Question

Why are water tables dropping around the world? What are some negative impacts of falling water tables?

Answer 1

Water table describes the boundary between water saturated ground and unsaturated ground. Water tables across the world are dropping down beacuse the ground water reserve is only slowly recharged over a period of time with water from snowmelts and rain. Ground water has accumulated for thousands of years to reach a decent water level that is suitable for pumping out water for human consumption. However, humans have a tendency to overuse things without any regards to future generations which has lead to a disturbance in the balance. Currently, humans are pumping out water from the ground water table at a much faster rate than it could be replenished. Other than that, various environmental concerns such as global warming, green-house effects have an adverse effect on the atmospheric water cycle leading to climatic disturbances which affect the onset of monsoon as well as the amount of rainfall that an area can get. Urbanisation and deforestation has played a great role in lowering of water tables across the world. Trees hold water in the soil, deforestation has left loose soil in it's wake which leads to run-off of rain water instead of seeping into the soil to replenish ground water table. Ground water supply is not infinite, any disturbance in the balance between demand and replenishment of ground water will lead to changes in the ground water table.

Some of the negative impacts of falling water tables are given as follows:

• Increased energy cost: With lowering water tables and increasing demand for fresh water, the drilling will go deeper in search of fresh water, leading to even higher energy costs that are associated with lifting of water to such heights. This will be an expensive affair for the user to dig wells of greater depth in search of fresh water.
• Reduction in surface water: The lakes and streams that are supplied with ground water will have a diminished supply of water leading to increasingly higher chances of them being drying up. Another adverse side-effect of this would be on the flora and fauna of the lakes and streams which may ultimately lead to loss of species.
• Land subsidence: Water in the soil is responsible for holding it together, when the water table is exceedingly low, water is taken out of the soil, the soil collapses, compacts, and drops.
• Deterioration of water quality: Most of the deeper undround water and water below oceans is salty. Oveerpumping may cause the saltwater to migrate inland and upward, resulting in saltwater contamination of the water supply.