harvesting the summer showers in a time of shortage
Summer rains are a great blessing to a city like Bangalore. While the dams on the rivers are running dry the city has received 163 mm of rain in the months of April and May. From a 100 sq mt roof area this is 16,300 litres of rainwater. Very, very useful if harvested and used.
As a blogger and a columnist in a newspaper it is still very pleasant to get e-mails like this below.
Water Shortage – an Open well Rainwater Harvesting solution.
brimming with water. These photos were taken last season.
The news on the monsoon front for Bangalore has been disappointing. After the least rainy month for 117 years which was June, July too has seen hardly any downpour in the first 10 days. The clouds are picking up and it is also true that the rainiest months are ahead being August, September and October. The Kabini reservoir which is one of the first to fill up and overflow is almost at rock bottom. It is from here that water flows and joins the Cauvery before it is pumped into the city to reach our taps. It is said that the prayer for rains in the Thanjavur area of the Cauvery delta, the rice bowl of South India, is for it to rain in Mercara so that the Cauvery will flow and reach their fields. Similarly Bangaloreans must pray for rain in Wynad as much as they pray for rain in their own city.
Apart from prayers there should be a Plan B for a low monsoon. What is that? As of now it is not clear that the city has a Plan A let alone a Plan B to distribute water to reach all its citizens. However here is what a Plan B could look like.
Make rainwater harvesting mandatory for all buildings in the city. The lesser the rain that falls on the city, the more precious the water that will be harvested and put to productive use. Every building should become a contributor to the water requirement of the city rather than only placing a demand on it.
Take up de-silting and improvement of all the tanks in the city on a war footing. Here is an opportunity masquerading as a crisis. When citizens have realized the scarcity of water it is for the government to wake up and make plans which are implementable in the short run and which focus on storing water and increasing the groundwater table to recharge the aquifer as and when it rains.
Make it mandatory for all parks and medians to use treated waste-water only. Stop the wasteful use of fresh groundwater in the 1000 or more parks in the city and use the bore-well water to supply it for domestic requirements. There is plenty of treated waste-water in the city which is not being used and the opportunity presents itself to put this to good use for construction activities also such as the metro and the large apartments being built in the city.
Quickly implement the groundwater bill and make sure that groundwater is treated and used as a community property resource rather than as a private good. Take over the large yielding bore-wells and make them part of the city distribution. Every bore-well must be mandated to have a recharge structure and as much of rainwater as possible to be recharged into the ground.
Storm-water drains must be made sewage free and those that are made sewage free should then have recharge structures in them to ensure that storm-water too is put to productive use.
Apartments and layouts – They play an important part in demand management and reducing demand by 20 % should be easy. Metering of each flat should be taken up quickly as is putting the waste-water treatment plants to good use. Treated waste-water must become the first charge for non-potable use and layouts must be mandated to put them into place and start using them immediately.
Watering of lawns and washing of vehicles should be banned and a social mobilization created against such waste quickly.
Individual homes: My friend from the neighbourhood and 14 years old Aravind suggests that school- children should be involved in water conservation efforts by their parents. One bucket of water for a bath is enough he says. By not getting clothes dirty much water can be saved in washing them and he also suggests that boys should clean their own plates and cups with as less water as possible in homes and schools.
The fragility of our water systems, their dependence on rain and the linkages of tanks and lakes and groundwater is clear to us. A crisis they is also spelled as opportunity in Chinese Mandarin. Will we make use of the opportunity? Will we put in place a Plan B ?
The news on the monsoon front for Bangalore has been disappointing. After the least rainy month for 117 years which was June, July too has seen hardly any downpour in the first 10 days. The clouds are picking up and it is also true that the rainiest months are ahead being August, September and October. The Kabini reservoir which is one of the first to fill up and overflow is almost at rock bottom. It is from here that water flows and joins the Cauvery before it is pumped into the city to reach our taps. It is said that the prayer for rains in the Thanjavur area of the Cauvery delta, the rice bowl of South India, is for it to rain in Mercara so that the Cauvery will flow and reach their fields. Similarly Bangaloreans must pray for rain in Wynad as much as they pray for rain in their own city.
Apart from prayers there should be a Plan B for a low monsoon. What is that? As of now it is not clear that the city has a Plan A let alone a Plan B to distribute water to reach all its citizens. However here is what a Plan B could look like.
Make rainwater harvesting mandatory for all buildings in the city. The lesser the rain that falls on the city, the more precious the water that will be harvested and put to productive use. Every building should become a contributor to the water requirement of the city rather than only placing a demand on it.
Take up de-silting and improvement of all the tanks in the city on a war footing. Here is an opportunity masquerading as a crisis. When citizens have realized the scarcity of water it is for the government to wake up and make plans which are implementable in the short run and which focus on storing water and increasing the groundwater table to recharge the aquifer as and when it rains.
