# how do I figure out how much water is in my well



## copperhead46 (Jan 25, 2008)

We had a well drilled and it is an 8 inch pipe in a 175 foot deep
P.J. well and the water is only 25 feet from the top, so that gives me 150 feet of water in the shaft. How do you figure how much volume of water that is??


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## wy_white_wolf (Oct 14, 2004)

http://www.online-calculators.co.uk/volumetric/cylindervolume.php

205 cubic feet

http://www.easysurf.cc/cnver6.htm#cfg4

1,534 gallons


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## Old Vet (Oct 15, 2006)

To get a real measure put a big pump on it and catch it when it pump it all out. The water will stay about the same level unless you put a big pump on it and pump it out but wait for a couple of hours and it will have water in it again.It is like knowing how much water there is in a 5 foot hole in a lake.


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## beowoulf90 (Jan 13, 2004)

wy_white_wolf said:


> http://www.online-calculators.co.uk/volumetric/cylindervolume.php
> 
> 205 cubic feet
> 
> ...


Not sure if I understand your figures...

There is 231 cubic inches in a gallon of water
So if I take pie x radius squared x height this equals 3.14x 16x 1800 inches(150ftx12) and equals90477.86842 cubic inches divided by 231 cubic inches equals = 391 gallons 

Am I mistaken?


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## BRYAN (Jul 5, 2008)

I checked beowoulf90's formula and math, the figure is accurate, but it only tells the static volume at that level in the pipe. A much more usefull figure would be the potential flow rate via Old Vets method.


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## agmantoo (May 23, 2003)

1 gallon [US, liquid] = 231 cubic inch

volume of a cylinder = pi x r2 x h

pi x (8in/2)2 x 1ft = 3.14159265358979 x 16 in2 x 12in = ~603.18579 in3

603.18579 : 231 = ~2.6112 gallons per foot of pipe containing water

Though you may not have the container nor the inclination you can pour as much water into a well as you can take out plus or minus a dab!


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## fantasymaker (Aug 28, 2005)

Copperhead Just out of curiosity why do you care?


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## Evons hubby (Oct 3, 2005)

copperhead46 said:


> We had a well drilled and it is an 8 inch pipe in a 175 foot deep
> P.J. well and the water is only 25 feet from the top, so that gives me 150 feet of water in the shaft. How do you figure how much volume of water that is??


the answer to your actual question has been answered already so wont go into to that. The real key however is the recovery rate, you would need to check and see how long it takes to recover after you pump a hundred gallons out of the well. You have a HUGE reserve suppy compared to most residiential wells, but if you have a slow recovery you could still end up with water problems. The thing to do is to mark your water level, pump out a couple 50 gallon barrels and time how long it takes for the well to fill back up. If it takes 10 minutes to refill, you have a ten gallon per minute water flow. If it takes an hour and a half you have a bit less than a gallon per minute. Which is still going to cover your average needs, but if you were pumping steadily, irrigating or filling stock water tanks, you could concievably come up short. if you cant lower the level of the water with steady pumping, you have a great water supply. 

I owned a property once that had a well only about 12 feet deep, there wasnt enough water in it to use a submersible pump, there was only about 6 inches of water in the bottom. I didnt think it was much for a well at all but an old guy that new the place said it was a good well, so I decided to test it. I hooked up a transfer pump I normally used for irrigating my garden, and couldnt pump the well dry!


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## Michael Kawalek (Jun 21, 2007)

fantasymaker said:


> Copperhead Just out of curiosity why do you care?


The reason this number is important is because of the well's "refresh rate". That is how fast water flows INTO the well. For example, if you are pumping water out of your well at a rate of 5 gallons per minute, and water enters the well at 1 gallon per minute, you will pump your well dry after about 90 minutes ({390 + 60}/5). My neighbor has a well with a low refresh rate, and he can pump about 250 gallons in one session before the well is pumped dry. He shuts the pump off, waits a day for the well to fill back up, and pumps more.

Most of the landowners in my homestead area are off-grid, and do batch pumping with generator power into storage tanks. The tanks are positioned uphill, and water flows back down to the point of use by gravity flow. This is how I produce my water, running the generator for about 3 hours per pumping session to get the amount of water I need to water my trees and supply the cabin.

If you have regular 120V electrical service, you're likely to have an "on-demand" pump that runs automatically whenever the water level is drawn down. In this situation, the refresh rate is a little less important because you are typically drawing lesser volumes of water more often.
Michael


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## copperhead46 (Jan 25, 2008)

Thanks all, I was curious mainly because I wanted to figure out my rate flow and the time it would take to fill back up. I will be watering cattle and horses out of it so it needs to be pretty strong.
I live on a hill over a good creek and I figured I'd hit water at about 40 or 50 feet, because thats where the creek is, but we didn't hit water till 150 feet. I'm still not sure the driller didn't just tell me that to get the extra footage, but, at least I have a good resavoir (sp). 
Thanks again, P.J.


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## wy_white_wolf (Oct 14, 2004)

beowoulf90 said:


> Not sure if I understand your figures...
> 
> There is 231 cubic inches in a gallon of water
> So if I take pie x radius squared x height this equals 3.14x 16x 1800 inches(150ftx12) and equals90477.86842 cubic inches divided by 231 cubic inches equals = 391 gallons
> ...


No I am. 

The first link was to an online calculator for volumn of a cylinder. I put in 8" for the radius instead of 4 of .33 feet. Works out to 52 cubic feet.

The second link is a calulator for cubic feet to gallons.


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## Windy in Kansas (Jun 16, 2002)

How much is in the well or how much water is available to pump and at what rate?

I would expect that your state requires testing and that the well driller will have conducted such and can furnish that record to you if they did not already. Is it not on paperwork that you have received? 

I would call the well driller and ask if he had to furnish records to the state and where you might obtain them. Certainly a law in Kansas and the information on newer wells is online. Try here for information: http://www.owrb.ok.gov/supply/wd/drillers.php


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