Editing Castile and León (section)

===Hydrography===

====Rivers====
{{Main|Category:Rivers of Castile and León}}

;Douro basin
[[File:Zamora (9223963842).jpg|thumb|The Douro passing through [[Zamora, Spain|Zamora]].]]
The main hydrographic network of Castile and León is constituted by the [[Douro|Douro river]] and its tributaries. From its source in the [[Picos de Urbión]], in Soria, to its mouth in the Portuguese city of [[Porto]], the Douro covers 897&nbsp;km. From the north descend the [[Pisuerga]], the [[Valderaduey]] and the [[Esla (river)|Esla]] rivers, its tributaries more plentiful and by the east, with less water in its flows, highlight the [[Adaja]] and the [[Duratón (river)|Duratón]]. After passing the town of [[Zamora, Spain|Zamora]], the Douro is confined between the canyons of the [[Arribes del Duero Natural Park]], bordering with [[Portugal]]. On the left bank are important tributaries such as [[Tormes]], [[Huebra]], [[Águeda (river)|Águeda]], [[Côa River|Côa]] and Paiva, all from [[Sistema Central]]. On the right they reach the [[Sabor (river)|Sabor]], the Tua and the [[Tâmega (river)|Tâmega]], born in the [[Galician Massif]]. After the Arribes area, the Douro turns west into Portugal until it empties into the [[Atlantic Ocean]].

; Other watersheds
Several rivers of the community pour their waters into the [[Ebro basin]], in Palencia, Burgos and Soria ([[Jalón (river)|Jalón river]]), that of [[Miño-Sil river confederation|Miño-Sil]] in León and Zamora, that of the [[Tagus basin|Tagus]] in Ávila and Salamanca (rivers [[Tiétar (river)|Tiétar]] and [[Alberche]] and [[Alagón (river)|Alagón]] respectively) and [[Cantabrian river confederation|Cantabrian basin]] in the provinces through which the Cantabrian Mountains extends.

====Lakes and reservoirs====
[[File:007333 - Provincia de Zamora (8707601613) edited.jpg|thumb|Of glacial origin, the [[Sanabria Lake]] is the largest natural freshwater lake in Spain.<ref>{{Cite journal|journal=Limnetica|volume=8|issue=1|url=https://www.limnetica.net/documentos/limnetica/limnetica-8-1-p-49.pdf|year=1992|title=The Sanabria Lake. The Largest Natural Freshwater Lake in Spain|page=49|first1=J. C.|last1=Vega|first2=C. de|last2=Hoyos|doi=10.23818/limn.08.05|first3=J.J.|last3=Aldasoro}}</ref>]]
In addition to the rivers, the Douro basin also hosts a large number of lakes and lagoons such as the [[Negra de Urbión Lake]], in the [[Picos de Urbión]], the [[Grande de Gredos Lake]], in Gredos, the [[Sanabria Lake]], in Zamora or the [[La Nava de Fuentes Lake]] in Palencia. Also emphasize a great amount of reservoirs, fed by the water coming from the rains and the thaw of the snowy summits. Thus, Castile and León, despite not having abundant rainfall, is one of the communities in Spain with the highest level of water dammed.

Many of these natural lakes are being used as an economic resource, boosting rural tourism and helping to conserve ecosystems. The Sanabria Lake was a pioneer in this.