Guadiaro river basin. Situated in some of the wettest and warmest parts of Andalusia, the Guadiaro river basin has its source near the town of Ronda (Málaga), located in the middle of mountains; receives runoff from the eastern slopes of the Sierra de Grazalema. A tributary of the Guadiaro, the Guadalevín, opened a deep cut of 300 m to cross the town of Ronda. Downstream it receives the Guadalcobacín and later as main tributaries, the Genal, on its left bank, and Hozgarganta, to the right. Macromia splendens, Oxygastra curtisii and Gomphus graslinii occur in this area, among other southern interesting species.
The Guadiaro is the largest and principal river of the basin and the most man adapted. A permanent watercourse which quality has been greatly improved in recent years and where a lot of dragonflies can be seen. In the surroundings of Cortes and Gaucín, there are several good places to see those protected especies menthioned and many others like Boyeria irene or Gomphus simillimus.
The river Genal runs through dense woodland cultivated for its Cork Oaks (Quercus suber) and Sweet chestnuts (Castanea sativa) and is rightly considered one of the true jewels of Spanish rivers. Wherever the public can gain access, they take advantage by bathing in its clear unpolluted waters. The authorities encourage this use of the river by creating temporary dams to make large pools and slow the flow, which not only benefits people but sometimes also creates more habitat for Macromia splendens.
Hozgarganta is the shortest and wildest of the three principal rivers. Much of its length is contained within the Alcornocales Natural (i.e. Regional) Park. In contrast to the Guadiaro and the Genal, which rise in the Sierra de las Nieves (the mountains of the snows), the Hozgarganta is sourced at a much lower altitude and, as a consequence, its waters are generally warmer and its adult dragonfly fauna flies earlier.