Nearly three decades later, is Kenya ready for another El Nino?

360 Degrees Estate in Katani submerged after heavy rains caused flash floods. [Kanyiri Wahito, Standard]

Nearly three decades after El Niño rains exposed Kenya’s lack of a coordinated disaster-response system, the country is once again preparing for a season of potentially heavy rainfall. This time, however, the question is no longer simply whether the country has the institutions to respond, but whether those systems have kept pace with the risks created by population growth, rapid urbanisation, expanding built-up areas and a changing climate.

Kenya’s meteorological authorities have forecast enhanced rainfall during the October-December 2026 short-rains season, with above-average rainfall expected across much of the country, including Nairobi. The season is expected to bring periods of heavy rainfall interspersed with dry spells, while regional climate outlooks point to wetter-than-normal conditions across much of the Greater Horn of Africa as El Niño strengthens.

The Kenya Meteorological Department has advised communities, farmers, county governments and other stakeholders to prepare for the anticipated rains, while the Intergovernmental Authority on Development’s Climate Prediction and Applications Centre has warned that excessive rainfall could increase the risk of flooding, infrastructure damage and water- and vector-borne diseases.

The forecasts do not mean every part of the country will receive the same amount of rain, or that the impact will necessarily be greater than during the 1997-98 El Niño, but they point to a season in which communities, infrastructure and public services could come under significant pressure.

But probably, the country may not need a stronger El Niño than the one experienced in 1997- 98, which is one of the analogue years compared to the 2026 El Niño, to suffer a bigger disaster.

The country has greatly changed since; from population growth and urban areas that have expanded into flood zones. Today, far more homes, businesses, roads and public infrastructure now depend on drainage systems and transport networks that can be easily disrupted by extreme rainfall.

Kenya is also entering it as a very different country from the one that faced the rains nearly three decades ago. Its population has grown, towns and cities have expanded, roads and buildings have spread into previously open spaces, and millions more people now depend on urban infrastructure that can be disrupted during heavy rainfall.

Kenya’s population has increased since the 1997 El Niño, while urbanisation has concentrated millions of people and a lot of economic activities in cities and towns. Consequently, development has expanded into wetlands, river corridors and other areas that naturally absorbed or slowed floodwaters.

Nairobi provides perhaps the clearest illustration. According to the Kenya National Bureau of Statistics, the capital’s population rose from about 2.14 million in 1999 to approximately 4.4 million in 2019, while the wider metropolitan area has continued to expand.

Prof Peter Ngau, an urban and regional planner and lecturer at the University of Nairobi, said the difference between 1997 and today is not simply the number of people living in the city. Nairobi’s physical landscape has itself been transformed, with natural surfaces increasingly replaced by roads, buildings, concrete, cabro and other impervious materials that prevent rainwater from infiltrating into the ground.

“Since the 1997 El Niño, Nairobi’s physical landscape has transitioned from a natural, absorbency-rich basin into a highly paved, concrete-dominated environment,” Ngau says.

Natural landscapes, wetlands, vegetation and open spaces once formed part of the city’s drainage system by absorbing and slowing rainfall before it reached rivers. As these areas disappear, the same amount of rain can generate more surface runoff, increasing pressure on drainage systems and concentrating water in low-lying areas.

Michael Wera, an urban planner and climate-change adaptation strategist working with Slum Dwellers International Kenya and the City Settlement Planning and Housing Department, describes this expansion as “brown development”, including buildings, roads and paved surfaces that prevent water from soaking into the ground.

Stormwater from new developments can ultimately be channelled into roadside drainage systems that were never designed to carry the combined runoff generated across entire neighbourhoods.

“Many of Nairobi’s drainage channels date from the late 1990s and early 2000s, even as the city has continued to grow,” Wera says.

The projected scale of the 2026 threat indicates that about 1.5 million people could be adversely affected by the rains, with up to 500,000 potentially displaced by flooding and another 450,000 exposed to mudslides, landslides and rockfalls.

With above-normal rainfall expected in 44 of Kenya’s 47 counties, the pressure is likely to affect many water basins and highly developed urban centres.

Charity Mwangi, an Urban Nature-based Solutions Associate at the World Resources Institute, similarly argues that Nairobi’s drainage and flood-management systems have not kept pace with urban growth. Blocked drains, inadequate culverts, poor solid-waste management and development in low-lying areas further increase the risk, particularly in informal settlements.

“The loss of natural infrastructure has compounded the problem,” Mwangi says. “Wetlands, riparian corridors, forests and open green spaces act as the city’s natural sponge, absorbing rainfall, slowing runoff, stabilising riverbanks and supporting groundwater recharge.”

She cites a loss of about 22 per cent of Nairobi’s vegetation cover over two decades, equivalent to more than 467 hectares of tree cover, and argues that wetland rehabilitation, green buffers, reforestation and sustainable urban drainage should complement conventional engineering.

Yet the argument is not that Kenya has failed to learn from 1997. One of the most significant changes is institutional. Colonel David Samoei, Director of the National Disaster Operations Centre, says NDOC did not exist when the 1997 El Niño struck. The devastation of those rains, followed shortly afterwards by the 1998 bombing, exposed the absence of a dedicated national disaster-response structure and helped trigger the development of the system that exists today.

Nearly three decades later, Kenya has a national disaster-risk management policy and strategy, a disaster operations centre and a multi-agency response system.

“The country is also working towards transitioning the disaster-response directorate into an authority,” Samoei says. “But the floods of 2023 and 2024 exposed limitations that remain.”

Samoei says the main lessons were the importance of resources and timing. During previous emergencies, resources were sometimes inadequate or arrived late, leaving authorities preparing while flooding was already underway. The current approach is to prepare earlier, strengthen coordination and pre-position supplies before the rains begin.

