Can continual blockages  in the rainwater drainage system that flood garages be the subject of a claim, and against whom?

If there were  one-off  problems – for example after torrential rain, due to a lack of  maintenance by the homeowners’ association, or to poor design of the municipal sewer main – it might not be the fault of the construction process. But if blockages in the rainwater drainage system occur repeatedly,  this is sometimes because the building’s drain connection has practically no drop in relation to the accessible sewer main,  so the building’s discharge meets the flow running through the network at the same level.

Bear in mind that – in this case the standard for Madrid,  issued by Canal de Isabel II – stresses that the building drain must have a drop of between 0.4 m and 0.8 m in relation to the sewer network’s inspection chamber.

As it turns out,  developers are usually aware of these defects, especially when the property administrators themselves tend to  report  incidents to them immediately (particularly in the early days of the homeowners’ association,  as the developer still owns many units that have not yet been sold).

Nor can the developer argue that the problems are due to a “lack of maintenance of the gullies or grates”,  because the incidents and blockages, with water entering and garages flooding,  usually  occur after the homeowners’ association has been set up;  and even  if it were a matter of huge volumes of water from severe storms,  the fact is that it  is a defect if water gets in every time it rains.

If you wish to claim for it, get advice.