# Nairobi floods: which roads go first.

By Kenneth Gathogo, founder of Rada. Reviewed by Carolyne Macharia. Updated 19 October 2026.
Source: https://rada.solidcreatives.co.ke/guides/nairobi-floods-roads/

Nairobi does not need a long storm to stop moving. A short burst of heavy rain is enough to put water across the same handful of places it always does. Below: where, why, how to decide whether to drive through it, and what Rada’s founder has driven through.

## What I’ve seen

Early in 2026 I met floodwater at the Ruai underpass on Kangundo Road, where it meets the Eastern Bypass, and on Thika Road near Kenyatta University.

I cracked my bumper trying to pass through a flooded spot on Kangundo Road, because there were potholes underneath the water.

Now I avoid crossing flooded roads.

## Why it happens so fast

Flooding here is rarely about the total rainfall. It is about how quickly that rain arrives and where it has to go.

- **Intensity, not duration:** Nairobi's rain tends to come hard and short. Drainage designed for a steady fall cannot take a downpour, so water sits on the carriageway rather than leaving it.
- **Hard surfaces everywhere:** as the city has built out, water that once soaked into ground now runs straight off tarmac and concrete into the nearest low point, arriving all at once.
- **Blocked drains:** silt, rubbish and construction spoil fill roadside drains between rains. The first heavy fall of a season is almost always worse than the ones that follow, because that is when the blockages announce themselves.
- **Gravity:** underpasses and dips have nowhere to drain to except a pump or a gradient. When either fails, they fill. They are the first places to go under and the last to clear.

## The places that go first

Nairobi drivers will recognise most of this list, because the same locations recur every season.

- **Underpasses, everywhere:** this is the single most reliable rule on this page. Any underpass in the city is a candidate, and an underpass that has filled once will fill again.
- **The low-lying approaches into the CBD:** the dips near Nyayo, the Haile Selassie and Uhuru Highway junctions, and the streets around Muthurwa and Landhies.
- **Mombasa Road through the South B and industrial stretch:** flat, heavily built up, and carrying water off a very large paved area.
- **Outer Ring and the Eastlands roads:** Kariobangi, Umoja and the Kangundo Road side, where drainage capacity is thin relative to the population it serves.
- **Jogoo Road near Muthurwa:** compounded by market activity that does not stop for the weather.
- **Waiyaki Way around Kangemi:** a long-standing problem stretch in heavy rain.
- **Kangundo Road at the Ruai underpass:** where it meets the Eastern Bypass, and with potholes hidden under the water.
- **Thika Road near Kenyatta University:** a low stretch that can close the road for hours in heavy rain.
- **Anything currently dug up:** a road under works has no functioning drainage by definition. Diversions onto unpaved ground become mud rather than merely slow.

Treat this as a pattern rather than a map. The exact spots shift as drains are cleared or blocked and as works open and close, which is precisely why a list on a website is worth less than a report from somebody who drove it ten minutes ago.

## How deep is too deep

Most people badly overestimate what a car can drive through, and floodwater on a road hides everything underneath it.

- **Moving water is the danger, not standing water.** Moving water can push a car sideways, and once the wheels lose grip you are a passenger.
- **You cannot see the road surface.** Floodwater regularly hides open drains, missing manhole covers, washed-out edges and debris. A puddle of unknown depth over an unknown surface is not a risk worth taking to save a few minutes.
- **Water in the engine ends the journey permanently.** Drawing water into the intake destroys an engine, and it can happen at depths that do not look dramatic.
- **Do not follow a matatu or a lorry through.** A higher, heavier vehicle clearing water tells you nothing about whether your car will, and their bow wave makes it deeper for you.
- **If you are not certain, turn around.** Turning back is slower. Being recovered from a flooded underpass is much slower.

## What the rainy season brings

Check the Kenya Meteorological Department’s outlook as each rainy season approaches.[1] For roads, frequency is what matters: repeated heavy falls give drains no chance to clear between them, so each one starts from a worse position than the last.

What that means practically, in a wet season:

- **Build the rain into your departure time,** not your route. Leaving earlier beats any clever alternative once the roads are already under water.
- **Know two ways home,** and know which of them has an underpass on it.
- **Expect the evening peak to stretch,** because rain and the outbound rush arrive together more often than not.

Seasonal outlooks change as the season develops, so treat this as the current expectation rather than a settled fact.

## Knowing before you set off

Flooding is the clearest case there is for hearing from other drivers rather than from a map. A congestion colour cannot distinguish between a slow road and a closed one, and no official notice will reach you in the twenty minutes between an underpass filling and you arriving at it.

In Rada you save the roads you actually drive, and you get a notification when another driver reports flooding, a closure or a hazard on one of them, with a thread underneath saying whether it has cleared. During a heavy rainy season that is the difference between choosing a different road at home and discovering the problem at the water's edge.

## Quick answers

**Which roads in Nairobi flood first?**

Underpasses go first, every time, and they clear last. After that it is the low-lying approaches into the CBD, the flat stretch of Mombasa Road through South B and the industrial area, parts of Outer Ring and the Eastlands roads, Jogoo Road near Muthurwa, Waiyaki Way around Kangemi, the Ruai underpass on Kangundo Road, and Thika Road near Kenyatta University. Any road currently under construction should be treated as flood-prone regardless of its history.

**How deep is too deep to drive through?**

If you cannot see the road surface, it is too deep, because floodwater hides open drains, missing covers and washouts. Moving water is far more dangerous than standing water and can push a car sideways. If there is any doubt at all, turn around rather than test it.

**Why does Nairobi flood after only a short rain?**

Because the rain arrives hard and fast, because so much of the city is now hard surface that sheds water instantly, and because roadside drains silt up between seasons. The first heavy rain of a season is usually the worst, since that is when the blockages become apparent.

**Is it safe to follow a matatu or lorry through flood water?**

No. A taller, heavier vehicle getting through tells you nothing about your own car, and the wave it pushes makes the water deeper for whoever follows. Judge the crossing on your own vehicle, or do not cross.

**How do I find out if a road is flooded before I leave home?**

Official channels are too slow for flooding, because it happens in minutes. The practical answer is reports from drivers who are there. Rada notifies you when somebody reports flooding or a closure on a road you have saved, before you commit to it.

## Sources

1. Kenya Meteorological Department. Official seasonal rainfall outlooks and forecasts. https://www.meteo.go.ke/