The Nairobi Rivers Commission (NRC) has completed the construction of an emergency spillway at Nairobi Dam, allowing water to flow through the structure as Kenya prepares for the anticipated El Niño rains.
In a statement issued on Monday, October 19, NRC Chief Executive Officer Brigadier (Rtd) Joseph Muracia confirmed that the spillway had been opened, calling on residents to remain alert as the rainy season approaches.
“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,” NRC stated.
Construction of the spillway and repairs aimed at mitigating floods commenced on October 13, bringing together the NRC, Nairobi City County Government and other relevant state agencies.
The intervention is intended to increase the dam's capacity to manage rising water volumes during heavy rainfall as part of preparations for its broader restoration under the Nairobi Dam regeneration programme.
The emergency structure provides an outlet for excess water, helping control reservoir levels and minimise the risk of water spilling over the dam during periods of intense rainfall.
It is also expected to protect the dam's embankment against erosion by directing excess water through a controlled channel, reducing the potential for structural damage associated with uncontrolled flows.
The project is further expected to contribute to flood control efforts across the Ngong River basin. However, water levels and river flows downstream may fluctuate depending on rainfall intensity and prevailing environmental conditions.
Residents in areas below Nairobi Dam, including Nyayo Highrise, Dam Estate, parts of Kibera, Nairobi West and Madaraka, have been urged to exercise caution as water continues to flow through the spillway.
Authorities have advised residents in the affected neighbourhoods to avoid river channels and fast-flowing water, observe safety precautions and comply with directives issued by relevant agencies ahead of the rainy season.
While the spillway is expected to help manage excess water and lower flood risks in downstream communities, the NRC has cautioned against assuming that the intervention will completely eliminate the threat of flooding.
Other areas further downstream, including the surroundings of Strathmore University, T-Mall, South C, South B, the Industrial Area and parts of Mukuru, could also experience flooding depending on river conditions and the intensity of rainfall.
The latest measures follow evacuation warnings issued by the NRC and other government agencies during the March long rains, after the Water Resources Authority (WRA) raised concerns over rising water levels that threatened the dam's embankment.
Residents of Kibera, Nyayo Highrise, Dam Estate, Lang’ata, Nairobi West and Madaraka were subsequently given 14 days to move to higher ground ahead of planned operations targeting structures built on riparian land and along river channels.
Kenya is currently in the October-to-December rainy season, with the Kenya Meteorological Service forecasting a more than 90 per cent probability of strong El Niño conditions continuing into early 2027. November is expected to record the heaviest rainfall, with some storms potentially delivering more than 50mm within 24 hours.
The effects of the ongoing rains have already been reported in different parts of the country, with Kisumu experiencing property damage while Nyeri recorded 147.8mm of rainfall over the past week.
