UPSC CDS GS Geography Questions Part 3

In urban areas, rainwater harvesting is done using rooftops of buildings. Paved and unpaved areas go waste in areas where the surface soil is impervious and large quantities of surface run–off is available within a very short period of heavy rainfall. Trenches or pits are made to store the water in a filter media and, subsequently, recharged to ground water through specially constructed recharge wells and recharge trenches. Gully plug method of rainwater harvesting is suitable for rural areas. Gully plugs are built using local stones, clay and bushes across small gullies and streams running down the hill slopes carrying drainage to tiny catchments during the rainy season.