Query on borewell yield

Need help on a water output from a rigged borewell


I hve a rigged point at my site measuring 370 feet, and having 4.5" water in ii. But because of heavy soil, I rejected the same.

Now I have rigged another point 60 feet away fromthe last point. The depth of the new point is 600 feet and the casing is upto 80 feet. There is no soil after 65 feet and upto 600 feet, only rockdust is found , so I stopped rigging, but did not take out the casing.

After 3 days I found water inside up till 90 feet. So I tried a 5HP pump with 10 stage inserting it at 340 feet. The water output flow with full force was there for 10 minutes, after which for about 7 minutes there was no force and then the the water flow stopped. Now, little water is flowing. Then after 12hours, the same thing was repeated.

What could be the reason for this? I need advice to increase the water yield. Please help me out with this.

Thanks & Regards