GO AHEAD, HIT THE ROOF!

GO AHEAD, HIT THE ROOF!

Simple interventions on your roof can help you harvest rain. Here’s how

In cities, buildings are usually constructed with rooftops of Reinforced Cement Concrete (RCC), Mangalore tiles, asbestos / galvanized iron / zinc sheets etc. Rooftop rainwater usually flows into storm water drains outside the plot area. As roofs are built with hard material, large quantities of rainwater runoff and loss due to evaporation and percolation are minimal.  So, rooftop rainwater is just waiting to be harvested. You can either store rooftop water on the roof itself, at ground level or below the ground, using storage devices like masonry tanks, ferro cement tanks, or plastic / metal containers.

The process

Collection: Roofs can be broadly categorised into flat roofs and sloping roofs.  Flat roofs with RCC have water proofing on the surface as a surface finish. This surface is provided with a slope towards the down-water pipes.  For efficient collection and effective usage, the roof needs to slope towards the storage device. This will minimize pipe length to the storage system.  

Sloping roofs with RCC, Mangalore tiles, asbestos sheets or steel sheets lead the water to the lower edge of the roof. A gutter made out of sheet metal or PVC has to be installed at the lower edge to collect and channel water to the down-water pipes.

 Channeling: Down-water pipes made of PVC, HDPE or cement, can be used for transporting rainwater collected from roofs to the filtration system before storing. The size of the down-take pipe varies depending on the roof area, which is connected to the down pipe.

Filtration: Rainwater collected on the roof is very pure and clean.  However, there are many substances, which may contaminate this water such as leaves, bird droppings, dust etc.  These contaminants need to be filtered before the rainwater is stored.  There are many filtration systems such as sand bed filter, PopUp filter and stabilization tanks.

Sand bed filter: Sand bed filter is the traditional method of filtration where coarse riverbed sand, pebbles and aggregates are filled as layers, one above the other, in a confined masonry structure. Rainwater is allowed at one level and filtered water is drawn from the other.

PopUp filter: A simple PopUp filter works effectively for residential buildings and smaller institutional or industrial applications. It has three components – rainwater receptor, flush valve and filter.  

Stabilization tanks: Rainwater is allowed to flow through a series of small tanks and, by providing an entry and exit for water at strategic positions, impurities are trapped in the stabilization tanks for subsequent cleaning.

Cost is determined by:

                     * Quantity of rainwater to be collected

                     * Type of surface from where rainwater is collected

                     * Existing structure and fittings for rainwater collection and flow

                     * Type and capacity of harvested water storage device

Rain dance on the rooftop

Rain dance on the rooftop

Bangalore is a unique city because it has neither river nor sea close by. Our erstwhile rulers had planned lakes and water bodies to collect rain water. It was the most systematic, common-sense community approach to address the water needs of the population.

Traditional Open well

The water thus collected was used through ‘kalyanis’ or step wells and open wells. Open wells were recharged by tanks, water bodies and surface water flow.

Kalyani being restored by volunteers

Kalyani in the premises of a temple

But as urbanization happened, this approach could not be sustained. Water sources got polluted and dried up. Encroachment and diversion of natural drainage of rain water soon turned most of these tanks into garbage dumps!

Ulsoor Lake

We began to look at far off places like Hesarghatta and Thippagondanahalli for water supply. As demand continued to mount, we went up to 95 km to River Cauvery to meet our water needs. And now we are in the unique situation of pumping water (most our requirement) from a distance of 95 km against a gradient of 500 



meters!
Urbanization and increase in population are exerting tremendous pressure on conventional water supply. The time has come to look for new sources or at recycling water. Recycling is not a phenomenon that is well-accepted in India due to social reasons. We just cannot imagine recycling our bath water!

