How to identify good borewell drilling points in Bangalore, Karnataka?

How can I identify groundwater points/location for drilling borewell; as well the approximate depth ?  I want to drill a at Bangalore Rural Nelamangala area. Water diviners use sticks, copper ring, coconut etc., to identify the source. Which of these is reliable and believable. Is there a scientific way like hydro-geology or  satellite mapping available for us common people in Bangalore area. In our case they used sticks and we did not get water at both points shown by 2 water diviners. We drilled 450 feet and 600 feet respectively and failed both points. They had promised water availability of about 3000 gallons at 350 feet and 500 feet respectively.  I guess this could be a question in many peoples' mind. So can someone provide an answer helping people like me, by saving cost of borewell drilling at wrong places/points.

Rajkumar R R

8 January 2008