Guadalix

The Guadalix is a river of Spain located in the centre of the Iberian Peninsula, a right-bank tributary of the Jarama.

Guadalix
Location
Country	Spain
Physical characteristics
Source	Puerto de la Morcuera [es]
• location	Miraflores de la Sierra
• coordinates	41°0′55″N 3°51′4″W
Mouth	Jarama
• location	Algete
• coordinates	40°36′58″N 3°34′24″W
Length	42 km (26 mi)
Basin features
Progression	Jarama→ Tagus→ Atlantic Ocean
River system	Tagus

It springs out of the Sierra de Guadarrama, in the valley flanked by the La Najarra Peak [es], el Puerto de la Morcuera [es], the Alto de la Genciana and the Cordal de la Vaqueriza.^[1] Featuring a total length of 42 km,^[2] it runs southeastwards through the Community of Madrid until discharging in the Jarama near the Santo Domingo housing development (Algete),^[3] next to the Jarama Circuit.

Its waters are impounded by the El Vellón Reservoir [es].^[1]

Regarding the etymology of the hidronym Guadalix; the prefix comes from the Arabic wadi ("river") while the suffix -alix has been identified either as an alleged Arab anthroponym or as possibly pre-Arab.^[4]

References

1. Mejías Moreno, Miguel; Pozo Tejado, Jesús del; Albacete Carreño, Lourdes; Villarroya Gil, Fermín (2016). "El agua en la Sierra de Guadarrama" (PDF). Boletín de la Real Sociedad Española de Historia Natural. Sección geológica. (110): 77. ISSN 0583-7510.
2. Nacional, Instituto Geográfico. "Datos geográficos y toponimia. Vertiente atlántica". Centro Nacional de Información Geográfica (in European Spanish). Instituto Geográfico Nacional. Retrieved 2020-01-21.
3. "Anejo nº 16. Estudio de impacto ambiental" (PDF). Ministerio de Transportes, Movilidad y Agenda Urbana. p. 66.
4. Elsayed Mahmoud, Rania (2018). La presencia del arabismo en la antroponimia hispánica contemporánea (PDF). Madrid: Universidad Complutense de Madrid. p. 213.