Why is rainwater harvesting necessary?

Question

plz elaborate

Answer 1

its necessary for u to drink water or to take water from the under ground.  and also it is necessary for ur future generation for the consumption of water.

Answer 2

Rain water harvesting is necessary  for the following reasons :

- Collected water can be used during lean season.

- If percolated into the ground it will help in accumulation of ground water which is a useful natural source of water.

- Increase in ground water  level which can be used for irrigation and other uses.

- Maintenance of fertility of agricultural land.

-Sustenance of ground water table for future emergency.

Answer 3

Because....

WATER WATER EVERYWHERE ,NOT A DROP TO DRINK.

Usable water that is freshwater is only 3% and the rest i salt water!

Answer 4

Due to population most of places ( top of the earth)  coverd by houses, shopping mall, congrete floor, Streets . Due to this we do against the nature.   If Rain fall no water go to inside earth.  It is goes waste one.  If it go to earth, we can use this water after some period through bore well etc., Rain harvesting give some remady for this.

Answer 5

to increase the groundwater level

Answer 6

Environmentalist will not like this idea! the endangered species in creeks, rivers need water more than us humans

Answer 7

Traditionally, rainwater harvesting has been practised in arid and semi-arid areas, and has provided drinking water, domestic water, water for livestock, water for small irrigation and a way to replenish ground water levels. This method may have been used extensively by the Indus Valley Civilization.

Currently in China and Brazil, rooftop rainwater harvesting is being practised for use for all the above purposes. Gansu province in China and semi-arid north east Brazil have the largest rooftop rainwater harvesting projects ongoing.

Rainwater harvesting in urban areas can have manifold reasons. To provide supplemental water for the city's requirement, to increase soil moisture levels for urban greenery, to increase the ground water table through artificial recharge, to mitigate urban flooding and to improve the quality of groundwater are some of the reasons why rainwater harvesting can be adopted in cities. In urban areas of the developed world, at a household level, harvested rainwater can be used for flushing toilets and washing laundry. Indeed in hard water areas it is superior to mains water for this. It can also be used for showering or bathing. It may require treatment prior to use for drinking.

Two residences in the city of Toronto, Canada, use treated harvested rainwater for drinking water, and reuse water (i.e. treated wastewater) for all other household water applications including toilet flushing, bathing, showers, laundry, and garden irrigation (Toronto Healthy House).

In New Zealand, many houses away from the larger towns and cities routinely rely on rainwater collected from roofs as the only source of water for all household activities. This is almost inevitably the case for many holiday homes.

As rainwater may be contaminated, it is often not considered suitable for drinking without treatment. However, there are many examples of rainwater being used for all purposes — including drinking — following suitable treatment.

Rainwater harvested from roofs can contain animal and bird f***s, mosses and lichens, windblown dust, particulates from urban pollution, pesticides, and inorganic ions from the sea (Ca, Mg, Na, K, Cl, SO4), and dissolved gases (CO2, NOx, SOx). High levels of pesticide have been found in rainwater in Europe the highest concentrations occurring in the first rain immediately after a dry spell;[5] the concentration of these and other contaminants are reduced significantly by diverting the initial flow of water to waste, as described above. The water may need to be analysed properly, and used in a way appropriate to its safety. In Gansu province, for example, harvested rainwater is boiled in parabolic solar cookers before being used for drinking.[citation needed] In Brazil alum and chlorine is added to disinfect water before consumption.[citation needed] Appropriate technology methods such as solar water disinfection, provide low-cost disinfection options for treatment of stored rainwater for drinking.

Answer 8

it is the purest water available on the land...

also energy utilized to purify the normal water into drinking water can be conserved....

Answer 9

Of the total water supply on Earth (326 million cubic miles) only a tiny proportion can be used by people. The average person in the UK now washes away a staggering 1,050 liters of water a week. It is the processing of this water that is environmentally expensive. Not just in terms of energy used in the water treatment process but also from the chemicals involved.

Some of the chemicals may be harmful, chlorine for example which is used to kill bacteria  may harm protein in human hair and skin. Even Ultra-violet light is now part of the process.

By harvesting water we can save money in our own pocket and prevent money from being wasted by unnecessary treatment. By harvesting water there are fewer chemical treatments.

A lot of clean tap water is wasted in the garden and for washing cars etc. Rainwater harvesting can help prevent that.

See these factsheets by the Center of Alternative Technology CAT on rainwater harvesting and using grey water. The other links are interesting too. Type water harvesting into the search box.

http://www.cat.org.uk/

Answer 10

1]There is depletion of water.

water table is alarmingly low.

2]Urban and rural people waste water mindlessly.

Treated potable water is wasted in washing car,gardening....

Borewells at close proximity and indiscriminate use of water for farming....

If rain water is not harvested immediately, there would be no potable water tomorrow.

Rain water harvested can be used to wash utensils and car, used for gardening, if filtered and processed could be used for drinking purposes too,

Answer 11

rainwater is usually the best source of drinking water, since most surface water is polluted, sometimes to a level that makes it undrinkable.

harvesting rainwater is important in places where no abundant natural reservoirs of water exist, such as the tropics.

Answer 12

Its great for using on lawns, watering plants... without draining the water supply.

Answer 13

So that u can use up water when there s a scarcity of water...

Answer 14

The ground water table is slowly receding and there is urgent necessity of replenishing the ground water table.  During monsoons rain water is wasted,  this should be avoided at any cost  by rain water harvesting.  Government should make it mandatory all the apartments owners should have facility of rain water harvesting.  People should be made aware of this scheme by wide publicity.

Answer 15

Yes, it is absolutely necessary to harvest rain water. If not then all the water will flow away to sea. In earlier days lot of space as open soil was available for the rain water to get into the inner layers of the land. This water was made available to the wells when it reached to the nonporous rocks. Now due to urban development, the land is mostly covered by the buildings, tar roads, etc.The open space around the buildings is also covered by tiles.Therefore water is drained to the drainage, then to river and ultimately to sea.  The land in urban areas remains dry. Therefore it is necessary to harvest and store the rain water to keep the land wet from inside.

Answer 16

All fresh water was originally rain water. Even well water started out as rain that soaked into the ground. So any fresh water that you collect is harvested rain water, technically, indirectly, ultimately. But usually when people talk about harvesting rain water they mean catching it directly as it falls from the sky without letting it hit the ground. Like putting rain gutters all around your roof and piping it directly to storage tanks. That is probably a good idea, if you have room for big enough storage tanks.

Answer 17

Its not.

Answer 18

Well most rainfall just evaporates so if you manage to store some you can use it for washing your car or watering your garden when its dry instead of wasting expensive treated water

Answer 19

Today we can well imagine what is life without water.  If there is no water there is no life.  So even a single drop of water is essential for the survival of human beings.  Keeping in view the scarcity of water at every level, rainwater harvesting is absolutely necessary.  We, in India, should learn the importance of water.  We should not spoil or waste water but we should preserve it by harvesting it also.

Answer 20

In some states you need just about every drop of water you can get. Especially for farmers.  It is cheaper to let rain fall on a crop then it is to draw a couple hundred gallons from a well to water your crop.

Answer 21

Yes to increase the underground water level and make the underground water more tasty rainwater harvesting is necessary.