New construction 12,000 gal. Pond Newby

[Turet]

3 questions. I have purchased a 40 EPDM Liner.

1- their will be a 8 foot water fall wall 4’ in water 4’ above. I intend to build cinder block wall the first 4’. I’ll Put on the liner than stack large rocks in front of the wall and liner 8’ high. The rocks will be on the footer with the liner sandwiched in between concrete footer and very heavy rock wall. Im afraid the liner will be ruined. Is this okay????

2-kids and dogs will be swimming in the pond. I plan to put 3” of pee gravel on the base. should I poor 2” of mortar over the floor of the pond above the liner and below the pee gravel. Just to protect it from kids????

3-I live in northern US. The pond will freeze solid but the cost of water to drain and refill yearly is alot. Can the pond remain full and freeze solid without damage to pond liner????

I’ve done tons of research but these are my last three questions as I watch the snow melt and dream of starting this project. I have all the materials stacked in the garage.

Thanks

 

[addy1]

Welcome to our forum!

A few have built swimming ponds on this forum. Most have just fish ponds.

Can the pond remain full and freeze solid without damage to pond liner????

Yes if you have fish in it you would want to keep a small hole open for gas exchange over winter.

 

[Lisak1]

Welcome to the GPF!

You are trying to build a very specific - and LARGE! - pond. I'm assuming you've specifically researched swim ponds as the filtration needs are definitely different than for a pond that will just be home to fish. Do you plan to have fish in this pond? Plants? What kind of filtration are you using?

I think you mean 45 mil EPDM - it's tough stuff. Weight on the liner isn't really a concern as long as it's A. not stretched taut and B. doesn't have anything with sharp edges or points poking into it. Freezing won't bother it. Dogs could potentially rip it with their claws, especially if they panic trying to get out. You want to make sure they have an easy entrance/exit and the liner is well protected.

3 inches of pea gravel (I did LOL at "pee" gravel, especially as this is intended as a pool... haha!) is probably not the best choice for the bottom of the pond. If you're doing a gravel bottom you want it to be just deep enough to cover the liner. any deeper and you will end up with debris getting trapped in the gravel, which can create a toxic environment. Most pond builders who advocate for gravel bottoms use a larger size gravel. But since you want your kids to be able to walk on the bottom, you may want to check out some of the swim ponds that are finished with flagstone bottoms. Here's one example from Aquascape:

 

[j.w]

@Turet
What state do you live in where it would freeze solid all the way to the bottom? How deep will it be?

 

[Turet]

View attachment 127251@Turet
What state do you live in where it would freeze solid all the way to the bottom? How deep will it be?

North Dakota and 4’ at deepest point.

Welcome to the GPF!

You are trying to build a very specific - and LARGE! - pond. I'm assuming you've specifically researched swim ponds as the filtration needs are definitely different than for a pond that will just be home to fish. Do you plan to have fish in this pond? Plants? What kind of filtration are you using?

I think you mean 45 mil EPDM - it's tough stuff. Weight on the liner isn't really a concern as long as it's A. not stretched taut and B. doesn't have anything with sharp edges or points poking into it. Freezing won't bother it. Dogs could potentially rip it with their claws, especially if they panic trying to get out. You want to make sure they have an easy entrance/exit and the liner is well protected.

3 inches of pea gravel (I did LOL at "pee" gravel, especially as this is intended as a pool... haha!) is probably not the best choice for the bottom of the pond. If you're doing a gravel bottom you want it to be just deep enough to cover the liner. any deeper and you will end up with debris getting trapped in the gravel, which can create a toxic environment. Most pond builders who advocate for gravel bottoms use a larger size gravel. But since you want your kids to be able to walk on the bottom, you may want to check out some of the swim ponds that are finished with flagstone bottoms. Here's one example from Aquascape:

Thanks for the great advise. I will do a flagstone bottom. No plants or fish. Your right about 45mil. Ive decided to start the large stones on top of the cinderblock wall with smaller stones under the water to reduce stress on the liner. If I understand right the solid frozen pond wont be an issue??? I am installing the piping to drain and will remove pump and filters in Winter.
Thanks again.

 

[Lisak1]

Nope - freezing won't hurt the liner.

 

[Turet]

Welcome to the GPF!

You are trying to build a very specific - and LARGE! - pond. I'm assuming you've specifically researched swim ponds as the filtration needs are definitely different than for a pond that will just be home to fish. Do you plan to have fish in this pond? Plants? What kind of filtration are you using?

I think you mean 45 mil EPDM - it's tough stuff. Weight on the liner isn't really a concern as long as it's A. not stretched taut and B. doesn't have anything with sharp edges or points poking into it. Freezing won't bother it. Dogs could potentially rip it with their claws, especially if they panic trying to get out. You want to make sure they have an easy entrance/exit and the liner is well protected.

3 inches of pea gravel (I did LOL at "pee" gravel, especially as this is intended as a pool... haha!) is probably not the best choice for the bottom of the pond. If you're doing a gravel bottom you want it to be just deep enough to cover the liner. any deeper and you will end up with debris getting trapped in the gravel, which can create a toxic environment. Most pond builders who advocate for gravel bottoms use a larger size gravel. But since you want your kids to be able to walk on the bottom, you may want to check out some of the swim ponds that are finished with flagstone bottoms. Here's one example from Aquascape:

That video is almost exactly what im doing just smaller. I have a 100’ creek plus 18’x18’ pond and large waterfall with 9000 gpm pump. And am using rain water from house gutters to fill and refresh the pond with an overflow at the far end.