For world water day Ogilvy & Mather, Mumbai decided to go the educational route and actually tech us how to make your urine drinkable water in this poster, which looks a lot like old school posters in its Art Direction/ Illustration style.

It's pretty simply actually, all you need is a hole in the ground, a bucket, some tarp and rocks, the sun itself and then of course, your pee. In fact I hear that the übertough French foreign league men and Chilean army soldiers do this all the time. So next time you're at a loss for water, here you go.