water for drinking, cooking, bathing, and all other domestic needs is only a small fraction of the requisite supply. A much larger amount is needed to grow our food as well as the fibers, such as cotton, in our clothes. On average, growing a single calorie of food demands a liter of water... A healthy diet of 3,000 calories requires at least 3,000 liters of water to produce; a vegetarian diet requires the least amount of water, while a Western, meat-based diet rich in corn-fed beef can require as much as 15,000 liters of water per person per day. Roughly seventy times as much water is needed to grow the food that people eat as to serve domestic purposes.There's much much more, including discussions of institutions, green versus blue water, etc.
Therefore, to understand the water crisis we need to distinguish two fundamentally different problems, which will require different solutions. The first, the drinking water problem, is about access to affordable water services: here we face a service crisis. The second is about the lack of the vastly greater water resources needed to grow food and maintain ecosystem services: here we face a problem of water scarcity, a resource crisis.
Bottom Line: Different problems will require different solutions (or different markets for different customers :)
hattip to JC