Do people have an inalienable right to have water? A related question is "do people have an inalienable right to clean water?" Preparing water to drink takes resources, resources that have alternative uses and, thus, costs. In short, clean water is subject to the scarcity problem, a problem that needs solving. So, it is not so much that people have a right to clean water, it's that they want and need clean water. And while politicians and activists do what they do, people obtain drinkable water despite them.
Violent protests have driven away corporate investment in desperately needed municipal water systems in developing nations. So the world's poor buy bottled water from Coke, Pepsi and other multinational companies.
And that's not a bad thing at all.