Percolation

Percolation is the process by which water moves downward through the soil under gravitational forces. The rate of percolation depends on the water content and the hydraulic conductivity of the soil. Hydraulic conductivity is a measure of the ability of a soil to conduct water in response to a gradient in water potential. During precipitation events when the soil is near saturation, if the hydraulic conductivity of the soil exceeds the precipitation rate, the water will move downward through the soil profile to the groundwater and eventually emerge as streamflow. This can lead to nutrient losses from the soil profile as nutrients are leached below the rooting zone.