Early warning has also improved, with meteorological information disseminated through national and county structures and onward through local administration, alongside television, radio, print and social media.

The challenge is turning a national warning into something useful for a household living beside a river or in a flood-prone settlement.

“Warnings alone are not enough if residents do not receive them in time, understand what they mean or have somewhere safe to go,” Mwangi says. Resilience requires last-mile warning systems, anticipatory support, safe evacuation, accessible shelters and reliable water and sanitation services.

This is where housing becomes inseparable from disaster preparedness. Many of the areas most exposed to flooding are densely populated settlements where residents cannot simply leave because an alert has been issued. Samoei acknowledges the dilemma: authorities can tell residents to move away from flood-prone areas, only for residents to ask where they are expected to go.

Dr Linda Nkatha Gichuyia, an urban housing specialist and federation leader whose research focuses on multi-hazard built-environment management, says the problem is even more complicated in Nairobi’s housing market.

Her work examines flooding alongside overheating, water scarcity and energy insecurity, arguing that these risks should be considered together. According to figures from her research, housing accounts for about 71 per cent of Nairobi’s built-form footprint, while roughly 90 per cent of Nairobians are renters.

“Climate-proofing homes therefore raises questions beyond engineering. Who owns the property, who pays for improvements and who benefits?” Nkatha says. A homeowner may be willing to invest in strengthening a house because the investment protects an asset they own. A tenant has far less control over such decisions.

“Your flood-risk proofing of a house, you’re flood-risk proofing it for a renter, not an owner,” Nkatha says.

In informal settlements, these challenges intersect with inadequate infrastructure and limited household resources. But residents are also developing their own responses.

“Communities in Mathare and Mukuru have participated in flood-risk mapping, while community groups have established climate-information initiatives, climate cafés and urban green spaces,” Wera says. “Residents have also participated in ward-level adaptation planning.”

Such initiatives matter because communities often know their neighbourhoods in ways that official systems may not. Residents know where water collects, which roads become impassable and which households are most vulnerable.

“This knowledge should be incorporated into formal planning, rather than treating communities as passive recipients of disaster assistance,” Wera says.

The question of exposure has also become central to the debate around Nairobi’s rivers. Following the 2024 floods, the government ordered people living within designated riparian danger zones to move and directed agencies to map, restore and protect river corridors. The Nairobi Rivers Commission says the Water Resources Authority began demarcating riparian boundaries along the Nairobi River in February 2026, while restoration work has continued along the Nairobi, Mathare and Ngong rivers.

The Commission says 47 kilometres of river corridor have been reclaimed following the 2024 directive, while its Joint Multi-Agency Coordination Centre reports that tens of thousands of young people have participated in river rehabilitation and related climate programmes but major questions remain about how much risk has actually been removed.

Publicly available government information does not provide a single consolidated figure showing how many flood hotspots identified after the 2024 floods have been fully cleared, how many residents remain exposed in riparian settlements, how many households are scheduled for relocation before the coming rains, or whether previous relocation programmes have resulted in permanent movement to safer housing.

That matters because relocation is not simply a matter of telling people to leave a riverbank. It is also about where they will go, how they will earn a living, whether children can remain in school and whether the new settlement is genuinely safer.

For Nkatha, the same issue applies to infrastructure. Although work has been undertaken to repair and improve stormwater drainage, she argues that Nairobi needs a clearer picture of what a fully resilient stormwater system should ultimately look like. Without that end-state, individual repairs can fix immediate failures without necessarily addressing the wider system.

Flooding also carries consequences beyond damaged roads and homes. During the 2024 floods, the Ministry of Health warned of increased risks of cholera and other waterborne diseases after latrines collapsed and water sources were contaminated. Heavy rainfall can overwhelm sanitation systems and create conditions favourable to diarrhoeal and vector-borne diseases, turning a flooding event into a public-health emergency.

The government has since strengthened disease surveillance and emergency preparedness and has focused on having supplies such as cholera response kits and water-treatment materials available ahead of emergencies.

“Emergency supplies are now being procured and pre-positioned before the rainy season,” Samoei says. “But financing remains a challenge, particularly because preparedness requires money to be available before disaster strikes.”

Counties also have an important role. Samoei says some have not invested enough in disaster preparedness, even though the first response to a flood will often come from people and institutions closest to the affected community; that includes residents themselves.

“Stronger community structures could allow information about local risks to move upwards to government while official warnings, resources and assistance move downwards to communities,” Wera says.

The coming rains will therefore test two very different aspects of Kenya’s preparedness. On one side is a disaster-response architecture that did not exist in 1997 but now has forecasting, coordination, emergency operations and early-warning mechanisms. On the other is a physical and social environment that has become more exposed as cities have expanded, natural drainage systems have been degraded and more people have come to depend on infrastructure designed, in many cases, for a smaller population. The two realities do not necessarily contradict each other.

Kenya can become better at responding to disasters while simultaneously becoming more exposed to the hazards themselves. The country cannot control how much rain falls, nor eliminate every flood risk but it can determine whether rivers retain functioning buffers, whether drainage systems are designed for the catchments they now serve, whether warnings reach the people most at risk and whether households living in dangerous locations have realistic alternatives.

Nearly three decades after the 1997 El Niño helped force Kenya to build a national disaster-response system, the challenge in 2026 is therefore more complicated. The country has learnt how to respond to disasters. The harder task is reducing the risk before the disaster arrives.

The test of preparedness will not only be whether emergency teams can reach people after the water rises, but whether the decisions made between one flood and the next have made fewer people vulnerable when the rains return.