In California, groundwater is being depleted faster than it can be replenished at a rate of 30.9 cubic kilometers per year, which is nearly equivalent to the amount of water contained in the largest reservoir in the United States. This trend is just as alarming worldwide. Fresh water makes up only 2.5% of water on the earth, and of that only 31.4% is accessible to humans. Groundwater is the largest source of freshwater, and worldwide groundwater levels are shrinking. In the U.S., 67% of the groundwater withdrawals were used for irrigation, and 18% were used for public supply. Using water at this rate is not sustainable, and will cause dramatic changes in the American lifestyle, unless changes are made. Some possible solutions to address this issue include reducing non-essential water usage, as well as removing water subsidies to reflect the true costs of water.