A ‘blue moon’ opportunity whilst we have the, one and only, chance to ever get a digger into this part of the site, so we invest in, well, a blue water tank. This will connect the rainwater discharge from the rear roof slope and the rear extension roof. It is a 1500 litre tank, about the size of 8 standard water butts – not huge, but as big as we can get into the space without major civil works and it will serve only to water the garden. The tank is a shallow dig unit from RainWater Harvesting. The photo shows the tank part-connected – with just the overflow connected to the underground surface water drain.