On 10 Feb, 13:28, Mike wrote:

Rather than let it go to waste, pipe it to an IBC* and store the water
for toilet flushing or for garden irrigation

I'm planning a divert a single waterbutt (it's a small garden), but
toilet flush wold require far too much piping and probably two stories
of pumped lift. This is for the workshop, which is detached and behind
the house. At present there's only 1/4 of it that even has guttering!

I have been thinking about a bathroom grey water system for flushing
the downstairs toilet, when that gets refurbed.
http://www.ecoplay-system.com/ or similar