Tributary of the River Elorz, the Sadar comes from the Sierras of Aranguren and Tajonar, flowing westwards through Pamplona’s Eocene loam. It is 19 km. long and drains a basin of some 70 km2. It receives an average precipitation of 700 mm, providing it with an estimated flow of 12 hm3 a year.
The Sadar runs through Pamplona for about 3.7 Km., crossing the Campuses of the Public University of Navarre and the University of Navarre before flowing into the Elorz a few metres further on.
It is a small river with very little flow, deeply set in the terrain and which hardly creates flood problems, save those caused at the point where it meets the Elorz. The average width of the riverbed, including banks, is 6-8 m.
