Hydrography

Río Duero

The Duero is the most significant river in the northwest of the Iberian Peninsula, ranking third in length after the Tagus and the Ebro.

As it traverses the Iberian Peninsula, the catchment area of the river crosses the Spanish regions of Galicia, Castile-León, Cantabria, Extremadura, La Rioja, Castile-La Mancha and Madrid, as well as several towns in Portugal.

The name Duero is derived from the Latin expression Durius flumen, which may be linked to the Celtic word dubro or dur, which refers to a deity or personification of the river. This term was later adopted by the Romans.

The River Duero originates on the southern slopes of the Picos de Urbión, at an altitude of 2,160 m, in the municipality of Duruelo de la Sierra in the province of Soria. The river extends for 897 km to its estuary in the Atlantic Ocean, located in the Portuguese city of Porto.

Due to its extensive length, the river has a wide network of tributaries, receiving water from the Cantabrian Mountains, the Iberian System and the Central System. Of note are the Pisuerga, Esla, Adaja and Tormes rivers.

The course then enters the province of Valladolid via Soria, passing through the town of Peñafiel, where the Duero and Duratón rivers meet.

As it passes through the Castilla y León region, there are extensive vineyards, such as the area between Tudela and the Monastery of Santa María de Retuerta. Furthermore, the river ecosystem's biodiversity has facilitated the growth of a thriving market garden.

The flora includes typical riverside vegetation such as juniper (Juniperus communis), oak (Quercus robur), cork oak (Quercus suber), holm oak (Quercus ilex), Portuguese oak (Quercus faginea), white poplar (Populus alba), willow (Salix), poplar (Populus) and ash (Fraxinus). And scrub vegetation with species such as rockrose (Cistus), common thyme (Thymus vulgaris), broom (Retama) or mountain broom (Cytisus oromediterraneus).

The Duero riverbed is a Site of Community Interest (SCI) and a Special Protection Area for Birds (SPA). In the immediate vicinity there are examples of: little ringed plover (Charadrius dubius), moorhen (Gallinula chloropus), coot (Fulica atra), white-throated dipper (Cinclus cinclus), kingfisher (Alcedo atthis), red-billed chough (Pyrrhocorax pyrrhocorax), red-rumped swallow (Cecropis daurica), western jackdaw (Corvus monedula) or ruddy turnstone (Arenaria interpres). As well as birds of prey, including the griffon vulture (Gyps fulvus), Egyptian vulture (Neophron percnopterus), Bonelli's eagle (Aquila fasciata), peregrine falcon (Falco peregrinus) and red kite (Milvus milvus).

And among the fish we find: barbel (Barbus barbus), carps (Carassius carassius), Cobitis paludica, bermejuela (Achondrostoma arcasii), brown trout (Salmo trutta) and bogue (Boops boops).