sherubtse College noticed regular outbreaks of typhoid and dysentery in their community and decided to tackle the problem at source. They set up a programme to clean and monitor local water tanks - and watched the number of ill people drop dramatically.

In the Banaripara Thana community in Bangladesh, local schools competed for a 'best sanitation coverage' prize awarded by the district commissioner. Students championed constructing latrines in their schools, homes and community areas.