Need to fix a leak in my waterfall

[Lump]

Hello again. I'm back!

Actually, I haven't made much progress on my pond over the last year, and I've been a little embarrassed about that. So I haven't posted.

But today I was trying to landscape the backside of the earthen mound that I build to support my multi-tiered flat-rock waterfall, and I discovered a leak. Crap.

So now my question. My little pond (about 1,000 gallons, I assume?) has a 4-level waterfall made from natural rocks. When I built it, I used expanding foam to seal each rock. But now I have found a leak. I THINK I have found the area where it is leaking. I do have some 2-part epoxy putty, which is water based and will cure even underwater. But we have 9 healthy and happy goldfish which have been with us for a couple years, and a host of frogs. I don't want to kill them.

Have any of you more-experienced pond builders ever had to stop leaks between rocks in existing waterfalls before? If so, were you able to do so without killing fish? What products did you use...please?

 

[poconojoe]

Spray foam is not meant to seal. Most use it to convince the water to flow in a certain direction to acquire a desired look. I never use any foam or adhesives...ever.

Correct me if I'm wrong, but from the way you describe it, you may not have a liner under the stones forming your falls.

The trick to building a leak proof falls is the following...
Form your soil mound in a concave fashion pitched toward the pond with ledges that will support your layers of flat stones. Then cover the mound with underlayment and EPDM liner. If you have properly shaped the soil, any water between and around your waterfall stones can only return to the pond. Water will find its way between the stones no matter what you do or what glue or sealer you attempt to use. So why fight it? Let it go where it wants because your liner will be underneath everything to guide it right back to the pond.

If this liner is an add-on and not part of your pond's liner, then make sure to have a significant amount of the falls liner overlapping on top of the pond's liner. As long as it's overlapping and shaped right, it will be fine. No seam or adhesives needed.

 

[mrsclem]

Just stacked stone is going to leak. Epoxy can be toxic so I personally would not use it. Agree with pocanojoe that liner needs to be placed under your waterfall to contain leaks.

 

[Lump]

Joe, you're not wrong. I actually did put the liner in behind my waterfall feature. But then after it was "completed" I tore some stones out (because they just didn't look right), but then went ahead and actually built it taller, extending above the limits of the liner (because the rocks are now higher than the soil). I guess that was another mistake I have made in building my first pond.

But you know, I do like the way it looks now. And the leak is pretty slight, over the last two years. So for now, I think I'll just let it leak a little, and water the plants which I am installing on the backside of the falls.

Thanks for your advice. Cheers!

 

[poconojoe]

Ok,

Joe, you're not wrong. I actually did put the liner in behind my waterfall feature. But then after it was "completed" I tore some stones out (because they just didn't look right), but then went ahead and actually built it taller, extending above the limits of the liner (because the rocks are now higher than the soil). I guess that was another mistake I have made in building my first pond.

But you know, I do like the way it looks now. And the leak is pretty slight, over the last two years. So for now, I think I'll just let it leak a little, and water the plants which I am installing on the backside of the falls.

Thanks for your advice. Cheers!

OK, great. Just keep an eye on that leak. You don't want to drain out your pond!