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INEP: What is rain water harvesting?Mr. Shivakumar: The source of water to wells, tanks andrivers is rain water. Rain water conservation has beenhappening from thousands of years and there is nothingnew in what we are doing now. As civilizations grow wehave more buildings, bigger villages and cities. Whensuch changes take place, the availability of waterdecreases. There is a need to conserve rain water apartfrom having water in tanks, rivers and other places. Thereis a need to conserve water in our own homes. We havea system called roof top rain water harvesting for thispurpose. The water collected on the terrace can befiltered, stored and used.

We have a lot of rainfall in our country. In Karnataka thereis 1200 mm of rain a year. We cannot store all the waterthat falls on the ground, but whatever we can is a lot ofwater. Rain water can be stored in tanks and sumps athome. If there is more water we have to redeposit it in tothe ground. For the last 30 - 40 years we have beendrawing ground water for our daily use. We have to

reverse the trend. If we do not redeposit what we havedrawn from underground we will be in deep trouble.There are some very simple technologies that will enableus to store and use rain water. This is known as rainwater harvesting. INEP: What is the need for storing rain water?Mr. Shivakumar: We are forced to conserve rain wateras there is a severe shortage of pure drinking water, be itin cities or villages. Moreover, whatever little that isavailable is polluted. Therefore we have to depend onrain water. If we don’t do this now, then the bottled waterwhich you buy for Rs.12 - Rs.15 per litre will be the waterthat will be seen only in a museum! We have to reallystruggle for water. Before such a situation develops it isbetter we store rain water.

INEP: What can be done to spread awareness about theneed to store rain water?Mr. Shivakumar: We were aware of the value of waterall along. We were also self-sufficient in water resources.

Save rain water…now!

Rain water harvesting can prevent water famine. Ground wateris meant for an emergency but we have been drawing it for ourdaily use. The reckless use of ground water can deplete ourwater resources dangerously. Storing rain water can preventsuch a calamity, says Mr. A. R. Shivakumar, Senior Fellow,KSCST, Bangalore

Rain water harvesting

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The first thing a housewife did in the morning was to carrya few copper vessels, clean them well with tamarind,make it shine, and collect water and worship it. The waterwas worshipped first and then the oven. All other activitieswould follow later. In other words water was treated likethe Goddess Ganga. They knew the value of water. Theycould see divinity in water. Water was respected earlier.Nowadays, we do not take water seriously. When we wantit, we turn on the tap and use it and forget about it.

Another factor is that we seem to assume that water isexclusively for human use. Even for a moment we do notthink that the bio-diversity around us is also part of natureand needs water. If you stand atop your building and lookaround, you can’t see a single patch of open water. Westore water and lock it safely in sumps and tanks. Wedon’t let dogs, foxes or birds or sparrows or even insectsto gain access to it. We have assumed that it is ours.One of the reasons for such an attitude is that there is ashortage of water. Less water is available now than inearlier days. Earlier we used to have a tank or a well ora lake around our house, from which we would drawwater. Now the demand for water has increased 100%.

As the demand increases the use of water also increases.As utilisation increases the demand also increases.

We use to have a lot of space around wells or tanks.There used to be paddy fields, farms and gardens. Inother words water had enough space to seep back intothe earth. The water that would get into the earth wouldget back into our wells and it was pure too. Now, tanksand lakes are surrounded closely by buildings. Roadsare tarred. Pavements are covered with concrete slabs.There is absolutely no space for water to getunderground. We have closed all channels.

And whatever little water that was there underground wehave used it either through bore wells or wells. Now ifyou don’t return the borrowed water to its original sourcethere won’t be any water left underground. Water is likemoney….if you keep withdrawing money from the bankand do not repay then one day there will be no money todraw. Similarly, one day water will cease to come up. INEP: So we will not have money when we really need it. Mr. Shivakumar: Underground water should be usedonly in case of an emergency. But we have been using iteveryday— for 24 hours, 365 days— for our daily needs.We shouldn’t do this. When it rains, the water that fallson the terrace comes out through the pipes. That waterhas to be stored in a bucket or a tank. This is sufficientfor all purposes for a day or two. This is a simple method.

If there is excess water that is collected in the drain or inany other place, it can be channelled undergroundthrough the help of a ‘sink pit’ or a dried up well. This in away is as good as replenishing the fixed deposit of water.This will also help the future generations and in therenewal of tanks.

Storage of water and groundwater recharge

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INEP: There is thisnotion that rain water canbe stored only during therainy season and that it isnot possible throughoutthe year.Mr. Shivakumar : Itnever rains throughoutthe year. In Bangalore wesee a rainfall of 1000mmper year. The rain fall isspread over 60-70 days.It does not raincontinuously for 60-70

days but spread over a year. It is spread in such a waythat rain water is available all through the year off andon. If there is a big gap between two rainfalls, then wecannot use rain water. We have to use the stored rainwater. We may have to use what has been depositedunderground. Thus rain water is available throughout theyear.

