Help me solve the mystery of the disappearing water

[NC Pond Man]

Long time browser and first time poster and I’m hoping I can get some help to determine where my pond is losing water.

The Pond -Looking at the pictures you can see there is a waterfall on one side and a small stream leading to the pond on the other. To make the stream I had to use a separate piece of liner. The pond liner is underneath the stream liner and there is 18-24 inches overlap. All liner is 45M EPDM.




The red line in the picture below gives an indication of where the lowest spot of where the liner is and in most spots it is much higher. I did remove the majority of rocks yesterday to verify the liner had not slipped anywhere. The red line is where the water level should be.


The issue – My water level is 2-3 inches below full pond and the top of my liner.
In the summer I attributed the water loss to spray from the waterfall and evaporation. Over the winter it is apparent this is not the case.

Troubleshooting – I have turned off the waterfall and stream pump and filled the pond. By the morning it has dropped 2-3 inches and I don’t know where the water is going. Also we have had a tremendously wet spring so all the surrounding soil is saturated. My first thought was the water was escaping where the stream liner overlaps the pond. Yet the pond liner extends far up the stream and the water level is much lower. It doesn’t make sense the water would be escaping there

Possibilities – 1)There is a hole in the liner. 2)The water loss is related to the overlap of the liners 3)????

If you have read all this and did your best to comprehend I appreciate it!! If you have any suggestions on what my next steps should be that would be great.

I want to get this fixed as I plan on moving the waterfall back several feet and creating a stream/waterfall into the pond.

 

[MajorDan]

I am new to ponds having just built my first pond. It is an aquascape kit that I decided not to rock in for one reason...if the liner gets a hole it from a mole or chipmunk you have to unrock to find the leak. The directions I have seen here are to let the pond leak until it reaches the lowest point, then inspect the liner at that level all around the pond. Another area to check is your water lines to and from the pump. Like my sprinkler system recently, the termite company screwed a termite “bait trap” right through a PVC line. It was easy to find as water squirted up out of the ground. If you have any valves in your lines this is another place to check for leaks.
As I noted above, I am new to all this so hope something I mentioned gives you a place to look.

 

[Tula]

If you suspect you may have a leak in your liner, there are dyes ( or I've even read of people using milk ) to put in the water and visually see where the water is traveling. I know other members have also lowered their pond water below its low point, so they could carefully visually inspect the liner for holes.

Sometimes roots wick water out of the pond, so check your plantings and tree roots. If you do find a hole / tear, there are products you can use to patch it ( just like a swimming pool liner ) as opposed to replacing the liner.

Other members with streams can weigh in on overlapping liners. Best of luck and welcome to the forum

 

[JamieB]

If you have fish, set up a tank/ kiddie pool for them. Then top the pond off and leave the plumbing/ filter, pumps off for a day. If the level drops, then let it drop to lowest it will go. That will eliminate the plumbing as the cause. If it doesn’t drop, check all hoses, connections, areas water could be lost there. If its a small enough hole, you may be stuck waiting till the ground dries enough to make leaks obvious to locate it.

 

[NC Pond Man]

Thanks for the replies.
I have left the pumps off and the level still drops so I can eliminate a plumbing issue as the root of the problem.
I think my next step will be to try the milk/dye option to see if I can identify a leak.

 

[mgmine]

Don't put dye or milk in it will only mix with the water and show you nothing. If the water has dropped with the pump off then you have a leak. The leak will be at the water level and that is where you need to look. Remove all the rocks down to that point and start searching, chances are that with that much water leaking the ground near the leak will be soft. If you can't find it you may have to roll the lining back which means that you will have to remove even more rocks. In the end, it may be easier to just remove the lining and put a new one in. Gluing is not always the best way to fix it because it takes a smooth clean surface for the glue to work. You could glue it only to find that it still leaks and you have to do it all over again. My recommendsation would be to eliminate the rocks completely except for the top which hide the edge.

 

[NC Pond Man]

I appreciate all the advice as I was able to find where I was losing water.

I had folded the liner where the stream comes in and initially it appeared it was high enough. I eventually removed all the rocks so I could thoroughly investigate and I found one of the flaps was low and water was escaping there.

Next step is to build up behind that and rebuild the stream and then move my waterfall back 3-4 feet on the other side for a little expansion.

Hopefully the weather cooperates this weekend and I can make some good progress.

 

[sissy]

all liners connected should overlap by 3 or 4 feet and you can use the goop addy uses to secure it and make sure nothing wicks up it .Plus i have found frogs will get between the 2 pieces of liner to over winter or just hide from heat or bad weather

 

[j.w]

@NC Pond Man Good to hear you found your leak.

 

[addy1]

I had folded the liner

I had that issue in a few places, one while building, oops folds wicks water out, and once just recently. One of my small ponds had a slight fold, one of our many deer walked on the edge, pushed down the liner and it drained the big pond down over a foot. I have learned over the years my weak spots, work on making them not weak. I have more issues with the small ponds than ever have with the big ponds.

They are in the water loop of the big one so when there is a leak the big pond drops water level.

 

[MajorDan]

So Addy, what is the goop!

 

[addy1]

I have used this a lot. The disclaimer, make sure the liner, rocks, whatever you are sealing are dry. It does not attach to wet/damp But once on it is on. I have areas I have used it still sealed years later.

 

[MajorDan]

Thanks

 

[sissy]

yep and it works I used it when I rebuilt my pond in both the waterfall pond and the new filter area where I had to piece a liner

 

[herzausstahl]

Follow @addy1 s advice! I did and my stream overlaps underwater. I used the goop, 2 sided sticky roof tape and one sided. Followed the process every time I joined 2 liners, never had a leak because of it. Always from something like you had. Test one is always what @JamieB said. Turn off pumps, fill pond &check water level. If it’s plumbing, check for leaks. If not remove rocks and check for low spots as new ones can develop over time.