It seems to me having asked this on my estate and that of a Spanish friend that the Spanish have found an ingenious way of filling their pools for nothing.
I can't condone this but this is what I have been told to do:
At night, at the weekend, fit a special pipe in-front of the water meter. Connect it to your water intake behind the meter. Then fill the pool. Of course the meter is bypassed. On Sunday mornings it is quite common to see huge streams of water pouring down the road. I always wondered what this was, it's the leak from bypassing the meter with a illegal connection!