Pond excavation

[Jon-uk]

Some advice please - If I am digging out a pond - say 42" deep, and want to put a bottom drain in, then I need a channeller the 4" pipe that will go to the filter area. The channel will be six inches wide to take this four inch pipe and will sit from the middle of the pond to a location about 3 metres from the pond. Should I a) Dig the Channel before I dig out the pond, then backfill this trench to reform eh pond wall, and then excavate the pond, or b) Dig out the pond then tunnel through the wall before staring the trench outside of the pond area. I want to chose the option that will save weakening the pond wall in any way.

Thanks.

 

[HERTS P&D]

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Mine is 2,000 gallons.

Andy

 

[r896neo]

You dont want to build on any kind of backfill. You should dig out the pond and then carefully dig out a narrow channel in the base for your pipe. Install your pipe and bottom drain and then pour your slab. (i'm assuming your going for a concrete slab and then building walls off that) You can leave it just outside your slab with a stop end in it and then dig the area for your filter etc after the pond walls are built. That way you wont be spilling spoil and have your trench collasping etc and you can use some of the dig out for backfilling.

That said digging the whole area out, slab base, pipe work and filter area all at once will be easier if you have good access and just want to blitz it.

 

[Jon-uk]

Thanks for the reply. I am only using concrete for the bottom drain fitting - The pond will be liner. If I was using blocking and walls, it would be much simpler!

 

[r896neo]

In that case you'll obviously be tapering the pond edges back sigificantly so having it fall back in is not relevant. With your method you will have to dig it all out at once anyway. Make sure your bottom drain is in a deep dished area as there may be some settlement of the surround earth and liner relative to the rigid concreted in drain.