TC Halli, Tindlu, and Handenahalli School Rainwater Harvesting Systems

Today, we visited three government schools in Bangalore, focusing on their different rainwater harvesting systems. All three of these systems had been installed in the last year. The first school we visited was TC Halli Government School. This school is an example of a sloped roof rainwater harvesting system. We learned that Biome had helped to install a rainwater filter, underground sump tank (4400L capacity), recharge well (3’ wide, 20’ deep), and a new overhead water tank for the roof. The school has a pre-existing borewell that they still use. Rainwater and borewell water are both used for daily use such as cleaning, gardening, dish washing, toilets, hand washing, etc. The handwash station was replaced to reduce water loss from dishwashing, and resistors were installed in the taps. The school uses RO water for drinking and cooking.

Toilet unit, showing the gutter connections to the rainwater filter, as well as the handwash station.

Left: Sump tank. Right: Recharge well.

The second school we visited was Tindlu Government School, which uses a flat roof rainwater harvesting system. Similar infrastructure was installed at this school. Since the roof area is reasonably large, the underground sump tank had a much greater capacity, at 12000L. A rainwater filter and recharge well (4’ wide, 20’ deep) were installed, as well as a handwashing station. Resistors for the taps were installed during our visit. This school also uses RO water for drinking and cooking, but meets all other water needs with either rainwater or borewell water. While we were at Thindlu the headmaster and students were very welcoming and also invited us to visit the school’s art room, where we saw some very impressive artwork!

 

Left: Recharge well. Right: Sump tank and hand wash station. 

Rainwater filter. Y-joint shown.

Student art classroom.

Our last visit was to Handenahalli Government School, which is an example of a flat roof rainwater harvesting system utilizing an above ground sump tank with a capacity of 5000L. This school also had a newly installed rainwater filter and recharge well. Similar to the previous schools, this school used RO water for drinking and cooking, and borewell or rainwater for other purposes. We observed students washing their dishes after lunch in the new handwash station fixed to the sump tank. Resistors were also installed during our visit. To end our day, we enjoyed a delicious lunch of rice and sambar with the school’s headmaster and teachers. 

Students using the new handwash station. Above ground sump tank and rainwater filter are visible behind.

Borewell and recharge well.

Overall, this was a very informative day and it was very interesting to see three new and different rainwater harvesting systems. It was great to see the student’s interactions with these systems as well. We learned that in many schools, they will train students to take care of the recharge well and sump tank, which we saw at Thindlu. Bhavani explained that the youth are the future of water conservation and that starting water education in schools can hopefully shape behavior at home as well.

Well Documentation Near Madiwala Lake

 Today we went to south eastern Bengaluru to meet with Neelima at Madiwala Lake. There we met with a well digger, Ramakrishna, who had been instrumental in digging several new wells and deepening another in the area. The first well was used for the nearby public bathrooms and for landscaping. The well was also used to recharge the groundwater by directing the rain from the bathroom roof into a silt trap and then into the well. When we looked in the well, we noticed that there was a small amount of leafy debris that had gotten through the mesh covering the well and was floating among a murky film on the surface. Ramakrishna was frustrated to see the well that he had worked so hard on wasn’t being properly maintained. He pointed to the bathroom roof that had leaves and foliage on it indicating that the lack of maintenance extended beyond the well. The vegetation on the roof, he explained, would block the gutters, clog the silt trap, and lower the water quality in the well if not cleared off before a rain.

Ramakrishna peering into the well with film floating on the surface, foliage on the
bathroom roof that needs to be cleared off.

We wanted to record some data about the well including water depth below ground level, well depth, well width, TDS (total dissolved solids), well use, etc. Neelima had brought a TDS meter, and we already had a tape measure, but we had forgotten to bring anything to collect a water sample with. A brief look around found the bottom of an old plastic bottle and some twine that we used to lower the bottle into the water. The TDS was slightly above optimum range but the water smelled clean, albeit slightly discolored. We measured the rest of the available data and asked Ramakrishna about the soil conditions he encountered when the well was dug. I was impressed by his detailed memory and knowledge–even a year after he had dug the well. 