Rain water can be stored in tanks or sumps. When it isexhausted, we can use ground water. We should useground water only if we have returned the borrowed water.Otherwise, we should not. The water has been storedunder the ground over a period of 100 or 1000 years. We do not have the right to extract this water. If you want10 litres of water then you have to give back 15 litres ofwater to earth. Only then will you have the right to draw.Only then can our children and grandchildren see water,otherwise we will have water famine.

INEP: If we want to use the legacy left behind by ourforefathers we have to work hard, return about 20%, andthen use about 10%. If one ‘spends’ whatever that is

stored before our time, we will be in deep trouble.Mr. Shivakumar: There is a proverb that says if you sitand eat, even a pot of money is not enough.

INEP: For what purposes can the stored rain water beused?Mr. Shivakumar: The stored rain water is pure water.You cannot dream of better or purer water than rain water.This can be used for all purposes. It can be used fordrinking. However, the terraces of our houses have dust,dry leaves, and droppings of birds and insects, whichcan pollute water. But if you filter this, you have puredrinking water. One can collect two to two and a half lakhlitres of water on a 40ft x 60ft site at places where therain-fall is 1000 mm. But you cannot store all the waterthat falls on the ground. Most of the water goesunderground. The stored water can be used for allpurposes like drinking, bathing, cleaning vessels,washing, mopping and watering trees and plants. In otherwords it can be used for various domestic and industrialpurposes. INEP: How much rain water can a person store?Mr. Shivakumar: It depends on how much water youneed. According to the World Health Organisation, aperson needs an average of 135 litres of water per day.A family may need 500litres per day or 1.5 lakh to 1.8lakh litres a year. The stored rain water will be sufficientfor an entire family for a year. Sometimes you get more.So you don’t have to go in search of water. One canbecome self-sufficient.

Where do you think we get our water from? The waterthat falls on our terrace reaches the drain, flows into a pitor a tank or a river, from where it is pumped and sentback to the city through water pipes. Instead of this cycle

Barrel method for recharginggroundwater

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of water supply,we can store rainwater and rely onit. INEP: What arethe other benefitsof rain waterharvesting?

Mr. Shivakumar: Rain water harvesting is one way ofgetting very high quality of water. People think that it isthe responsibility of the government to supply water. Ifyou store rain water that falls on the terrace we can beself-sufficient and do not have to depend on anybody.Secondly, we get pure water. Thirdly, we get fewerdiseases. We can also reduce soil erosion because waterthat falls on the terrace or on the road is stored and notallowed to flow away. The water that is supplied toresidences has to be pumped and purified. If rain wateris stored, one can save on purification and electricity usedfor pumping. It can also help ground water level toimprove. So rain water harvesting offers us multiplebenefits. INEP: What are the methods adopted to store rain water?Mr. Shivakumar: There are several methods. One isstoring rain water that falls on the terrace of individualhouses. When rain water falls on vacant sites, roads,playgrounds, drains and paddy fields, the water can becollected for community use. Thirdly, wells and tanks canbe used to store rain water. These three can complete arain water chain. Having just one of the three is noteffective.The rain water that falls on the terrace flows down through

a pipe. We need to have a filter at the end of the pipe,and this filtered water can be safely stored in a sump ora tank. One can use a sand-bed filter or in some cases even acloth filter can be used. For channelling rain waterunderground a plastic barrel system designed by me canbe used. A plastic drum, cut off at the bottom, is placedat about two to five feet in the ground. Rain water getsinto these drums and reaches underground. In the sameway, a dysfunctional bore well or a bore well withinsufficient water can be revived if rain water is allowedto enter it. INEP: How can stored rain water be used in industries?Mr. Shivakumar: In our factories we use more waterthan in our residence. It is also expensive because it isnot subsidised as in the case of water supplied toresidences. Factories do not need pure water like drinkingwater. But they are using pure drinking water or Cauveryriver water. Instead, harvested rain water can be usedfor industries. Factories already have a system to get ridof water collected on their terraces which are quite large.The same system can be used to store rain water whichcan be used for recycling purposes. It can be used forgardening. This way, industries can become self-sufficientin water. They can save money on water which isexpensive. Thus they can increase their profit on theirproduct. INEP: How can stored rain water increase ground waterlevel?Mr. Shivakumar: I said earlier that about 80% of therain water drains away. Around 20% of water seeps intothe ground. This quantity is getting reduced because wehave blocked the channels of water to get underground.Now, we have started using artificial methods to recharge

Pop up filter for filtering rainwater

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ground water. This plastic barrel technology has to beused both in rural and urban areas. We have to rechargeour underground water so that water level in our wellsand bore wells will improve. It will stabilise for a whileand then sink underground. So with very small and simpletechniques we can recharge ground water in an economicmanner. INEP: Instead we use old and dried-up wells as dust binsfor old clothes, tyres, plastic and other wastes. If we cleanand use dried-up wells for storing rain water it willreplenish ground water. People say that there is nothingnew in rain water harvesting and that it has been practisedin some form or the other for several centuries. Comment.Mr. Shivakumar: That is very true. Some form of rainwater saving or storing has been going on since the dawnof civilization. Man always lived around water spots orwater bodies. He took steps to ensure water supply didnot dry up in summer. That was also a form of rain waterharvesting. Hundred-year old buildings in Rajasthan tellus that this system was in practice centuries ago. Onecan see a system of collecting whatever little rain thatfell on the terrace of those buildings in small tanks ortroughs. There was enough drinking water for a year ortwo.

