close zoom control

'Use 'ctrl and +' or 'ctrl and – ' to zoom in and out'

Skip to main content


Tree Seedlings

The Nairobi Greenline


Nairobi National is the only game reserve that borders a capital city in the world and the park is threatened with extinction.

The Kenya Wildlife Service (KWS) in partnership with the Kenya Association of Manufacturers (KAM) embarked on an ambitious programme designed to protect and defend the park from the pressures of urbanisation, industrialisation and pollution. Reminded of Nairobi’s “Green City in the Sun” status, the indigenous tree buffer zone was named “The Nairobi Greenline”.

The M-PESA Foundation granted Kshs. 43 million of the Kshs. 60 million needed to achieve the Nairobi Greenline ambition in 2011. The donation ensured that the green buffer zone was completed in June 2013.


Simon Waithaka’s story is a forester with the Nairobi Greenline, his task has been to plant 250,000 indigenous trees over a 30-kilometre stretch measuring 50 metres wide. This shield of green, will in addition to the parallel electric fence, safeguard the precocious national treasure from extinction.

“When you’re on the outside of the park, you don’t really see what the effects of pollution have been. From inside, it is very clear especially here at the eastern boundary. These factories and oil refinery are polluting the park. Animals won’t even come up here!

Because of the terrain and the soil types, it has been very challenging to put up the Greenline. There’s black cotton and a lot of rock. During the wet season and because of water logging, many of the trees that we planted have drowned. When it has been hot, a number of them have wilted and died.

Using trees indigenous to its two ecosystems, the Nairobi Greenline stretches from Athi River’s Cheetah Gate to the Carnivore off the busy Langata Road. “As a result, the animal’s natural habitat has been enhanced. The bird life has improved. The air quality is better, and will continue to improve as the trees grow”, Wanja Kimani, the Project Coordinator of the Nairobi Greenline says.


From the first tree planted in February 2010, the Greenline’s attractability is witnessed in improved corporate and individual participation. “More schools have visited the unique project and it has been fitted into geography and environment curricula”, says Wanja Kimani. “International students studying masters’ programmes on the sustainability of the environment next to urbanization come here,” adds Wanja, the Project’s Coordinator.

“Most of the trees are acacia as that is what is native to the area. The way we have planted them, when they grow, we will trim them and they will interlock. When this happens, they will become a natural barrier. No one can come across the park from the outside.

There’s the education aspect. People can come here and learn how to plant and grow trees. We have also seen botanists come and study all these 11 species of acacia that are in the Greenline. In ordinary circumstances, they would have to travel far and wide to study any of them. They are all here in one place.”

Plans to improve transport and utilities infrastructure in Nairobi have also threatened the sanctuary. Moat of this network will be developed around the southern boundary where the migration corridor lies.

Home to large herds of Thomson’s gazelle, eland, impala, buffalo, giraffe, zebra and wildebeest, the Nairobi National Park’s two ecosystems also host about 500 permanent and migratory bird species. It is also one of the biggest rhino sanctuaries in Kenya, with both the black and white rhinos hosted in its reserves.

“There have been calls to fence the entire park meaning that Nairobi National Park becomes a closed ecosystem.

We haven’t fenced the southern boundary, as that is migration corridor.

If we end up doing this, then we lose the essence of what is the only one of its kind in the world. It is only the elephant of the Big 5 that can’t be found here, ” adds Simon.


With the continued involvement of M-PESA Foundation, the Nairobi Greenline has started to work on Phase II. The walking, jogging and bicycle path has already been earmarked, stretching from the KWS clubhouse up to the Cheetah Gate in Athi River. “8 picnic sites along the stretch have also been reserved. Elevated watch towers for bird watching and animal spotting will be made available at each site”, Wanja the project coordinator discloses.

For Simon this is the project of his career. “I have been a forester all my life and I have worked in many challenging environments but this will be my most rewarding assignment.

In five years’ time or so, these acacia trees will flank the half marathon route. The wildlife will have been protected and the air free and clean from pollution.

People will be walking the line.

The Nairobi Greenline Gallery

View more images

The Nairobi Greenline