Measuring the TDS of the first well and looking out over the beautiful Madiwala Lake

As we walked to the next well by the lake, Ramakrishna quickly passed us on his motorcycle. I was a bit surprised as he rode past the park entrance onto the smaller pedestrian path just past the park security guard. Neelima explained that the entire community loved Ramakrishna because of the wells he had dug in the area, they would let him do anything. The next well had a beautiful square stone wall covered with a metal grate and more mesh to keep leaves out. When we got there, we saw Ramakrishna sweeping all of the vegetation off of the mesh to ensure that it was clean. Neelima said that he regularly will return to wells he’s worked on, unpaid, just to make sure they are being maintained and to offer advice to stakeholders if the wells needed anything. We measured the water elevation and Ramakrishna turned on the submersible pump to get us a water sample. He guided us around a building, showing us another recharge well he’d dug. Before we left, we took several photos of us standing in front of the stone well.

The water at the second well looked much cleaner-and had a lower TDS. Group photo of us with Ramakrishna.

We walked to a nursery where we saw the last well near the lake. He had remodeled it from a shallow recharge well into a deeper well that could be used to water the nursery’s plants. It was 10 feet in diameter and Ramakrishna explained what we couldn’t see; during the rejuvenation, in addition to desilting the 10 foot well, Ramakrishna had dug a smaller 13 feet deep, 5 foot diameter well in the bottom of the original well for a total depth of over 20 feet. As if to illustrate this, The nursery worker came over with a piece of string tied to a rock and lowered it into the edge of the well to show us how deep the water was. There was only 3 feet of water. Ramakrishna took the rope from him and swung the rock out to the center of the well, dropping it with a splash. It sank much further, proving the presence of the smaller well. When he pulled it up, he measured the length of the rope by holding it up to the tip of his nose. When I laughed, he looked at me and said “five feet” and indicated he wanted me to check. I used our tape and measured 5’ on the nose–excuse the pun.

The 10 foot well with the submerged 5 foot well in the bottom.

Neelima joined us in our taxi and directed our driver to a delicious restaurant for breakfast where we were joined by Ramakrishna. The food was amazing. During breakfast, Ramakrishna scrolled through photos on his phone, showing us different wells he had dug and examples of different soil types he had encountered while digging some of these wells. In one example, he showed a photo where the well had been dug through 8 different vibrant colors of soil in only a few meters depth. Another showed a unique well he had dug with a local university to gather samples of buried flora from differing depths. A photo looking up from the bottom of a deep, narrow well proved that this wasn’t an occupation for the claustrophobic.

After breakfast we went to what is thought to be one of the oldest wells in Bengaluru. It’s an unassuming stone well nestled between small homes next to a busy street. It was covered with a rusty metal grate and had litter floating in the water inside. Ramakrishna explained he had planned to remove the garbage and desilt the well in the past few weeks but due to an electrical problem with his pump, he had been forced to postpone and hoped to get it done next week. We again measured the TDS and water level, this time putting a small amount of water in a bacteria testing vial to determine if the water is safe, as the community would like to use the well water for drinking. The water in the vial should turn black within 48 hours if the water is unsafe.

The old stone well, a sample of the water we pulled from it, and the bacterial testing vial.

Lastly, we went to the home of an IT worker who had contacted Biome about groundwater seeping into his basement garage. The home was constructed 10 years ago and the entire neighborhood is built on a filled-in historical lakebed. During construction, two borewells were dug to depths over 900 feet, and both were dry, indicating that the deep aquifer is very far below the ground surface. Due to groundwater encountered during construction of the home and the presence of a shallow aquifer, an open well had also been dug to provide water for construction which is still used for flushing toilets and landscaping. Neelima suggested having the well water tested to see if it could be used for more activities such as cleaning, laundry, and possibly even drinking after minor filtration. Any additional water that could be used out of the well might lower the groundwater and potentially eliminate the seepage. Other options that were discussed involved much more work and the associated cost could quickly skyrocket.

As we left the home, we saw a water truck delivering water to homes just up the road. It was fascinating to see multiple different water issues all in one small area: dry bore wells, flooding basements, and a lack of available water requiring the truck. It was a fitting finale to a day where we’d seen wells in various stages of maintenance being used to manage water sustainably in several different ways. I think we all gained a greater appreciation for some of the water problems facing Bengaluru and some of the solutions being implemented.