A good thing about storing rain water is that it can beused for several months and even years, if it is filteredand stored. But technology varied as towns and citiesdeveloped. Earlier there was no need for much filtering.Now it is necessary to do so. We have to ensure thatpipes do not have cracks. Some measures have to betaken while building tanks and sumps. Steps should betaken to ensure that sun rays do not fall on water. If theyfall, water gets contaminated. It is necessary to learnabout such small details. Then rain water harvestingbecomes very easy too.

INEP: Can youname someplaces whererain waterharvesting is asuccess?Mr. Shivakum-ar: When ourorganisation, theKarnataka StateScience &Technology Cor-poration, withthe help of the government of Norway began the rainwater harvesting programme in Bangalore, it adopted themethods that I have been using in my house as a model.

I am using only rain water in my house. We used onlystored rain water to build my home. I have not taken the‘water connection’ from the BWSSB or the Cauvery WaterScheme! Every drop of water used at my home for tenyears has been the rain water harvesting method. Weare using that source for drinking too!Our parent body, the National Institute of AdvancedStudies, has successfully adopted this method in theVidhana Soudha, the General Post Office, the Fire Stationat Rajajinagar, the Kengeri Beedi Workers HousingColony and Kidwai Hospital and a few other majorbuildings in Bangalore. Apart from this we have conducted hundreds of trainingworkshops and awareness programmes all over the state.People have to accept that storing rain water is anecessity. Along with the assistance of the Departmentof Panchayat Raj and Rural Development we have takenup a programme to popularise this scheme in all districtsand taluks.

RWH at KSCST

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It has been made mandatory by the government to haverain water storing kit in all new buildings. Student: Is it safe to drink stored rain water?Mr. Shivakumar: Rain water is like nectar. It will notharm us. But rain water fallen on the terrace, road andother such places is polluted with dust, droppings ofinsects, birds and animals. It has to be filtered beforeuse. But if you can manage to drink rain water directly, itis safe and does not harm you.

The first rule of rain water harvesting is to avoid storingthe water for ten minutes. Allow it to flow for ten minutesso that it washes the dust and other pollutants settled onthe terrace. The water that is collected and storedafterwards is clean and drinkable. If you are stillapprehensive, then you filter the water with a well foldeddhotis or a cotton sari by placing it at the edge of thewater pipe. The water you get then is fit for drinking. Itdoes not harm you. Student: Can rain water be used for agriculture?Mr. Shivakumar: It is rain water that is used for agricultureall over India. The source of water for wells, bore wells,tanks, lakes, reservoirs and rivers is rain water. The useof rain water does not adversely affect agriculture. Student: Can rain water be stored in all types of houses? Mr. Shivakumar: I can see that the moment the terms,‘Solar water heaters’ or ‘rain water harvesting’ arementioned, people assume that these are not for them.They presume that it is suitable for upper class peoplewith large open spaces on terraces. It does not matterwhether the terrace is big or small, sloping or flat. If theterrace has a slope, the water can be stored with thehelp of a pipe or a ‘gutter’ made of bamboo or bronze.

The bamboo has to be split open and the nodes have tobe cleared for a smooth flow of water. Student: People use wood of areca nut trees as ‘gutters’to store water….Mr. Shivakumar: That can be done too. If it is a flat roofterrace, the water that needs to be collected can be storedwith the help of pipes. On open sites, people can filterthe rain water with the help of dhotis or saris whose fourends are tied to pillars or branches of a tree.This can be done at a height of three feet above theground. The water stored after this process is cleandrinking water. Thus we can see that water can be storedin many ways. Student: Where can we get more information regardingrain water storing?Mr. Shivakumar: People are becoming aware about rainwater harvesting. Our institution, The Karnataka StateScience and Technology Corporation, is situated inBangalore. We provide information for all who want toknow more by fax or by e-mail or by telephone. Rainwater harvesting models are kept in all the zilla panchayatoffices. All the ZP officers have been trained in thismethod. Builders and contractors have been trained andare familiar with this scheme. People can contact any ofthem for more details. There are several organisationsthat are familiar with this programme. In Bangalore thereis a Rainwater Harvesting Club. There is an organisationcalled ‘Caught’ at the National Institute of Engineering inMysore. In Mangalore and Udupi regions people cancontact Sri Padre, a well known journalist. There areseveral other organisations that can be contacted formore details on rain water harvesting.