We figured out how to install the rain barrels – that’s wasn't the hard part.
Finding a place for the water to go once it's collected: that's where the instructions get a bit vague, and now I know why. Here's how the barrels looked this morning:

There's 220L in the first barrel, 190L in the second one and 75L in the backup overflow, which as you can see is full. That's a grand total of 385L, and there must have been overflow from that – the garbage can is brimming. We emptied them last night, so this is all from overnight rainfall.
We could point the overflow hose out on to the lawn, but it's a bit higher than the patio, which means overflow goes back toward the house. (Thanks, Mr. Concrete!)
We may end up digging a dry well, though in a household where 'We need a project!' is a running joke, I'm not sure when I'd get to it.
Here's the forecast:
