I have a 100 x 200 pond. Im going to put in a well because We aren't getting enough rain to fill it up. If I got a well that produced 12 gal a minute, how many days would it take to rise the water level 5 more feet?

Not allowing for ANY evaporation, 43.286..... days

Since you didn't tell us what the slope of the pond is, Rex's figures are calculated on straight vertical walls....

This also assumes your pond is tight as a drum with zero leakage

Is it common for some ponds to need a well to help keep filled? I like a nice full looking pond. Anyone else here use a well.

I have a two acre pond in northern Michigan. In the summer it takes 65 gallons per minute to keep up with evaporation and leakage. I run the output thru a 2 inch poly pipe to the center of the pond to a floating fountain. This helps with areation and tempers the water a bit. You will also need a ball valve to adjust the flow and a check valve to prevent siphoning.

How many days do you run it?

You are correct esshup. A 3:1 slope would I think nearly triple that time and a 4:1 slope would more than quadrupal the time.

I run it 24/7 year round but adjust the flow as required. It also keeps a good area free of ice in the winter.

Our pond gets zero run-off and is not spring fed, so a well is the only way we have of raising its level significantly without a major precipitation event. It is two acres in size and it takes about 3 days to raise the water level 5-6 inches. I will have to check the exact specs on the well, but it pumps a heck of a lot of water out a 6 inch diameter pipe.

My advice is to put in a well and pump that exceeds the size of what you think you might need. It will cost you more initially, but you will save in energy costs over the long run.

thanks for the help.

I have an artesian well that flows into the pond 24/7. This year, we have had to pump from that well about every couple of weeks for a few days to raise the water about 4 inches. The pond is about 1 acre in size. By pumping the water, i am able to increase the volume dramatically. I pump it to the front of the yard where it utilizes a round fountain and limestone rock configuration before it tumbles down a rock stream to enter the pond.

One thing to consider is that the D.O. of the well water was only 2.5 mg/l when I measured it yesterday! The water temp is a constant 46 deg.F. It might be something to consider and you may want to shoot the water in the air via a fountain or have it tumble over a rock bed to try and aerate it some before it reaches the pond?

I know what you mean about the appearance of a full pond. It starts to look a little on the sad side when the water level drops. I try to stay on top of it.

One other question. How do you determine what size pump to get. A friend said I can have his old well pump thats still in the hole. Not sure how big it is though. Will the well digger tell me what to get? In this area wells are about 12-14 gpm. Is that enough to raise a pond even in the dry season?

Talk to your well driller and ask him what you should expect for GPM out of the well. Ask him if the GPM would increase any if you put a double screen on it.

If your pond isn't a groundwater pond, and is sealed tight, that low of a flow might do it. If it isn't tight, I doubt it. My pond is a groundwater pond, i.e. not sealed tight. 30+ gpm pumping 24/7 (one hp submersible motor) is enough to keep even with evaporation and what leaks out during these dry times, but not enough to gain any.

I don't think you will be happy with 12-14gpm in the summer. I would try for 25-30gpm minimum. Your driller will size the pump for you once he knows the depth and does a draw down test.