Acceptable pond leak?

[Phil Tod]

Hi,
New pond recently constructed and filled for the first time, however I am observing falling water level over time.
I've monitored it over the last 42 hrs and is dropped 25mm. I've taken evaporation into consideration by placing a large open bucket adjacent to the pond (3.5mm in same timeframe) which equates to a net loss of 21.5mm (approx 0.5mm hr)
Not sure if it makes any difference but taking the pond surface dimension into consideration (2020mm x 1560mm) my maths, if correct, gives a loss of 1.6litres per hour. This doesn't seem an awful lot but over a week would equate to 85mm level drop or 268 litres without rainfall
Is this acceptable?...and if not, what is deemed an acceptable leak (you could spend a lifetime chasing pin-prick leaks)....Frustrated!!! Please help ☺

 

[Lisak1]

Evaporation can definitely be a factor. Do you have a waterfall? Splashing will also equate to water loss. Plants? It's amazing how much water can be taken up by plants in a pond.

My metric conversions are lacking - how many inches/gallons are we talking? And how big is your pond?

 

[mgmine]

1.6 liters per hour is way too much. You have to have a leak or your math is wrong.

 

[Mmathis]

Evaporation can definitely be a factor. Do you have a waterfall? Splashing will also equate to water loss. Plants? It's amazing how much water can be taken up by plants in a pond.

My metric conversions are lacking - how many inches/gallons are we talking? And how big is your pond?

I had to look it up.....
25mm = 0.98"
1.6L = 0.42 US gals

@Phil Tod Ditto what Lisak1 said above. Also, heat and wind can be factors with evaporation. And is your pump/waterfall [if you have one] running? If so, turn them off and watch to see if your water levels out at a certain point. That's one way to pinpoint the location of a possible leak. Waterfalls are notorious.

 

[EricV]

I don't think your evaporation test is valid since agitating the water should increase the evaporation, probably a lot. Around here with temps in the high 80s (~35 for you), a 25mm/1 inch drop over the course of almost two days would not worry me.

I'm using a trickle-flow top up system and I figure I have to add 1 gallon/4L per hour just to keep up with evaporation right now. I add double that which then comes out of the overflow. (My pond is 2400 gallons/9000 L)

 

[Mmathis]

Evaporation can definitely be a factor. Do you have a waterfall? Splashing will also equate to water loss. Plants? It's amazing how much water can be taken up by plants in a pond.

My metric conversions are lacking - how many inches/gallons are we talking? And how big is your pond?

I had to look it up.....
25mm = 0.98"
1.6L = 0.42 US gals

@Phil Tod Ditto what Lisak1 said above. Also, heat and wind can be factors with evaporation. And is your pump/waterfall [if you have one] running? If so, turn them off and watch to see if your water levels out at a certain point. That's one way to pinpoint the location of a possible leak. Waterfalls are notorious.

 

[Meyer Jordan]

Recalculated after converting from metric. You are losing about 10 gallons a day. More importantly and relevant is that you are showing 0,48 inches loss per day. This is a leak albeit maybe a small one.

 

[Nepen]

I would wait a week before you try to find any leak. See if you continue to lose water.

I had quite a lot of water loss last year and I thought it was a leak. It was mostly evaporation. we have a long stream and water flow over rocks and dry up. I thought it was excessive but it only lasted a few days each time. I have not experience the same water loss this year. someday my water evaporate more then the other.

 

[crsublette]

@Phil Tod , I would wait until Late Fall, Early Winter to make any determination... and then turn off all streams, water features, and waterfalls... have your pump only circulate water in your pond... so then to determine this...

If you do have a leak, then the pond will eventually stop dropping so fast at the location where the leak is...

There really is no easy way to determine this...

Normally, when a leak happens, water drop is rather quite big and fast...


Ya might be surprised by how much streams, water features, and waterfalls increase evaporation... especially on windy days... Evaporation increases even significantly more, the more water flow you have through these...

 

[Mmathis]

@Phil Tod
Ya might be surprised by how much streams, water features, and waterfalls increase evaporation... especially on windy days... Evaporation increases even significantly more, the more water flow you have through these...

Agree!

 

[Phil Tod]

Thanks for all replies guys...just to clarify...
First time pond fill - no waterfalls, no pumps, no fountains, no plants.
It's been warm-ish (circa 18-20°C) and quite breezy - nothing out of the ordinary.
I accept I have a leak - but is it an acceptable one?.....I'm sure not every pond is 100% watertight....it's what can I/should I live with?
Pond size is 2.02m x 1.56m x 1.2m deep if that matters... (approx 80"x61"x47")
I'm currently monitoring water level to assess over a period of time.

 

[Mmathis]

Thanks for all replies guys...just to clarify...
First time pond fill - no waterfalls, no pumps, no fountains, no plants.
It's been warm-ish (circa 18-20°C) and quite breezy - nothing out of the ordinary.
I accept I have a leak - but is it an acceptable one?.....I'm sure not every pond is 100% watertight....it's what can I/should I live with?
Pond size is 2.02m x 1.56m x 1.2m deep if that matters... (approx 80"x61"x47")
I'm currently monitoring water level to assess over a period of time.

OK, so this is with a totally still pond, no water movement? So take that out of the equation -- thanks for clarifying!

 

[Tula]

For me, I'd want to find the leak, especially before I plumbed pumps, run waterfalls and add plants.

 

[Lisak1]

I think ponds generally ARE water tight. If you are reasonably careful with your liner (especially while installing) it will last for many, many years leak free.

The great majority of "leaks" turn out to be low edges from rocks shifting in waterfalls or streams or natural settling that occurs when you disturb soil. Most of those happen rather soon after a pond build and get worked out relatively quickly. To me, no amount of leaking would be acceptable as it may lead to water ending up where you don't want it and cause problems down the road.

 

[Meyer Jordan]

Only you can determine what size leak is "acceptable". Just keep in mind that the leak may or may not remain constant, it could, depending on the cause, increase.