What is water harvesting? List two main advantages associated with water harvesting at the community level. Write two causes for the failure of sustained availability of groundwater.

Rainwater harvesting is the method of collection and preservation of clean rainwater directly from the roof and transferring it to the underground constructed tanks that be pumped out for future use.

Rainwater harvesting is a very crucial method for the preservation of clean water as due to the growing demand for clean water, scarcity had increased and resulted in the depletion of groundwater. This method is simple, cost-effective and eco-friendly in nature.

The various advantages of water stored under the ground are:

(i) Groundwater does not evaporate like open water bodies such as river and lake.

(ii) Groundwater also helps in recharging wells by increasing their water level.

(iii) It also provides moisture for the vegetation over a vast area as roots can absorb the groundwater and provide to growing crop.

(iv) As groundwater is well protected beneath the ground, it is protected from contamination by animals, human wastes and also prevents the breeding of insects.

Causes for the failure of sustained availability of groundwater:

The groundwater is decreasing due to its over usage from the ground level for industrial use.

Also, due to the construction of concrete roads, the water doesn't seep into the ground, causing early depletion of groundwater.