I bet you haven't thought about water today. Exactly.

We are lucky to live in an era of history when water is not a concern for many of us: we can go about our daily lives without even thinking about it, and just get as much water as we like at any moment. This would have astonished our ancestors.

Charles Fishman, in The Big Thirst, warns that this might change soon, as new shortages force us to value water more (again.) But here are at least two pieces of good news excerpted from that book, one historical and one current:

"One hundred years ago, with the dawn of bacteriology, two things happened. Cities started aggressively separating their freshwater supplies from their sewage disposal, something they had been surprisingly slow to do. (Philadelphia is just one of many cities whose sewage system, 100 years ago, emptied into a river upstream of the city water-supply intakes from the same river.) And water utilities discovered that basic sand filters and chlorination could clean and disinfect water supplies, all but assuring their safety. … Between 1900 and 1940, mortality rates in the united States fell 40 percent. … Clean water [also] cut child mortality in half."

"It is a mistake to imagine that small changes don't matter, or that even big water issues are not manageable. One of the most startling and least well-known examples involves the United States. The U.S. uses less water today than it did in 1980. Not in per capita terms, in absolute terms. U.S. water use peaked in 1980, at 440 billion gallons a day for all purposes. Today, the country uses less than 410 billion gallons a day. That performance is amazing in many ways. Since 1980, the U.S. population has grown by 70 million people. The U.S. GDP has more than doubled in constant dollars: We use less water to create a $13 trillion economy than we needed to create a $6 trillion economy. It has been nothing less than a revolution in water use in the biggest economy in the world, a completely silent revolution. Most of the change has come in water use by power plants and farms. Farmers today use 15 percent less water than they did in 1980, and produce a 70 percent larger harvest."