Historically, people lived well without vast amounts of purified water. The Saturday night bath was normal not that long ago. With the introduction of modern water systems, our water usage has skyrocketed, but there have been serious prices to pay for this luxury. Environmental costs are high and unsustainable, with depletion of aquifers threatening future generations, and the high power usage to gather, pump, purify, distribute water and then remove and treat the waste water. 

What if systems begin to deteriorate? Or what if we decide people in the future have rights, too, and we will actually protect our aquifers and not use more than can be replenished? Or we want water for vitally important local food in quantities that would actually provide sustenance for our city’s population? What is the calculation planners would use to begin to rethink our water systems?