Groundwater and soil water can work together to provide plants with water and nutrients, especially when the groundwater is close to the soil's root zone. When the groundwater is about two meters below the soil surface, it significantly helps plants by supplying water to their roots. The movement of water from groundwater to the soil depends on the soil's properties and the depth of the groundwater table. The drainage of water from the soil due to a drop in the groundwater level can be calculated using specific equations. These equations help determine the depth, distance, and size of pipe drains needed in a uniform soil for effective drainage.