Well, looks like my plans are scuppered! I've discovered that my site only allows hand held hoses and my irrigation system does not comply with the rules... how disappointing!
interesting as even when we have a hose pipe ban in the thames valley, irrigation systems are allowed as they use a lot less water than hoses.
i have an irrigation system at home which waters my salad crops and into my greenhouse for the tomatos but this runs from a battery timer from my outside tap. i did try one from my water butt, however it just didnt have the pressure to do the job andor my water but wasnt big enough.
i suppose it would only work from a tap on an allotment if you had sole use of it (although my timer has 2 nozzles, one for the irrigation system and another as a tap (although you have to reset the timer each time you use the tap only facility).
at home my irrigation system is brilliant as im away for days at a time and i always know things will get a drink....my allotment crops are less needy and jsut get a drink when i get the chance, tbh