Thursday, March 24, 2022

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.

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

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