California Water What do we use all this water for? Of all the water that falls to California, 60% is immediately returned to the atmosphere by evaporation or native plant use. The rest runs off into rivers, lakes, streams and the water table, where it is available for human use. We will explain what happens to all this water, show exactly how much water we do use, and give ways to reduce water use in and around your home. The single largest user of water is industry. Industries use 46% of our annual water supply. One industrial use is manufacturing, in various ways such as cooling of materials, washing of materials, products, tools, and equipment. For example, by the time a Sunday pa