                  Ulsoor Lake

Why fret when there’s an easy solution on hand: Rainwater. It is available in abundance in a place like Bangalore which receives 1000 millimeters of rain water (or 40 inches of rainfall) annually. This translates to 2, 30, 000 liter of pure water in a plot of 2400 sq ft — a plot where an individual can comfortably build a house / apartment. When we have such a boon, why don’t we use it? If we do, at least 50 per cent of our water requirement can be met with this intervention. And the pressure on a service provider like the Bangalore Water Supply and Sewerage Board (BWSSB) will dramatically come down. The BWSSB currently supplies water to around 7,00,000 properties only (against over 18,00,000 properties of Bangalore). If everyone practices rain water harvesting in Bangalore, an equal number of new connections can be facilitated and in the next 25 years, Bangalore can still sustain with its available water sources.

So what exactly is rain water harvesting?

It is a very simple intervention to collect rainwater. The first and easiest approach is rooftop rainwater harvesting. Collect the roof water which is already flowing through a down water pipe, attach a filter at the end of the pipe to separate the dirt, dust, bird dropping and leaves and divert the filtered rainwater into a storage unit such as a tank / sump. This can give you sustained water supply during the rainy season.

Cement ring well in a residence of Bangalore created for ground water recharge from roof top rainwater 

The excess water which overflows from the sump or tank can be used to recharge the groundwater through a pre-cast cement ring open well. When the rainwater is discharged into this well, it slowly percolates into the groundwater table and can be withdrawn through a borewell or an open well. These two systems can provide sustained water supply throughout the year. Rainwater can also be collected in playgrounds, parks and roads for large-scale groundwater recharge. Harking back to the time when I was in school, I remember fetching water twice a day from an open well outside my village, Ammanaghatta in Gubbi taluk in Tumkur district. I did this religiously all through my childhood! I saw piped water only when I moved to Bangalore. But soon the bore well in our house in Vijaynagar dried up and I had to fight for water for the first time in my life! At that time, I was working on sustainability projects. So I started planning a house which would use Nature’s gifts for its needs. The outcome is ‘Sourabha’. I will take you on a tour of ‘Sourabha’, in my future posts!

SWM - Let’s talk R U B B I S H!!! Bangalore Burning….

Let’s talk R U B B I S H!!! Bangalore Burning….

Vidio Link : https://youtu.be/qniQAdS_SOQ

Solid Waste Management has always been a matter of concern because anywhere in the world it operates on a “reverse flow” system. Unlike power / water supply, the service generates outwards. No one wants to keep garbage at home for a long period of time.

Years ago, the Bangalore City Municipal Corporation (now BBMP) did come up with the idea of bringing in a rule for garbage disposal. According to the rule book, garbage could be piled on a Civic Amenities (CA) site in a locality before it was collected for disposal by dumpsters. But, this turned out to be impractical because no one but the rare civic-conscious person would trudge all the way to the CA site to dispose rubbish! Then, cement-ring dustbins were installed at street corners. It was decided -- after much deliberation -- to install these bins on the left corner of every street. But overnight, people would move the rings elsewhere because they couldn’t stomach the stench or the mess near their houses! The cat-and-mouse game between residents got to a point where court cases were filed by neighbors against each other! Those who swept the streets piled garbage into the cement-ring bins, contractors dumped debris into them; butchers discarded poultry waste; and some nursing homes clandestinely dumped their bio-medical waste in them! So, cement-ring bins were phased out in 2004-05. 

Cement ring garbage bins kept at street corners

But before that, Karnataka State Council for Science and Technology (KSCST) - through the Indo-Norwegian Environment Programme (INEP) -- partnering with Environment Support Group (ESG) -- began a small experiment in solid waste management in Basavangudi area in Bangalore. They also wanted to change the image of pourakarmikas, who were treated rather shabbily and had no proper equipment. The other objective of the experiment was to phase out the ring bins so that secondary dumping of garbage is avoided. Those handling garbage were given uniforms. Their health was monitored. They were given gloves, masks, biodegradable brooms with long handles, and shoes. They were also provided with the wheelbarrows to collect garbage. Residents were given three bins: one for “green” waste which is degradable, one for “non-degradable” waste like plastic, metal and glass which can be recycled, and one for “hazardous” waste like unused medicines, blades, razors, needles, batteries etc.

