Luján River source, mouth, route, tributaries

The Luján river It is located in South America, in the province of Buenos Aires in eastern Argentina. It has an approximate extension of 128 km from its source to its mouth.

It has an average flow of 5.4 m³/ sec, fed by the rainfall it encounters along its route, as well as a basin with a surface area of ​​3,778 km^two that make it the largest basin that bathes the territory of the metropolitan area of ​​the Argentine capital.

The Luján River describes a curve that goes in a southwest-northeast direction, supplying with its waters 16 of the 135 districts / municipalities that make up the province of Buenos Aires. It supplies about a million people, which generate a great environmental impact in the basin.

Article index

• 1 Source and mouth
  • 1.1 Data of interest
  • 1.2 Origin of his name
  • 1.3 Prehistoric finds
  • 1.4 Religious landmarks
• 2 Tour
  • 2.1 Upper basin
  • 2.2 Middle basin
  • 2.3 Lower basin
• 3 tributaries
• 4 Pollution
• 5 References

Source and mouth

El Luján is born from the confluence of two streams: the Durazno and Los Leones, approximately 8 km from the city of Suipacha, in the homonymous district in the northwest of the province of Buenos Aires.

After a journey of 128 km of its main channel, in which it bathes exclusive territories of Argentina, it empties through its delta into the La Plata River. This meeting takes place at the level of the San Isidro Nautical Club, in the San Isidro district located in the north of Buenos Aires.

Data of interest

Like other waterways in the world, the Luján River is not exempt from stories that give it its character and cultural meaning for the inhabitants of the region..

Origin of its name

The Luján River receives its name from a historical event that occurred on its banks. It was the year 1536, in the middle of the process of conquest and colonization of the current Argentine territory, when the Spanish conqueror Pedro Luján died on its shore, as a result of serious injuries suffered after a battle with the fierce natives that occupied the region..

Prehistoric finds

The banks of the Luján River have a rich prehistoric past and due to the chemical composition of the soil and its humidity, it is a perfect area for the preservation of fossil remains..

In 1785, during the movement of earth for the execution of a work on the banks of the Luján, Fray Manuel de Torres made an unexpected discovery: bones of a giant animal unknown until now in perfect condition, which he perceived among the sediments of the Bank.

The fossil was named Megatherium, gigantic herbivore ancestor of today's sloths, which roamed the continent in the Pleistocene period approximately 15 million years ago.

Adults could measure up to 6 meters and weigh several tons. Its large size makes it the largest mammal that inhabited the continent until its extinction, approximately 9 thousand years ago. Remains of this species have been found in Peru, Venezuela, Argentina, Cuba and Chile.

Religious landmarks

In 1630, two images of the Virgin were transported by cart to Santiago del Estero. On its way, when night came, the caravan stopped to rest.

The next day it was impossible for them to advance with the cart that loaded the images and a slave who accompanied them affirmed that the image of the Immaculate Conception wanted to stay in the place. It was not until she was taken off the transport that it was able to advance.

In the middle of the Argentine pampas, just above the room that served as a refuge for the image, the Chapel of the Miracle Our Lady of Luján was built, which can still be visited today located in the neighborhood of Villa Rosa.

Route

In its 128 km, the Luján River crosses the territory of Suipacha, Mercedes, Luján, Pilar, Exaltación de la Cruz, Campana, Escobar, San Fernando, Tigre and San Isidro.

The basin can be divided into four sections with different characteristics, which derive mainly from its slope and the tendency it has to form wetlands..

Upper basin

It goes from his birth to Jáuregui, in the Luján district. It occupies approximately 45 km with a slope of 0.45 m / km classified as a high plain made up of clay sediments dating from the Pleistocene.

Middle basin

It runs from the town of Jáuregui for 30 km to El Pilar in the homonymous district, near the junction with national route No. 8. It has a slope of 0.36 m / km, an intermediate plain with lands that flood to form wetlands.

Lower basin

It goes from National Route 8 to its mouth in the Río de la Plata. It has an approximate slope of 0.04 m / km where wetlands proliferate within a low plain formed by post-Pampa sediments..

Tributaries

The Luján River receives the waters of streams and rivers in the area on its way to the Río de la Plata. Among the most important streams we can mention Escobar, Grande, Garín, del Chimango, Claro, Chico, de las Tunas, Balta, de La Cruz and del Oro.

The waters of the Reconquista river and the Paraná de las Palmas river are also added to its channel, with which it communicates before reaching the La Plata river..

Contamination

The Luján river basin is occupied by more than 1,000,000 inhabitants according to the 2012 registry. This population generates a great impact on the ecosystem (fauna and flora) that develops in its waters, as well as on the quality of the liquid. The use of land for agriculture and its passage through populated areas are the main sources of pollution that affect Luján.

One of the biggest concerns for river conservationists is the high concentration of glyphosate in its waters. This chemical is used to fumigate the plantations, mainly soybeans and wheat, which develop in the basin and filter through the soil, reaching the river through groundwater and its tributaries..

Industrial use brings phenols and heavy metals to the river, among which cadmium, zinc, chromium and copper stand out; as well as solvents for industrial use.

The presence of cities on the route of Luján and its tributaries causes a harmful effect due to neglect and mismanagement of the water resource, in which the water for domestic use is returned to the river without adequate treatment, in addition to the deficient disposal of solid waste. that end up being thrown into the river intentionally or as an effect of dragging by rainwater.

Due to domestic use, ammonia nitrogen and nitrites that come from the decomposition of organic waste and coliform bacteria from untreated sewage are also incorporated..

In March 2019, the Argentine government, in coordination with different national and international non-governmental entities, began exchange sessions seeking solutions for the sanitation of the Luján River.

References

1. Río Luján Basin, Metropolitan Observatory, taken from observatorioamba.org.
2. Floods in the Luján River Basin: Faced with the governments' laziness, the community proposes real solutions, Observatory of the right to the city, August 13, 2015, taken from observatoriociudad.org.
3. Gustavo Buzai, Delimitation of the Luján River Basin, Province of Buenos Aires, Argentina, Technical Report October 19, 2015, GESIG-INIGEO National University of Luján, taken from researchgate.net.
4. The wetlands of the Lujan River Basin under threat due to the absence of regulations for land use planning, WebWetlands International, September 19, 2014, taken from lac.wetlands.org.
5. Sánchez Caro, The quality of the water of the Luján River (Buenos Aires) and the potential contribution of the biofilm for its evaluation, Aquatic Biology Magazine N ° 27. Year 2012: 191-208, taken from sedici.unlp.edu.ar.