My idea to demonstrate the world water day in 2020 would a challenge. To get the attention all local radio station will talk about the problem with the water. They do not play music that day. Instead there will be challenges on the radio with questions about poor countries and their problems with the water. To win a price you have to call the radio station and answer at least three questions right. You can win prices like tickets for music events or for the cinema.
In addition there will be booths in the city to inform about the problem. So that hardly anyone can ignore this issue.
And if you want to buy water in the supermarket you will get a flyer with a lot of information about the possibilities how you can safe water at your home.