Green roof - does anyone have one? I have a question...

[fallenoverflowerpot]

Simple question: how much water drains off the roof when it rains, and could you/do you collect it in a water butt?
Thank you!

the water draining off is the same as from a normal roof just slower

Is it too silty/sandy? Will it clog up taps etc? And what about storing it longer-term (winter into spring/summer): will it start to smell etc?

basically have been told it's impossible and haven't managed to find anyone/anywhere to say that it'll be fine!

??
I have a green roof on part of my house
it all feeds into the same but system that I have all my house gutters attached to
if the green roof is losing soil then rain wash is the LEAST of your problems

sorry, I'm not being clear here.
green roof about to be installed. It's on quite a steep incline (several inclines).
architects/landscapers say that run-off from a green roof can't be collected in water butts because it is too 'dirty' (will mess up filters/clog things etc.)
I'm dubious about this, but only because I am, if you see what I mean - I don't actually know anything about it. And the steep slopes might make a difference, I guess.
?? what do you think ??

I suspect they are talking hogwash.
have a look at a couple of the green roof sites
if the frame is right and the substrates are set up right and the plants get established quickly, the runoff will be like that from your lawn!!!

mine is flat- but because there is no actual soil - we used clay granules - the water comes through clear

I have a green roof due to moss growing on it!

You can get a special filter for water collection - look at the Rainwater Harvesting Assoc site. Green roofs are pretty mainstream now, most of the roof manufacturers offer them so you could always contact them direct for advice from their technical team.