Any water I send down the drain goes right back in to the same river (Niagara) that we pull our drinking water from. I don't see any harm in that, except the energy involved in pumping it to my house, and the cost of running the sewage treatment plant. The number of times I flush my toilet has very little to do with whether persons living in slums in Mozambique can afford plumbing.
Likewise, the statement that it takes 10500 lbs of water to make a hamburger is kind of silly. That water can be used more than once. And does the 312000lbs of water per car figure include the water used by the assembly line workers, their families at home, and the hamburgers they eat for lunch?
The real issue is economic development of the third world, as all of the world's water problems can literally be solved with money. Look at sub-saharan Africa. No "areas of water shortage" according to the infographic. It should be a breadbasket, but instead, it's very much reliant on food imports. What can I do to promote scientific crop rotation, fertilization, irrigation, and mechanized agriculture in places like Zimbabwe? That's a genuine question, and I do have some funds set aside for charity.