Leitzaran

Leitzaran
Aqueduct over river Leitzaran in Ameraun
Country	Spain
Basin features
Main source	Leitza about 600 m (2,000 ft)
River mouth	River Oria 92 m (302 ft)
Basin size	124.02 km2 (47.88 sq mi)
Physical characteristics
Length	42 km (26 mi)
Discharge	Average rate: 2.88 m3/s (102 cu ft/s)

The Leitzaran (pronounced [leiˈts̻aɾan], or Leizarán in Spanish) is a river and a valley in the Navarre and the Basque Country (Spain). It flows into the river Oria from its right.

Its source is in the Leitza municipality in Navarre, and it is 42 kilometres (26 mi) long. It enters into Gipuzkoa in a place called Urto. It takes water from the municipalities of Areso, Berastegi, Elduain, Villabona, Urnieta and Andoain and has an area of 124.02 square kilometres (47.88 sq mi), of which 69.72 square kilometres (26.92 sq mi) belongs to Gipuzkoa.

The Gipuzkoan part of its basin is known as "Valle de Leizaran" (Leitzaran Valley, while the very name Leitzaran means 'the Leitza valley' in Basque), and it mostly shapes up in the "Macizo de Cinco Villas", formed by materials formed in the Paleozoic (concretely in the Carboniferous), mostly slate and sandstone, fold during the Hercynian orogeny. The Leitzaran is very crooked and shows several meanders.

The gipuscoan Leitzaran is bounded in the east by the river Urumea’s valley, divided by the Adarra-Mandoegi mountain chain. Altzadi in this chain treads into the valley and separates the gipuscoan and the navarre Leitzaran. The dividing line in the west starts in Arizmendi and joins the Uzturre-Ipuliño chain later, in Belabieta. This mountains separates the valley from Zelai and Elduain, as well as the small valleys in the area of Amasa-Villabona.