Saturday, June 12, 2021

Rejuvenation of Two Open Wells in Lalbagh

 

Lalbagh botanical garden is a 240 acres (0.97 km2) garden and is located in south Bangalore. It is managed by the Department of Horticulture, Bangalore. There are 5 open wells in Lalbagh. Of these 3 wells have water however, water from these wells are not being used. Two of the wells were closed by filling it with waste materials.  One of the closed wells was taken for rejuvenation in the month of March 2021.  After rejuvenation of the well 5ft of water was seen indicating the presence of shallow aquifer. With a pump house next to these wells indicated that these wells were used before borewell was introduced.


To manage the flooding in the north western part of the park during the rainy season, 100 recharge wells are being dug. This will help in recharging the aquifer and also  mitigate flooding.


Location of Lalbagh, Bangalore

Say Trees approached Biome Environmental Trust to identify a well in the city for rejuvenation.  The objective was to create awareness about the connection between groundwater, shallow aquifers and open wells. Since Lalbagh sees hundreds of people every day, rejuvenating a well in such a location will meet the objectives. 

To create awareness a poster/board will be placed with information next to the well. 

This project was funded by Say Trees.



Open Wells in Lalbagh

There are 5 open wells in Lalbagh.  Of these, 3 wells (Well no. 1,4,5) have water.  2 of the wells (Well no. 2 and 3) were closed by dumping construction debris, garden waste and other waste.  It was decided to take up Well no. 2, located close to the SunDial park, for rejuvenation. The dimension of the well is 10ft diameter  and 29ft depth.


WellDigger Ramakrishna inspecting Well no. 2 for rejuvenation


After taking the necessary permission from the Deputy Director of Horticulture, well digger Ramakrishna and his team started cleaning the well for rejuvenation.


The well was filled with tree branches, leaves, stone, construction debris, paper and plastic waste.  Ramakrishna and  team worked for 14 days to remove the waste and completely clean the well. They used a crane to remove the heavy material and silt. They hit water at the bottom of the well. After cleaning and treating the well  5ft of standing clear water is observed.


Cleaning of the well


Well diggers removing the waste dumped in the well

Paper and plastic waste


        
Stone and construction waste



Tractors carrying the plastic and paper waste out of Lalbagh

Outside of the well after cleaning

8 tractor loads of plastic/paper waste were taken out of Lalbagh.  The stone, garden waste and silt was left in the garden to be used.

Inside the well after rejuvenation

The dimension of the rejuvenated well is 10ft diameter  and 29ft depth. The static volume of the well is 64000 liters.


A perforated metal cover with a door was fixed on top of the well for safety purposes.  This also prevents leaves falling into the well.



Perforated Metal cover 




Second well (Well no. 3)

Opposite The big Silk Cotton Tree - near the temple was taken up for rejuvenation in July 2021


This well was also filled with waste  such as garden, plastic, paper, construction materials etc.

Well diggers, Ramkrishna and team at the well to be rejuvenated


Status of the well before rejuvenation


Ramkrishna and team cleaned the well.  They used a crane to remove the heavy material and silt.

After cleaning the surrounding of the well

Waste removed from the well

                       
More waste being removed

They hit the bottom of the well at 37ft.They did not hit water and the well was dry. The next couple of days due to heavy rains the water started seeping into the well. 8 ft of water was observed in the well after two days of rain. The well is 13ft diameter and 37ft deep.

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          Bottom of the well     Water seen in the well after rain

Approximately 50-60 tractor loads of waste were removed from the well.


Tractors carrying the waste removed from the well out of Lalbagh


As the well was on ground level a 2 ft parapet wall was constructed and a grill was fixed so that leaves do not fall into the well and hence the water remains clean.

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A parapet wall and a mesh for safety and preventing leaf and garbage falling into the well. Helps keep the well and water clean.

A 3hp submersible pump has been installed inside the well. Now the water from the well can be used in the garden near the well.

Water from the well being used in the garden


Open wells help manage the shallow aquifer by being structures that can both draw water from the shallow aquifer as well as serve as structures that can recharge the ground. Open wells with water are also the source of water with the lowest amount of energy required to source the water. More details about Bangalore and its open wells can be found here
http://bengaluru.urbanwaters.in/our-open-well-heritage-510/


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