ᐅ The garden pond is overflowing into an unknown area. How can I find out where the water is going?

Created on: 25 Feb 2022 15:38
A
ateliersiegel
For a few years now, we have had a house on a slope and feel comfortable living in it.
On the east side, there is a small attached pool where goldfish live.
When it rains, water flows into it, but it never gets any fuller than usual – which means there is an overflow or a leak somewhere.
I’m surprised that it is even that watertight (considering how it looks), but it is. 😎
The wastewater does NOT go into the public sewer system but seeps away somewhere... I have no idea where that could be...

and unfortunately no idea how to find out.
When it rains and the water (presumably) flows somewhere in the garden, everything is everywhere wet, and I can’t tell if the moisture might be coming from the pool or from the rain.
The garden is about 600 sqm (6,458 sq ft) (visible in one of the aerial photos).

I once emptied the pool almost completely (the fish and newts were temporarily kept at the neighbor’s), but the bottom is quite muddy (with lotus plants blooming repeatedly), and I couldn’t find any outlet (which should actually be at the water level).

As long as it works this way, that’s fine, but I would really like to know where the excess water goes.
I assume there is no trick (like with a bicycle tire, submerging it in water to find the leak), but I still want to give it a try: Does anyone have an idea how I could solve this mystery?

Concrete basin with dark water, drain pipe and staircase on grassy slope leading to the white house.


Rusty outdoor faucet on a crumbling wall, grass growing at the ground.


Open rectangular water basin next to the house, overgrown with moss, with pipe nearby.


Top view of garden: large leafless tree, wooden box, solar panel, garden furniture on the ground.
ateliersiegel1 Mar 2022 09:11
A submersible pump is a must-have, but it doesn’t transport any sludge or remove root balls. The newts hiding there also need to be handled carefully, and there were other obstacles as well, but those aren’t important for my question, so I didn’t list them individually and left them as a background puzzle instead 😉

The matter is settled. Thanks 🙂
AxelH.1 Mar 2022 11:17
ateliersiegel schrieb:

The matter is settled.
Now we are all very eager to learn the solution to the mystery ... 😉
ateliersiegel1 Mar 2022 11:21
That is a misunderstanding. I did not find the course of the drain but rather an answer to my question on how I could find it out.
AxelH.1 Mar 2022 13:08
ateliersiegel schrieb:

This is a misunderstanding.
I did not find the course of the drainage; rather, I found an answer to my question about how I could find it out.
Well then, let's continue to wait patiently and see how the puzzle gets solved...
P
Pinkiponk
2 May 2022 16:13
AxelH. schrieb:

Well, then we will wait patiently to see how the puzzle is solved...
I would also be interested in the solution. :-)
Musketier2 May 2022 16:43
The nice weather is coming. The mulled wine has been replaced by beer... let’s get started.
driver55 schrieb:

But you only need to check the overflow; the "pond" doesn’t have to be empty for that. 🙄
If the water level is consistently about 14 cm (5.5 inches) below the top edge, there must be something at that height limiting the fill level!
In theory, the overflow could also be lower down, similar to how a siphon works.