The Reconquista River basin in Argentina, home to approximately four to five million people across 18 municipalities, faces severe environmental challenges from pollution and drought. The river, which flows into the Luján River and ultimately the Río de la Plata estuary, has been polluted since at least the 1970s by untreated sewage, industrial waste, and landfill leachate.
Much of the contamination originates from the industrial district of San Martín, a major manufacturing hub where several factories discharge waste directly into the river. Additionally, inadequate infrastructure in residential areas along the river forces many residents to connect domestic waste pipes directly into the water. This has led to widespread pollution of the water, soil, and air, rendering local aquifers unsafe for drinking water, according to Natalia Gavazzo, an anthropologist and researcher with the National Scientific and Technical Research Council. Gavazzo also directs the Migrantas en Reconquista project, which supports socio-environmental initiatives led primarily by women in the affected communities.
“The women here are more than victims; they are key agents in mitigation and adaptation,” Gavazzo said, highlighting their critical role in community survival amid these challenges. Despite their efforts, pollution remains a pressing issue and is compounded by persistent drought conditions affecting the broader La Plata basin, which includes the Paraguay River.
A recent report by the World Meteorological Organization (WMO) indicated that parts of the La Plata basin have experienced below-normal water levels consistently between 2021 and 2025 due to ongoing multi-year drought. Water levels in the basin have been anomalously low in recent years, with 25 of the driest months since 1991 occurring after 2020, amplifying the environmental stress on rivers like the Reconquista.
The impact of pollution and drought on the local population is significant. Residents of Costa Esperanza, a neighborhood situated along the Reconquista, report foul odors — described as acidic and nauseating — and various health issues including skin irritations, respiratory problems, and gastrointestinal diseases. Community groups hold monthly meetings to address these problems and engage with local officials to advocate for better waste management and water services.
Efforts to rehabilitate the river include the establishment of the Reconquista River Basin Committee by the Buenos Aires province in 2001. However, early 2026 reports indicate limited success, with sections of the river still classified as severely degraded. High levels of E. coli and low oxygen content characterize parts of the waterway, rendering it inhospitable for aquatic life and dangerous for human health.
In response, local academic institutions and environmental organizations are exploring innovative solutions. The School of Habitat and Sustainability at San Martín University is developing artificial wetlands to filter pollutants and restore biodiversity. Meanwhile, community groups such as Foro por la Recuperación del Río Reconquista are campaigning for the creation of an ecological preserve in the area, seeking to reclaim marshlands once rich in wildlife.
Residents like Zulma Monges, who participate actively in neighborhood clean-up squads, emphasize the community’s commitment to preserving and restoring green spaces amid dense urbanization. “It’s beautiful when it’s clean,” she remarked, sharing images of recently revitalized streams.
Experts acknowledge that addressing the basin's pollution requires comprehensive and costly measures. Hydrologist Juan Borús noted that tackling each source of pollution individually demands strict regulation, a challenge compounded by the ongoing evasion of rules by industrial polluters.
The situation in the Reconquista basin underscores the intertwined challenges of environmental degradation and climate change faced by many river systems worldwide, particularly in regions bearing the brunt of global emissions they did not produce.