Jean-Luc has fitted the greenhouse and summer house with water butts. He's also fitted an overflow butt.
When we left to visit my parents on Friday the two larger butts weren't completely full and the overflow butt was dry. While we were away there was some torrential rain here as well as a massive thunderstorm today. Now all butts are full and the overflow butt is overflowing into the field ditch next door. We have 520 litres of water to use on the garden and greenhouse. Jean-Luc is thrilled that it all works as a system. Mind you with all the rain we won't need to water anything much for ages - even the greenhouse is nice and humid.