How Do I calculate The Flow of a Well?

WP Law - Thursday, July 21, 2016

A properly functioning well will disperse its contents at the appropriate speed. But, what is the correct flow rate for a well? Whether you own a home that operates on a well or a business that relies on well water, calculating the appropriate flow rate for your well can help you to troubleshoot any potential malfunctions.

Calculating The Flow Rate For A Well

Generally speaking, the flow rate of a well is defined by the rate, measured in gallons per minute, that water can be extracted from the well. Measuring this calculation is a fairly simple task as long as you don't have a combination well pump and pressure tank. If you simply need to calculate the flow rate for a standard well, then follow these three steps:

1. Measure the flow of the well into a bucket.

2. Be sure to time the flow using an accurate stopwatch.

3. Divide the gallon size of the bucket by the number of seconds it took for the bucket to be filled, then multiply by 60. This will give you the flow rate measured in gallons per minute (gpm).

Let's say that you used a five-gallon bucket and that the bucket was filled in 45 seconds. Using the formula outlined above, your well flow rate would be: 5 gallons divided by 45 seconds x 60 = 6.6 gallons per minute.

If you have a well with a well pump and pressure tank, then you will need to use a different tactic.

1. Open a faucet until the pump turns on.

2. As soon as the pump turns on, close the faucet so that the pump can fill up the pressure tank. Once the pump has turned back off, begin step three. 

3. Open the faucet into a five-gallon bucket. (you may need more than one bucket) Measure the entirety of the water discharge before the pump turns back on. 

4. As soon as the pump turns on, shut the faucet and use a stopwatch to time the pump cycle.

5. Make a note of the pump cycle time (round to the nearest second) once the pump has turned back off.

6. Divide the total number of gallons collected in step three by the number of seconds calculated in step five.

7. Multiply your answer from step six by 60 to calculate the average pumping capacity, or flow rate, of the pump in gallons per minute. 

Contacting The Well Experts

Are you still wondering if your well is flowing at the correct rate? Are you worried that you might have a clog, a damaged valve, or an inefficient well pump? If so, contact the experts at W.P. Law, Inc. W.P. Law specializes in helping customers identify and resolve issues with their well pumps, controls, and pump valves. With the help of W.P. Law, your well can soon be flowing at the correct gallons per minute rate.

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