Pond Boss Forums INTRO Questions & Observations Using well aquifer for circulation

Hello there

Very much new to this and planning for a garden pond (about 15x20ft and max 4ft deep, avg depth about 3ft)

I am trying to decide in advance how to circulate and filter the water and I see various systems and products that may work but - one thing that can't to mind that I can't seem to find any accounts of is allowing the pond to slowly drain into the same aquifer as our well and just continually top it up using the well pump.

I figure that natural drainage through the soil is an excellent way to filter and I suppose would have the added benefit of not having to necessarily use a liner ( I am thinking trees growing nearby will also be happier if there is a pond draining into the soil naturally as well)

Would likely use a float switch to control an electronic valve that allows water to flow from our well system. I suppose I would also need to find a way to get an acceptable rate of drainage so the well pump isn't running too often - I suppose I could do this by perforating the liner or if I decide not to use a liner could maybe adjust rate of drainage with bentonite?

Anyhow just wanted to get your thoughts on this to see what I may not be considering other than perhaps reducing the life of my well pump!

NOT an expert on small, garden ponds, but I don't believe I have seen people do it that way. (And there is usually a reason!)

The water from your well is generally going to be unoxygenated, which could be detrimental for the organisms in your pond. For example, if the float switch stayed in the "on" position, then you could quickly flush the entire volume of your garden pond with "dead" water.

What creatures and plants do you intend to support in the garden pond?

Many people use a tub, or an isolated portion of the garden pond, as the "biofilter" section. Frequently, the tub is elevated (good time to add a small waterfall feature for beauty and oxygen). The intake for your recirculating pump is located near the bottom of the garden pond. The discharge piping is routed into the biofilter tub. There is a spillpoint on the tub to set your water level.

I think you will find that is easier to control, than the flow of water through the permeable and variable subsoils and back to your aquifer. Also, you DO NOT want surface contaminants being drawn down into your aquifer and water well.

Good luck on your garden pond project!

Thanks FishinRod for your reply! I did hope to have some cold-hardy goldfish in there (Canada).

That is good to know re:the water coming back from the well being unoxygenated. I will probably go with the more tested approach of having a liner and use the circulation system with biofilter like you describe (just trying to figure out how to do it on the cheap at the moment haha!)

Also, with an open discharge into the pond, that usually means that the house looses water pressure.

Cheers esshup - the water pressure is definitely a consideration. My hope was that the discharge would be slow enough that I could top it up periodically (or control to top-up at night)

I guess if I am going to do this I need to do some testing to see how quickly it drains - I have the pond dug, it doesn't appear to drain *that* quickly if I observe how the water can puddle up but I may be (or probably am) underestimating how many gallons per hour I would lose. I'm also basing this on times when we had freeze/thaw, e.g., rainy week water would puddle up and then freeze. I imagine the soil has different properties in the summer?! Let's see, I'll try a "test fill" this weekend perhaps.

To fishinrod: I wonder if I could oxygenate the water by sourcing the pond via an open stream with rocks, etc. instead of discharging directly from well to hose to pond. This may be more work than just doing a closed system though! My reason for looking into this was paranoia about managing leaks long term though not necessarily the amount of work/cost upfront.

Garoth, stick a metal yardstick in the pond vertically so you can accurately measure vertical water rise/fall. You then can accurately determine how many gallons based on the surface area of the pond at that water level.

To oxygenate the water, google "packed column".

If you buy a heavy, quality liner, then those things are darn near leak proof.

I did a water feature in our back yard about 15 years ago for my wife. (It is only about 4'x4' though.) I drilled 2 sandstone boulders and ran pump discharge hoses up inside the boulders to create two separate "waterfalls". I believe it has zero leaks after all that time. My wife just tops it off with hose water every spring before she starts using it.

I believe (not an expert) that liner leaks are most frequently caused by improper installation.

1.) If the base horizon is not prepared properly, then a sharp stick or rock can puncture the liner.

2.) In large liners, a failure to create perfect seals on the seams will cause a leak.

I think I would plan on a leak-free pond and do your design and labor based on that. (Of course, I have been wrong before!)


Do you have a clay soil that will hold its own shape, or a sandy or loam soil that will slump or only hold a gentle slope? I ask, because I have seen videos of people that literally carve a very interesting pond into the clay with all kinds of features to the pond bottom. These are then accented with round river stones in the visible portions, both above and below the water level. If you can only create a bowl shape, then you still do some attractive features by created a secondary shelf our berm in your base horizon a few feet from the liner's edge and create some stone-lined pools.

You could even use the round, river stones to create a small goldfish pond - if you stack the stones tight enough to not allow any "goldfish size" crevices to escape into the "main" pond. Beware though, raccoons and herons love shallow pools with fish. My neighbors IN THE CITY had raccoons completely clean out their shallow (< 3') koi pond in a single night. The didn't lose the koi in their deep (5-6') pond that they use for over-wintering.

Finally, I had a buddy that used to build backyard water features for wealthy homeowners. When he built a very complicated elevated feature, or a biofilter system for "living" ponds, he usually ran the main pond liner under that feature - and then used a small piece of liner for the feature. That way, his feature could leak, or have splash losses, but the pond DID NOT lose water. (It just leaked into the main pond, and caused a tiny percentage loss in the net efficiency of the water recirculation pump.)


I hope that helps you generate some good ideas that will actually apply to your project!

A good liner is absolutely the way to go. Add a filter system of some sort. I built an under-gravel filter in my lined garden pond that does nothing to remove nutrients from the water column, so I am constantly fighting water clarity from life, not suspended particles. That is very similar to what you are thinking of. If I were you, I would build a bog filter or purchase a filter system that is easily serviceable that has a pump. My rule of thumb is size it up at least 2x the water volume recommendations on the box so it doesn't saturate too fast and need constant work to keep it clean. I plan on adding this to my garden pond at some point.

A liner will give you far more control over your water quality if you need it. Many times, the mineral content and PH of well water needs some adjustment before being usable for a small pond. In my case, my well water is too "soft" and I need to add calcium to buffer the PH so it doesn't swing too much on a night and day cycle in my aquarium. The water in the garden pond is fine as runoff from heavy rain events brings in plenty of CA buffering.

Much of your water will evaporate in the cycle you are thinking of in the summer, and much will also percolate well away from your draw. Depending on where your water table is at any given part of the season, you may find your water loss is too great to keep the fish thriving.

Good luck!