Friday, March 25, 2022

Wells at ACF Office, Madiwala

1.0 Overview and Background

Madiwala lake is situated in BTM layout in East Bangalore, and is part of the Koramangala-Chalaghatta 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.

 

 

Forest office at Madiwala Lake

 

Office of the Assistant Conservator of Forest, Madiwala is located on 13th Cross, 29th Main, BTM 2nd Stage, adjacent to Madiwala Lake. The area around the office building gets waterlogged in the rainy season.

The building has 5 downpipes, 2 in the front, 2 at the back, and one on the side of the building. There is also overflow from the overhead tank where the water puddles on the side of the building. Water for the building is pumped from a borewell into the overhead tank from the Range Forest Office which is about 100m away.

The groundwater table at the office is high as it is close to the lake. Therefore, it was proposed to dig two wells, to mitigate flooding and also to use the well water in the garden.

2.0 Potential for recharge

The ACF office has a rooftop area of 100sqm and the open area around the area of the building is approximately 300sqm.

Taking the average annual rainfall as 974.5 mm, the actual harvestable rainfall for the rooftop is 87 KL (80 sqm x 0.9 x 974.5 mm) and for the open area is (assuming that 20% of surface runoff can be harvested, 300 sqm x 0.2 x 974.5 mm) 58 KL.

 

3.0 Work done

Plan (Figure not to scale) 

 

With the help of funding from Purvankara CSR, Ramakrishna and the team dug two wells, over a period of 10 days. The work commenced after a brief pooja/prayer in the presence of the team at Forest Office, Biome team, Puravankara, and all the well diggers.

 

Prayer and inauguration of the well-digging

 



A 6ft diameter and 15ft deep open well was dug at the Southeast corner.
  • 20 concrete rings of 9” height each have been added
  • A silt trap of 3ft diameter and 3ft deep is provided
  • Water from the two downtake pipes from the front of the building and the garden area has been diverted to this well, via the silt trap
  • A 1 HP, 0.76 KW, single phase submersible pump has been installed in the well to use the water in the garden.
  • A 3ft parapet wall is constructed around the well and a pulley to draw water manually has been installed.

 

  

Left - commencement of well-digging       

 

         

Left - Digging in progress; Right - Well digging in progress, water table hit at 7f bgl 

 

Pump and tap provided, for water to be pumped out from the 6ft dia well 

 


A 4ft diameter and 15ft deep recharge well was dug at the Southwest corner
  • 20 concrete rings of 9” height each was added
  • A silt trap of 3ft diameter and 3ft deep is provided
  • Water from the downtake pipes at the back of the building is diverted into this well through the silt trap.
  • A grill has been provided just below the last ring, for safety purposes
  • Additionally, overflow of the OHT is also diverted to this well, via a silt trap.

  

Silt trap and 4ft dia recharge well

 

4ft dia, 14ft depth well, with water at 7ft bgl 

 

The water from the down take pipes has been diverted to an open channel, sloped towards the silt trap. A mesh has been provided, so that leaf litter and other debris do not enter the silt trap.

4.0 Water usage from the wells 

 

The water level is up to 7ft below ground level in both wells i.e. there is 3KL of water in 4ft dia well and 6.3KL of water in 6ft dia well. The water from the bigger well is used for gardening and in the nursery around the Madivala Forest Office.

 

The water level in well

Completed well - 6ft dia, 15ft depth well, provided with a 3ft height parapet wall



Communication Board installed in front of the well


Thursday, March 24, 2022

"Well" Connected: Groundwater and Wells

BIOME Trust and BWSSB in collaboration with Citizen Matters is organizing a series of events on water management. The first event focused on Rainwater Harvesting and the second event on Water Demand management. The third in the series, "Well" Connected: Groundwater and wells (Antharjala mattu bhavigala sambanda) was held on 26th February on Zoom platform.

Several speakers from different walks of life - residents, CSR groups, govt agencies talked about their engagement with Groundwater. The talks covered the significance of open wells and recharge wells in enhancing the groundwater table, reducing the demand for Cauvery water and borewell water, mitigating the flooding and seepage issues.

Event poster

Citizen Matters pre-event press note which covered the event objectives and objectives. The post-event press note captured the detailed talks of each speaker.

The event recording is uploaded on BIOME Trust YouTube channel.

The two minute individual recordings of each speakers are uploaded on the our YouTube channel:

                     B M Manjunath, BWSSB

                     Raghuram Giridhar, Vidyaranyapura

                     Ramya Coushik, Ascot Apartments

                     Balasubramanian, Vidyaranyapura

                     Neeru Goyal, Adarsh Palm Retreat

                     Ajay Singh, Rail Wheel Factory

                     Minol, Puravankara

                     Meena Dave, India Cares

                     Manjunath N, India Cares

                     Ramprasad, Friends of Lakes

                     Kusuma G, Horticulture Department

                     Peddanna and Venkatesh Peddanna, Well diggers

                     Dr Meenakshi Bharath, Malleshwaram

                     Subbu Hegde, Classic Orchards 

The detailed Case Study videos of around 5-6 minutes were made for each story. The same are uploaded on BIOME Trust YouTube Channel:

"Re-imagining the shallow aquifer in Bengaluru" captures the insights from Mr Vishwanath S on groundwater, its history, functions and significance in Bengaluru city. Citizen speakers, Corporate agencies and public institutions talk about their engagement with groundwater and wells. 

- Rakshitha M L

Rejuvenation of Library Well at Lalbagh

 Lalbagh is a 240 acres Botanical garden located in south Bengaluru. The Lalbagh lake (within the park) spreads over about 30 acres and is full of water for most of the year. The groundwater tables have been observed to be high in many parts of the park. 

