I am part of the HOA Managing committee at an Apartment complex in Banglore (Bellandur area), with 264 apartments. We have a borewell at 675 ft depth, which for the last 1 year had been unused due to the motor+pump not working (we were using water from another borewell). Recently, we extracted the motor and got it fixed. We are unsure of the current yield of this borewell. It was recommended that we flush this borewell and clean it up and at the same time, check the yield as well.

The specifications of the borewell are as below:

 Exact location is Near Bellandur Gate on Outer Ring Road in Bangalore – Zip code: 560103, it is 6” in diameter and 675 Feet deep. MS casing used for 100 ft. It was constructed around December 2006.

What are the practical considerations to take when flushing a 6inch borewell at 675 ft depth? We are trying to get a person who claims he can flush this with a 1.5 inch hose pipe and exerting 150PSI of pressure. Is that expected to work? He cautioned us that if there are cracks/fissures in the borewell, the pressure might get dissipated and no water will get ejected (ie flush won't be successful).

We basically prefer to clean this borewell and get some sense of the water yield -- mainly to figure out what motor to insert (we have a 15HP Motor as well as a 20 HP motor -- both with 30 stage pump). If I keep my ear to the borewell, I can hear some gushing sound -- like a flowing water stream down below. When we were extracting the motor, the pipes from 350ft onwards came out wet. Does that mean water level is at 350 ft, or could it be due to some other reason?

Kindly advice on the best method to render the borewell productive & also to estimate its yield.

Raj
rao@nvidia.com