The

river A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of ...

Tresa leaves

Lake Lugano Lake Lugano ( or , from ; ) is a glacial lake which is situated on the border between southern Switzerland and northern Italy. The lake, named after the city of Lugano, is situated between Lake Como and Lago Maggiore. It was cited for the first t ...

at a point between

Lavena Ponte Tresa Lavena Ponte Tresa is a ''comune'' (municipality) on Lake Lugano in the Province of Varese in the Italy, Italian region Lombardy, located about northwest of Milan and about north of Varese, on the border with Switzerland. Lavena Ponte Tresa bord ...

in Italy and

Ponte Tresa Ponte Tresa () is a former Municipalities of Switzerland, municipality in the district of Lugano (district), Lugano in the Cantons of Switzerland, canton of Ticino in Switzerland. On 18 April 2021 the municipalities of Croglio, Monteggio, Ponte T ...

in Switzerland and flows into

Lake Maggiore Lake Maggiore (, ; ; ; ; literally 'greater lake') or Verbano (; ) is a large lake located on the south side of the Alps. It is the second largest lake in Italy and the largest in southern Switzerland. The lake and its shoreline are divided be ...

near

Luino Luino (Western Lombard: ''Lüin'') is a small town and ''comune'' near the border with Switzerland on the eastern shore of Lake Maggiore, in the province of Varese, in the Italian region of Lombardy. Luino received the honorary title of city wi ...

, a few hundred metres after joining the

Margorabbia The Margorabbia is the river (Stream#Intermittent and ephemeral streams, intermittent stream) of Valtravaglia, a valley in the province of Varese, Lombardy, Italy. It is a tributary of the Tresa which it joins a few hundred metres upstream of La ...

. At the outflow from Lake Lugano the river is crossed by a bridge which unites the Swiss and Italian parts of Ponte Tresa; a customs post divides them. The river is about long, and for most of its course marks the boundary between the Italian

Province of Varese The province of Varese () is a Provinces of Italy, province in the Lombardy region of Italy. Its capital is the city of Varese (population of 80,857 inhabitants), but its largest city is Busto Arsizio. The headquarters of AgustaWestland, the compa ...

and the Swiss

canton Canton may refer to: Administrative divisions * Canton (administrative division), territorial/administrative division in some countries * Township (Canada), known as ''canton'' in Canadian French Arts and entertainment * Canton (band), an It ...

Ticino Ticino ( ), sometimes Tessin (), officially the Republic and Canton of Ticino or less formally the Canton of Ticino, is one of the Canton of Switzerland, 26 cantons forming the Switzerland, Swiss Confederation. It is composed of eight districts ...

. It passes through the Swiss communes of Ponte Tresa,

Croglio Croglio is a former municipality in the district of Lugano in the canton of Ticino in Switzerland. On 18 April 2021 the municipalities of Croglio, Monteggio, Ponte Tresa and Sessa merged to form Tresa. History Croglio is first mentioned in 133 ...

and

Monteggio Monteggio is a former municipality in the district of Lugano in the canton of Ticino in Switzerland. On 18 April 2021 the municipalities of Croglio, Monteggio, Ponte Tresa and Sessa merged to form Tresa. History Monteggio is first mentioned ...

, and the Italian communes of Lavena Ponte Tresa,

Cremenaga Cremenaga is a ''comune'' (municipality) in the Province of Varese in the Italian region Lombardy, located about northwest of Milan and about north of Varese, on the border with Switzerland. As of 31 December 2004, it had a population of 780 and ...

and Luino. A dam on the river, known as the Creva dam serves two purposes: to use the difference in elevation between the lakes to produce

hydropower Hydropower (from Ancient Greek -, "water"), also known as water power or water energy, is the use of falling or fast-running water to Electricity generation, produce electricity or to power machines. This is achieved by energy transformation, ...

, and as far as possible to regulate the flow of water into Lake Maggiore in order to avoid or limit the dangers of flooding.

External links

Hydrological data of the Tresa
at

{{Authority control Rivers of Italy Rivers of Ticino Rivers of Lombardy Rivers of the Province of Varese Italy–Switzerland border International rivers of Europe Rivers of Switzerland

See also

External links