Rain Water Harvesting

INTRODUCTION:

The most suitable solution to meet the increasing demand of thescarce water supply

is but rainwater harvesting. An effective efficient and cheapsolution, it has a lot more

to offer. Claiming to have the potential for a self-sustainabledevelopment let us see

why we need it and how simple is it toincorporate it in our day to day lives.The total

amount of water on earth remains constant. The rapid growth in population together

with the extension of irrigated agriculture and industrial development, are putting

stress on the natural ecosystems. In the face of growing problems, society has begun

to realize that it can no longer subscribe to a use and discard philosophy with any

natural resource. One such resource is WATER. To deal with it, a technique called

RAIN WATER HARVESTING was introduced where rain water is used to meet

some of our daily needs.

WHAT IS RAINWATER HARVESTING?

Rainwater harvesting is the accumulating and storing of rainwater for reuse

before it reaches the aquifer. It has been used to provide drinking water,

water for livestock, and water for irrigation or to refill aquifers in a process

called ground water recharge.

The principle of collecting and using precipitation from a catchments surface.

Rain water harvesting means to make optimum use of rain water at the place

where it falls i.e. conserve it and not allow draining away and causing floods

elsewhere.

The term rain water harvesting is being frequently used these days, however,

the concept of water harvesting is not new for India. Water harvesting

techniques had been evolved and developed centuries ago.

An old technology is gaining popularity in a new way. Rain water harvesting

traces its history to biblical times.

Extensive rain water harvesting apparatus existed 4000 years ago in the

Palestine and Greece.

In ancient Rome, residences were built with individual cisterns and paved

courtyards to capture rain water to augment water from city's aqueducts.

As early as the third millennium BC, farming communities in Baluchistan and

Kutch impounded rain water and used it for irrigation dams.

WHY RAIN WATER HARVESTING

Surface water is inadequate to meet our demand and we have to depend on

ground water.

To arrest ground water decline and augment ground water table

To beneficiate water quality in aquifers

To conserve surface water runoff during monsoon

To reduce soil erosion

Due to rapid urbanization, infiltration of rain water into the sub-soil has

decreased drastically and recharging of ground water has diminished.

BENEFITS OF RAIN WATER HARVESTING

Rainwater is free; the only cost is for collection and use. It lessens demand on

the municipal water supply. It saves money on utility bills. It makes efficient

use of a valuable resource. It diminishes flooding, erosion, and the flow to

storm water drains. It reduces the contamination of surface water with

sediments, fertilizers and pesticides from rainwater run-off resulting in

cleaner lakes, rivers, oceans and other receivers of storm water.

It can be used to recharge ground water. It is good for irrigation and plants

thrive because stored rain water is free from pollutants as well as salts,

minerals, and other natural and man-made contaminants. It is good for

laundry use as rain water is soft and lowers the need for detergents. It adds

life to equipment dependent on water to operate, as rain water does not

produce corrosion or scale like hard water. It can help achieve LEED Green

Building Rating Credit.

Rain water is the purest form of water. In rain water, we have total control

over our water supply. It is very ideal for cities with water restrictions. It is

socially acceptable and environmentally responsible. It promotes self-

sufficiency and helps conserve water. Rain water is better for landscape plants

and gardens because it is not chlorinated. It reduces storm water runoff from

homes and businesses. It can solve the drainage problems on your property

while providing you with free water.

It uses simple technologies that are inexpensive and easy to maintain. The

potential cost savings especially with rising water costs. It can be used as a

main source of water or as a backup source to wells and municipal water. The

system can be easily retrofitted to an existing structure or built during new

home construction. Systems are very flexible and can be modular in nature,

allowing expansion, reconfiguration, or relocation, if necessary. It can provide

an excellent back-up source of water for emergencies.

RAIN WATER PATTERN IN INDIA

Total annual rainfall in India: 400 million hectare-meters (area x height)

India’s area: 329 million hectares

If evenly spread, average height: 1.28m

Actual distribution:

Highly skewed area-wise

Thar desert receives less than 200mm annually, while Cherrapunji

receives 11,400mm

But almost every part of India receives at least 100mm annually

RAIN WATER HARVESTING IN ANCIENT INDIA

Rain water Harvesting is Very Old Process for conserve rain water.

In earlier time, It was used in different areas.

This Process was found in Harappa civilization (2500-1900 BC)

Now some Example of Place. Where rain water harvesting was implemented

RAIN WATER HARVESTING TECHNIQUES

Rainwater harvesting is a technology used for collecting and storing rainwater from

rooftops, the land surface or rock catchments using simple techniques such as jars

and pots as well as more complex techniques such as underground check dams. The

techniques usually found in Asia and Africa arise from practices employed by

ancient civilizations within these regions and still serve as a major source of drinking

water supply in rural areas. Commonly used systems are constructed of three

principal components; namely, the catchment area, the collection device, and the

conveyance system.

Roof top rainwater harvesting.

Surface runoff harvesting.

ROOF TOP RAINWATER HARVESTING

Rainwater harvesting refers to structures like homes or schools, which catch

rainwater and store it in underground or above-ground tanks for later use. One

way to collect water is rooftop rainwater harvesting, where any suitable roof

surface — tiles, metal sheets, plastics, but not grass or palm leaf — can be used

to intercept the flow of rainwater in combination with gutters and downpipes

(made from wood, bamboo, galvanized iron, or PVC) to provide a household

with high-quality drinking water. A rooftop rainwater harvesting system might

be a 500 cubic meter underground storage tank, serving a whole community, or

it might be just a bucket, standing underneath a roof without a gutter.

Rainwater harvesting systems have been used since antiquity, and examples

abound in all the great civilizations throughout history.

