How to Calculate Well Water Flow Rate
- 1). Time the amount of time it takes to fill the water bucket up to the 5-gallon mark with a stopwatch.
- 2). Convert the time to straight seconds if the stopwatch measured the time in minutes and seconds. Multiply the minutes by 60 and add to the seconds.
- 3). Divide the total seconds by 5. Divide the result by 60 to get the correct GPM flow rate.
- 4). Measure the GPM at every faucet along the line for the water well.
- 5). Add each GPM measurement together and divide by the total number of faucets measured to arrive at an average GPM flow rate for the system.
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