When a pit is dug in soil, it commonly happens that at a certain depth, water seeps from the soil to form a shallow pool at the bottom; at this point, the pit is said to have reached the water table. When the pit is dug below this point, the water surface in it will equilibrate to the water table level. Soil below this level will be saturated and the water under pressure. Above this level, the soil will be unsaturated and the water under tension.