I believe that everyone should have the right to have access to sufficient, clean water. Sadly, this is not currently the case - and this is not limited to developing countries. Many large cities will soon experience "Day 0", meaning they will have to shut off the water supply since there is simply not enough.
I envision a world in which water is valued by everyone and they are mindful of their water use. I know that many people use water and do not think twice about it because they think it is plentiful and cannot even imagine it ever running out. It is important to educate these people and spread the word. This has the potential to have powerful impacts, like the impacts seen in Cape Town - where "Day 0" was postponed because citizens started using water more conservatively.
I think an intervention that has the power to initiate this change is increasing the price of water. This operation would involve many parties such as utility companies and governments to pass these policies. Understandably, this may not be fair or feasible to groups that are unable to