Rain Water Harvesting
Water is one of the basic necessities for all beings on the earth. Its scarcity is emerging as a major issue confronting mega cities like Mumbai, Delhi etc
According to an MMRDA report, the city's demand for water is expected to rise to 7950 MLD (million liters daily) by 2011, from the present demand which is 3026 MLD. There is already a shortfall, as the present water supply in the city is 2500 MLD as stated in the report
It is a known fact that Mumbai faces a problem of water scarcity despite receiving abundant rainfall. And this problem stands to increase manifold
It's a nature gift to all our being and we should understand the importance of it and try to preserve it.
Ever imagined a time in the future when there won't be water for even drinking, leave alone wasting? That time is nearer than you think. And more than anything else, our mindless wastage of water is prime reason. Today we are on the brink of water scarcity, So let's try our best to optimally use these precious limited resources.
Rain Water Harvesting is an age old idea which was used by our ancestors to preserve and use water optimally.
What is Rain Water Harvesting?
The rain water Harvesting is the process of capturing the water, storing and recharging it, and later using it during prolonged parched periods, This happens naturally in open rural areas. But in congested, over-paved metropolitan cities, we need to create methods to capture the rain water.
Rainwater is one the purest sources of water. Its quality almost always exceeds that of ground or surface water. It does not come into contact with soil or rocks where it can not dissolve minerals and salts nor does it come into contact with May of the pollutants that are often discharges into local surface waters or contaminate ground water supplies. However, rainwater quality is influenced by where heavy industry or crop dusting is prevalent may not have the same purity as rain falling in other areas.
Rainwater is soft. It can be significantly lower the quantity of detergents and soaps needed for cleaning. Soap scum and hardness deposits do not occur. There is no need for a water softener as there often is with well water. Water heaters and pipes are free of the deposits caused by hard water and should last longer.
Urban centers in India are facing an ironical situation today. On one hand there is the acute water scarcity and on the other, the streets are often flooded during the monsoon. This has led to serious problems with quality and quantity of groundwater. This is despite the fact that all these cities receive good rainfall. However, this rainfall occurs during short spell of high intensity (most of the rain falls in just 100 moors out of 8760 hours in a year) Because of such short duration of heavy rain, most of the rain falling on the surface tends to flow away rapidly leaving very little for recharge of groundwater.
Most of the traditional water harvesting systems in cities have been neglected and fallen into disuse, worsening the urban water scenario. One of the solutions to the urban water is rainwater harvesting-capturing the runoff.
This is practiced on a large scale in cities like Chennai, Bangalore and Delhi where rainwater harvesting is a part of the state policy. Elsewhere, countries like Germany, Japan, united sates, and Singapore are also adopting rainwater management.
Rain water harvesting promotes self-sufficiency and fosters an appreciation for water as a resource. It also promotes water conversation. Also, rainwater harvesting conserves energy as the energy input needed to operate a centralized water system require only a small pump to create water pressure in household pipes.
Local erosion and flooding from impervious cover associated with building is lessened as a portion of local rainfall is diverted into collection tanks.
Why Rain Water Harvesting? (Facts and Figures)
Let us understand supply comes from the sky. in order to meet demand, what we actually need to do is harvest the rain. Not dam a river, and block its flow. Not boost water out the ground, and suck the earth dry. Not build canals, lay kilometers of pipes. But merely harvest the rain. In the sense, harvesting the water.
In India, the monsoon is the deluge. Flash floods churn up dry river beds. Dry wells come life; lakes and ponds brim with water. In India the monsoon is brief. We get about 100 hours of rain in a year. It is this 100 hours bounty that must be caught, stored and used over the other 8660hours that makes up a year.
According to a study, India receives 400 million hectare meters (mham) of rain and snowfall. Another 20mham of flow in as surface water from outside the country. This total 420 mham provide the country with river flows of 180 mahm. Another 67 mham is available as groundwater. Another 173 mham is lost as evaporation or becomes soil moisture. - Which can be captured directly as rain water or as runoff from small catchments in and near villages or towns? If even 20-30 mham can be captures through rainwater harvesting, tremendous pressure can greatly extend the availability for clean water. Why is cherrapunji today short of drinking water when it gets more than 11 meters of rainfall annually? Simply because it does not capture the rain that falls over it.
Any land can be used to harvest rainwater. In tune with the terrain, with nothing imposed. It is just a matter of using material locally abundant-stones, mud, bamboo
Procedure For Rain Water Harvesting
Structures to harvest rain require little space. A dried bore well, a row of soak pits or a tank--concealed below the ground- are all that you need. The open spaces -- rooftops and ground - can be used as your catchments (surface to catch rain).
Depending on the area of your roof and other structures that you will use to harvest rain. But rainwater harvesting does not require major construction work, so the expenses suit most of our pockets.
