Nairobi Dam emergency spillway opened amid El Niño preparedness

The Nairobi Rivers Commission (NRC) has officially opened the emergency spillway at the Nairobi Dam.

Water is now actively flowing through the newly constructed structure as national and county authorities ramp up emergency measures for the anticipated heavy El Niño rainfall.The announcement, contained in an official statement released on Monday, October 19, 2026, was confirmed by NRC Chief Executive Officer Brigadier (Rtd) Joseph Muracia.

The development marks a critical milestone in both immediate disaster risk reduction and the broader, long-term regeneration agenda for the Nairobi Dam and its surrounding river basins.

Construction on the emergency spillway and urgent flood mitigation repairs commenced just days earlier, on October 13, 2026. The rapid execution of the project is the result of a concerted, multi-agency collaborative effort involving the NRC, the Nairobi City County Government, and other critical national infrastructure bodies.

According to the commission, the primary objective of the intervention is to significantly enhance the dam's capacity to safely handle drastically increased water volumes during severe weather events.

Furthermore, the infrastructure serves as a vital regulatory mechanism designed to divert excess water, control reservoir levels, and prevent water from dangerously overtopping the dam's crest during torrential downpours.

"The Nairobi Rivers Commission (NRC), in collaboration with relevant government agencies and the Nairobi City County Government, wishes to inform the public that the emergency spillway at Nairobi Dam is now open, and water is flowing through the spillway as part of ongoing preparations for the anticipated El Niño rains and the wider Nairobi Dam regeneration programme," stated Brigadier Muracia

Engineers highlight that establishing a controlled route for excess water is paramount for protecting the dam's structural integrity. By regulating flow, the emergency spillway guards the embankment against severe soil erosion and minimizes the threat of catastrophic structural failure caused by unmanaged, high-pressure water surges.

While the intervention is expected to provide substantial relief to flood management along the entire Ngong River basin, officials have issued stern warnings that downstream water levels and flow dynamics will fluctuate dynamically based on local rainfall intensity and broader environmental variables.

Residents living in vulnerable neighborhoods situated downstream from the Nairobi Dam have been placed on high alert.

The affected areas include Nyayo Highrise, Dam Estate, parts of Kibera, Nairobi West, and Madaraka.

Authorities have strongly urged local communities to exercise maximum caution, stay entirely clear of active river channels and fast-flowing spillway discharge, and closely adhere to safety directives issued by disaster management personnel.

While the spillway is engineered to mitigate severe flood threats, the NRC has cautioned residents against a false sense of security, explicitly emphasizing that the intervention does not eliminate the danger of flooding entirely.

Further downstream, secondary flood risks extend into densely populated commercial and residential sectors, including Strathmore University, T-Mall, South C, South B, the Industrial Area, and parts of Mukuru.

Today's operational milestone follows a tense backdrop of prior eviction and relocation warnings issued earlier in the year.

During the March long rains, the Water Resources Authority (WRA) raised serious alarms regarding dangerously high water levels that were directly threatening the stability of the dam's embankment.

At the time, residents residing within riparian zones in areas such as Kibera, Nyayo Highrise, Dam Estate, Lang’ata, Nairobi West, and Madaraka were given a strict 14-day window to relocate to higher ground ahead of state-backed demolitions targeting illegal structures constructed along natural river channels and riparian land.

The opening of the spillway coincides with a grim meteorological forecast for the country. The Kenya Meteorological Service Authority has projected an over 90% probability of strong El Niño conditions persisting across Kenya well into early 2027, marking the peak of the current October-to-December short rains season.

Forecasters warn that November is likely to experience the most severe weather, with localized storms potentially surpassing 50 millimeters of rainfall within a strict 24-hour window.

The effects of the changing weather patterns are already being felt nationwide; Kisumu has reported extensive property damage due to flash floods, while Nyeri County recently recorded a staggering 147.8 millimeters of rainfall over the span of a single week.