Two years after a water crisis that led the Colombian capital to ration water city-wide, Bogotá is once again looking to the sky. The mid-year arrival of a likely high-intensity El Niño phenomenon has led authorities to prepare to avoid, at all costs, cuts like those that extended until 2025. The Bogotá Aqueduct and Sewerage Company, responsible for guaranteeing supply to the capital and 11 neighboring municipalities, offers reassurance: “We are much better prepared than in 2024,” says an official spokesperson, “rationing is not an option.”
Alerts are coming from the Pacific Ocean. Monitoring by the U.S. National Oceanic and Atmospheric Administration (NOAA) shows accelerated warming of waters in the Niño 3.4 region, located in the central equatorial Pacific, where sea surface temperature is measured as one of the main indicators to anticipate the phenomenon’s appearance. This indicator is key because it allows estimating its intensity, explains Juan Guillermo Saldarriaga, a professor in the Civil and Environmental Engineering department at the University of Los Andes.
The World Meteorological Organization estimates a 40% probability of El Niño forming between May and July, while NOAA raises it to 61%, with persistence until the end of the year. Intensity is only determinable when the phenomenon is underway, although there is a 25% chance it will become a very strong one, explains Saldarriaga. In Colombia, the Institute of Hydrology, Meteorology and Environmental Studies (Ideam) speaks of a 90% probability that El Niño will consolidate in September.
Germán Poveda, professor in the Department of Geosciences and Environment at the National University, Medellín Campus, describes an “unprecedented convergence of factors”: the rapid weakening of La Niña, the displacement of warm waters from the western Pacific, and changes in winds that favor heat accumulation in the ocean. Current conditions, he adds, are similar to those that preceded the El Niño events of 1982-1983, 1997-1998, and 2015-2016.”
In this context, Bogotá appears as one of the critical points in Colombia. The Regional Autonomous Corporation (CAR) of Cundinamarca requested the activation of contingency plans, warning that the Bogotá River basin would be one of the most vulnerable in the country. “It would be irresponsible to ignore what is coming,” stated the director of the environmental institution for the city’s surroundings, Alfredo Ballesteros.
Preparation is essential, as the 2024 crisis exposed the system’s fragility. That year, explains Diego Montero, manager of the EAAB’s Master System, hydrological projections were not met: the driest period since the Chingaza reservoir system, the most important for the city, was built in the 1960s, was recorded. The lack of rain was compounded by the high pollution of the Bogotá River, which forced the use of clean water from Chingaza to dilute its liquid and treat it, further reducing reserves; and the Tibitoc plant, which treats the waters of that river, was not operating at full capacity due to being under construction.
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The city depends 70% on Chingaza, a complex of reservoirs that captures water in the Orinoquía basin and is located in the mountainous massif east of the city; 26% comes from the so-called northern aggregate, where Tibitoc is located; the remaining 4% comes from the southern system, where Bogotá’s modern aqueduct originated. In 2024, Montero explains, Chingaza only had 46 million cubic meters of water, enough for just 28 days if used to supply 100% of the 1.6 million cubic meters consumed daily. Today, however, it has 120 million and is at 42.6% of its capacity, above the usual 38.9% for this time of year. In addition, the northern system is around 55% and the southern, 56%. This margin, coupled with operational improvements, provides more response capacity in the face of an eventual rainfall deficit.
Thus, although Montero acknowledges climate uncertainty, he insists that “something absolutely catastrophic would have to happen worldwide” to return to a scenario like that of 2024. Even, he says, if it stopped raining tomorrow “for many months in a row” and consumption increased, the city has the installed capacity to respond. “For us, rationing is not an option,” he emphasizes.
Even so, the EAAB is taking preventive measures. Among them, increasing the use of the Tibitoc plant, which today can cover up to 45% of the city’s demand, to reduce pressure on Chingaza and preserve its reserves. This is a response to the water security strategy organized by the public company, which has seven pillars: scenario modeling, groundwater exploration, treated water reuse, loss reduction, drought protocols, governance, and basin conservation. “We can take many more measures before reaching a crisis.”
Even so, resilience remains a challenge, and the risk does not depend solely on the climate. Around 34% of water is lost due to illegal connections and leaks, a critical waste during droughts, when less water enters the reservoirs than is consumed and reserves begin to fall. Therefore, in addition to technical measures, citizen behavior remains key. Although consumption has remained stable after rationing, experts insist on reinforcing savings campaigns.
Despite the signs, experts call for avoiding alarmism. Poveda warns that calling this event the “worst of the century” is premature. What is clear is that the context has changed. “Even a moderate event, on the hottest planet in history, can produce impacts equivalent to those of extreme events of the past,” he points out.