Your groundwater will be recharged. But as groundwater moves, your neighborhood will gain too. So for best results, get all your neighbors to become rainwater harvesters as well.
Once or twice a year, at very little cost. Remember rainwater harvesting means that you have to get involved. This is about making water all our business. This is about building our relationship with water. With the environment. Harvest rain. Learn the value of each raindrop.
If you live in a single dwelling house or a multi-tenant apartment complex, you already have 80% of the RWH system. We just need re-orient the plumbing design.
The present design of the house will take all the rainwater from the roof and all the ground level areas surrounding the house and flow the water towards the street. (where it floods the street, clogs the storm drains and sewer lines for a few days, before flowing away as sewage water)
From the roof tops, bring the rainwater down using closed PVC pipes and direct it to a sump. Include a simple 3-part filtration unit consisting of sand, brick jelly and broken mud bricks
If you do not have sump, use a well. In many parts of the country, old wells when they go dry, is used as garbage dumps. Please clean the well and put the rain water into it.
If you do not have a well, construct a baby well (about 2ft in diameter and about 16 feet deep based on soil structure)
Other types of RWH - collect the ground water and stop their flow at the gate. Put a concrete slab with holes in it; build a 2 feet deep pit, across the full width of the gate. Collect and connect a pipe and flow the water to a well or a baby well.
Costs
Most often, the cost is from the PVC pipes. A 4" diameter PVC pipe costs Rs xx per linear foot. A 5" pipe costs lot more than a 4" pipe.
If you do not have a sump, include about Rs 5 per liter of water storage. So, a 10,000 liter size sump will cost Rs 50,000. (For a family of 4, using about 80 liters per day per person, this 10,000 liter size sump will contain 1 month's water needs for this family.
If you do not have old style well - 6' to 8' diameter and about 60 feet deep, it will cost about Rs 5,000.
If you wish to construct a baby well, it may cost around Rs 2,500
Asian Paints and its initiative
Asian Paints, India's largest paint company today took a huge stride. Towards promoting the cause of total water management by giving the city (and Neighboring districts like Thane) it's first Total Water Management (TWM) Centre. The Honorable BMC Commissioner Shri Johny Joseph (IAS), today formally inaugurated the centre, which is located in the premises of Asian Paints manufacturing facility at Bhandup.
At Asian paints, understand this and it's our endeavor to create awareness on this alarming issue.
Asian Paints has built a Total Water Management (TWM) Centre, at its Bhandup manufacturing facility, which is a first of its kind in the entire country.
The TWM centre showcases live working models on water conservation and rainwater harvesting.
Asian Paints provides expertise to citizens free of charge to implement Rainwater harvesting and total water management concepts.
The water management schemes could be designed in phases, so investments are not significant. Also a payback period can be determined for investments.
So if you are interested in implementing rain-water harvesting and total water management solutions in your society, institution on your organization, do let us know. We would be glad to prove you all expertise at no cost. You can also visit the TWM centre to understand the various concepts of total water management.
Fresh water is a limited and precious resource that is often taken for granted. While many areas of the developing world lack supplies of safe drinking water. Water shall be a major issue for the 21st century and water resources a real source of international & interstate conflict.
The development of water sources must be within the capacity of nature to replenish and to sustain. If this is not done, costly mistakes can occur with serious consequences.
Total Water Management (TWM) is a method of inducing, collecting, storing and conserving roof top water runoff and local surface water runoff. It depends on end use application.
What does Water Management Center at Asian paints provide?
WM centre is aimed to educate interested parties and provide them perspective on Water issues. Help people to understand modalities of implementing various water conservation projects in all type of buildings, structures and natural sources.
- Information on Water Supply systems
- Issues of Tanker Water Supply
- Methods and issues with storage of Water
- Issues and ideal process of Water Distribution
- Rain Water Harvesting (RWH)
By visiting TWM centre all the above concepts can be understood with the help of following working models
- RWH Model for High Rise Building
- RWH Model for Industrial complex
- RWH Model for Commercial Building
- RWH Model for Bungalows
- Tanker Water Model
- Water Collection and Pumping Model
For a free visit to the centre all one has to do is log on to www.asianpaints.com/twm/index.phpl and register.
Asian Paints Corporate Social Responsibility Initiatives
Asian Paints approaches Corporate Social Responsibility (CSR) from the perspective of being a responsible corporate citizen.
The Company has identified projects across all its manufacturing locations in the country in areas of education, health care and rain water harvesting. In Ankleshwar (Gujarat), the company has been involved in improving infrastructure in local schools, while in Kasna (UP), Patancheru (AP) and Sriperumbudur (TN), the company has undertaken a number of initiatives to facilitate convenient and affordable healthcare. In Mumbai, Asian Paints has taken up the cause of Rain Water Harvesting in a major way. Through its various CSR projects, in the last two years, Asian Paints has managed to touch the lives directly of at least 75, 000 people in the country.
Bibliography
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