Deadly Flash Floods Hit Nairobi as Long Rains Begin, Exposing Infrastructure Gaps

Rain hammered the tin roofs of Mukuru kwa Njenga late Friday until the sound became a roar. Around midnight, residents on the eastern edge of Nairobi woke to find water seeping under doors and through cracks in concrete floors. Within minutes, the alley outside had turned into a churning brown stream, swallowing sandals, cooking pots and, in some places, the flimsy walls of homes.

By dawn on Saturday, March 7, at least 25 people in the capital were dead and thousands more were homeless after torrential overnight rains triggered some of the worst urban flash flooding Nairobi has seen in years. Nationally, authorities later said up to 49 people were killed across several counties as rivers burst their banks, drainage systems failed and homes collapsed.

Police in Nairobi said many of the dead drowned in their houses or vehicles, while others were electrocuted when rising water reached live power lines and cables. More than 100 vehicles were damaged or overturned, some trapped in flooded underpasses as motorists tried to navigate water that, in places, rose to hip height.

“What we are dealing with is not just heavy rain but a disaster in the way our city is built,” one rescue worker with the Kenya Red Cross Society said, speaking near a submerged footbridge in Mukuru. “The water had nowhere to go except into people’s homes.”

Warnings issued, but city overwhelmed

The Kenya Meteorological Department had warned days earlier that heavy downpours were likely between March 6 and 9 as the country’s March-to-May long rains began. A weather station in Nairobi recorded about 112 millimeters of rain in the 24 hours to Saturday morning—roughly the average for an entire month.

Despite those alerts, large sections of the city appeared unprepared. Storm drains were quickly overwhelmed or blocked by garbage, and the city’s rivers—the Ngong, Nairobi and Mathare—overtopped their banks, inundating densely populated settlements built along their edges.

The worst damage was concentrated in low-lying and informal neighborhoods, including Mukuru, Kibera, Mathare, Huruma, Pipeline, Githurai and Kahawa West. In these areas, many homes consist of single-room structures made of sheet metal and timber, often erected directly on riparian land or alongside open drainage channels.

“We did not sleep,” said a mother of three in Mathare, standing in front of a room where mattresses and schoolbooks lay soaked in muddy water. “Every time it rains like this, we wait to see if the river will come inside. This time it came too fast.”

Deaths and displacement beyond the capital

Outside Nairobi, officials reported deaths and displacement in Kiambu, Kajiado, Machakos and sections of the Rift Valley. By March 8, Public Service Cabinet Secretary Geoffrey Ruku said at least 42 people had died nationwide. A subsequent update from the National Police Service put the toll at 49, with 2,624 families displaced.

The floods also crippled transport and basic services. Major highways into and out of Nairobi—including Mombasa Road, Thika Road and the Southern Bypass—were partially cut off after sections filled with water or were blocked by stalled vehicles. Jomo Kenyatta International Airport experienced disruptions, with some flights diverted to the coastal city of Mombasa.

Power outages were reported across several neighborhoods after substations and overhead lines were affected. In informal settlements, open sewers mixed with floodwaters, raising the risk of disease.

Health risks as standing water spreads

The Ministry of Health warned the long rains could trigger outbreaks of cholera, malaria and other water- and vector-borne illnesses, noting that contaminated standing water and damaged sanitation systems created ideal conditions for pathogens and mosquitoes.

Government response and calls for long-term fixes

President William Ruto ordered a multiagency response, including deployment of the military to assist with evacuations and search and rescue operations. He said the government would cover hospital bills for those injured and distribute food and other relief to affected families, stating that the state “stands in solidarity with every citizen affected” and was working to “safeguard lives and alleviate suffering.”

The Kenya Red Cross dispatched teams across Nairobi, but the scale of flooding made access difficult. Secretary General Ahmed Idris said on social media that crews were working “tirelessly” yet were “severely limited by the traffic and the situation on what used to be roads.”

Nairobi Governor Johnson Sakaja acknowledged that the city’s infrastructure was not built to cope with the intensity of recent storms.

“What we are experiencing is a generational infrastructure deficit,” he told local media, arguing that the problem could not be solved by the county government alone.

Sakaja estimated that overhauling storm-water drainage and rehabilitating river corridors would require tens of billions of shillings, far beyond current budgets. He announced a 30-day waiver on county levies and approvals for property repairs to speed reconstruction. He also defended recent relocations of residents from riverbanks, saying earlier evictions from high-risk areas had prevented even more casualties.

A recurring debate over growth, housing and climate risk

The flooding has revived debate over how Kenya has handled urban growth and flood risk after a series of deadly events in recent years, including national floods in 2023 and 2024 and a catastrophic flash flood in Mai Mahiu in April 2024.

In response to those disasters, the government ordered large-scale evictions from riparian land around Nairobi’s rivers and launched a 50 billion-shilling Nairobi River regeneration initiative, promising to deepen river channels, build sewers and flood defenses, and construct tens of thousands of new housing units.

Human rights groups and some residents have criticized the demolitions, saying families were pushed out with limited compensation—often the equivalent of about $75—and insufficient alternative housing. While some high-risk areas were cleared, new informal structures continue to appear along waterways and drainage lines, driven by a shortage of affordable housing.

Urban planners and climate specialists say the March floods fit a broader pattern in East Africa, where climate change is contributing to more frequent and intense rainfall events, especially when combined with naturally occurring phenomena such as El Niño. Many of Nairobi’s drainage networks and roads were designed for lower historical rainfall levels, leaving them vulnerable when short, intense storms dump large volumes of water in a matter of hours.

“This is no longer a one-off,” said a Nairobi-based environmental engineer who studies urban flooding. “We are getting storms that overwhelm systems in a single night. Without investment in proper drainage, solid waste management and safe housing, these tragedies will repeat.”

Economic toll still being counted

Economically, the losses are still being tallied. Small businesses in flooded estates and industrial zones remained shut for days as owners cleared mud and salvaged stock. Families who lost homes now face the cost of rebuilding with little or no insurance, as many standard policies exclude flood damage. County officials warn that without substantial new funding for infrastructure, emergency relief will continue to consume money that might otherwise go toward long-term resilience.

For now, many of those worst affected are focused on immediate survival. In Mukuru, residents dried clothes on fences and sorted through debris piled where living rooms had been hours earlier. The long rains season has only just started, and the meteorological department says more heavy downpours are likely.

“We are told to move away from the river, but where do we go?” the Mathare mother asked, cradling a child as she watched volunteers reinforce a mud wall with sandbags. “If the rain comes again like this, it will be the same story.”