In many cases, groundwater or surface water may be unavailable for drinking

water. The groundwater level may be too deep, groundwater may be

contaminated with minerals and chemicals such as arsenic or salt, surface

water may be contaminated with faeces or chemicals. In these cases, rainwater

harvesting can be an effective and low-cost solution.

The good thing about rainwater is that it falls on your own roof, and is almost

always of excellent quality. Several studies have shown that water from well-

maintained and covered rooftop tanks generally meets drinking water quality

standards. It enables households as well as community buildings, schools and

clinics to manage their own water supply for drinking water, domestic use, and

income generating activities.

Rainwater harvesting is a technology which is extremely flexible and adaptable

to a wide variety of settings, it is used in the richest and poorest societies on the

planet, and in the wettest and driest regions of the world.

NEED FOR ROOFTOP RAIN WATER HARVESTING

To meet the ever increasing demand for water.

To reduce the runoff which chokes storm drains.

To avoid flooding of roads.

To augment the ground water storage and control decline of water levels.

To reduce ground water pollution.

To improve the quality of ground water.

To reduce the soil erosion.

To supplement domestic water requirement during summer, drought etc.

SURFACE RUNOFF HARVESTING

Surface runoff (also known as overland flow) is the flow of water that occurs

when excess stormwater, meltwater, or other sources flows over the earth's

surface. This might occur because soil is saturated to full capacity, because

rain arrives more quickly than soil can absorbit, or because impervious areas

(roofs and pavement) send their runoff to surrounding soil that cannot absorb

all of it. Surface runoff is a major component of the water cycle. It is the

primary agent in soil erosion by water.

Runoff that occurs on the ground surface before reaching a channel is also

called a nonpoint source. If a nonpoint source contains man-made

contaminants, or natural forms of pollution (such as rotting leaves) the runoff

is called nonpoint source pollution. A land area which produces runoff that

drains to a common point is called a drainage basin. When runoff flows along

the ground, it can pick up soil contaminants including, but not limited

to petroleum, pesticides, or fertilizers that become discharge or nonpoint

source pollution.

In addition to causing water erosion and pollution, surface runoff in urban

areas is a primary cause of urban flooding which can result in property

damage, damp and mold in basements, and street flooding.

Surface runoff can be generated either by rainfall,snowfall or by the melting

of snow, or glaciers.

Snow and glacier melt occur only in areas cold enough for these to form

permanently. Typically snowmelt will peak in the spring and glacier melt in

the summer, leading to pronounced flow maxima in rivers affected by them.

The determining factor of the rate of melting of snow or glaciers is both air

temperature and the duration of sunlight. In high mountain regions, streams

frequently rise on sunny days and fall on cloudy ones for this reason.

Harvesting of surface runoff and storage of the same into reservoirs such as

water pans makes it available for use when required.

In this method of collecting rainwater for irrigation, water flowing along the

ground during the rains will be collected to a tank below the surface of the

ground.

URBAN RAIN WATER HARVESTING

Urbanization increases surface runoff, by creating more impervious surfaces such

as pavement and buildings, that do not allow percolation of the water down through

the soil to the aquifer. It is instead forced directly into streams or storm water runoff

drains, where erosion and siltationcan be major problems, even when flooding is

not. Increased runoff reduces groundwater recharge, thus lowering the water

table and makingdroughts worse, especially for farmers and others who depend on

the water wells.

When anthropogenic contaminants are dissolved or suspended in runoff, the human

impact is expanded to create water pollution. This pollutant load can reach various

receiving waters such as streams, rivers, lakes, estuaries and oceans with resultant

water chemistry changes to these water systems and their related ecosystems.

DISADVANTAGES OF RAINWATER HARVESTING

The water used for harvesting is full of pollutants leading to health problems.

Polluted environment results in:

Increasing amount of nitrates and fluorides in the water

High content of cadmium, lead, iron and chromium in the water.

Bacteriological contamination levels are rising in water.

ADVANTAGES OF RAINWATER HARVESTING

An ideal way to solve the water problem

The ground water levels will rise

It reduces the runoff which chokes the storm water drains

It reduces flooding of roads, also reducing soil erosion

The quality of water improves

Power consumption is reduced as a one-metre rise in water levels results in

saving 0.4 Kw H of electricity.

RAIN WATER HARVESTING IN VILLAGES

Rooftop rainwater harvesting (RTRWH) is the most common technique ofrainwater harvesting (RWH) for domestic consumption. In rural areas, this is most often done at small-scale. It is a simple, low-cost technique that requires minimum specific expertise or knowledge and offers many benefits. Rainwater is collected on the roof and transported with gutters to a storagereservoir, where it provides water at the point of consumption or can be used for recharging a well or the aquifer. 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

PRINCIPLES UNDERPINNING WATER DEMOCRACY

Water is the elixir of life !

The most precious gift of nature !

Water is the lifeblood of a community and Life is interconnected through

water

Water must be free for sustenance needs

Water is limited and can be exhausted

Water must be conserved

No one holds a right to destroy

Water cannot be substituted

Water is a commons and it is everybody’s business !

Rain water Harvesting

Why Rain Water Harvesting

Benefits of Rain Water Harvesting

Rain Water Harvesting In Ancient India

Rain Water Harvesting Techniques

Roof Top Harvesting and Direct Usage

Roof Top Rainwater Harvesting

Surface Runoff Harvesting

Urban Rain Water Harvesting – Chennai City

Rain Water Harvesting in Urban Areas

Rain Water Harvesting in Villages

Rain Water Harvesting Structures along Highways

In Our India or not even India, The hole World

Need of water is.

Catch & Collect every Rain drops Save Earth Save Life

If we cannot save

water than condition

will be

If save water or harvest rain

water than condition will be