Welcome to Pond Boss!
(I don't know any of the pond/water diversion regulations in Ireland, so make sure you follow those rules BEFORE following any "technical" advice you may receive on Pond Boss.)
I can't tell from the close-in photos if that is surface water run off that has pooled in a low spot, or if it truly groundwater due to a rising water table. Can you examine the lay of your land and make a determination? It doesn't take much of a slope or much of a depression to collect water like that.
Your gleying is a good sign that you probably have sufficient clay to make a sealing pond (if the other conditions can be met). Even when there is good clay present to keep the soil horizons water logged, there may also be some sand/gravel layers present that also affect the water flows. These layers, or even just stringers of sand, must be disrupted and sealed if you are going to attempt to make a sealed pond.
Is the "field next to your parents' house" a working farm or rural property? (That gives you more room to develop your project.) Do you have any excavating equipment on the property?
I would just start digging with a shovel when it is dry at that location and see what you get. If the soil is still damp, then you should be able to make a ball in your hand if you have sufficient clay. If you can start to roll the ball into a "worm" then you have really good clay. If you can excavate with equipment, then keep taking samples on your way down. Eventually, your sample trench will probably start to fill with water. If it is safe (from humans and animals), you might leave the trench open and keep some records of the water level.
If it is surface water collecting in a depression AND you have good clay, you can easily make a nice, little pond there. If it is groundwater, that is a little more complicated, but you also have several options that might be able to create a nice pond there.
Can you give some dimensions of the potential pond? (If you work in metric only, post it in metric and I will convert.)
Good luck on your future pond project (I hope)!
Many thanks for the input. It's a good question re surface run off vs groundwater. I suspect it's actually surface water run off as, on closer inspection, this area of the field is in a slight dip.
This field is not a working farm, simply a field which houses a single horse. It is not used agriculturally or for anything else. I do not have any excavating equipment.
I think that's a good plan, to just dig when it eventually tries here. Do I understand correctly that you sort of recommend that I keep digging until the soil seems to reach a point where there is more clay? Is it correct at all to assume that there is more clay the further down you go, generally speaking?
I guess if I stop and it rains and it doesn't hold anything I can either keep digging or else just fill it up and try elsewhere.
So surface water is a better prospect? Seems like good news. The dimensions would be very modest initially, as a trial, maybe 2.5 feet deep and 5 feet long and maybe 4 feet wide.
Many thanks!