Before we said goodbye to Ramakrishna, I asked about worker safety. How does he check for bad air before descending in a well? He explained they lowered a lit candle, if it stayed lit, that meant there was oxygen and it was safe. I also asked how he ensured that the wells won’t collapse on his crew as they are digging. He replied that well diggers understood the stability of the soils that they work in. They could tell which soils risked collapse and which were safe. They know the geology of the areas that they work in to such a degree that they can generally anticipate if a well can be dug safely and even provide an estimate as to the depth of well needed to reach groundwater. He mentioned that they appreciated harder soils even though it required them to use heavy metal bars to break up the ground, as it meant the soil wouldn’t collapse.

I find myself wondering how we can best capture and record all of the information that the well diggers have. Their knowledge of the different soil types, the geology under Bengaluru, the understanding of how and where groundwater flows under and through the city. How can their experience be shared with others working in the field to maximize efforts to bring about sustainable solutions that can be used to solve the problems that we are facing. The amount of expertise that is available is staggering, and it would be a waste to not take advantage of it or, even worse, lose it.

A water sample was taken from the old well at 12°53'55.2"N 77°36'56.8"E and used for a bacteria test:

After 48 hours

After 72 hours

School Rain Water Harvesting System

Today, Chloe and I started out the day by meeting Rakshitha at Sonnappanahalli Government School. We jumped right into learning about the rooftop rainwater harvesting system that had been installed by Biome. This system starts out by collecting rainwater from the roof of the school, which is then fed into a pipe system that leads to a Y-joint. The Y-joint allows for rainwater from the first rain that may be contaminated by debris on the roof to be diverted to a reject pipe. After the first rain, once the roof surface is clean, the rest of the water is directed through the other arm of the “Y” to a filter that directs the rainwater through three layers of filtration media: larger stones, charcoal, and smaller stones. After filtration, the water flows into an underground sump tank with a 12000L capacity. Rakshitha explained that this capacity is determined by analyzing annual average rainwater volume. The water in the sump tank then goes into a recharge well that is 4’ in diameter and 15’ in depth. Upon inspection, the recharge well seemed to have very clear water! 

The rainwater harvesting system’s Y-joint and filter.

It was very exciting to see a rainwater collection system in use and Rakshitha was very detailed in her explanation of the system. We also learned that before the rainwater system was installed, the school was facing water scarcity and was getting water from tankers, which is quite costly. Currently, the school uses water from the recharge well for washing dishes, gardening, and other cleaning uses. The rainwater would be safe for drinking if it were boiled, but the school still uses reverse osmosis water for drinking purposes, as do many peri-urban areas of Bangalore. The water collected from this rainwater harvesting system is currently meeting the school’s needs for about 100 days out of the year. 

I loved being able to see the implementation of a rainwater system and it was very fascinating to see how the school uses it. It made me very excited to visit other schools next week and see how their rainwater harvesting systems have been implemented and how they are using them. 

After a nice lunch, we headed to an open well nearby. To our excitement, Mr. Shankar, a well digger who we had met briefly the previous day, was at the well we were visiting. This was quite a nice surprise, as he was very eager to share information and insights about the well. This was probably the largest well I had yet seen, at 25’ in diameter and 65’ in depth! Mr. Shankar passionately showed us many aspects of the well, including two small spouts of water entering the well from the shallow aquifer, which demonstrated that the water table was rising above the well’s current water level. This well is currently providing water to a nearby hotel, college, and a couple of apartment buildings, with plans to also pump water to the nearby village, consisting of about 200 residents.  We then traveled a few hundred meters away to another well of similar size. To Chloe’s, Rakshitha’s, and my horror, Mr. Shankar immediately began walking around on top of the metal grate covering the well opening. After some words and encouragement from Mr. Shankar and his jumping up and down to prove to us the structural integrity of the grate, we joined him on the grate for a photo. I can now say that I have stood on top of a 100 year old well! 

Chloe, Mr. Shankar, and I on top of the second open well we visited.

