Environmental disasters often go unnoticed until they attract international headlines, but the Endhó Dam represents a stark exception. Located in Mexico’s Hidalgo state, the reservoir has operated as a dumping ground for decades, earning the grim nickname “Mexico’s toilet bowl.” Despite its scale, the site remained shockingly unknown to many until 2023, when the Society of Environmental Journalists recognized a feature story about the region as a finalist.
The Transformation Into a Toxic Basin
Constructed in the 1950s, the Endhó Dam initially served as a freshwater reservoir for the arid Mezquital Valley. That purpose changed in the 1970s as Mexico City’s population surged. Federal officials began diverting the capital’s storm runoff and wastewater into the structure. Over the past 50 years, all wastewater from a metropolitan area of roughly 20 million people has flowed into the dam.
Each year, the reservoir receives approximately 326 million cubic meters of largely untreated wastewater—enough to fill more than 130,000 Olympic-sized swimming pools. While about 60 percent of this water passes through a treatment plant, it mixes with discharge from a nearby oil refinery and thermopower plant before reaching the reservoir. The result is an environmental and public health nightmare described by locals as the world’s largest cesspool.
Yury Uribe, a resident and activist with El Movimiento Social por la Tierra, has spent years organizing her community to demand that the Mexican government recognize the dam as an environmental emergency. Despite the area being declared an ecological restoration zone in 2024, the declaration included no funding for cleanup. Consequently, residents continue to face severe health consequences.
Cancer rates in the region have tripled between 2007 and 2018. Communities surrounding the dam report cancer and kidney failure rates that are sometimes double the national average. The dam contaminates local wells, which serve as the primary drinking water source for towns nearby. Additionally, the hyacinth growing on the surface has become a breeding ground for mosquitoes, forcing residents to stay indoors during evenings.
Even experienced reporters have struggled to process the severity of the situation. Emiliano Rodríguez Mega, a science reporter covering Latin America, admitted that he had never seen something like the Endhó Dam. The broader pattern suggests that marginalized communities are frequently viewed as expendable.
A System of Exploitation
Dr. Robert Bullard and Beverly Wright, renowned environmental justice advocates, explain that communities viewed as expendable suffer from having “the wrong complexion for protection.” The low-income farming communities around the dam, a significant portion of whom are Indigenous people from the Otomí Nation, are being sacrificed to protect Mexico City from flooding and to sustain the agricultural area surrounding the Tula River.
He noted that these areas illustrate egregious human rights violations, particularly against poor, vulnerable, and marginalized communities.
Recognizing this systemic issue is the first step toward addressing it. The Climate Justice Alliance, a coalition of over 100 frontline communities, argues that society cannot build a more just and healthy economy if communities continue to be seen as expendable. However, eliminating these zones is a complex process that requires prioritizing the protection of current residents and allocating resources for cleanup and regulation.
Media Spotlight and Awards
The piece accompanied a feature called “Los Olvidados de Hidalgo,” which secured third-place recognition at the Society of Environmental Journalists’ 22nd Annual Awards for Reporting on the Environment.
Judges highlighted the story’s “shockingly unknown” status, noting that over 20,000 residents have been compelled to live beside the contaminated water for roughly fifty years.
Community Response and Ongoing Struggles
Local organizers have intensified efforts to draw governmental attention, emphasizing that the ecological restoration designation in 2024 failed to provide any cleanup financing.