Good day!
One minute before resources regenerate at 7:00 ST, a mineral water source has 6/10. Out of curiosity, i did not refreshed my page and immediately used my dowsing tool few seconds after 7:00 struck, successfully i got 3 from it.
After that i refreshed my page, it displayed 3/10 (normally i get 3 mineral water per item use because of my dowsing stat) and again i refreshed my page: and saw the source regenerated to 9/10! I refreshed my page again and again for like 5 times and it stayed at 9/10. Of course i used my tool again to collect those 'extra' mineral water, and now it is down to 6/10.
I see this as a possible way to abuse and collect few extra resource.
FYI.