Make it mandatory for all parks and medians to use treated waste-water only. Stop the wasteful use of fresh groundwater in the 1000 or more parks in the city and use the bore-well water to supply it for domestic requirements. There is plenty of treated waste-water in the city which is not being used and the opportunity presents itself to put this to good use for construction activities also such as the metro and the large apartments being built in the city.
Quickly implement the groundwater bill and make sure that groundwater is treated and used as a community property resource rather than as a private good. Take over the large yielding bore-wells and make them part of the city distribution. Every bore-well must be mandated to have a recharge structure and as much of rainwater as possible to be recharged into the ground.
Storm-water drains must be made sewage free and those that are made sewage free should then have recharge structures in them to ensure that storm-water too is put to productive use.
Apartments and layouts – They play an important part in demand management and reducing demand by 20 % should be easy. Metering of each flat should be taken up quickly as is putting the waste-water treatment plants to good use. Treated waste-water must become the first charge for non-potable use and layouts must be mandated to put them into place and start using them immediately.
Watering of lawns and washing of vehicles should be banned and a social mobilization created against such waste quickly.
Individual homes: My friend from the neighbourhood and 14 years old Aravind suggests that school- children should be involved in water conservation efforts by their parents. One bucket of water for a bath is enough he says. By not getting clothes dirty much water can be saved in washing them and he also suggests that boys should clean their own plates and cups with as less water as possible in homes and schools.
The fragility of our water systems, their dependence on rain and the linkages of tanks and lakes and groundwater is clear to us. A crisis they is also spelled as opportunity in Chinese Mandarin. Will we make use of the opportunity? Will we put in place a Plan B ?
The city is faced with a massive challenge when it comes to treating wastewater. Of the 1000 million litres per day of wastewater generated only about 430 million litres gets treated every day. Stormwater drains are thus full of sewage and this ends up in our rivers, lakes and groundwater.
Under a new set of projects additional waste-water treatment plants are being put up yet they may prove to be inadequate. On the other hand when one looks at smaller wastewater systems the city has more than 2000 of them according to Dr Anant Kodavasan, a member of an expert committee looking into the issue. Many of them are however are either dysfunctional or are performing below par. The installed capacity of these systems are close to 200 million litres per day, a significant volume.
The best bet is for all the apartments and institutions that have these plants to get them evaluated and brought into efficient performance levels. The cost of the treated waste-water ready for use as non-potable water could vary between Rs 18 to Rs 30 a kilo-litre , significantly less than the water being purchased from private water tankers.
The State Pollution Control Board insists on every apartment or layout which has more than 80 flats to have its own waste-water treatment plant. If these plants are located well , not hidden in basements, they consume less energy , treat water well and produce quality good enough to be used for flushing toilets and for the landscape. A systematic re-evaluation of these plants is therefore necessary to fit them into the overall strategy of managing waste-water in the city.
The other advantage with these systems such as the one in the Jayadeva Institute of Cardiology, a hospital in the southern part of the city , is that they produce not only treated wastewater for reuse but also other byproducts such as biogas for cooking and bio-sludge manure for gardening. As Dr Ravishankar the designer of the system explains ‘ these plants not only look well, there is no odour and there is no waste. All byproducts are reused and the system pays back for itself in 4 to 4 and a half years.”
With some treatment plants there is an excess of waste-water available on site. A system of sharing between apartments has to evolve and a market for its distribution created. ITC –Windsor Manor for example is able to give its treated wastewater to the golf club opposite since it has more than its requirement. These markets need to evolve further and should be facilitated by the BWSSB and the Karnataka State Pollution Control Board.
Apartment owners, layout residents and institutions are doing the right ecological and economic thing by installing these WWTP’s for not only do they save money they ensure that the environment is not polluted. Investing in R and D , developing better models for operations and maintenance and better consumer education will go a long way in ensuring better water management for the city.
(This article was written circa April 2008 – a full 5 years ago)
With a vast majority of houses not connected to the main sewage lines in Bangalore the only recourse is to build septic tanks to receive waste water. Apartments on the outskirts too have septic tanks. Some house do away with this and build large soak pits, simple holes in the ground which receive the waste water and collect the solids but allow the liquids to leach away.
These septic tanks and soak pits are highly polluting, transferring the nitrates and pathogens into the groundwater aquifer and contaminating it severely. Most borewells in Bangalore report high nitrate even to the depth of 600 feet. All the nitrate contamination comes from domestic sewage primarily.
