Lake Lugano

Lake Lugano
Lago di Lugano
Location Ticino, Lombardy
Primary inflows Vedeggio, Cassarate, Cuccio, Laveggio, Magliasina, Bolletta, Scairolo
Primary outflows Tresa
Catchment area 565.6 km²
Basin countries Switzerland, Italy
Surface area 48.7 km²
Average depth 134 m
Max. depth 288 m
Water volume 6.5 km³
Residence time 8.2 years
Surface elevation 271 m
Sections/sub-basins North basin, South basin, Ponte Tresa
Settlements Lugano, Melide, Campione d'Italia, Ponte Tresa

Lake Lugano (Italian: Lago di Lugano or Ceresio) is a glacial lake in the south-east of Switzerland, at the border between Switzerland and Italy. The lake, named after the city of Lugano, is situated between Lake Como and Lago Maggiore. It was cited for the first time by Gregory of Tours with the name Ceresio in 590 AD,[1] a name which is said to have derived from the Latin word cerasus, meaning cherry, and refers to the abundance of cherry trees which at one time adorned the shores of the lake.[2] The lake appears in documents in 804 under the name Laco Luanasco.[1]

The lake is 48.7 km2 in size, 63% of which is in Switzerland and 37% in Italy, has an average width of roughly a kilometre, a maximum depth of 288m found in the northern basin and bathing in the lake is allowed at any of the 50 or so bathing establishments located along the Swiss shores.[3] The Italian waters of the lake and the exclave of Campione d'Italia are considered by Italian law as non-territorial for fiscal purposes and as such enjoy a special tax status as a duty free area, exemption from EU VAT[4] and offer residents other advantageous tax privileges.

In 1848, the dam of Melide was built on a moraine between Melide and Bissone. The A2 motorway and the Gotthard railways cross the lake there, linking Lugano to Chiasso. The dam separates the northern (27.5 km²) and southern (21.4 km²) basins. The lake retention time of the northern basin (11.9 years) is considerably higher than the southern one (2.3 years) (8.2 years on average).

Well known mountains and tourist destinations on the shores of the lake are Monte Brè (925m) east, Monte San Salvatore (912m) west of Lugano and Monte Generoso (1,701m) on the south-east shore. The World Heritage Site Monte San Giorgio (1,097m) is situated south of the lake.

Contents

Pollution

Pollution has long been a problem in Lake Lugano. In the 1960s and 1970s it was officially forbidden to bathe in the lake[5]

Despite the continued introduction of sewage treatment plants - e.g. in Gandria, factors such as lake retention time and lake of oxygen and increasing phosphor concentrations means it is unclear if the lake will recover.

The Federal Office for the Environment last published report on Lake Lugano dates from 1995[6]. To summarise that report,

The Swiss/Italian organisation CIPAIS in its most recent published report[7] says:

Considering the results obtained in 2009 it can be affirmed that, notwithstanding
the observed improvement, Lake Lugano is still in a state of high eutrophy, the
highest among Swiss lakes.

The italian environmental group Legambiente in its 2007 study of all Northern Italian Lakes[8][9], found Lake Lugano to be the most polluted of all.

all water samples were even beyond the legal limits. At the polluted sites should not be bathed for
health reasons. The bacteria can cause in the worst case, skin infections, diarrhea and vomiting.

According to Legambiente, the only reason swimming was not banned on the Italian Lakes was because the State of Lombardy changed the law. They state that pollution levels in the lakes do not conform to European rulings and the lack of sewage treatment is illegal.

Their 2010 measurements[10] found samples taken at Ponte Tresa, Ostene and Port Ceresio to be "Heavily Polluted" (more than 1,000 UFC/100ml intestinal enterococci and / or greater than E.coli 2000 UFC/100ml).

Fishery

Fishery in the lake (and Lake Maggiore) is regulated by an agreement between Switzerland and Italy of 1986. The current agreement on navigation dates from 1992. In view of the pollution problems it is unclear whether eating fish from Lake Lugano represents a health hazard.


