How high can i rock pond wall

[Lisak1]

@Lisak1 You beat me to it, LOL!

And I meant to add the part about the walls not being perfectly vertical - slope them back a bit. Give yourself a little help with the stability!

 

[GBBUDD]

IN THE BEGINNING OF THIS VIDEO I USED WATERFALL FOAM IN JUST OVER 30" DEEP TO STACK THE ROCKS WHERE THE FISH SWIM BY before you enter the main area of the pond

 

[DerekOR]

What if I tried something like this where there is more than one rock on the very bottom and foamed the whole thing in. Is that workable, or would it still be very unsafe?

Each of those blue blocks is supposed to be a rock .

I have watched probably over 200 hours of pond construction videos from Greg Whitstock, Pond Digger, Tussey, Jaak Harju, etc. I guess a lot of it didn't really sink in and get into my shoveling hands when we were going to town though....

 

[Jhn]

As was mentioned, you need to get those larger rocks at the bottom and stack them progressively smaller as you go up. 200lb. Rocks aren’t that heavy get some buddies over there that could help lower them down. Your picture in post #18 if you are using the rock that you already have it is a little small to stack and have it stay, most likely will tumble down at some point.

I work with that type of rock every day not the best choice for a swim pond as the edges are rough and can scrape yourself up if they shift around will climbing or swimming around them or even if you slip on one.

GBBUDD’s rocks are boulders that weigh up to 5000lbs. While not using rocks that big in a pond as small as yours, if you are going to go up 4’ feet I would try to use something bigger. If you are doing a bog you could use that granite rock in the bottom of the bog, I used that as the initial layer over the aquablox in the bottom of my bog, as it is cheap for me to get.

Also, don’t count on the rocks and gravel holding down the liner if it gets water pressure under it, it can still push it up. I’ve seen hydraulic pressure from water push stone revetments made of 1000-3000lb rocks 3 and 4 feet thick.

I would just dig an upper shelf about a foot to a foot and a half wide and deep and use that rock dry stacked to hide the edge of the pond liner and blend it into the yard, since you already have the rock.

Just tossing out ideas to use what you have for what you plan to do.

 

[Mmathis]

@Mmathis
can you draw a quick sketch with the shelves aquascape way each shelf a foot to a foot and a half high ? with the top shelf only 4 inches deep ?

I don’t follow what you are asking.

 

[IPA]

I don’t follow what you are asking.

@GBBUDD This?

Hello my first pond build

Hi die to lockdown i thought to get into the garden and start building a pond Now two weeks down the line i have it filled up with water basically cycling for fish the pump does around 3800 litre and hour to the top of the water fall i reused plastic tub thats food safe in their will house the...

www.gardenpondforum.com

 

[Phaewryn]

What if I tried something like this where there is more than one rock on the very bottom and foamed the whole thing in. Is that workable, or would it still be very unsafe?
Each of those blue blocks is supposed to be a rock .

Just remember that foam is not structural, it fails eventually. Your stones need to stay where you put them without any gloop holding them in place, because gloop fails eventually (by gloop, I mean mortar, glue, foam sealant, silicone, anything that one would use to glob between stones to make them stay in place when they are not stable on their own accord).

Never having done this in a pond, but having built several dry stack stone retaining walls, if I got stuck with the stone you have, I'd tilt the wall (dig out more, but at an angle, or backfill and pack to get a leaning wall) and then stagger the stones so each layer locks the layer below it in, sort of like shown below. I have tried to consider that you have more small round/square stones than good deep ones, you will still have to buy more longer stones to make this work and the angle may have to be tilted more. You should be able to stand on your stack and climb up it and it should stay. If it doesn't, it needs to be redone until it does. Also, like Mmathis said, if your soil is prone to splooging down over time, you may need more tilt and or more earthen shelves (a break in the line so you're stacking on earth instead of layer upon layer of stone). I live in a place where I can't use a shovel, I have to get out the pickax to dig a hole, nothing moves.

