The woman, who has not been named, was travelling in a car with her 19-year-old boyfriend attempting to reach a caravan site to attend a family celebration on Saturday evening.
But the GPS system led the couple to cross a ford, which for most of the year is a dry river bed but after torrential rain had filled with water.
The young couple still attempted to drive across but their engine cut out and water began gushing into the car. They both attempted to climb out of the vehicle and the man succeeded after clinging onto the overhanging branches of a tree.
The woman, however, was swept away in the torrent and a huge search party consisting of 60 members from various Catalan emergency services, including the fire brigade and regional police force Mossos d'Esquadra.
After two days of searching by emergency services her body was located 11.5 km downstream in debris caught beneath a bridge in Martorell.