Hi all,

I am the new owner of an approx 1/4 acre pond. 150'x70'... 12' at its deepest. Clay lined (so I was told). The pond was dug 11/22 next to an existing 1 acre farm pond that has been there for decades, so I assume it has the same soil makeup.

My pond was built next to the existing pond with a bridge (or dam) in between, there is a12" overflow pipe in the dam. My pond will overflow into the neighbor's pond, and then he has an overflow outlet on the opposite side.

The pond is fed by runoff water. It is at the bottom of a development so it gets water fast. The whole pond filled in approx 6 months.

Everything seemed fine. However as soon as it got full, it started losing water. I can't tell if it's the new pond settling, evaporation, or a leak.


Details:
The pond has lost 7" over the last month.. So basically 1.75"/week or .25"/day. I live in upstate NY, and in that month it has only rained 1 day, and it has been unseasonably hot.

From what I read on here and online elsewhere, that seems somewhat normal of evaporation....Im not sure if I am looking too far into it or not, I just hate seeing the level drop after it was finally nice and full.

Im new here, I tried attaching 5 photos of the project, let me know if you guys cant see them or if you need any more details. Thanks in advanced!

I'm not an expert at pond building however I do have a pond. My pond was clay lined. Is your pond just dug earth or was some sort of lining used?

Thank you for the reply, the pond was earth dug. No lining. The contractor is a reputable earth mover in the area and assured me that it was good clay. However Im wondering if maybe he went too deep? Not sure if there was sand or gravel down there, or how that effects things.

Photo Links of the pond if you cant see them via attachment

https://ibb.co/hWBRLmf
https://ibb.co/bWykbJ2
https://ibb.co/F0fyFSg
https://ibb.co/xY8bQbQ
https://ibb.co/bd9xmsn

Exact evaporation rates are difficult to estimate because there are so many atmospheric variables. However, 1/4" per day of losses during unseasonably warm weather (which is also usually dry) seems to be about right.

Was the water level in your pond higher than in the adjacent pond? If so, then there may be a slight leak through to that pond.

That should NOT be a problem if the old pond usually stays nearly full. You might place a water gauge staff in both ponds. After the next big rain fills your pond, mark both pond levels. Evaporative losses should be roughly the same from both ponds. However, if yours is leaking, it should go down faster. If yours is just leaking to the adjacent pond, then it should go down faster UNTIL the pond levels equalize, and then your rate of water loss should slow substantially.

Have fun with your new pond!

Rod,

My pond when full was indeed higher than the neighboring pond. About 2 feet higher, just because of the grade of the land. His pond is going down as well, but at maybe half the rate of mine. His is down 3-4” compared to my 7”.

I wasn’t sure if the fact that his is 4x the size of mine if that’s why his was going down slower. Or if your speculation is correct and mine is slowly leaking into his.

If that seems to be the consensus on here, what should I do next? Will my new ground self compact over time and fix the issue? Should I get a couple of buckets of DamIt and spread along the shared dam?

I just worry that if they equalize and if in the dead of summer his is down a foot, mine would be down 2 feet based on the grade.

I’m almost the same scenario, I’m probably down 2’ as well

Dug it last fall, 9’ deep, filled quickly, we haven’t had rain in weeks (besides just raining briefly today) decently hot out. I was worried about the drop so I added damit pond sealer in about a month ago before having it stocked, still having loss in water and after all the reading I’ve done, I’m chalking it up as the soil is being saturated. I have really good clay so I was surprised it was dropping at the rate it was.

I do plan to add a sand point well in with a pump to get it back to full so I don’t need to worry but don’t think it’s necessary. I just know I will be using the well in the future for other uses in the so I don’t mind digging it.

May be soil saturation, evaporation, or a leak. Either way, I’d love to be able to top off the water when needed. We often have brutal summers with no rain. I never considered a well. After reading your post, I did some brief research on a sand point with a pump. That sounds like a great solution. I will just have to do a bit more research. No idea how to know if/where the water in my area would be.

I live about 90 miles south of you and have been experiencing the same drought since early May. My pond was dug last year and is down about 4-5" from full. I am not an expert, but assume some of my loss is "new pond" as well, so evaporation (FishinRod) and some absorption could be enough.

I looked at the pictures and would like to ask if they dug a core trench for the dam, did they use a roller to compact anything, and did they see sand or gravel layers or veins? I would guess that it could be that some of the loss is due to seams or veins in the soil not fully compacted.

Thank you for the reply, nice to hear from someone upstate. So your evaporation and or absorption is about on par with my neighbors. Which is about half of mine.

There was definitely no core trench for the damn. We basically dug one pond next to another. The piece in between which we call a land bridge serves as a dam, but wasn’t constructed as such. The pond was not rolled, only graded with the dozer.

I just looked back at old pictures I took from when it was dug. It seems there are definitely sand and gravel veins at the very bottom. I didn’t notice anywhere else other than the deepest areas. I thought it seemed strange at the time of the dig, but as a novice I didn’t know that it may be an issue. If anything, I thought it would help fill the pond from below. The contractor is pretty reputable and does million dollar projects all over the area, he didn’t seem too concerned, so it was never addressed. Here are some photos…

https://ibb.co/m8YVryD
https://ibb.co/9v0mYvq
https://ibb.co/8XkHgF1
https://ibb.co/3NxNKBg

So short of emptying, lining with more clay over the veins and compacting, what are my other options… do you believe something like damit or another polymer would work?

Another user said he was digging a sand point well to feed his pond. Maybe I dig one of those knowing there is Sandy ground just past 12’?

Hello

I help folks with pond construction, rehab, and leak mitigation nationwide and as a volunteer here my time is always free to my Pond Boss family. You have several options and I’m happy to review and help strategize moving forward. Feel free to reach out anytime, happy to help however I can.

TJ

Tj@hudlandmgmt.com

Guys, NOAA and NWS have charts and online stats on evaporation and more words I can't spell... lol... Good place to start building your knowledge.

https://www.weather.gov/ict/Evapotranspiration

https://www.cocorahs.org/ViewData/ListETReports.aspx

Cool tools, Stressless!

However, their data is for SOIL evaporation, and transpiration from plants. Not quite showing pond evaporation rates.

(I suspect it would be a good "relative" tool most of the time - when soil evaporation rates go way up, then pond evaporation rates are probably going way up also.)