You will probabley find that no one has turned the water pressure down, when more people use the water supply on a supply network that is probabley to small to start with, and this is normal in Spain, the water pressure will fall and maybe stop all together for consumers towards the end of the pipe.
In the UK, the water companies use lots of pumping stations to supply a near constant pressure, here in Spain the do not and sometimes just rely on gravity. To compound the matter, you have the promoters building these large urbanisations without a care to where the water or power supplies come from or how their customers will cope after.
We live in the campo near Albatera and are supplied from a private source by pipes that are to small and only gravity fed instead of pumped. In the summer and particular in August when the Spanish are on holiday, I have to boost our water pressure by a pump from a large water tank, this works fine out here in the sticks.
I am afraid your water problem may not go away until the weather cools and the Spanish are back to work.
Welcome to life in Spain.