Weather info

Does this help at all? https://weatherspark.com/y/42579/Average-Weather-in-Aspe-Spain-Year-Round
If your concern is the recent heavy rainfall then this happens a few times a year and it is pot luck where the heaviest rain falls with Madrid and the Balearics being particularly badly affected this time. In April it was the Torrevieja area (among others) where precious little rain falls for the rest of the year.

Cheryl,

I was more wondering if installing an underground waterreservoir is worth while.

Does it rain enough to recover the investment?

Gr

I have no idea what that would cost but what water do you have already, as in mains or an open balsa (reservoir) and what will you need it for? We are on agricultural water and have an above ground, covered water store plus a well underneath the house which fills from rainwater from the roof. Our water store lasts us a month for household use and irrigation to the garden and a small orchard (total plot 3000 m2) The well water only gets used now and again in the garden in the summer months. I have no idea how much water the well holds (or the water store) but it was nearly empty before the last downpour and we had to disconnect the downpipe during the storm to stop it overflowing. I doubt we will need it again until next summer.
In my limited experience, if you've purchased an older country house the existing water facilities are usually adequate unless you are planning to do something totally different from any previous owners. With my house there were 8 people living here and now just two of us and we just added a filtration system to it.

Cheryl,

We are going to build a new house, garden 3000 m2.

My intention is to use an underground waterreservoir, filled by rainwater from the roof, for garden use,  I was just wondering if it rains enough.

By the sound of you it does, so maybe we can add household use to it.

Thx.

I would concur with Cheryl.

I´m in a similar situation. When my house was built, there was no "mains" water, only pumped up from a depósito de agua. Before I bought, Mains irrigation water was installed.(irrigation water, filtered as described by Cheryl). I have just placed to sell my house at the moment. The deposit underneath remains, & is useful for surrounding trees,gardens etc. If you need extra water (which is already not expensive, but good for conservation) its worth considering.

Villas   

This is very informative:

http://aspemeteo.blogspot.com/p/blog-page.html

For anybody looking for weather info in Aspe or nearby towns, here you can find it all, for the entire valenciana area, very detailed:

https://www.avamet.org/mx-mes.php?id=c29m019e01&data=2020-08-01