Earth Dam

[renewablejohn]

I reinstated an earth dam this year approx 3 mtrs wide at the base 2mtrs wide at the top and 2 mtrs high and 5 mtrs long. Normally have no problem sealing dams but this one refuses to seal. In desperation I have added a plastic sheet to the front wall held with 2 foot deep sand bags and still the wall is leaking. Any suggestions on how to remedy unfortunately concrete is not an option.

 

[Bury the Trash]

Is there anywhere local you could dig out some clay for the purpose.

 

[RWG Contracts]

did you dig a trench to start your dam in or did you start it on the surface?

 

[Bury the Trash]

did you dig a trench to start your dam in or did you start it on the surface?

neither but i know a contractor who always uses clay - i would think that you would deff need to dig a 'foundation' first.

 

[renewablejohn]

Is there anywhere local you could dig out some clay for the purpose.

I dug the clay out making a pit adjacent to the dam and it has filled up with water. The only thing I can think of is the clay was to dry when I compacted it.

 

[renewablejohn]

did you dig a trench to start your dam in or did you start it on the surface?

Its a reinstatement of an existing dam that was breached last winter. A channel was cut through the existing breached dam then a fibreglass partition panel 4 mtrs long x 1mtr deep placed in channel and backfilled. Dam is not leaking until it reaches 6 inches below the storm overflow pipe unfortunately the normal overflow pipe is set at 4 inches below storm overflow.

 

[renewablejohn]

The white behind the tractor wheels is the fiberglass partition panel with clay rammed up to the top of the white panel. The clay storm pipes rest on top of the white panel. Tractor was used to ram the clay down.

 

[RWG Contracts]

Sorry for Obvious question but it is leaking through dam isn't it and not going round it? Looks quite low on left compared to dam?

 

[renewablejohn]

Sorry for Obvious question but it is leaking through dam isn't it and not going round it? Looks quite low on left compared to dam?

Yes leaking through the middle of the dam. On the left is the existing embankment that includes a similar partition which is higher than the clay pipes. The theory being a river surge will use the clay pipes but if the volume is to high then it can still flow over the embankment.

 

[renewablejohn]

Anyone used lime grout in such circumstances

 

[RushesToo]

Bentonite - or good clay that hasn't dried out before compaction.

Don't try and fix something that isn't right, drain it now when rainfall is low and fix it. Be lazy about this and just get it properly fixed, you want to be able to forget this and it will trouble you until it is right,

 

[Kevtherev]

When we make pools or reservoirs I strip the soil away to get to clay or other soil to get a good seal.
A tracked machine is the key and track layers as you build the banks up.
Probably your best answer would be to line it with clay and track it in.
Other option is to line it.

 

[renewablejohn]

Bentonite - or good clay that hasn't dried out before compaction.

Don't try and fix something that isn't right, drain it now when rainfall is low and fix it. Be lazy about this and just get it properly fixed, you want to be able to forget this and it will trouble you until it is right,

Very helpful it looks like my problem is the width of the dam at the base is not wide enough so will try again while it is still dry.

 

[renewablejohn]

Well disaster struck. Rain the last 2 days has finally pulled the plug. Back to the drawing board for next year.