With the combined knowledge from Rakshitha and Mr. Shankar, I learned lots and am looking forward to more visits like these. It was very inspiring to spend time with Mr. Shankar and see how undeniably passionate he is about his work. This last open well visit wrapped up our first Wednesday with Biome, and I couldn’t be more excited for the many days to come! 

Devanahalli Kere Lake Water Treatment Plant and Sir M. Visvesvaraya Rain Water Harvesting Theme Park

 On January 24th, the ground breaking ceremony for a new water treatment plant occurred along the bank of the Devanahalli Kere Lake. Rotary Club members, ZEISS employees, village locals, Biome members and many more joined together to celebrate this momentous occasion. Although we faced a bit of a struggle to find a cab in the morning, we arrived in time to catch all of the proceedings. In a mix of Kannada and English, several stakeholders took time to communicate their excitement for this project and their gratitude for all those who took part in making the project possible. Avinash took special care to introduce Shankar, a traditional well digger who had helped rejuvenate the well that was to be the source for the new water treatment plant. Next the local priest led a puja, the ground was broken, and the festivities concluded in a round of handshakes and warm goodbyes. 

Several stakeholders pose for a photo to commemorate the day.

A Rotary Club member literally helps to break the ground to signify the start of the water treatment plant. 

Afterwards, Shivanand and Avinash took some time to make introductions and provide a little more context for the day's proceedings. Then, we walked towards the residential area of the town and Avinash shared about the sewage flowing in the storm water drain and the farmer’s use of it. It was an interesting discussion about the importance of facing water issues as social issues, and favoring infrastructure lean approaches to such problems. Following our discussion, Avinash suggested we use the rest of the afternoon to explore the Sir. M. Visvesvaraya Rain Water Harvesting Theme Park made by Bangalore Water Supply and Sewerage Board (BWSSB).

We traveled south back into the city, stopping for lunch before arriving at the theme park. There, we were warmly greeted by Mr. Nikhilesh. Once a group of students from a local college arrived, we tagged along with their tour of the impressive park. The outdoor section of the park included examples of various types of rainwater harvesting infrastructure including groundwater infiltration wells, first flush bypasses, and various methods of catching rain from a roof. Inside, two different exhibits educated us on water and sewage management through life-size displays. We ended in a comfortably air conditioned auditorium where we watched an admittedly dated but informative video on Bangalore’s main water source: the River Cauvery.

The exterior of the park included pervious pavers, sloped and flat roofs that collected rainwater and various storage tanks.

Cross section of a sand filter, a popular filter device for roof captured rainwater before entering a storage tank.

A comparison between three taps: normal, aerator and flow restricted. Each ran for 1 minute and the volume of water spent was measured.

Overall, the schedule of our day kept my mind very occupied and supplied much to chew on. The morning’s ceremony made me more aware of how many people can be involved in a single water project. Our discussion with Avanish challenged my typical outlook on water problems and their solutions. Our time at the rainwater harvesting theme park made me curious about the degree of implementation of such infrastructure throughout Bangalore and what the possible delays in widespread adoption are. There is still much to learn, but today was a great continuation of our education with Biome!

Kalkunte Lake Rejuvenation

Today was our first official meeting with Biome Solutions. We are all excited to be able to work with them for the next 7 weeks. We’ve been in India for 3 weeks as part of our study abroad program with the University of Washington in America. During this time, we’ve been learning about design thinking, entrepreneurship, and exploring the complexities of problem solving in a social context. We’ve also gotten to meet with several organizations that are doing incredible things in and around Bengaluru including a brief introduction with Biome during a tour of Lake Jakkur led by Suma, Priya, Neelima, and Nikita that showcased the rejuvenation of the lake, the fish farming practices, and some of  the potential problems and solutions associated with many of Bengaluru’s lakes. 

Today’s visit focused on Kalkunte lake, which lies on the edge of the rural village of Kalkunte Agrahara, east of Bengaluru. We started by visiting an open well near the lake which, although covered with a metal grate, still had a layer of solid waste floating on the surface. It didn’t have an odor like we’ve smelled in other wells, which we were told indicated that it wasn’t being contaminated by sewage.

