Monday, January 31, 2022

Open well in Bengaluru South

 A resident of Bengaluru South chose not to drill a borewell to construct a new house. He learnt the groundwater table is high and would hit water if he digs an open well. He engaged well digger  Venkat (Ph: 93536 39969) and dug an open well. The well is 2.5ft in diameter. The well hit water at 3 ft, and was dug up to 15 ft depth.

Monday, January 10, 2022

Rejuvenation of an Old Open Well in Forest Department park, Madiwala Lake

1.0 Overview and Background

Madiwala lake is situated in BTM layout in East Bangalore. It is one of the biggest lakes in Bangalore spread over an area of 114.3 hectare. Legend has it that the lake was built by the Cholas in a day. It is a home to many migratory birds. The lake comes under the administration of Karnataka State Forest Department which carries out the routine maintenance of this lake. There is a children's park as well.

Next to the forest Department office there is an open well which receives rooftop rainwater. The depth of the well is 9ft. The well is 10ft diameter and 9 ft deep and acts as a recharge well. There is water at 3ft blg. So far, It has not had water in summer.  This well was deepened further so that it receives water from the aquifer and has water through the year, and can become a source of water for the plants in the nursery.

Location of Madiwala well, 13th Cross, 29th Main, BTM 2nd Stage, adjacent to Madiwala Lake

Open well, before rejuvenation 

2.0 Work done

The depth of the well has been increased by adding a smaller well of 5’ dia and 13’ deep, and thereby increasing the holding capacity of the well from 20 KL to 27 KL . 

Ramakrishna and team worked on this well, over 3-4 days. The smaller well was dug and 14 rings were added subsequently. The surrounding paved area water has been sloped to ensure water goes into the silt trap before entering the well. The well grill has been painted and a motor connection was given to draw water. 

Deepening of the well with an inner well of 5ft dia and 13’ depth


Left: Well after the concrete rings have been added, and jelly around the side. 

Right: Alum added to the water, and submersible pump installed with pipe connection


Grill painted and the well covered 

3.0 Observation

In one day, the water level came up to 5ft bgl. The water after 24 hours has recharged 20 KLD. 

Left: Rejuvenated open well with silt trap. Right: Pipe provision for pumping water for use in the gardens

Visit to Syngenta India Lmt, Nelamangala

Syngenta Global is an agricultural R & D company providing technology to the farming community focusing on increasing productivity, reducing input costs and increasing the return on investment. Syngenta India Ltd has branches across the country. Rakshitha visited Syngenta India Lmt located in Nimbenahalli village, Nelamangala. It is an agricultural farm spread across 30 acres and started around 15 years ago. It works on producing Seeds, Seed Care, Crop Protection, Crop Nutrients and Yield Protection. It is a 30 acre campus. 

Map of Syngenta farm

Images of Snygenta farm

Water management 

Water is a key requirement of Syngenta as farming happens in 30 acres throughout the year. The farm has 2 borewells which were drilled when the farm was started 15 years ago. These are around 1000 ft deep. There is one failed borewell. The farm did not face any water crisis till. In the words of the manager, RWH was implemented recently to have water security in the long run. 

Functional borewell

Defunct borewell

Recharge wells and Percolation pond

Well digger Raghu Muniyappa has dug 8 recharge wells and 1 stonelined percolation pond in the farm. Raghu Muniyappa made the concrete rings himself on the farm and it took about 25 days to complete digging Rws and percolation pond. These RWs are dug in a channel which carries stormwater. There are 4 RWs dug in one channel and 4 RWs near poly houses. There are 8 small bunds dug along the channel to reduce the speed of water flow and to collect the silt at the bottom of the bunds. These bunds will help in passing only clear water to the recharge wells. The overflow from the RWs are connected to the percolation pond. The RWs are 4 feet in dia and 20 ft deep.

Silt settling bunds in the channel

Recharge well near poly houses

Percolation pond (left) and recharge well (right)

Raghu Minyappa has dug 2 silt traps to a RW and a percolation pond of 3 ft dia and 4 ft deep to further avoid the silt accumulation in the wells. The percolation pond is stone lined. It is 40 ft in length and 40ft wide. The depth of the step well is 20 ft. There is an inner well of 4ft wide and 4ft deep inside the percolation pond.

The percolation pond

Rooftop rainwater harvesting: 

There are four poly houses on the farm. Rooftop water from one of the poly houses is connected to the dead borewell directly. The inlet is given to the borewell by making a 4 inch hole to the casing pipe at a depth of 3ft from the ground level. 

Rooftop RWH implemented to the Poly house 

The manager is expecting positive results in the coming years. 

Listen to Raghu Muniyappa here:

- Rakshitha