Mazingira Day 2026: Nairobi turns to residents as El Niño rains loom

City Hall wants residents in all 17 sub-counties to clear drains and plant trees, but the bigger test will be keeping Nairobi’s waterways free of waste after Saturday’s exercise.

Nairobi will put its residents at the centre of its latest flood-prevention push on Saturday, October 10, with a citywide clean-up planned across all 17 sub-counties.

The exercise will combine drainage clearing, neighbourhood clean-ups and tree planting as the capital prepares for a wetter-than-normal October–December season.

But there is a bigger issue behind Saturday’s mobilisation.

Nairobi already produces thousands of tonnes of waste every day. County officials say about 3,200 tonnes of garbage are collected daily, while previous county data has put the city's waste generation even higher. The challenge is not simply collecting rubbish once. It is stopping waste from getting back into roads, rivers and drainage channels.

That makes Mazingira Day more than a symbolic environmental event.

For City Hall, it is also a test of how well residents can work with county teams before heavy rain exposes blocked drains and other weak points.

Residents asked to take part

The county's Green Environment team is organising Saturday's exercise, which is scheduled to begin at 9am.

Residents have been asked to join clean-up activities in their neighbourhoods, with drainage unclogging and waste removal among the main tasks.

Tree planting will also be part of the exercise.

Areas including Roysambu, Embakasi, Kibra, Westlands and Starehe are among those where residents have been encouraged to participate, although the county has asked people to confirm their local meeting points and work areas.

The message from City Hall is straightforward: keeping Nairobi safe from flooding cannot be left to county workers alone.

The county has urged residents to help protect drainage systems and keep their surroundings clean.

Nairobi is already in clean-up mode

Saturday's exercise is not the county's first major clean-up this month.

On October 3, Governor Johnson Sakaja led a citywide operation involving all 17 sub-counties, residents, county staff and about 4,500 Green Army personnel.

The teams worked on roads, neighbourhoods, public spaces and drainage channels as part of preparations for the expected heavy rains.

Sakaja has repeatedly called on residents, businesses and institutions to take responsibility for the areas around them.

The county is also carrying out drainage works in areas considered vulnerable to flooding.

At Kamulu, for example, the county says drainage works are under way. Work is also being coordinated with the Kenya National Highways Authority and the Kenya Urban Roads Authority around Ruai Junction, including work on drainage crossings.

The county has also been conducting drainage clearance and flood-prevention work across the city.

So Saturday's event comes as part of a wider operation rather than a standalone clean-up.

Why the timing matters

The exercise comes as Kenya enters the October–December rainfall season.

The Kenya Meteorological Department has forecast above-average rainfall in several parts of the country during the season, while climate authorities have warned of heightened rainfall associated with the strengthening El Niño conditions.

For Nairobi, heavy rainfall can quickly turn a blocked drainage channel into a flooding problem.

Plastic, soil, household waste and other debris can restrict the movement of storm water. Once drainage capacity is overwhelmed, roads and neighbourhoods can flood within a short time.

That is why clearing drains before the rains is important.

But it is only one part of the problem.

The waste challenge does not end on Mazingira Day

Nairobi's waste figures show why a single clean-up cannot solve the city's flooding and sanitation problems.

The county has previously described Nairobi as producing about 3,200 tonnes of solid waste each day. More recent county discussions have put daily generation at around 3,600 tonnes and said only between 45 and 55 per cent is collected, leaving a significant amount vulnerable to illegal dumping.

Some of that waste can eventually find its way into drainage channels and waterways.

The county has acknowledged that illegal dumping remains a major challenge.

In 2024, Green Nairobi officials said the city's growing population and illegal dumping were putting pressure on the county's environmental workforce.

That leaves City Hall with a difficult task.

It must keep expanding collection and enforcement while also convincing residents that waste disposal is not only a government responsibility.

Mazingira Day has a national target too

The Nairobi exercise is part of a wider national environmental campaign.

Kenya will mark National Mazingira Day on October 10, with this year's activities focused on tree growing, environmental restoration and community action.

The Kenya Forest Service says the national campaign is targeting 17.24 million trees during the Mazingira Day activities.

Environment Cabinet Secretary Deborah Barasa has also urged Kenyans to record and monitor tree-growing activities through the Jaza Miti platform. The government says 2.2 billion trees have so far been planted against the national 15 billion-tree target.

The national theme is “Our Environment, Our Responsibility: Collective Action for Tree Growing and Environmental Stewardship.”

For Nairobi, that message has a practical dimension.

Trees matter for the city's long-term environment, but unclogged drains can make an immediate difference when a storm hits.

City Hall's preparedness goes beyond cleaning

Nairobi has also been working on its emergency response.

Earlier this month, the county conducted an Operation Okoa Maisha simulation involving multiple agencies as it prepared for possible flood emergencies.

The county says its emergency coordination arrangements are intended to bring different agencies together so that response teams can act quickly during a crisis.

The county has also introduced a six-borough coordination structure covering Nairobi's 17 sub-counties and 85 wards.

Sakaja says the arrangement is intended to make it easier for county officials to consolidate reports and identify emerging problems without having to manage every ward separately.

That infrastructure will matter if the rains become severe.

But prevention remains cheaper and safer than waiting for an emergency.

The real test begins after Saturday

The photographs of residents planting trees and clearing drains may dominate Mazingira Day.

But the harder work begins once the event is over.

A drainage channel that is clear on October 10 can be blocked again days later if rubbish continues to be dumped into it.

A tree planted during a national campaign will only contribute to Nairobi's green cover if it survives.

And a clean neighbourhood will remain clean only if waste collection keeps pace with the waste being generated.

That is where residents and City Hall meet.

The county can provide workers, trucks, enforcement and drainage maintenance. Residents and businesses, in turn, have a role in how waste is handled before it reaches those systems.

With the rains approaching, Nairobi has little room for a clean-up that lasts only one day.

Mazingira Day may clear the drains. The real measure of success will be whether they are still clear when the heavy rain comes.

About the Author

Maureen Onyango is a journalist passionate about storytelling, life coaching and spiritual lessons. She studied at the Kenya Institute of Management and enjoys telling stories that inform, inspire and empower communities.