noise disturbance from marijuana growers outside my property

Go to the police-station in person and take a written report (translated into Spanish from Google Translate, if you don't speak/write Spanish) of everything that's happening.

If this is an illegal marijuana farm as you say, then the police must act on the information.

Just calling the police is probably not enough as it can then be ignored, particularly if they don't understand the problem! - They need it in writing (in Spanish).

If you don't feel able to do this yourself, take a translator with you who can also explain for you.

Please let us know how you get on.

What would you do in the UK ?

Contact the police.

Thanks so much for replying.  We have found out since I posted, that the growers are apparently gypsies and they have also broken though into another property behind the derelect building where we suspect the marijuana farm is.  The second building is unoccupied but owned by someone who visits once in a blue moon.  The unoccupied building has a large swimming pool which the gypsies have filled ( we saw the water truck in action) and the loud music 24/7 was a pool party which went on for 3 days.  The music has thankfully stopped now but the noisy generator is still running night and day and nobody is there except for the poor dog.  We’re all waiting anxiously now to see if the pool parties become a regular thing.

I will take your advice and visit the police myself. One of our neighbours is a Guardia who admits that he suspects something but that he can’t act unless he actually sees something happening.  Everyone here seems to know that it’s a drug operation but the Spanish and Moroccans are reluctant to report to the police, even though we all hate the noise and loss of our tranquillity.

Thanks again for your advice