Effective decision on borewell digging required to be taken by Chennai based NGO

Dear Experts,


We are a not for profit organisation functioning in Chennai, collaborating with organisations with similar interest... we are in tie up with a rural agency working for upliftment of women and in order to support their enterprises, they have requested us to support them for digging bore well...  we agreed and have received quotations for a bore well to be dug up to 700 ft. Since we are completely new to this and have absolutely no idea what to ask / whom to ask, i am seeking your expert advise on the following.


1. They have followed some traditional methods to identify water availability. Should we ask them and reason out how or should we suggest employing a geologist to give his/her opinion.


2. what if there is no water after the bore well is dug for about 500 - 700 ft? We are worried that the money involved should not go waste or not benefit any one... 


3. How do we ensure the depth of the borewell dug


Looking forward your advise