Colored bins for segregation of waste

Push carts for garbage collection

Similarly, there were three bins in the wheelbarrows. Door-to-door garbage collection would be done by 11 am every day. Trucks would wait near the CA site in the locality and take the garbage to treatment plants - green waste to vermi-compost heaps near Parappana Agrahara; recyclable waste to identified vendors; and hazardous waste to specially-designed landfills which had impermeable plastic lining to prevent pollution of ground water. But, KSCST and ESG could monitor the movement only till the garbage reached the truck.

Then, shockingly, the systematically segregated garbage would be mixed and dumped in the landfills! While cement-ring bins have been phased out and there is door to door collection of garbage in most part of the city, segregation and treatment remain on paper and dumping continues unabated. 

Stories of Mavallipura, Mandur ……… took over the front page of the media attention.

Today Bangalore Burning…… 

most street corners have piles of leaf litter along with plastics set on fire mostly by “BBMP” sweepers / contractors to choke the city. Most of us haplessly turn the other side……??????

Be the change you want:

1. Don’t litter and don’t throw garbage on the road or in front of someone else’s house. Put it into your dustbin at home.
2. Don’t hang plastic covers with garbage outside your door / gate the previous night. That’s criminal and lazy! It can attract rodents and dogs.
3. Don’t entrust garbage disposal to your maid. She will invariably chuck it into the nearest ditch, gutter, vacant site or park.
4. Use covered bins and keep them outside for the garbage collector if you leave early to work or are a late riser.
5. Follow segregation to the extent possible. Don’t dump batteries and medicines with vegetable peels and paper. Collect them over a period of time and take them to collection centers of the Pollution Collection Board in certain Food World outlets…..  in your city. 
6. Treat solid waste collectors with dignity. Remember, they are cleaning up after you!

Lake to support Forest, Forest to support Lake - Military Green in Bangalore

“Lake to support Forest, Forest to support Lake” - Military Green in Bangalore

Do you know that the city of Bangalore has a thriving urban forest with over 50,000 trees? 

Army Supply Core (ASC) Centre

When you picnic above the city in the zooming Metro, you are sure to exclaim at what lies beneath. Sleek cars, shining malls, mushrooming apartment blocks some trees and the stray lake. Over the years, Bangalore has lost 29 sq km of green cover. A city that once boasted 18 native varieties of tamarind can now barely claim to six. Villages such as Devanahalli with groves of flowering trees like ‘nagalinga pushpa’ must now make their peace with flyovers, underpasses. No, this is no sob story about a city that’s gone to seed. This is actually the story of a thriving forest in the heart of the city, where 45,000 -50,000 trees stand tall.

Military Engineering Services - ASC Centre in east Bangalore has a campus of around 1000 acre. Annual rainwater potential from the campus is around 4000 Million Liter. Rainwater harvesting interventions are part of campus development. Three large open ponds, 30 Cement ring wells for accelerated recharge of ground water with Infiltration Trenches at various locations are part of RWH interventions.

Pond area in the midst of trees

At the Army ASC Centre on Old Airport Road near Domlur is ‘Sena Aranya’, an urban forest that has been quietly and efficiently playing the role of a ‘carbon sink’, giving Bangaloreans more than a lungful of fresh air!
Key players in this miracle include students in Bangalore, Tumkur and Kolar, their Botany teachers, organizations such as Eco Watch, the Karnataka State Council for Science & Technology, the Forest Department and - most important of all - the Army. Young jawans worked all day to green the area which they proudly call ‘Sena Aranya’.

Students plant saplings at the Army ASC Centre.

Seeds of a dream
The urban forest, funded by the Indo-Norwegian Environment Programme (INEP), was a project to show the viability and usefulness of creating ‘carbon sinks’ in bustling cities, where trees are cut and open areas concreted.

The additional focus at ‘Sena Aranya’ was to grow trees native to Bangalore. Volunteers from Eco Watch visited forests in Tumkur, Kolar and Bagalore Rural districts.

