NAIROBI, Kenya — Several of Kenya’s major road corridors could face flooding, closures and transport disruption if the anticipated El Niño rains intensify, with disaster-response agencies identifying North Eastern Kenya and parts of the Lake Basin, Rift Valley and Tana River regions among the areas of greatest concern.

The National Disaster Operations Centre (NDOC) has identified a number of strategic transport corridors considered vulnerable to flooding, including the Nairobi–Garissa–Wajir–Mandera corridor, Garissa–Tana River road, Nairobi–Narok route and Kericho–Kisumu corridor.

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The warning has major implications for public transport because these roads carry buses, matatus, trucks and private vehicles between Nairobi and large parts of the country.

North Eastern Kenya is expected to face particularly elevated exposure, with Garissa, Wajir and Mandera identified among the principal hotspots.

Other areas of concern include communities along the Tana River, Kisumu, Migori and Busia in the Lake Basin region, Murang’a in Central Kenya, and Baringo, Elgeyo Marakwet and Narok in the Rift Valley.

North Eastern transport links face major test

Transport disruption in North Eastern Kenya can become particularly serious because major highways provide critical connections between towns separated by considerable distances.

Flooding or damage to sections of the Garissa–Wajir–Mandera transport corridor could therefore affect not only passenger movement but also the transportation of food, fuel, medicine and other essential supplies.

Unlike Nairobi, where commuters may sometimes switch between several roads, matatus and even railway services, alternative transport options become considerably more limited on remote intercounty corridors.

The NDOC is consequently preparing resources that could be required if conventional road transport becomes impossible in severely affected areas.

“We will be involved in medical evacuations and we will also position boats to help in crossing major water bodies,” NDOC Director Col (Rtd) David Samoei said.

“We are working with Kenya Coast Guard and KDF and Kenya Navy to ensure transport is facilitated.”

Nairobi–Narok corridor also under watch

The Nairobi–Narok corridor has also been identified among the roads requiring close attention.

It is an important passenger, freight and tourism connection between Nairobi and the Rift Valley and provides access towards Narok and western Kenya.

The corridor also interacts with Kenya’s growing railway network. Metros’ Nairobi–Suswa passenger train guide shows that the railway runs from Nairobi Terminus through Ongata Rongai, Ngong, Nachu and Maai Mahiu before reaching Suswa in Narok County.

However, rail should not automatically be assumed to be immune to extreme weather.

Kenya’s railway system has previously suffered significant flood damage. Severe flooding in 2024 damaged tracks around Uplands, Kijabe and Longonot, disrupting passenger operations towards Limuru and Kisumu.

That history demonstrates how extreme rainfall can affect multiple forms of transport simultaneously.

Kericho–Kisumu corridor could affect western Kenya travel

The Kericho–Kisumu road is another important corridor identified as potentially vulnerable.

Disruption there could affect passenger and freight movement towards Kisumu and other parts of western Kenya.

Concerns extend beyond the highway itself.

Communities in Kisumu, Migori and Busia are among those being watched because of the wider flood risk around the Lake Basin.

Kenya Red Cross Secretary General Ahmed Idris said communities that have already experienced displacement caused by changing water levels are of particular concern.

“We are worried about counties around the lake regions that have experienced displacement in a number of years due to the rising waters situations,” Idris said.

The Red Cross is also concerned about vulnerable communities in urban informal settlements, where intense rainfall can overwhelm drainage systems and quickly affect homes, roads and pedestrian access.

Tana River faces another extreme-weather threat

Tana River is another area attracting particular concern because communities there have repeatedly experienced both drought and flooding.

Idris highlighted the vulnerability of counties such as Tana River that have been moving between different weather extremes.

“Counties like Tana River that have been fluctuating between extreme weather conditions like drought and floods” are among the areas causing concern, he said.

Flooding along river systems can cut roads and bridges, isolate settlements and make it difficult for public transport vehicles to maintain normal operations.

This is one reason the planned positioning of boats and coordination between disaster agencies, the Kenya Coast Guard, Kenya Defence Forces and Kenya Navy could become important if communities become inaccessible by road.

Public transport could feel the impact quickly

For commuters, prolonged heavy rainfall can produce effects long before a highway becomes completely impassable.

Waterlogged roads can slow buses and matatus, increase congestion, cause vehicles to divert and lengthen journey times.

Where roads are damaged or temporarily closed, operators may have to use considerably longer alternative routes.

This can eventually affect fares as well.

Additional kilometres, longer journey times and congestion increase fuel consumption and operating costs, particularly for buses and matatus running several trips every day.

Within Nairobi, the impact of severe rainfall can be magnified by the size of the existing road-based public transport network. Metros’ Nairobi Matatu Routes and Numbers database shows how services are distributed across major corridors including Mombasa Road, Jogoo Road, Thika Road, Waiyaki Way, Ngong Road, Lang’ata Road and Outer Ring Road.

Flooding at strategic junctions or along major roads can consequently affect multiple routes simultaneously.

Rail could provide alternatives — but remains weather-exposed

Nairobi commuters have more transport alternatives than passengers in many other parts of Kenya.

The Nairobi Commuter Rail network connects the CBD with Ruiru, Embakasi Village, Syokimau and other metropolitan destinations, while western railway services extend towards Dagoretti, Kikuyu and Limuru.

The Nairobi–Syokimau service, for example, provides an alternative to travelling entirely by road along the Mombasa Road corridor.

During severe road congestion, such alternatives can become increasingly valuable.

But commuters should not assume trains will automatically continue operating during extreme rainfall. Railway embankments, tracks and bridges can themselves be damaged or affected by flooding.

Passengers should therefore check current service information before relying on an alternative mode during severe weather.

Food production and disease outbreaks also feared

The potential consequences extend beyond transport.

Kenya Red Cross has warned about the possibility of reduced food production, disease outbreaks affecting people and livestock, displacement and loss of lives and property if severe rainfall materialises.

Idris said poorer and more vulnerable households could face some of the greatest consequences because they have fewer resources available to recover from flooding, displacement or loss of livelihoods.

Urban informal settlements are another particular concern because dense populations, inadequate drainage and housing close to waterways can combine to increase vulnerability.

Transport disruption can further compound the situation by making it harder for emergency services and humanitarian organisations to reach affected communities.

Agencies preparing for strong El Niño possibility

Authorities are preparing against forecasts indicating a high probability of a significant El Niño event.

The projections cited by disaster officials point to a probability above 80 per cent for a strong event, with some assessments placing the probability higher.

The precise severity and location of rainfall will ultimately determine the effect on Kenya’s transport network.

But the identification of vulnerable corridors before the heaviest rains arrive gives transport operators, county governments and emergency agencies an opportunity to prepare.

For commuters, it also makes weather information increasingly important to journey planning.

Metros already treats weather as part of commuter intelligence because changing conditions can directly affect traffic, public transport reliability and journey times. Recent Nairobi traffic and weather reporting has shown how conditions on major roads can rapidly translate into commuter delays.

As the expected October rains approach, that relationship could become considerably more important.

For passengers travelling long distances, particularly towards Garissa, Wajir, Mandera, Tana River, Narok, Kericho and Kisumu, checking weather conditions and road advisories before departure may become as important as checking the fare and departure time.

If the stronger El Niño projections materialise, Kenya’s public transport system will face a straightforward but significant test: keeping people and essential supplies moving when some of the country’s most important roads are under water.