The water table, or aquifer, provides much of our drinking water, and a lot of water is pumped for agricultural use, especially in California’s Central Valley. Much of that agricultural water comes from the water table instead of from dams, particularly in years of drought. The image shows the continued loss of the California Central Valley aquifer, a huge aquifer that provides water for about a quarter to a half of the produce grown in the United States. Because the aquifer has been used for about one hundred years, however, the elevation of the California Central Valley has dropped about 70 meters (230 feet). If the water table is not carefully monitored and naturally replenished, it will eventually be unusable.