People Are Competing With Nature for Water
Freshwater ecosystems occupy less than one percent of the Earth's surface but they provide irrigation water that grows 40 percent of the world's food; they provide us with 12 percent of the fish we eat; they provide 20 percent of the world's electricity; they provide habitat for 12 percent of all the animals in the world, and most of the rest depend upon freshwater for their survival.
Economics is the science of scarcity; if resources are abundant then there is no need to worry about their price. In the last generation we have gone from relative abundance of freshwater in many parts of the world to relative scarcity. Freshwater resources have been both over extracted and degraded by people and governments that have not yet learned the value of water. For example, irrigation systems typically lose more than half the water they take to seepage and evaporation. Mark Twain described a summer in the Pacific Northwest as the mildest winter he ever experienced, and yet even in the rainy Northwest we hear every week reports of people competing with each other, and with the salmon, over water.