They roped in high school and college students who were happy to scour the forests with their Botany teachers to find, tag and transplant native plants. Seed and sapling collection centers were set up in each of these districts.

The seedlings were brought to the ASC Centre, where they were planted. More than 75 species, such as local fig, banyan, jackfruit and tamarind, were identified and nourished, first in a nursery, and then transplanted in the field, and tagged.
Today, ‘Sena Aranya’ has close to 50,000 trees.

Students identifying local tree varieties for planting

Kingfisher’s flight
Film maker and founder of Eco Watch, Suresh Heblikar, says: “Procuring the saplings was the biggest challenge. We wanted only plant species that thrive in the southern dry zone, so we went into the history of Bangalore’s vegetation 300 years ago.”
Community participation was the key to the success of ‘Sena Aranya’. “Student participation was phenomenal. So phenomenal that we set up bio parks in Kolar and Tumkur with all the seedlings and saplings we had after ‘Sena Aranya’, a three-year project, was completed.”
All the trees at ‘Sena Aranya’ - barring the Singapore cherry which was planted because it flowers quickly and attracts birds are native to Bangalore. “When we sighted the first kingfisher at the lake, we were ecstatic! A Scientist from IISc told us there are 35 species of butterflies here. Army jawans said they even saw a huge snake devouring a small hare! Oh, such news really thrilled us.

Green Teachers
As part of the urban forestry project, Eco Watch conducted 70-80 teachers’ training sessions called Green Teachers Workshops’ covering 100 schools in Tumkur, Kolar and Bangalore. They in turn started teaching students about the importance of bio diversity.
If you do not destroy trees, you don’t have to worry about rainwater harvesting. Trees store water, they transmit water through the ground and they feed lakes and ponds. Students must be sensitized to this because Bangalore has lost 29 sq km of green cover. Bangalore’s topography was such that any amount of rain that pounded the city was absorbed by the trees. But now, we have flooding.

“More trees More water, more and more Eco-Friendly benefit to Bangaloreans”

Growing trees in ASC Centre

Grown up trees in urban forest

Storm water being harvested

RWH in buildings of ASC centre

High Court of Karnataka - Judiciously harvesting rainwater from its roof

The legacy from British raj and the local knowledge - Tantalising tunnels, scintillating stories

An idea is born

In 2000, I was working as Program Manager – Karnataka for the Indo-Norwegian Environment Program (INEP). The councilor of Norway had suggested that I replicate the ‘Sourabha’ (First ecofriendly home of Bangalore) model of sustainable living, especially the rainwater harvesting technology that I had used in my house, in public buildings in the City of Bangalore. I hoped to get an entire locality – Vidyaranyapura – with four layouts, to harvest rainwater and make the entire community independent of City water supply. But I was told that public grant cannot be channeled into individual houses. I was directed to implement my proposal in public places or Government Housing Quarters. I chose 10 landmark buildings and 2 exhibition plots for the project. And of the 10 landmark buildings, the two that gave me sleepless nights but immense satisfaction were the Vidhana Soudha and the High Court. Here’s why.

The Cubbon Park Site of the High Court`s rainwater harvesting project

Every drop counts

The High Court building in Bangalore was built by the British years and years ago. None of the PWD engineers I spoke to seemed to know where the rainwater pipes were. In desperation, I scrambled on the rooftop, poured water on the roof and raced down to follow its trail! And, in the process, I discovered many startling facts:

a) All the rainwater pipes in the High Court building are hidden in pillars which are inside thick walls.

b) There is a tunnel in the High Court basement which exits towards the eastern side of the Court building inside Cubbon Park.

c) This basement tunnel connects to an underground stone masonry tunnel, which exits at the Lotus Pond inside Cubbon Park.

