Question

There are ten tube wells in a lane of fifty houses. What could be the long-term impact on the water table?

Answer 1

Hint: You can start by explaining the water table and the use of the wells in brief. Then explain how groundwater is replenished. Then explain how extracting water for fifty households from tube wells, will lead to the lowering of the water table.

Complete step-by-step answer:
The water table refers to the groundwater present in the earth. We build tube wells so that we can extract water directly from under the ground. Tubewells are mainly used in rural areas but modified versions of the well are used in urban areas for agriculture with a motor attached to pump the water.
This groundwater is not infinite so it has to be replenished regularly. The water from our houses, from the run, from the river and lakes, slowly seeps through the gaps in the soil and joins the reservoir of underground water. So, it is a cycle of extracting and replenishing groundwater.
Now, in the problem, we are being asked what will be the long-term impact of ten tube wells (modified wells also used for extracting groundwater) that are installed in a lane of fifty houses. It can be safely assumed that these households will be using underground water regularly. This will slowly deplete the amount of underground water. Now, as discussed earlier the underground water is also replenished, but generally, the amount of underground water replenished in nowhere near the amount consumed. So in the long run the underground water will deplete.
So, the long-term impact of fifty houses consuming underground water will lead to the water table going down.

Note: A real example of the lowering of the water table going down can be seen in the United States. In the United States groundwater is the primary source of water for half the population. The people of the United States consume over 50 billion gallons of groundwater every day for agricultural purposes and obviously, this groundwater is not fully replenished.