Coming from the river-filled country of the Netherlands moving to the South of Spain was quite interesting. Most riverbeds over here are dry....and remain dry for a large part of the year. People will park their cars on the riverbeds....and every couple of years the rain is quicker and cars float out to see.
So Andalusia lacks beautiful big rivers but they have many places where they have many pantanos where water is collected.. so it´s not a river but those places are awesome to visit,