Water wells typically have a linear type drawdown. This is not an exact statement, but for all intents and purposes this is true. For example, take a well that has a static of 50’, a total depth of 150’, and the pump is set at 100’. Let’s also say that the driller performed a pumping test on the well and determined that the well would pump 10 gpm at a drawdown of 100’. Do the division and you would get a specific capacity of 1 gpm per 10’ of drawdown. This specific capacity is basically a linear function through the depth of the well. So, you could say I want 5 gpm, this would mean 50’ of drawdown.
Okay, on to my point. I stated above that the example pump is set at 100’. If I am trying to pump this well at 10 gpm, I can probably get that. I might get 10 gpm for 5 minutes, 15 minutes, or even 15 hours, but eventually the 10 gpm pumping rate is going to lower the water level in this well below the pump and I will run out of water at the surface. For this well, if I want to pump continuously and not run out of water I can only pump at 5 gpm or 50’ of drawdown. According to the drillers test pump results I can pump at this rate forever.
Alright, how does this apply to your well? You can continue to let your pump run out of water and only get 15 minutes worth of water or you can let it pump at 5 gpm and pump water forever. For example sake lets say it takes 15 minutes for the well to recover. In on hour you would pump 10 gpm for 30 minutes or 300 gallons. If you pumped 5 gpm for 60 minutes you would also get 300 gpm.
So what is the advantage of 5 gpm? The toughest thing on a motor is starting and stopping. This is the case for any electric motor. When a motor starts it builds up a lot of heat and works on destroying the insulation. On the 10 gpm pump you will start the motor 48 times in a day and you will only start the 5 gpm motor once in a day.
There is also a well development method called "rawhiding." This involves pumping water from the well until the well draws way down. Then the pump is stopped until the water returns. Then the pump is turned on again and this cycle continues. This is called “rawhiding†and it encourages sand to come out of the formation and into the well water. On a well screened well this will not cause sand in the water, but on a poorly screened well or a well with very find sand you will get sand in the water. Also, some wells will pump sand at higher flow rates and not at lower flow rates. This is another advantage to slowing down a well.
The best protection you could actually get would be to install a flow control and Pumptech or whatever Goulds calls it in the lower horsepowers.
I do agree that you should keep some records of your well and pump information.