The problems are a few fold.
One is the whole toddler cliff diving conundrum.
There are also some plants/shrubbery items/ivy type deals that need to be removed as they are currently sliding into the brook and have also grown over the brook and are hanging over the railings into the park. They need to go, which will destabilise the ground further.
Losing those plants, creates a massive gap so I then need to reclaim some privacy.
I'll already be giving up two or three feet with where the fence will go (the tiny violins are deafening). Anymore and it will encroach on shed space, compost, random wildening of the end of the garden etc etc.
Even if I did just put up a fence further in and leave the retaining wall for later, I reckon quite a bit of earth would make its way into the brook before it got resolved. This could then compromise my neighbours fence. So I'd rather do something now that is good enough, but not janky.
This isn't a 3m² garden in Islington you need to eek every bit of space possible out of.
True. But the previous owners took that to the extreme and when they left that's about all there was that was useable. I'm hugely privileged to have this place, any wastage would feel criminal if I could avoid it.