This information is crucial for crop management as well as the engineering design of water control structures and flood control. Infiltration Infiltration is the entry of water into the soil surface. Infiltration constitutes the sole source of water to sustain the growth of vegetation and it helps to sustain the groundwater supply to wells, springs and streams. The terms infiltration and percolation are often used interchangeably. Percolation Percolation is the downward movement of water through soil and rock.
Percolation occurs beneath the root zone.
Runoff Runoff is the movement of water, usually from precipitation, across the earth's surface towards stream channels, lakes, oceans, or depressions or low points in the earth's surface. The characteristics that affect the rate of runoff include rainfall duration and intensity as well as the ground's slope, soil type and ground cover.