hey, I'm a medi fella too

I'm a little further north and east from your location,, although there are no frosts here, the temps drop below 10C in December, Jan, Feb quite often,,, I followed the advice of some spanish growers and found that they were wrong,, I lost a shaman plant and 7 skunk passions to the cold here,, it may be warmer where you are but just as a warning.
Also, go to your prospective grow site before planting or taking anything incriminating there, I was scouting for sites recently and have been stopped by the Guardia Civil and have seen them in 2 other very remote locations when I have been hunting for sites. That old bit of advice about taking some bird spotting books and a camera is definately a good tip.
The mountains do get snow, I went into the mountains 3 hours from here recently and found there was piles of snow around, they were about 900 altitude.
most spanish growers swear by the lunar calendars.
regards the water,, you can pretty much watch what the spanish farmers do, they know what they are doing,,
their troughs and mounds work well,, also the water table is not all that deep in many places inland, and the water is very good quality mostly, or on a slope its easy to collect it on a "shelf", but shade is crucial here as you know the temps go well above 30C at times.
Deer and rabbits are rife,, a good piss around your crop will help, not too close ofc. but it marks your territory.
I was looking to do my first med outdoor grow here this year but have been scared off by the Guardia Civil, and am very wary now. I will keep looking,, the grow shops are quite helpful and are a good place to get friendly, and there are loads on the costa del sol,, get a soft secrets paper or go online and you will find a local one im sure,, people seem to love the lowryder here as they can plant it in the middle of a field growing asparagus and no-one is the wiser,,, but ofc on your own land that is

I look forward to hearing more mate,as I'm hungry to get some good tips also

oh yeah,,, the soil here is poo