Places at the lake in Switzerland (CH) and in Italy (I) include (from Lugano, clockwise):

View of Lake Lugano from Monte San Salvatore, with Lugano to the left and the dam of Melide to the right

History

The first certain testimony of a political body governing the shores of the lake is from 818 AD. Occupying an area of strategic importance, the lake was then part of the feudal dominion of the County of Sperio. Around 1000 AD, it came under the control of the Bishop of Como. The region was the site of the war between Como and Milan over control of Alpine traffic from 1218 to 1227. As the lake and its shores became progressively incorporated into the Duchy of Milan they became the subject of political and territorial contention during the 15th century, and Lugano became the lake's main town. The lake definitively ceased to belong to a single sovereign political entity following the establishment of the transalpine bailiwicks of the Swiss cantons at the beginning of the 16th century. The Italian-Swiss border was fixed in 1752 by the Treaty of Varese, and has since remained virtually unchanged.[1]

Fauna

The lake is full of fish. Apart from a few protected areas, such as the mouth of the River Cuccio in Porlezza, fishing is allowed anywhere, although according to various regulations. Protected species are the bleak and the white clawed crayfish (Austropotamobius pallipes). The bleak is almost extinct here, unlike in Lago Maggiore, and planning is under way for the controlled repopulation of the lake, particularly around Ponte Tresa.

In 1895 the brook trout was introduced from Lake Zug, while between 1894 and 1897 the common whitefish was introduced. Since 1950 attempts have been made to introduce the whitefish Coregonus macrophthalmus from Lake Neuchâtel, but it has not established itself effectively.

The Common Roach is present in large numbers and took around ten years to colonise the entire lake, thereby replacing the bleak. Still present are the European chub, tench, carp and a few examples of European perch, largemouth bass, zander and burbot. Recently the wels catfish has also been spotted.

Fossils

The whole area behind the southern shores of Lake Lugano is rich in fossils. The focal point of these fossil deposits is Monte San Giorgio, where since the 19th century many fossils have been found dating from the mid Triassic (around 220 million years ago). The deposits on Monte San Giorgio stretch towards the west into Italian territory and the deposits of Besano. Fossils dating from the early Jurassic (around 180 million years ago) have also been found along the southern shores but more towards the east and Osteno.

References

  1. ^ a b c "Historic Dictionary of Switzerland - Lake Lugano". http://www.hls-dhs-dss.ch/textes/i/I8661.php. Retrieved 2008-11-23.  (in Italian)
  2. ^ "Il Gommone: Itinerari - Il Lago dei Ciliegi". http://www.ilgommone.net/scripts/risposta.asp?Mese=Ottobre+2005. Retrieved 2008-11-22.  (in Italian)
  3. ^ "Società Navigazione Lago di Lugano - Stato di Salute del Ceresio". http://www.lakelugano.ch/it/41/stato_di_salute_del_ceresio_.aspx. Retrieved 2008-11-22.  (in Italian)
  4. ^ "Italia Internazionale - Concept of Territoriality". http://www.itint.gov.it/ice/cda/templates/doganali1_restyle.jsp. Retrieved 2008-11-22.  (in Italian)
  5. ^ SNL "Better quality of life on the lake - the swimming ban in the 70s", Societa Navigazione del Lago di Lugano - Website, 2011, accessed March 31, 2011.
  6. ^ Federal Office for the Environment "The condition of the lakes in Switzerland", Swiss Federal Office for the Environment - Website, 2009, accessed March 31, 2011.
  7. ^ CIPAIS [http://www.cipais.org/pdf/Limno_Lugano_-_Rapporto_2009.pdf "Ricerche sull'evoluzione del Lago di Lugano"] Institute of Earth Sciences of the University of Applied Sciences of Southern Switzerland IST-SUPSI Report 2009, CIPAIS - Website - Summary in English, 2009, accessed March 31, 2011.
  8. ^ Belfast Telegraph "Italy's lakes have sick water", Belfast Telegraph - Website, July 27, 2007, accessed March 31, 2011.
  9. ^ North Italy lakes are heavily polluted "State of Lake Lugano", Die Welt Website (translated), August 3, 2007, accessed March 31, 2011.
  10. ^ Legambiente"monitoring data on the lakes Maggiore, Lugano, Varese" Legambiente,2010, accessed March 31, 2011.

External links