The Tanaro (; pms, Tane ; ; la, Tanarus), is a long river in northwestern

Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...

. The river begins in the

Ligurian Alps The Ligurian Alps are a mountain range in northwestern Italy. A small part is located in France. They form the south-western extremity of the Alps, separated from the Apennines by the Colle di Cadibona. The Col de Tende and the Vermenagna valley ...

, near the border with

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan area ...

, and is the most significant right-side tributary to the Po in terms of length, size of

drainage basin A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, ...

(partly Alpine, partly Apennine), and discharge.

Geography

Sources

The Tanaro rises at the border between

Piedmont it, Piemontese , population_note = , population_blank1_title = , population_blank1 = , demographics_type1 = , demographics1_footnotes = , demographics1_title1 = , demographics1_info1 = , demographics1_title2 ...

and Liguria at the confluence of two smaller streams: the

Tanarello The Tanarello is a small river (stream) in Italy that gives rise to—alongside the Negrone—the Tanaro river in Liguria. Rising from springs located on the northern slope of Monte Saccarello in the Ligurian Alps in Piedmont, the Tanarello ...

and the

Negrone The Negrone is an long stream principally in Italy that flows through the regions of Piedmont and Liguria. Rising at Cime de Missun in the Ligurian Alps of France, the river, alongside the Tanarello, forms the Tanaro river, itself a tributa ...

. The main source of the Tanarello is on the slopes of

Monte Saccarello , photo = Vetta del Saccarello.JPG , photo_caption = , elevation_m = 2201 , elevation_ref = ''Alpi Marittime e Liguri'', 1:50.000 map n.8, I.G.C. (Turin) , prominence_m = 165 , prominence_ref= , range = Ligurian Alps , listing = , ...

above Monesi, a village belonging to the commune of

Triora Triora ( lij, Triöra) is a ''comune'' (municipality) in the province of Imperia in the Italian region Liguria, located about southwest of Genoa and about northwest of Imperia, on the border with France. As of 31 December 2004, it had a populati ...

. This mountain straddles the French

département In the administrative divisions of France, the department (french: département, ) is one of the three levels of government under the national level (" territorial collectivities"), between the administrative regions and the communes. Ninety ...

of Alpes-Maritimes, the Piedmontese province of Cuneo and the Ligurian

province of Imperia The Province of Imperia ( it, Provincia di Imperia, french: Province d'Imperia, Ligurian: ''Provinsa d’Imperia'') is a mountainous and hilly province, in the Liguria region of Italy, situated between France to the north and the west, and the L ...

and marks the juncture of the watersheds between three

s: Tanaro itself; Roya ( it, Roia), which rises in France but enters the sea at

Ventimiglia Ventimiglia (; lij, label= Intemelio, Ventemiglia , lij, label= Genoese, Vintimiggia; french: Vintimille ; oc, label= Provençal, Ventemilha ) is a resort town in the province of Imperia, Liguria, northern Italy. It is located southwest of ...

; and

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

, which flows into the Ligurian Sea at Taggia. The sources of the Negrone are not far from Punta Marguareis and very close to the French border.

Course

The Tanaro flows through the towns of

Ormea Ormea is a ''comune'' (municipality) in the Province of Cuneo in the Italian region Piedmont, located about south of Turin and about southeast of Cuneo. Ormea borders the following municipalities: Alto, Armo, Briga Alta, Caprauna, Cosio di ...

, Garessio,

Ceva Ceva, the ancient Ceba, is a small Italian town in the province of Cuneo, region of Piedmont, east of Cuneo. It lies on the right bank of the Tanaro on a wedge of land between that river and the Cevetta stream. History In the pre-Roman period t ...

, Alba, Asti, and Alessandria before flowing into Po river near Bassignana in the Province of Alessandria. At its confluence with Po, the Tanaro is about 50 km longer than the upper Po, a case similar to the famous

Missouri Missouri is a state in the Midwestern region of the United States. Ranking 21st in land area, it is bordered by eight states (tied for the most with Tennessee): Iowa to the north, Illinois, Kentucky and Tennessee to the east, Arkansas t ...

tributary being longer than

Mississippi Mississippi () is a state in the Southeastern region of the United States, bordered to the north by Tennessee; to the east by Alabama; to the south by the Gulf of Mexico; to the southwest by Louisiana; and to the northwest by Arkansas. Miss ...

in the United States.

Tributaries

The main tributaries to the Tanaro are the

Stura di Demonte Stura di Demonte ( la, Stura) is a long river in northwestern Italy (Piedmont). Geography The river is a tributary to the river Tanaro, which is a tributary of the river Po. Its source is in the Alps, near the border with France. It flows thr ...

, the

Pesio The Pesio is a long river in northwestern Italy (Piedmont). Geography The river is a tributary to the river Tanaro, which is a tributary of the river Po. Its source is on the Northern slopes of the Marguareis, the highest summit of the L ...

, the Ellero and the Borbore from the left and the Bormida and the Belbo from the right.

Regime

The flow is subject to a great seasonal variation. Although the river has an Alpine origin, which is unique among the Po’s right-side tributaries, the Ligurian Alps are of an insufficient elevation and too close to the sea to allow for the formation of snow fields or glaciers large enough to provide a steady source of water during the summer. Furthermore, the Alpine zone forms only a part of the basin drained by the Tanaro. The seasonal regime of the river is therefore more typical of an Apennine stream, with a maximum discharge that can reach , in spring and autumn and a very low rate of flow in the summer.

Flood events

The river is highly prone to flooding. During the two hundred-year period between 1801 and 2001, sections of the Tanaro basin were affected by floods on 136 occasions, the most devastating ones being in November 1994, November 2016, October 2020, when the whole valley was affected by severe flooding.

History

The left bank of the Tanaro River near Asti is the scene of the

Battle of Pollentia The Battle of Pollentia was fought on 6 April 402 (Easter) between the Romans under Stilicho and the Visigoths under Alaric I, during the first Gothic invasion of Italy (401–403). The Romans were victorious, and forced Alaric to retreat, thou ...

on April 6, 402.

References

* The article draws on material from related articles in the

Italian Italian(s) may refer to: * Anything of, from, or related to the people of Italy over the centuries ** Italians, an ethnic group or simply a citizen of the Italian Republic or Italian Kingdom ** Italian language, a Romance language *** Regional Ita ...

, French and German Wikipedias, as retrieved 14 June 2006 *
SUL MONTE SACCARELLO :: Una camminata alla scoperta delle sorgenti del Tanaro
* * Luino F. (1999): “The flood and landslide event of November 4–6, 1994 in Piedmont Region (North-West Italy): causes and related effects in Tanaro Valley”. XXII General Assembly dell’European Geophysical Society, Vienna (Austria). 21–25 April 1997. Ed. Elsevier Science Ltd, Vol. 24, N. 2, p. 123-129.