There is a ruling that no construction activity can take place inside Cubbon Park. I had to seek special permission and ensure that the flora and the fauna were undisturbed. No blasting activity or the environmentalists would have had me! My challenge, therefore, was to intercept rainwater inside the tunnel at 15 ft below from ground level, design filtration systems for it and store it – 15 ft below the ground level as I could not mess around with the heritage building. And we – my team and I – achieved the impossible. We began work in 2003 and by the end of 2005, we had the RWH system in place.

The Karnataka High Court building in Bangalore

The Cubbon Park Site of the High Court`s rainwater harvesting project

Rainwater Harvesting process in High Court of Karnataka

Saving a lake from choking to death - Destination Bangalore

Saving a lake from choking to death - Destination Bangalore

Plants to eat up pollutants, fish to enhance water quality and silt that’s turned into a joggers’ track keep Hebbal Lake in Bangalore safe from garbage dumpers and greedy land sharks

When you zip past the sparkling Hebbal Lake on your way to the Bangalore International Airport, you wouldn’t imagine that it was once covered by layers of water hyacinth, filth and sewage, would you? Migratory birds nest in trees on its green islands, joggers pound the 7-km track on the lake’s periphery and the lake itself showcased as a tourist attraction. How did this magical makeover happen?
Rejuvenation may sound like a fancy word but truth be told, it boils down to simple, practical, common-sense ideas. Here’s how we achieved the impossible. But first a quick mention of the project that made this happen: The Indo-Norwegian Environment Programme (INEP) supported the rejuvenation of three lakes in the City: Hebbal, Madiwala and Dodda Bommasandra near Vidyaranyapura. I chose to work on Hebbal Lake first because of its strategic location: it’s on National Highway 7 and it has a single water inlet channel which makes the clean-up drive relatively easy. Upstream are HMT Layout, Tata Nagar and Vidyaranyapura, and downstream is Nagavara Lake and Manyata Tech Park.

The 64.5 hectare lake was putrified, covered with water hyacinth and had no visible water sheet. It was as if one could walk on it! Sewage from all the nearby layouts were discharged into this lake. With funds from INEP, help from experts in water conservation and cooperation of the Forests Department, the lake became a living, breathing entity.

Ø  We identified the source and entry points of sewage discharged into the lake and found that domestic sewage discharge was heavy, leading to water hyacinth growth. Water recharged into the ground was full of contaminants, including heavy metals.

Ø  The lake was isolated from the sewage and the storm water flow was regulated. On the northern side of the lake is land belonging to the army. Skirting this land, we built a diversion canal downstream. The upstream sewage flow now bypasses the lake and flows into the canal and then into Nagavara. Ideally, it should have gone into a sewage treatment plant. This was a temporary solution, no doubt, but we shifted it downstream to show that an urban lake can be restored. There’s a lot of science behind this. Segregation sewage and rainwater has to be done carefully.

Ø  A wetland system was created within Hebbal lake, where plastics, bottles and large objects can be removed through filtration. Biological purification was achived using hydrophytic plants which absorb dissolved pollutants and toxins. The wetland also acts as a silt trap. There are vents from which water can flow from a certain height to the main lake. This ensures that relatively clean water is made cleaner.

Ø  We desilted the lake and removed accumulated sludge and sediments. This process took us three years (2000-2003) because the sludge had accumulated over 40 years! The obvious question we faced was: Where would the millions of tonnes of sludge go? We couldn’t dump it just anywhere! It wasn’t fertiliser-quality because it was full of detergents, heavy metals, toxins etc. It was too expensive to transport to a faraway landfill. Then, we had a brainwave: the lake was being developed as a recreation centre. So, we created a jogging track of 7 km with this silt! Over that we put good soil and planted ornamental plants, grass etc.

Ø  We also created islands using the silt. Here, we planted fruit-bearing trees. The islands were so designed that dogs and rodents couldn’t access it. It became a nesting place for birds such as purple moorhens, cormorants, Brahminy kites, darters, kingfishers, weaver birds, purple herons, grey herons, pond herons etc.

Ø  We strengthened the existing bunds and wetlands with stone pitches.

Ø  A chain-link fence was built to protect the lake from garbage dumpers.

