We have a brick/concrete koi pond in the garden about 5′ deep. I’ve finally decided to fill it in and have a lovely raised bed for growing some veg in.

Presumably I need to break up the bottom then fill it with clean hardcore and topsoil?

Anything I should be aware of before doing this?

Take the fish out first.

From (recent) experience, you can normally get subsoil delivered from a local skip merchants for nothing but the cost of delivery. That (and building rubble) did for us for a similar depth pond. However, once you’ve estimated how many tonnes of soil you need (a builders bag is about a tonne) – treble that figure. I shovelled and barrowed about 20 tonne of the piggin stuff last year. Which was great fun.

How about a sunken garden? #lazybastard

I shovelled and barrowed about 20 tonne of the piggin stuff last year. Which was great fun.

ours is tucked away a long way from any delivery point, down a narrow winding path with lots of steps (up and down) on the way…it ain’t gonna be fun!

get subsoil delivered from a local skip merchants for nothing but the cost of delivery. That (and building rubble) did for us for a similar depth pond.

did you go for clear layers of rubble, sub soil then top soil? if so any suggested depths of each?

I filled a similar sized pond in our garden in. Ours just had a plastic liner with carpet underneath. I removed the liner and carpet and then used it as a bit of a landfill site for a few months. We had just moved into the house which needed renovating so I managed to generate a bit of rubble from the house and garden. When it was maybe 30cms or so from the top I levelled it with topsoil and then turfed – looks fine now. Like you no easy access to the pond, so it took loads of trips with a wheel barrow to put in the topsoil.

Ours wasn’t very deep-2ft max. so I half filled with rubble, compacted as best I could then washed in some topsoil to fill the gaps and try to avoid sinkage. Then topped it with topsoil & seeded. 2 years later it’s still flat but the new grass area is still slightly visible. Topsoil around my way (Cambridge) is blimmin’ expensive though. In hindsight I used soil that was way too good to bulk fill, should have got any old stuff to fill and just topped with good stuff for the seed.

We moved into a house that came with a pond that was surrounding by patio on 3 sides; the 4th side lining up with the lawn and the edge of the patio.

We kept it for a while (the previous owner left the fish in it) and then decided to get rid as it was too much faff.

As ours was half sunken & half raised, once it was demolished we had a lot of bricks/rubble to fill the hole with (once we’d got rid of the fish and removed the liner, that was).

Because of the position of it, I wanted to put some slabs over the top of it, just to make the area usable until we could get the patio properly re-done.
I chucked all the rubble in along with a load of small-ish hardcore, as I was concerned that the large-ish bits of rubble would settle over time and make the whole thing sink.
I then just levelled it (ahem, it’s roughly level) and cemented some slabs in place.

This was after getting the lining out & knocking the wall around it down. The obvious deep end just had a couple of brick high edging, whereas the other end was about 0.7m high. The whole thing was 4m long

This was halfway through paving:

[url=https://flic.kr/p/kLKFep]13-11-09 DSCN5311[/url] by STW stumpy01, on Flickr

and this was once finished.

[url=https://flic.kr/p/kLKAmZ]13-11-11 DSCN5320[/url] by STW stumpy01, on Flickr

Once all the other million & one jobs are done around the house/garden (in about 20yrs) I’ll smash it all up & put something proper down….

OP it was bloody hard work!

Our old pond was only a couple of feet deep, but we had very confused frogs sat on the patio that replaced it for a couple of years afterwards in the amphibian breeding season!