The top of the groundwater aquifer is referred to as the water table, and if the water table drops it might affect drinking water availability. Groundwater levels are measured by measuring the depth from the land surface to the water table. Groundwater levels can change over time and are affected by precipitation patterns. Drought can cause the water table and groundwater levels to drop, while periods of above average precipitation can cause groundwater levels to rise. Groundwater levels can also be affected by groundwater pumping. High-capacity wells can cause localized draw-down, referred to as a cone of depression; regional draw-down can occur when many high-capacity wells are installed in the same aquifer.
Monitoring groundwater levels requires an extensive network of wells. You can check to see if groundwater level information is available for your region by visiting Groundwater Levels for the Nation.
