Theory:

In general, the water that is drawn from the ground is restored by the seepage rainwater. Due to this water table may not be affected. The level of the water table may decrease if this water is not restored sufficiently. Several factors lead to the depletion of the water table. Increase in population, agricultural activities and industries are the major factors that affect the water table. Certain other minor factors that affect the water table are scanty rainfall, deforestation and decrease in water seepage.
Increasing population
With the increase in the population and urbanisation of open areas the usage of freshwater increases. This reduces the possibility of the rainwater to seep into the ground, which clearly shows that the consumption of groundwater is more than the replenishment of water tables, thereby leading to the depletion of the water table of that region.
Agricultural activities
In India, a majority of the farmers depend on rains for the irrigation of the crops. When there is no or low rainfall, the irrigation systems lack water. Due to this, the farmers use groundwater for irrigation. The increase in the population increases the pressure on the agriculture, thereby increasing the use of groundwater. This overuse of groundwater leads to the depletion of the water table.
Increasing industries 
All the industries use water for their production process. With the increase in the number of industries, the depletion of the water table increases.
Deforestation 
The plants and the trees keep the soil bounded together and allow absorption of water in the soil. Deforestation leads to the exposure of the first layer of the soil, which may get washed away easily. This leads to the depletion of the water table in that region.
Inadequate rainfall
In general the water table is low in the places where there is low or scanty rainfall.