A well will always contain water if it is dug

A well will contain water if it is dug below the water table. The water table is the level below the Earth's surface where the ground is saturated with water. When a well is dug below the water table, water will seep into the well from the surrounding soil and rocks. This water will fill up the well, making it a source of water. If the well is dug above the water table, there will be no water to fill it up. However, in some cases, drilling deep enough into the Earth's crust can reach aquifers, which are underground layers of rock or sand that hold water. So, in such cases, drilling a well below the water table or to reach sand bearing water can be necessary to access water.