What can be the impact of drilling a borewell close to an existing open well?

I have an open well about 90 feet deep. My neighbour is now trying to dig a borewell of about 200 feet depth, just 30 feet away from my open well. We live in a hilly area which has acute water shortage from February to May of every year. I would like to know what are the possible negative impacts of digging the borewell on my open well. I have already stopped the borewell digging by getting a stop memo from the government. But my neighbour is trying to cancel the stop memo and continue drilling. Can I permanently stop this borewell digging? Please suggest.