Ø  Fish culture and boat jetty services were introduced. The fish enhanced water quality and yield revenue while the pedal boats were for recreation for the public and churned the water, thereby aerating it.

Ø  A waste weir was built to maintain water level in the lake. The weir also avoids breaching and flooding.

Ø  As a tribute to people’s power, a citizens’ committee was formed. The Hebbal Lake Development and Protection Group, headed by Former Chief Secretary of Government of Karnataka, made sure the lake stayed clean and safe.

Ø  Total investment on restoration: Rs 3 crore.Returns on investment: Immeasurable, because after desilting the lake, borewells in the vicinity were recharged and began overflowing! 

Part of Lake before rejuvenation

Development of wetland system for pre treatment

Fresh Rainwater collected in Hebbal Lake after rejuvenation

Island inside Hebbal Lake and City development on the foreground

Boat jetting for recreation in Hebbal Lake

Winged visitors to Hebbal Lake, Bangalore

Do or dry: Lessons in RWH - Probably world’s biggest!

Do or dry: Lessons in RWH - Probably world’s biggest!

Reeling under water shortage, over 23,000 rural schools in the State of Karnataka began to harvest rainwater. The results are amazing!

If public water supply in most Indian cities is unreliable, the situation in our villages is far worse. Hence rainwater harvesting (RWH) is not only the ideal solution but also the most sustainable one.
Rainwater harvesting entails the collection of rain, where it falls, in a scientific and controlled manner for future use. RWH consists of roof-top water harvesting, water from open areas such as paved ways, parks, roads, fields and in lakes and ponds.
Among the three projects initiated by the Karnataka State Council for Science & Technology (KSCST), ‘Rainwater Harvesting in Rural Karnataka’ is probably the most ambitious and successful RWH project in the world.
Funded by the Rural Development and Panchayat Raj Department (RDPR), Government of Karnataka, the project studied all government schools of Karnataka for water availability, quality (fluoride contamination) and proximity to a secondary water source. Under this programme 23,683 schools were identified, in the first phase, to provide drinking water through roof-top rainwater harvesting using a very simple yet robust system. Generate safe drinking water from the school roof itself.

* Roof-top rainwater is collected and channeled through PVC pipes.
* A first flush separator is part of the pipe line, which allows the rainwater to be flushed out with the contaminants on the roof and subsequent, relatively cleaner water, to pass through sand-bed filter to be stored in the tank.

Design-wise!
The tank and the sand-bed filter are carefully designed in order to maintain the quality of harvested rainwater. The surface tank is deliberately built without a direct manhole, and one or more taps are provided at the base of the tank. This prevents sunlight from entering the tank (the presence of sunlight and air leads to the growth of bacteria, algae etc). The absence of a regular manhole prevents removal of water by dipping vessels, and also prevents lizards, cockroaches and dust from entering the storage tank. The bottom of the sand-bed filter itself is fabricated as a manhole with perforations and can be removed to clean the tank when the sand bed is removed for periodic cleaning.
The size of the tank and the pipes for collection from the roof are designed using the parameters like local annual rainfall, seasonal variation, number of students in the school and roof area available.

The rainwater harvesting experiment is a thumping success in almost every rural school in all the 29 districts of the Karnataka state. Not only because it has solved the schools’ drinking water problems, but also because it carried home an important social message. The children, who have witnessed the traumatic effects of fluorosis — caused by contamination of bore well water — have become ardent converts to rainwater harvesting. They get a liter of harvested rainwater in school every day and, in many houses, rainwater harvesting has become a way of life.

The simple technique of sand-bed filter and locally available material to build the storage tank ensures that costs remain affordable.

One success story in a school will etch the impression on hundreds of young minds to educate their parents each year on sustainable rainwater harvesting.

At this school in Tumkur District, the students get a liter each of harvested water, every day

A Rainwater Harvesting Demo in progress at KSCST, IISc, Bangalore

      

RWH in a large urban school

Principles of RWH are set in stone in a school in Koppal District of Karnataka State