 The eastern sector of the buffer zone is made up of the Ucayali River; while the western sector is in the basin of the Pachitea and Pichis rivers.The Ucayali River, originating in the Peruvian Andes, borders the eastern part of the El Sira mountain range, with a south - north route.It is characterized by being meandering with few lentic environments in the area adjacent to the aforementioned Cordillera.