There are a number of things in the pipeline here, and after just receiving torrential rain in Catalonia I wished I could have got this done earlier. Basically the head pressure to operate the drip irrigation comes from a small water tower which needs to be raised by another two levels. It works at the moment with a battery-operated water timer which opens and closes a valve once a day feeding water into 7 irrigation lines; each can be turned on and off according to what is growing at the time. The small pond I am building in front of the central bed will be waterproofed and house beneficial wildlife all the year round. It stays continually topped up because the next stage in construction is to waterproof the paths also between the beds, thus collecting quite a lot of run-off after it rains. This is then directed into the pond, and a bilge pump with a float switch will control the level by starting up, triggered by a 12-volt battery to take water into the raised metal tank. Hence, despite its small capacity all excess is fed into the tank, which can expand to two in the near future. Another major part of the process is to prevent evaporation, and this I am doing by allowing natural ground cover on the beds, and also building up the sides of the polytunnel with woven cane, which I must say looks rather gorgeous. See other blogs.