The first open well we’ve visited with Biome.

We then walked along the bund on the south side of the lake. During our walk we learned about the lake and some of the issues facing it. The lake is artificial, at least 300 years old. It is 28 acres and has 1 outlet and 3 inlets, one of which is fed by another lake. The outfall flows into the river Dakshina Pinakini. There used to be a sluice gate that was used by farmers below the bund to farm approximately 30 acres of rice, but it was inoperable and appeared to be sealed closed. There is no known sewage flowing into the lake. 

There was thought to be some encroachment in some areas of the lake. The lake had not been rejuvenated within the known history of the village. It has recently been cleaned up to remove solid waste but still needed to be desilted - which was evident by how shallow the lake appeared to be despite how high the water level was. There was significant farming activity on all sides of the lake. Areas of the bund that were steeper showed significant erosion on the upstream side. Locals said that the lake had never been full that they could remember and it would dry up completely in the summer months prior to 2018. Now that it has water in it year round and fills up completely in the rainy season, they wanted to see it rejuvenated. 

View of the lake from the west and east (by outlet) ends of the bund

We met some of the farmers who lived alongside the lake and they showed us the location of a well that they had historically used for agriculture. It was overgrown and had branches that had fallen in it. They explained that when the lake was dry it also dried up and they had started using water from a bore well instead and the well had fallen into disrepair from disuse. 

We learned about the planned rejuvenation of the lake which will start with the cleaning of all three inlets. The rejuvenation will continue by building a temporary bund to divide the lake in half and desilting each half of the lake separately to remove a total of 4800 cubic meters of material and increase the current water storage capability by approximately 48 lakh (or 4.8 million for those new to Indian numbers) liters. The bund will also be built up 2-3 feet and areas that were being eroded will be reinforced with stone pitching as needed. Finally a stone or concrete wall will be erected around the lake to protect it from waste being dumped and from encroachment.

After the tour of the southern edge of the lake, we drove into town where the rejuvenation community meeting was being hosted at Kalkunte Sri Ranganatha Swamy Temple. There community members including a member of the local Grama Panchayat, funders, NGOs and even children from a local school came together to learn about the rejuvenation project. The meeting began with a delicious breakfast provided by the temple. We then proceeded upstairs into a meeting room setup with a projector where a Pūjari gave a Puja in Sanskrit followed by every person present introducing themselves. The school children were asked how they felt about the lake and we heard their responses. It was obvious that the entire community, even the children, cared about the lake. 

The majority of the rest of the meeting was done in Kannada and we were grateful for the translator that had come with us who was able to take notes throughout the presentations and explain what was said after the meeting concluded. Most of the slides used both Kannada as well as English which helped us follow along. The meeting continued by introducing Biome and another organization Arohana, that is “working towards women empowerment, environmental protection and development of rural education.” Arohana has already done a similar rejuvenation project in other lakes. 

We also heard from one of the Rotary clubs that are sponsoring the rejuvenation project. The Rotary clubs were also helping the temple build a new room and helping the local government school upgrade their facilities and education. The members of the Rotary that we heard from talked about growing up in the community. While they no longer lived there, they still held strong ties to the community and returned for events and festivals and obviously desired to give back to the community they came from. The meeting covered the lake rejuvenation benefits, discussed possible options, and even covered a variety of water conservation methods that we all could be doing to live more sustainable lives. We finished the meeting with several group photos before returning to the ground floor for another amazing meal.

The Rotary International’s project sign and one of several group photos taken for posterity.

We finished the visit by talking with Biome about what projects we might be working on over the next 7 weeks. We could potentially be developing methods to teach children in schools about water sustainability topics, teaching schools about rainwater harvesting methods, helping with documentation for rainwater harvesting infrastructure that’s already been installed, inspecting hand dug wells all over Bengaluru to monitor water levels, cleanliness, and meet with the well diggers, or continue to work on the project we visited today to determine the total catchment area of the lake and monitor the rejuvenation process. We are all excited to see what the coming weeks will bring and are looking forward to meeting more of the Biome team and learning all that we can from them while contributing to what is being accomplished.

Map of Kalkunte Lake

Detail of Eastern end of lake