California grows more than 90 percent of the tomatoes, broccoli and almonds consumed in the U.S., as well as many other foods. These crops require a lot of water. In the spring of 2015, after four years of little winter rain, the state was in a severe drought. Reservoirs were far below capacity, and underground aquifers were being heavily tapped. Mountain snowpack, an important source of meltwater throughout the spring and summer, was nearly gone in many areas.