I`d love to know how you get on with your soil soakers Bugleone. However; there is no getting away from the fact that with current rainfall patterns, large storage facilities are going to be necessary. I don`t think a few normal (say 200 ltr) butts come close. I`m thinking on the lines of a lagoon possibly with a pond liner holding at least 10 tonne. A solar pump could be used to deliver the water. Of course there will be problems esp safety so it may need to be covered. It may be possible to dig a well to use ground water but I don`t what the legal implications are. Funnily enough I filled in an old well recently so the issues may not be new.
Pete