Collapsing sides

Joined
May 18, 2020
Messages
38
Reaction score
13
Location
MD.
Hardiness Zone
7b
Country
United States
I have a pond about 15 years old. The liner and underlayment have each been replaced once, 6-7 years ago. The pond is hour glass shaped; about 14' x 8'. The walls are collapsing down, dirt sliding in from the bottom, sliding inward under the pond. I have a large liner and underlayment already. They have been in a closed box in a completely dark room. When I unfolded them, there was a white "sort of" powdery stuff on the liner...it did have an odor. Is it some mold, dry-rot, I don't see any cracks where the white substance is.

What will be the best way to reline and shape the pond so that the sides are strong and able to support rocks back about 6-8" from the edges? I want to place the sandstones around the outer edges of the pond but many of them are pretty heavy.

I have already removed all of the rocks around the edges.
 
Joined
Dec 16, 2017
Messages
13,380
Reaction score
10,484
Location
Ct
Showcase(s):
1
Hardiness Zone
6b
Country
United States
The white power is possibly a retardant from the manufacturer I believe you have a commercial roof epdm not a fish guard. Either way wash it good you should be fine. As far as your edges are concerned I would look into bond beams its a concrete skirt around the pond to sit the cap on and or each shelf if need be. You can always get boulders to insure tge sides are held in place just don't forget fabric under the liner and again inside under the boulders and rocks if not the whole pond
 
Joined
Sep 18, 2020
Messages
2,956
Reaction score
3,094
Location
Pacific NW
Hardiness Zone
8b
Country
United States
A few ideas. One of them may work for you:

1. Shallower walls. A collapsing wall is nature telling you that you've dug beyond your soil's "angle of repose." So, without any other reinforcing, you'll need to make your walls less steep.

2. Geo-grid. Dig out the collapsed areas and replace the soil, adding a layer of geo grid fabric every 12-18" or so. Reference.

3. Rock the pond. Boulders against the walls inside the liner.

4. Retaining wall outside the pond, behind the liner. You can use cheap landscape retaining wall blocks or CMU with rebar and solid grouted. This option is only great if your wall is less than about 4' tall and you have free draining soil behind it (sand or sandy loam).

5. Bond beam / collar like @GBBUDD mentioned. This is much harder to do as a retrofit unless you can expand the footprint of the pond so that you can use the earth as your form.
 

Mmathis

TurtleMommy
Joined
Apr 28, 2011
Messages
13,893
Reaction score
8,087
Location
NW Louisiana -- zone 8b
Hardiness Zone
8b
Country
United States
I had to rebuild my pond after about 2 years. Yes, collapsing sides. Lots of clay soil and a high water table. My solution was to incorporate a collar of cinder block around the entire perimeter. I built it so that the top edge was about a foot above ground level so that the water level would always be above ground level. It was a lot of work, but well worth the effort!
 
Joined
May 18, 2020
Messages
38
Reaction score
13
Location
MD.
Hardiness Zone
7b
Country
United States
Hi, The liner seems very hard to shape around the pond's curved sides. Will I need to get a much thinner one to mold it correctly?
 
Last edited:
Joined
Dec 16, 2017
Messages
13,380
Reaction score
10,484
Location
Ct
Showcase(s):
1
Hardiness Zone
6b
Country
United States
The best solution is to remove the failing walls . Make the hold your breath . Say it ain't so . MAKE THE POND A LITTLE BIGGER. . There I said it .
 
Joined
Jul 12, 2009
Messages
3,990
Reaction score
2,682
Location
Mount Pocono, Pennsylvania
Hardiness Zone
6a
Hi, The liner seems very hard to shape around the pond's curved sides. Will I need to get a much thinner one to mold it correctly?
I can't say for sure, but it sounds like you have an EPDM liner, which is what you want.
You don't want anything thinner.

You just have to fold it like you are wrapping a gift. It takes a bit of work, but you'll get it close. It may not be absolutely perfect, but once your pond matures and gets a layer of beneficial biofilm, you shouldn't notice your liner much.
 

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.

Ask a Question

Similar Threads


Members online

Forum statistics

Threads
30,781
Messages
508,577
Members
13,042
Latest member
lucaryan

Latest Threads

Top