DIY groundwater pond

[WildBrook]

Hello, I’m brand new to pond creation. We’ve just moved to a 8acre former farm in East Sussex and have several ponds already as well as two brook/streams. We have an area alongside one of the brooks which is a depression and is waterlogged all year round with groundwater and some surface run off from the steep field around it (not fed by stream at all). I’ve started digging down to explore a few test holes and there is a foot of top soil and then grey clay. Test holes are currently holding water but expecting them to dip or perhaps dry totally in summer. In which case we may use the summer to dig the full pond and puddle the clay and seal the pond. Likely the long pond will either be around 8 metre long x 2-4 metre wide or a series of smaller ponds adjoined. Has anyone dug a groundwater pond? Would love to exchange ideas and hear how they have fared. Particularly interested to know if puddled clay line ponds can fill with groundwater if the clay acts as a seal.

 

[Mmathis]

Hello and welcome! Even if you decide not to turn it into an official pond, that looks like a lovely place for a rain garden!

 

[j.w]

@WildBrook
I've never dug out a groundwater pond.

 

[addy1]

Welcome I have never dug a pond and used clay to seal it. Can't help much.

 

[GBBUDD]

Not all clay areas are created equal in retaining water if your test pits hold tge water level constant for a week your off to a good start. Run off from surrounding areas is not ideal as cattle dung or fertilizers can spike your waterside for algae blooms that will never go away.
If the water shows signs of dropping you can mix bentonite in with the clay . The percentage varies on your type of clay. I would bet there are forums out there did a test pit say 4x4 and 4 foot deep will equal x and if your soil leaches in x add x . It's out there I would not bet against it.

A roots tiller is needed to mix the bentonite in . Or a farm tiller

 

[Solar guy]

I'm in Tennessee, in the USA and ground water ponds are all over the place around here; generally used for watering livestock. The only requirement I've ever heard of for one of these is a clay layer and a source of water, either a spring (ground water) or runoff. This with ground water preferred due to the contaminants in runoff as mentioned earlier. Unless you have enough ground water to be able to exclude the runoff by diversion ditches and berms, my observation is you will not have a clear pond. It will always be muddy and prone to algae.

 

[GBBUDD]

I'm in Tennessee, in the USA and ground water ponds are all over the place around here; generally used for watering livestock. The only requirement I've ever heard of for one of these is a clay layer and a source of water, either a spring (ground water) or runoff. This with ground water preferred due to the contaminants in runoff as mentioned earlier. Unless you have enough ground water to be able to exclude the runoff by diversion ditches and berms, my observation is you will not have a clear pond. It will always be muddy and prone to algae.

Your thinking and talking about farm ponds not a garden or recreational pond . Where the rules get far more stringent At least they do in the north east, deep south and west coast

 

[Solar guy]

Like I said, "usually used to water live stock". That is exactly what I was talking about; a farm pond, and this guy has a new farm of 8 acres and wants to add another pond.
I've never heard of using ground water for a garden or recreational pond. I assumed the OP was suggesting adding a farm pond; unless I misunderstood the post.