Our rainwater doesn't get disposed off but is plainly spilled on the floor. I suppose this was okay decades ago when Spain was still very dry, but nowadays we can have heavy rain for months at a time. This starts to cause problems in the house (infiltrations downstairs).

This is an opportunity to collect the water, say for gardening and take care of the vegetation during arid summer periods.

On 12 May (2025), I put a 200L container in the south-east downspout, it overflew in one night so I'm not sure how much was collected, in not too-heavy rain (less than a mm), from this corner only.

The data is taken from AEMET [1] which has a station in nearby Colmenar Viejo. Soto del Real is in a mountainous area (Sierra de Guadarrama foothills), while Colmenar Viejo is slightly lower. This can cause minor differences in rainfall, especially during localized storms or orographic effects (where mountains influence rain). For example, Soto del Real might get slightly more rain if clouds are forced upward by the terrain. Still, in good approximation, very little rain produce fairly large quantity of rainwater.

This requires a more detailed study. 1mm precipitation produces 1L of water from 1m² of collection (roof). If 1mm precipitation causes at least 200L from one corner, not even the most active one, then a very rainy day like that of only few days ago would cause several tons of water to collect, and with surplus to be dispatched away anyway. I will study in more details the water collection as compared to national and homemade precipitation calculations.

Two days later. A new meteo blog was created as a result.