Location of Lalbagh

There are 6 open wells in Lalbagh. Of these 4 have water. And 2 wells which were filled with construction debris and garden waste were rejuvenated in March and June 2021 respectively.  After rejuvenation both the wells have water in them.  Water from these wells are being used in the garden.

Rejuvenated Wells and Open Wells in Lalbagh

Rejuvenated well - 1 at Lalbagh



Rejuvenated well - 2 at Lalbagh

A well behind the library near Lalbagh main gate was closed with concrete slabs. This  was opened after getting the necessary permission. Water could be seen in the well. Some pipes were observed inside the well and we were informed that these pipes bring the water from the storm water drain into the well.

Closed well in the foreground

.
After removing the concrete and the stone slab well with water  was found

Puravankara group came forward to rejuvenate the well.  Well digger Ramkrishna and his team started working on the well to rejuvenate it in the month of February 2022. Water and silt from the well was removed.  Large stones were found at the bottom of the well.  As these were very heavy they were left at the bottom of the well.  Some stone pitching was required after removing unwanted pipes.  After the well was cleaned one could observe water gushing into the well.  Water was observed 10ft bgl


This well is 9ft in diameter and 32 ft in depth. The well recuperates in 6 hours when all the water in the well is used. This well has about 40000 L water at present  and can hold upto 60000 L.


Well cleaning in progress

Large stones at the bottom of the well

Water being pumped out of the well

Stone pitching inside the well

Here is a video of the water gushing into the well

https://photos.app.goo.gl/qvR8YWCpo9PCfdo46


A parapet wall of 3 ft has been constructed around the well.  A pulley is also placed to draw water manually if required.  Motor is also fixed to pump water which will be used in the garden. A grill is provided to cover the well to prevent leaves and other materials falling into the well.


Rejuvenated Well - 3 covered with grill
Water 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/

Open Well at Satish Dhawan Park

1.0 Overview and Background

Satish Dhawan Park is located in North Bangalore in Tatanagar. The park is named after Padma Vibhushan Prof. Satish Dhawan, Director - IISc, Secretary - Department of Space, Chairman - ISRO.   The park is spread over 2.3 acre.  There are many trees and plants in the park.  The park comes under the administration of BBMP.  They have a caretaker who maintains the park.  Resident Welfare Association, Tatanagar are closely involved in the maintenance of the park as well.


Satish Dhawan Park
The park is located at 6th A Cross, ​​Tatanagar, Devinagar, Bengaluru, Karnataka 560092.  The water table at the park is high. There is a pond at the lowest part of the park. There are around 4 borewells.  Source of water for the park used to be Borewell.  However, these borewells stopped functioning due to silting issues.  Tanker water is being used in the park to water the plants.  RWA members started exploring different options for water sources. The RWA in consultation with residents Dr. Mohan Kumar, Dr. Sivakumar Babu and Biome decided to dig a well of 4ft diameter and 30ft depth and utilise the water from the well in the garden.

2. Digging an open well


The place for digging the open well was identified next to the pond near the gazebo. Well digger Ramakrishna and team worked on the well.  They hit water around 7ft.  They continued digging till 15 ft.  At this depth they hit soft soil which was collapsing. They had to stop going deeper as there was a scare of the structure collapsing.  Jelly and concrete rings were installed to give support and stability to the structure. A 2HP submersible pump was installed to pump the water from the well to use it in the garden.

Inauguration  of the well-digging

Well digging in progress

Water hit at 7ft bgl

Inserting the concrete rings

Here is a video of the soil collapsing at 15 ft.

https://drive.google.com/file/d/1a26GOAbGEO4bthjc9xkBVtKRmz5dae1E/view?usp=sharing



Filling the space where soil collapsed with jelly and placing the rings



Fixing the plumbing  and motor for pumping water. A safety grill at ground level

Completed well with a grill on top



Water being pumped and used in the garden

3. Observations

When all the water from the well was pumped out it was observed that the well required about 8 hours to recuperate ie. time taken by the percolating water to fill the well to a particular level  noted.  


The well has about 2500L of water.  The 2 HP pump requires 20 minutes to pump 2500 litres of water.  

Units of electricity used for pumping 2 x .746 x 20/60 = 0.5 units of power. 

This pumps out about 2500 litres or 2.5 kl of water.  

Cost of power at Rs 5.50 per unit hence cost per kilolitre of water  0.5 x 5.50 / 2.5 = Rs 1.10 per kilolitre. 

This water from the well can be pumped to the external storage twice in a day and 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/











Wednesday, March 23, 2022

World Water Day -2022

 Biome Environmental Trust was invited to participate in an event organised by BWSSB and KSCST on the 10th Anniversary of Sri.M Visvesvaraya RWH Theme Park.  The event was organised in association with Indian Plumbing Association-Bangalore Chapter, Bangalore Apartments Federation, Bengaluru on 22 March, 2022

A statue of Sri.M Visvesvaraya was inaugurated at the Theme park.  Technical session was also held. CGWB, State Ground Water board, BAF, BIOME, Indian Plumbing Association, BWSSB and KSCST were part of the technical session. It was a well organised event with interesting discussion.  It was interesting to note that KSCST has identified about 14000 Kalyani's in Karnataka, many of which require rejuvenation.  BWSSB, KSCST, BAF and BIOME shared some interesting success stories of sustainable management practices by apartments and layouts in Bangalore.  Few pictures from the event are shared below.