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

river A river is a natural flowing watercourse, usually freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the ...

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, 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 ar ...

, 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 Discharge may refer to Expel or let go * Discharge, the act of firing a gun * Discharge, or termination of employment, the end of an employee's duration with an employer * Military discharge, the release of a member of the armed forces from serv ...

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 Liguria (; lij, Ligûria ; french: Ligurie) is a Regions of Italy, region of north-western Italy; its Capital city, capital is Genoa. Its territory is crossed by the Alps and the Apennine Mountains, Apennines Mountain chain, mountain range and is ...

at the confluence of two smaller streams: the Tanarello and the Negrone. 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. This mountain straddles the

French French (french: français(e), link=no) may refer to: * Something of, from, or related to France ** French language, which originated in France, and its various dialects and accents ** French people, a nation and ethnic group identified with Franc ...

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- ...

Alpes-Maritimes Alpes-Maritimes (; oc, Aups Maritims; it, Alpi Marittime, "Maritime Alps") is a Departments of France, department of France located in the country's southeast corner, on the France–Italy border, Italian border and Mediterranean Sea, Mediter ...

, the Piedmontese

province of Cuneo Cuneo ( Italian), or Coni (Piedmontese), is a province in the southwest of the Piedmont region of Italy. To the west it borders on the French region of Provence-Alpes-Côte d'Azur (departments of Alpes-Maritimes, Alpes-de-Haute-Provence and Hautes ...

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

watershed Watershed is a hydrological term, which has been adopted in other fields in a more or less figurative sense. It may refer to: Hydrology * Drainage divide, the line that separates neighbouring drainage basins * Drainage basin, called a "watershe ...

s between three

s: Tanaro itself;

Roya Roya may refer to: * ''Roya'' (alga), a genus of green algae and a subgroup of Zygnemataceae * Roya (river), a river of France and Italy * Roya (genus), a synonym of ''Williamia'', a genus of small sea snails * Roya (given name), a female prope ...

( 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, t ...

, which flows into the

Ligurian Sea The Ligurian Sea ( it, Mar Ligure; french: Mer Ligurienne; lij, Mâ Ligure) is an arm of the Mediterranean Sea. It lies between the Italian Riviera (Liguria) and the island of Corsica. The sea is thought to have been named after the ancient ...

at Taggia. The sources of the Negrone are not far from

Punta Marguareis The Punta Marguareis ( It) or Pointe Marguareis ( Fr) is a mountain in the Ligurian Alps, on the boundary between Italy and France; It is the highest peak of the Ligurian Alps. Geography Administratively the Marguareis is divided between the I ...

and very close to the French border.

Course

The Tanaro flows through the towns of Ormea, 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 ...

Alba ''Alba'' ( , ) is the Scottish Gaelic name for Scotland. It is also, in English language historiography, used to refer to the polity of Picts and Scots united in the ninth century as the Kingdom of Alba, until it developed into the Kingdom ...

Asti Asti ( , , ; pms, Ast ) is a '' comune'' of 74,348 inhabitants (1-1-2021) located in the Piedmont region of northwestern Italy, about east of Turin in the plain of the Tanaro River. It is the capital of the province of Asti and it is deeme ...

, and Alessandria before flowing into

Po river The Po ( , ; la, Padus or ; Ancient Ligurian: or ) is the longest river in Italy. It flows eastward across northern Italy starting from the Cottian Alps. The river's length is either or , if the Maira, a right bank tributary, is included. Th ...

near Bassignana in the

Province of Alessandria The Province of Alessandria ( it, Provincia di Alessandria; pms, Provincia ëd Lissandria; in Piedmontese of Alessandria: ''Provinsa ëd Lissändria'') is an Italian province, with a population of some 425,000, which forms the southeastern part o ...

. 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 U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it is bordered by eight states (tied for the most with Tennessee ...

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. Mis ...

in the United States.

Tributaries

The main tributaries to the Tanaro are the Stura di Demonte, the Pesio, the

Ellero The Ellero 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 ''Pian Marchisio'', a large plateau of the Ligurian Alps. It flows ...

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 A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such a ...

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, tho ...

on April 6, 402.

References

* The article draws on material from related articles in the Italian,

and

German German(s) may refer to: * Germany (of or related to) **Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ger ...

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.