I have a 375' deep well for my rural home. I presume there's no way to know how much water is in the well. Last summer, which was very hot, I stupidly ran the well dry trying to water a new lawn. With all the modern technology we have- it would be nice if I had a gauge in my kitchen to tell me how much water is in that well. I don't know how this would be engineered, but I can imagine it's not that tough an engineering problem- if the well companies wanted to install some kind of measuring device- and I don't see how it should add all that much cost to the well.
In answer to your subject question. There's a way to figure out how much water you have in a well. You need to know 3 things and you already know one of them, the depth of the well. The others are; how far down to the water level and, the diameter of the casing. Example, 6" dia and 50' to the water. A 6" well has 1.47 gal per foot of water so, 375-50=
325*1.47=477.75 gallons. I have a chart for various diameters.
That doesn't answer your question but we're half way there. If you know how deep the pump is set, with the above info you then can determine how much of the water in the well is usable. But then as you use water the well 'recovers', meaning water runs into it as you take water out of it. So... you'd need a pump test of the well (4-8 hours minimum) to get an idea of how long you could pump water until you ran out or didn't want to use anymore but you shouldn't run out. Problem is all wells change and the change is more the more water you use. BTW, that's a change for the worse, the recovery rate will usually decrease. And now we get to the other part, how do you know when you should stop using water so the well doesn't go dry, or really, the pump sucks air. Well there's a number of ways to do that. You can simply change your pressure switch to a low pressure safety cut off type. Meaning the pressure falls to 20 psi and the switch opens shutting off the pump until you rest it. Roughly $25 anywhere you buy pressure switches.
As to some sort of alarm when you're getting close to being out of water, sensors can be had but, I'm not sure they don't have to be wired separately from the pump cable. So if you don't have a means to provide them power due to the cable being buried without a conduit or way to get the wire out of a conduit and down the well, do you want one enough to dig up the yard? Driller supply houses can explain all this in more detail and provide you with what you want, it just won't be a gauge at the sink from what I know, it would be an multiple stage audio and/or visual alarm.
You would think in this day and age of technology they would have a pressure sensor mounted just above the submersible pump that would measure head and take in account well size(6"-8" etc.), then convert to gallons with a digital read out in the home. This is actually quite simple to do. O.K. Gary it's my idea you market it and we'll be partners.
Ok, but I we have a design change (already!). I go for a wireless sensor floating on the water in the well programed to the pump depth with the signal sent to a receiver we can make into a 'fridge magnet display and we're done. I'll do the sensor and you do the receiver. It should be a pretty blue.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.