Alternatives
But there are many good alternatives emerging for the septic tank. One of them is called the DEWATS or the decentralised waste water treatment system. This in a broad sense is a major improvement on the septic tank with several up-flow chambers to promote anaerobic digestion. The treated waste water then comes to a reed bed chamber which makes use of sand filtration and reed bed treatment which takes up the nutrient load from the liquid effluent. Ultimately the remaining liquid is collected in a polishing pond and can be used for landscape use.
Eco-san or ecological sanitation systems is another alternative. Here the liquid and solid waste in a toilet are collected separately. The liquid which has a major component of nutrients and very little pathogens is often used as a soil nutrient or fertilizer. The solids which have a high degree of pathogens is collected separately and carefully composted to eliminate all the pathogens before being used as a soil fertilizer.
Waste water recycling plants are also coming into the market at an apartment scale and not yet at a domestic scale. These generally digest the organic load in the wastewater through a process of anaerobic digestion. After filtration and further treatment such as UV the remaining liquid is of sufficient quality to be used in landscapes or in gardens.
All these systems have the potential of reusing the nutrient value of what we term ‘waste.’ They also reuse the water for non-potable purpose and prevent pollution of soil and water.
Specially designed
But what if you already are using a septic tank or have a soak pit which is full? In Bangalore recently one sees a small spurt in specialised vehicles which make available the service of cleaning these filled septic tanks or soak pits. For a sum of Rs.1,300 or thereabouts, these vehicles, specially designed in Andhra Pradesh, will come to your doorstep and in a matter of 20 minutes empty your septic tank, sucking all the waste into the tanker through specially designed pumps. They will then transport the waste to the nearest treatment plant of the BWSSB for further processing or will ship it to the nearest agriculturist who will then use the manure rich in nitrates and phosphates.
Better process
Earlier, cleaning of the septic tank was a smelly, gut-wrenching process, dehumanising with respect to those who cleaned it and leaving a scar in the entire neighbourhood.
Nowadays, with entrepreneurship and modern technology, it has become easy to solve the problem. This is one sector where privatisation seems welcome.
Now, if a safe handling and disposal protocol is built, it will make the handling of waste in the city cleaner and more hygienic, stop pollution of the soil and the aquifers and make city living a more pleasant experience. More power then to these technologies and the people who make it happen.
Creating a business where opportunity exists and doing so to provide service to the community is but one small step in water wisdom. Managing wastewater is protecting fresh water and the water wise know that.
In the small town of Mulbagal, Kolar District , Karnataka, an NGO drove a water project for some years based on the Integrated Urban Water Management approach. One of the key success of the project was the de-silting of a large step well called a ‘Kalyani’ . The step-well is adjacent to a temple and the reason for its being filled with garbage and debris is not known. The de-silting and cleaning was an affair of great pride for the town and especially the Councillor of the area.
In the warm month of March, one saw boys diving and swimming in the rather green waters and having a whale of a time. The high groundwater table in the town ensures that there is water for swimming. Clearly the festival of Holi is an everyday event here in the well.
Water in a town is not to be seen and planned only as a functional engineering construct meant to flow through pipes and be distributed by pumps. Water is a recreational, aesthetic, ecological and even spiritual a material.
Swimming pools are few and far between in India and for many a luxury they can ill afford. Hundreds of boys and girls in rural India and in small and medium towns have therefore learnt the art of swimming in open, dug wells. With a declining water table there are no more swimming lessons to be learnt and fun had. An entire generation has lost a very significant experience of water. This is so with the polluted rivers and lakes too. Mulbagal has discovered a treasure serendipitously.
Close by to the town we come across a full well of water. A tank above stores and recharges water from a rock catchment and recharges the aquifer. A villager informs us that the name of the well is round well . It is always full and people come from miles to just have a swim and enjoy the pleasure of dunking oneself and splashing in its blue-green waters.
Is there a value attached to such human activities and their loss through a collapsing water table ? Should we not attach the same importance to the non-functional aspects of water which are good for the soul rather than only concentrating on the functional aspects of consumption in taps?
The festival of Holi came and went. With drought prevailing in many parts of the country there were calls for muted celebrations and to play ‘dry’ Holi. For children and the young the essence of Holi is the splashing of coloured water on each other. Should we as a society go on a guilt trip about this one beautiful experience?
In our neighbourhoods, in our villages and in our towns and cities let us plan that there is wise use of water. Let us also plan that our lakes and tanks are full and that our wells have water throughout the year. It is not an impossible task but requires dedication and a vision.
This monsoon be prepared to harvest the rain, in tanks, in lakes and in the aquifers. Individually and collectively let us stop polluting water bodies and treat them with respect.
Let the children have the experience of water which is not of shortage and worry but one of plenty and one of fun. Let them swim in the full wells of life. That would be water wisdom.
http://www.youtube.com/watch?v=rKKl-cVWE4I
