See if the pump will run "over the side" for an hour or two, then measure how many gallons per minute in a bucket. This will be how much your WELL will make. Then put a tee with a gauge sticking up and a ball valve going out on the discharge pipe. Choke back on the valve until the gauge reads about 40 PSI, then let it run for a while. Use your bucket again to find out how much you PUMP is making at 40 PSI. Then you can work on the controls needed to make an automatic system, and figure out how many sprinklers to run at one time.