That being said, I would just never do this. I'd consider it a waste of good stone. The stone will be mostly indistinguishable from a plain liner once the layer of algae grows on it and you can't scrub the algae off rocks once it's on them.

If I wanted the underwater stone look (if I liked the look of furry green rocks under the water), I might do just the first 1.5-2 feet, like this. I would be using flatter stones: we have a lot of slate around here and it's easy to work with, other than having to knapp the sharp edges off. This would also save you a ton of money on stone and not be a lot of additional work if you have 3-5 more feet you can extend outward from your current hole.

The stone you have looks pretty irregular and hard to work with. Again, speaking as a stone retaining wall builder, not a pond builder, you ideally need lots of 1.5-2' long flat stones to interlock the smaller stones in the layers to really make a good solid structural wall, and it doesn't look like you have many of those. You can do it with more round/square/irregular stone, but it has to be a thicker wall (more horizontal depth of stone at the bottom, so you can stack it up into a triangle shape on itself) and you'd still need a few good longer flatter capstones to lock it all in at the top.

Someone who has built earthen stone rimmed ponds would probably be better able to draw the correct angle. I'm not sure how much the difference between the weight of stone in air versus in water comes into play in this case. My stone walls stay very solid on dry ground, but I can pick up a stone in the water three times the size of the biggest stone I can pick up on dry land and that has to come into play. The downward forces of each layer pin the ones below it into place, so I'm sure the math changes dramatically under water.

Many times when you see a stone wall with mortar, it's not actually structural, just a veneer, like shown below, which will fail, sometimes very quickly, sometimes it may take a while. There is such a thing as dye you can add to mortar to make it any color you like to match your stone. It's designed for indoor grout and may or may not be toxic to fish though.

 

[poconojoe]

Anything you line the pond with will eventually get covered with a nice (and necessary) biofilm. It won't matter what color your stone or mortar presently are, it will all be covered.

Leave the rocks out and give the fish more room to swim.

I don't think using mortar is a very good idea. But, I'm not one for rocks in my pond either. Matter of opinion, I guess.

No pointy rocks are allowed anywhere near my pond, inside or out. Leaks are a real pain to locate, believe me. You don't want to be searching for a leak in the dead of Winter...been there....done that.

 

[BKHpondcritters]

I'm in no way an expert on stacking rocks, building stone walls, or the best way to contour a sloping interior pond edge, BUT! I will say that, as someone who's entire pond is lined in stone & gravel, I can *absolutely* see the colors & contours of my rock/gravel through the entire pond (down to the 3' + deepest area) Does the gravel darken & take on a bit of a green-ish hue over time? Yes. Does it all become one, solid, indistinguishable color? NO! I can absolutely see the variety of gravel on my pond bottom, as well as the variety of colors in stacked stone on the ledges & edges under water. It does not all look 'just like bare liner'. I have a couple of areas that the fish habitually rearrange the gravel, thus exposing an area of liner or fold (which I fix by redistributing the gravel to recover the exposed parts)

I realize that the whole 'gravel or no gravel on the bottom' is largely a matter of aesthetic opinion, but - bare liner vs rocked pond bottom does NOT look the same. It just doesn't.

 

[Phaewryn]

can you draw a quick sketch with the shelves aquascape way each shelf a foot to a foot and a half high ? with the top shelf only 4 inches deep ?

An Aquascape stepped terrace using smaller, rounder stones laid up against slanted edges:

 

[DerekOR]

Thanks everyone for the very helpful replies. I have much to think on…

Maybe I should have started with a very basic and perhaps dumb question. I was so set on getting help out of the current dilemma (half the bottom of the pond rocked in and feeling frustrated because it didn’t feel like it was working) and I didn’t step back to ask it.

Would it work OK if I skipped the rock altogether to have the 40” – 48” sides with no rock – just liner. Or would that much of a vertical wall in clay soil be a very bad idea? As several folks have mentioned, I can go back in and backfill if that’s what is needed to get the sides more angled. But obviously if I can just rock around the top and move forward that would be preferable . My only thinking of adding the rock was it looked nice and it would help the clay from collapsing.

