Open Well for Toilet Block - Madiwala Lake

1.0 Overview and Background

Madiwala lake is situated in BTM layout in East Bangalore, and is part of the Koramangala-Challaghatta valley. It is a part of the Varthur lake series. It is one of the biggest lakes in Bangalore spread over an area of 282 acres and was built by the Cholas in a day. It is home to many migratory birds. The lake comes under the administration of the Karnataka State Forest Department which carries out the routine maintenance of this lake. There is a children's park as well.

 

Location of the Toilet Block

Near the main gate of the lake there is a toilet provided for the visitors.  The toilet block has a rainwater harvesting system. The downpipes were connected to a 6000L sump for storing the rainwater and pumping this water into the overhead tank.  It was observed that the sump was damaged and hence could not store water.  There was no other water source for the toilets.

 

 

 

Toilet building at Madiwala

 

2.0 Rain Water Harvesting 

The toilet block has a rooftop area of 100 sqm 

Taking the average annual rainfall as 974.5 mm, the actual harvestable rainfall for the rooftop is 44 KL (50 sqm x 0.9 x 974.5 mm).  The rain that falls on this roof used to be diverted into the sump. It was found that the sump was damaged and could not hold water. Hence, a plan to dig a 5ft x15ft well was decided. The rooftop rainwater was diverted to the open well which was dug by the well diggers.

3.0 Work done

With the help of funding from Puravankara CSR, Ramakrishna and the team dug an open well in June 2022, over a period of 4 days.  Roof top rainwater was diverted to the well as the sump was not functional.  

A 5ft diameter and 15ft deep recharge well was dug at the Southwest corner 

• 23 concrete rings of 9” height each was added 

• A silt trap of 3ft diameter and 3ft deep is provided 

• Water from the rainwater harvesting pipes of the building is diverted into this well through a silt trap.

• A grill has been provided at ground level and on the top, for safety purposes

• A 1 HP, 0.76 KW, single phase submersible pump has been installed in the well. Water from the well is pumped to the OHT to use in the toilets. 

   

Location for the well                                        Well diggers in action

   

Water hit at 6 ft                                    Silt trap and the well

    

    

Ramkrishna and his team

4.0 Water usage from the wells 

The water level is up to 6ft below ground level in the well i.e. there is 5KL of water in the well. The water from the well is used in the toilet by pumping it to the overhead tank in the toilet.

              

Motor installed in the well                               Switch for the motor fixed on the wall

    

  

Communication Board installed in next to the well, near the walking path

Cubbon park walk for Bangalore Design Week 2022

As a part of Bangalore Design Week, Biome in collaboration with Art in Transit conducted a walk in Cubbon park titled WACH (Water, Art, Culture and History) on 29th November 2022. Water is intricately tied to the city’s culture and history and this is beautifully portrayed in the artistic murals inside Cubbon park metro station. The walk aimed to showcase these connections while also elucidating the intricacies of the behaviour of ground water with focus on the hydrogeology of Bangalore.

The event was open to public. Posters and announcements were posted and promoted on social media prior to the day of the walk to attract as many participants as possible. Design students were also invited from Srishti college to help develop designs that could facilitate the education and understanding of groundwater in various contexts. We were joined by nine enthusiastic participants from diverse backgrounds with age groups ranging from about 12 to 50.

Instagram post

The walk started from the metro station entrance where the audience were introduced to the park and its history. From there the conversation drifted into natural history discussing the formation of the Deccan plateau to understand a brief geology of the area. Focus then shifted to the current water usage by the city, its role in the local culture and its associated economic and political aspects.

This naturally led to discussions on the problems associated with some of the erroneous mainstream groundwater management practices. Scientific solutions employed in Cubbon park for better groundwater management were then demonstrated with focus on shallow aquifer management using recharge wells and open wells. Surface water management was also demonstrated with the help of ponds that are strategically located in the park. The participants were led to a pondside for a short rest. A few minutes of quiet and rest next to the water instigated deep contemplation in everyone’s minds. Water’s influence on the ecosystem as a whole and natural patterns associated with ecosystem remediation were discussed at length. This included the significance of lakes and wetlands in eco remediation and water management in the city as well.

Demonstrating the recharge well

Discussing surface water near the pond

Discussing natural patterns

The participants were then led to the culturally significant well associated with Karagada Kunte and the ancient Karaga festival of the region. They were mesmerised by the story of the festival and its association with water was greatly appreciated. The realisation of the presence of intricate cultural practices in the highly cosmopolitan IT capital of the country left the participants in awe.

Telling the story of the Karaga

Finally, a visit near the STP next to the park illuminated the role of treated wastewater for proper water management. STPs, natural greywater systems, black water management, dry toilets and their historic and cultural associations were discussed at length by the extremely enthusiastic and well informed group of participants.

Discussing wastewater management near the STP

The walk ended with a visit to the murals in Cubbon park metro station. The subjects portrayed in the artistic murals were explained and the discussion was directed towards the Mannu Vaddar (Bhovi) community, to which the traditional well diggers belong.

We hope that we were able to instil some significant understanding about groundwater and its proper management for an ecologically stable and an economically beneficial environment in the city.

Seeing the artistic murals at the metro station

- Neelima Ramesh

(neelima@biome-solutions.com)