Problems
Causes of Water pollution in Valencia Lake, Venezuela
Lake Valencia is the largest natural freshwater lake of Venezuela. It is located in the central-north part of the country, which is the most densely populated. The endorheic lake has natural discharge level at 427 m above sea level; the water level declined below this height about 250 years ago. Its surface level currently is 410 m above sea level. The lake has a number of small islands, with some inhabited. Among the fish in the lake is the diamond tetra, which is commonly kept in aquaria, while two species of catfish, Lithogenes valencia and Pimelodella tapatapae are entirely endemic to the lake basin. As it developed, flowing waters of river Valencia were dammed. Intense human intervention in the catchment area and a decrease in groundwater runoff have caused a rapid decrease in the lake level. Deforestation and water diversion for irrigation led to the desiccation of Lake Valencia by dramatically reducing water levels. The use of the lake as water source for domestic activities and for irrigation is restricted by the high salt content. The lake suffers from algal blooms caused by continual influx of untreated wastewater from the surrounding urban, agricultural, and industrial land uses. This contributes to ongoing eutrophication, contamination, and salinization of the lake. Since Lake Valencia is an endorheic basin, it tends to accumulate pollutants in the water and maintain contaminated sediments at the bottom. Polluted water has caused floods on Lake Valencia. Collectors are siphoning only off some of those waters. The purification process has disadvantages due to the high salinity and electrical conductivity of water. The permanent flooding of Lake Valencia threaten hundreds of families living around who are at risk of losing their homes and even drowning in sewage.
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Timelines
2025
A multitemporal study by Venezuela's Fundacion Instituto de Ingenieria, comparing Landsat imagery from 1995, 2015, 2020, and 2025, confirmed the lake's continuous expansion. The La Punta and Mata Redonda urbanizations remain formally designated "zonas de peligro potencial" (potential danger zones) under Decree 3219.
2024
Lake Valencia's level reached 415.08 meters above sea level on August 9, up 70 centimeters from July 2023 and more than 13 meters since 1978, submerging an estimated 30,000 hectares. The containment dike was reinforced with a further one-meter raise, and engineers estimated more than 40,000 people were living under the risk of a catastrophic wall failure.
2022
The containment wall was reinforced again in 2022-2023 and pumping stations at La Punta were rehabilitated, though residents and engineers said the work only slowed, rather than solved, the lake's advance.
2021
Imagery taken by one of the Copernicus Sentinel-2 satellites shows a massive algal bloom in Lake Valencia in northern Venezuela.
2020
An NGO report by Unidos por la Calidad del Agua found that contamination from the 2007 water transfer had degraded the supply for an estimated 1.5 million people served by the Alejo Zuloaga treatment plant, forcing it to cut production and increase its use of chlorine, aluminum sulfate, and other treatment chemicals.
2017
The La Punta-Mata Redonda containment wall and its earthen berms were raised again, by up to two meters in places, as the lake continued to encroach on surrounding neighborhoods in the south of Maracay.
2012
Flooding and infiltration of contaminated lake water displaced more than 8,500 people into emergency shelters in military units, hotels, and schools; many families remained displaced for as long as seven years, and the barrio El Aguacatal was declared an "open refuge." As the lake kept rising, authorities raised the containment wall's maximum safety level from 408 to 413.36 meters above sea level and reinforced it with sandbags and rock.
2007
Under a decision by President Hugo Chavez, a water transfer scheme began operating, diverting an untreated 6,000 liters per second from Lake Valencia to the Pao-Cachinche reservoir in an effort to slow the lake's rise. Venezuela's Comptroller General later reported (2010) that the transfer had been carried out without prior environmental studies, and it went on to degrade the reservoir's water quality.
2005
Was built the Wall of La Punta as a temporary solution for 3 years, which has been in existence for many years. Leaks in the wall are visible.
2002
Since 1991, lake clean up scheme with finance from IDB has been described along with information on pollution loads, reuse opportunities and wastewater collection and treatment infrastructure.
1990
Since 1960, due to pollution and other human induced changes, almost 60% of the native fish species in the lake were lost.
1976
The water levels in Lake Valencia have risen due to diversion of water from neighboring drainage basins—it currently acts as a reservoir for the surrounding urban centers Maracay and Valencia.