If I can just remove the rock out, keep the ~48" vertical clay walls behind the liner, and keep going then great! I'm OK with settling, I just don't want rocks up around the top/surface to cave in down the road... I was thinking adding in this rock wall would help prevent that sort of thing, but it seems like the overall concept is just a terrible idea with where things are at for me now.

Sorry if I’m a bit slow to all of this. I’m very emotionally involved with this whole project, and sometimes I may need to hear what I’m doing isn’t going to work a couple of times before it sinks in! I'm going to go back and re-read everyone's responses here again just to really let it sink in.

When I first started with the pond, I did have a bunch more shelves, but I removed them all thinking it would be more room for the fish... Sounds like that was a very bad idea and I really screwed up! Here's what it looked like earlier during excavation in the first picture. Then in the second picture you can see where it's at today before the carpet, underlayment, liner, and more underlayment. The second picture also shows where the bog is going to be on the top right.

 

[GBBUDD]

It's ok i think the videos show it and i think derek gets the idea

An Aquascape stepped terrace using smaller, rounder stones laid up against slanted edges:
View attachment 132456

This is what i was talking about minus one step as i would build a foot and a half per step rock up above the botom of each step to hold back river rock . nice job

 

[Phaewryn]

Maybe I should have started with a very basic and perhaps dumb question. I was so set on getting help out of the current dilemma (half the bottom of the pond rocked in and feeling frustrated because it didn’t feel like it was working) and I didn’t step back to ask it.
Would it work OK if I skipped the rock altogether to have the 40” – 48” sides with no rock – just liner. Or would that much of a vertical wall in clay soil be a very bad idea?

When I first started with the pond, I did have a bunch more shelves, but I removed them all thinking it would be more room for the fish... Sounds like that was a very bad idea and I really screwed up! Here's what it looked like earlier during excavation in the first picture.

I think I have to agree with you, sadly. The first hole looked much better with the shelves, much more stable. I'm not sure if the vertical wall will hold or not, I would err on the side of caution and say probably not. I would fill it back in to something similar to what you had before, that was a better design. You might could do one tier instead of two though, so long as it's walls are sloped (instead of upright like you had them).

 

[GBBUDD]

Maybe I should have started with a very basic and perhaps dumb question. I was so set on getting help out of the current dilemma (half the bottom of the pond rocked in and feeling frustrated because it didn’t feel like it was working) and I didn’t step back to ask it.

don't feel bad the ladies use to yell at us all the time not asking for directions . thank god for Garmin and now google maps .

The build looks good to me we just have to figure out how to rock the steep side. You can use Fabric like i showed in the video to move what we call two and three men boulders. a couple of those on the bottom would do the job or you can

the yellow is where i would rebuild and extend the shelf thats off to the right bring that shelf acros to the left filling in the yellow area lessening the height . on theupper left side of photo 1 i would cut off the top of the concrete down about 6 inches if you have 10 inch rocks if you only have 6" rocks then make that top shelf a bout 3" so part of the rock is underwater and the other half is above " this looks natural. The other thing you can do where the height is 48" is to work that wall with flat rocks turned on edge that is how i built the walls in the begining of the video i shared above . and with foam between the rocks like you had mentioned .

i CAN SEE YOUR INENT WITH THE WATERFALL AREA instead or pulling appart your work you can always make damns so that when you place the rubber over your dig the steep areas that won't stay you lay the rubber over the damn / coral and have that hold the rocks from slipping . if you catch my drift. Fortunately for me i build better then i am at putting thoughts to words

 

[DerekOR]

Finally found it - this is the video I was trying to go for. Has ~4-5ft tall shelves with mortared rock. About the same size rock as what I have - just need to remove some of the smaller stuff I think.

Anyone heard of a pinterest fail? That's kinda what my stuff looks like right now compared to Eric's 25+ years of experience!