Question

Explain Rain Water Harvesting in Urban Areas (City Areas )

Answer 1

Rooftop rainwater harvesting (RTRWH) is the most common technique of rainwater harvesting (RWH) for domestic consumption. It can be done easily, doesn’t cost much ant is applicable at small-scale with a minimum of specific expertise or knowledge; or in more sophisticated systems at large-scale (e.g. a whole housing area). Rainwater is collected on the roof and transported with gutters to a storage reservoir, where it is either used for groundwater recharge or provides water at the point of consumption. Rainwater harvesting can supplement water sources when they become scarce or are of low quality like brackish groundwater or polluted surface water in the rainy season. However, rainwater quality may be affected by air pollution, animal or bird droppings, insects, dirt and organic matter. Therefore regular maintenance (cleaning, repairs, etc.) as well as a treatment before water consumption (e.g. filtration or/and disinfection) are very important.

Advantages

Local people can easily be trained to build RWH systems themselves. This reduces costs and encourages more participation, ownership and sustainability at community level (HATUM & WORM 2006)

Rainwater is better than other available or traditional sources (groundwater may be unusable due to fluoride, salinity or arsenic) (HATUM & WORM 2006)

Costs for buying water and time to extract from the city water supply can be saved (SHRESTHA 2010)

It provides water at the point of consumption (HATUM & WORM 2006)

Not affected by local geology or topography (HATUM & WORM 2006)

Almost all roofing material is acceptable for collecting water for household purposes (HATUM & WORM 2006)

Rooftop RWH reduces the amount of rainwater going into sewers, drains and may reduce flooding and clogging of water channels and uptakes (WATERAID 2008)

Disadvantages

Limited by the amount of rainfall and the size of the catchment area and storage reservoir (HATUM & WORM 2006)

Supply is sensitive to droughts: Occurrence of long dry spells and droughts can cause water supply problems (HATUM & WORM 2006)

The cost of rainwater catchment systems is almost fully incurred during initial construction (HATUM & WORM 2006)

Proper operation and regular maintenance is a very important factor that is often neglected (HATUM & WORM 2006)

Rainwater quality may be affected by air pollution, animal or bird droppings, insects, dirt and organic matter (HATUM & WORM 2006)

Answer 2

I am not writing answer so long but concept can be cleared
in it we water was collected
water harvesting is the most easiest way to save water
it do not need any cost
this water can be used to give to plants in urban areas