There are said to be about 1,800 rivers in Spain, though many are dry for much of the year. When the river beds do fill with water they quickly turn into raging and destructive torrents. Following the same general direction as the major mountain systems, there are five major rivers, four of which –the Duero, Tagus, Guadalquivir and Guadiana—flow into the
Atlantic and one –the Ebro— into the Mediterranean. At some point, they are all dammed –as are many of their numerous tributaries— and the reservoirs provide much of the water and electrical power for the country.
The Ebro, over 900 kilometres long, rises in the Cantabrian Mountains and empties via a large delta into the Mediterranean at the southern edge of Catalonia. Fed by several tributaries from the Pyrenees to the north and the Sistema Ibérico to the south, the Ebro is Spain’s largest river in volume. On its way it touches Castilla-León and the Basque country before crossing La Rioja, Navarra, Aragón and Catalonia.
Given the volume of the river, plans were approved by the government in 2001 to redirectsome of the Ebro’s water to the parched communities of Valencia, Murcia and Almería in the south. Opposition was fierce because of the ecological damage to the Ebro delta and to the land crossed by the pipeline, and because a lot of the water would be used for more urbanization as well as golf courses and swimming pools. The plan was abandoned by the government in 2004, but the issue is still very much alive.
The largest city on the Ebro is Zaragoza (Saragossa). Towards the end (1938) of the Civil War, the lower Ebro was the scene of one of the fiercest battles between the Franco Nationalists and the Republicans, raging for 4 months.
The Duero starts not far from the Ebro, but takes the opposite direction, crossing Castilla-León then turning south to form the boundary with Portugal. After about 100 kilometers it passes into Portugal (where it is called the Douro), and flows through some narrow gorges before entering the Atlantic at Oporto.
The Duero is not particularly deep river, but much of its northern bank is steep and forms a modest barrier in the flat Meseta.
For a long time, the Duero valley was the frontier between Christians and Muslims and subject to raids from both sides until the end of the 10th century when the Christians took control. Many towns along the Duero are on ridges on the northern side of the river protecting the valley against Muslim raids from the south. The largest Spanish town on the Duero is Zamora, appropriately called la bien cercada (“well encircled”) thanks to the formidable strength of its walls.
The Tagus (Tajo in Spanish, Tejo in Portuguese) is the Iberian Peninsula’s longest river, rising in the wilds of the Serranía de Albarracín only some 90 miles from the Mediterranean. It loops sharply westward through Castilla-La Mancha and Extremadura and then heads in a south western direction through Portugal before emptying into the Atlantic at Lisbon.
There are several large dams on the Tagus creating huge lakes that are a vital source of agricultural irrigation, as well as drinking water for Madrid and Toledo. A significant amount is also siphoned off from dams on the upper Tagus to the Segura river basin to water the south east.
Despite the length of the Tagus, Toledo is the only sizeable town that stands on it, primarily because for much of its course it has very steep banks and runs through arid, difficult land.
The source of the Guadiana is generally given as the Lakes of Ruidera, a series of interconnected lagoons and waterfalls in the hills of Montiel (Castilla La Mancha). However, shortly after leaving its source, the river disappears underground before reemerging about 40 kilometres west at the wetland reserve of the Tablas de Daimiel. Not everyone agrees that the river runs underground. Two tributaries, the Zancara and the Cigüela (both rising in the Sierra de Cuenca) combine just before reaching the Tablas de Daimiel and one of them might reasonably be considered to form the upper reaches of the Guadiana.
From the Tablas de Daimiel the Guadiana moves sluggishly westward through Castilla-La Mancha and Extremadura. At Badajoz it turns south, forms part of the border with Portugal, then moves entirely into Portugal only to return as a border line before entering the Atlantic at the town of Ayamonte.
A major series of dams about half way along the route of the Guadiana have created large man-made lakes, essential for the irrigation of this largely arid landscape. Inaugurated by General Franco in 1952, they were completed in 1960.
The Guadalquivir (Arabic Guad al-Quivir: “the Great River, B(a)etis to the Romans) rises in the Sierra de Cazorla, heads north, loops sharply to the west and then, running parallel to the southern slopes of the Sierra Morena, crosses the middle of Andalusia before entering the Atlantic just north of Cádiz. The Guadalquivir valley is probably the most fertile agricultural area in Spain, producing cereals, cotton, citrus fruits, vineyards and rice. After descending from the mountains and the undulating, olive-tree covered hills of Jaén province, the Guadalquivir opens broadly towards the Atlantic. After passing through Seville, it feeds an expansive wetland wilderness, the Coto Doñana National Park, one of Europe’s greatest wildlife parks and a major migratory stop for birds.
Córdoba and Seville are the two major towns on the Guadalquivir. Seville is situated some 85 kilometres from the Atlantic, but it is a sizeable inland port capable of taking ocean going vessels. Still, there is a perennial battle with silting and larger ships normally dock at Cádiz.
River Ebro at Zaragoza: By Владимир Шеляпин – Own work, CC0, https://commons.wikimedia.org/w/index.php?curid=14631431
Viking River cruises in Europe provide outstanding opportunities for exploring the continent’s scenic waterways