Hi Lisak,
Regarding the edge work, basically this pond is mostly made up of embankments. It's on a slope going downhill towards the stone retaining wall. So rather than dig out a deep hole, I mostly had to dig down and then bank the dirt up in a big embankment mound at the lower part of the hill.
I just kept digging out and mounding up the dirt I had dug out until the main lower embankment was level with the much smaller mound further up the top of the hill. I also piled some rubble into the base of the embankments and the dirt I was digging up was largely clay, which helped turn it into a solid mound. Then I pinned down some hessian over the top of the mound and wet it all with a hose, so the clay would run together and form a solid lump. That was the structural basis for the pond. In image 5 below you can see the angles of the hill, and the angles of the pond embankments.
However, that meant that when I put the liner in I had a big 2 foot+ rounded mound at the bottom edge by the wall, and a small half foot mound at the top. So to cover all that up I just got a huge amount of bush rock and laid it both inside and outside the embankments, inside and outside the pond, leaning on the embankments themselves to add additional weight on the embankment to keep them in shape over time. It took a lot of rock. And I had to carry each piece down 4 storeys of stairs to get it into the backyard. I do not recommend that to anybody.
It looks pretty good though I think. At the front of the lower embankment I left a foot or two for a garden bed, and planted it out with birds nest ferns, bromeliads, and fuscias. Still very much a work in progress. Unfortunately the tree ferns don't seem to be taking but that's the fun of plants I guess. I'm also going to fill in lots of the holes between the rocks on the pond with plants that can root into the embankments and give it some added strength there.
Since last update I've rocked in the last wall of the pond so it's all rocked up now. There's also a few more bog plants, though still a lot more to come in there.
In the images below:
1- Garden, you can see the upper level of the garden where the pond is etc
4 and 5 - You can see the angle of the embankments
7 - This is the intake bay. The pump is under those pebbles, in a 100L plastic tub that's buried in the ground being a pump vault. There's an upside down plastic crate with holes cut into the bottom forming most of the surface area of the bay, then the rocks around it are foamed in to hold them in place. That's the only area that is foamed up, the rest of the rocks are just stacked up.
8 - The bog has a single 2 inch PVC pipe going down the middle of it, with a couple of short offshoots. There's a flush cap on the end buried just under the gravel. It still needs a bag or 2 of gravel though, the water is half an inch over the top of the gravel.
10-12 show the pond from the lower garden.
You can still see the plastic liner at the bottom, but I'm hoping that when I get a few good established aquatic plants going, and matting up on the top a bit, then the bottom liner will be hidden. Otherwise I will just pour a few bags of river sand on the bottom. I'd like to avoid the river sand if possible though as it would make cleaning the huge amount of leaves that will fall off the mammoth gum tree above more difficult.
If you want to see a video there's one at this link. You can see heaps of the baby fish in the video, which I couldn't get shots off unfortunately. There are hundreds of them. I bought 10 little native fish (that grow to like 1 inch size) and in a week they bred and now there are hundreds of babies everywhere.
You can also see the flow out of the bog, and the massive gum tree above.
www.dropbox.com
