Friday, June 10, 2016

Well ... well!

Plants in the farm need irrigation during hot and dry summer months. That needs a water source. Usual water source in this part of the world is a well. We have one well near the stream running adjacent to the farm. Though it was supposed to be a well, it did not remain a well more than 30 years after it was dug. It became a dirty water pond. This is how it looked when we bought the farm:

Pond? No, it is a well! Silt from the
stream converted the well to a dirty pond.
Efforts to manually de-silt this pond failed because the silt was very slippery and soft. It was almost like quicksand - a worker entering this drowned few feet of depth and came out fearing for his life! There was no way I could have pumped out water for irrigation from this dirty pond. Therefore I decided to convert it to a proper well so that we can use it easily.

Soft soil all around the well needs reinforcement to hold the sides of the well in place. In earlier times people used to line such wells with a stone wall (round shaped stone wall). That works only if the sides of the wall are strong enough to stay until the well is dug and the lining work is completed. Also, stone lining means there is very less chance for further deepening the well if need arises in future. Modern solution to the problem is using concrete rings for lining. Well diggers place the concrete ring liner as soon as they find soft soil. Therefore there is no danger of the well collapsing at any time. Expert well diggers can dig under the concrete ring and deepen the well further if need arises. Digging under the ring and sinking them vertically is an art form well diggers have perfected over the years. But it all comes at a cost - they demand a premium for risking their life for this kind of work.

Concrete rings cast on site and ready to go into the well
I decided to use 10 ft diameter concrete rings for the well. Ring height is 1 ft and thickness is 5 inches. Obviously they are very heavy with all the steel reinforcement inside and the concrete. Therefore they are almost always cast on site and placed into the well after curing the concrete.

Well diggers don't dig such large diameter wells manually now. They use earth moving equipment to dig such large diameter wells up to 25-30 ft depth (provided there is enough space around the well for the earth moving equipment to move around and work). They use the same equipment to lift and place the rings into the well.

Earth moving equipment digging the well

We had our well ready after 10 hours of heavy digging, moving the soil, dropping the rings into the well, adjusting the rings for proper alignment and filling gravel between the rings and outer wall of the well. Gravel is filled between rings and outer wall of the well for the oozing ground water to filter through and enter the well. We started at around 10:00 am and it was well past mid night when we finished. This is how finished well looks:

Finished well, photographed almost at the
same angle as the pond photograph above.
Best part of the well is - water; it has lot of water. We saw water oozing from all sides of the well when the work was in progress. It started filling up as the work was progressing. There was close to 8 ft standing water in the well by the time we finished the work. When I saw next morning water level was around 5 ft from ground level (10 ft deep water in the well) - means ground water table is at a depth of 5 ft in this land. According to my back-of-the-envelope calculation this well is holding approx. 25000 liters of water. Even if I completely empty the well it fills up overnight. Imagine such a good source of water at this peak summer after a drought year. It was worth spending close to 150,000 INR for the well. That too not heeding the advice from several "well wishers" of drilling a tube well. I got a well which can be recharged instead of exploiting the water stored thousands of years back deep under earth surface.

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