Coastweek website



Yes, Green Cities Need Trees And Plants
But Watch Out What Happens With Roots

Coastweek -- Continuing on the theme of unintended consequences, there are some that happen in the course of trying to improve our public lives, writes TETI KAMUGUNDA.

We have infrastructure projects that end up creating more misery than value.

Others create nuisances that we could better do without.

My biggest beef is when town planners and avid “greens” get together in the pursuit of making towns greener.

We had such a case in Nairobi when the former City Council was keen on restoring Nairobi to its former tag of “Green City in the Sun”.

The green bit was always a full opportunity the Town Fathers could implement.

The “in the Sun” bit was out of their control but they could exert a positive influence through some affirmative action. However, the green bit first.

One of the simplest responses by any county, town, municipal or city government to a greening imitative is to do so in the areas that they control.

This would be the parks, the schools, markets, playfields and the road verges.

They could also go on a campaign to get residents to plant trees in their compounds or on the boundaries of their compounds.

All have been tried to varying degrees of success.

Nairobi’s big effort was to plant trees on the verges of the roads in the Central Business District and other adjacent locations.

This was done with gusto with the pavements being dug up and tree boxes created.

Trees were planted almost every ten metres along the pavements and the city resident applauded the effort.

The same was done in our town of Mombasa over time and I have seen similar efforts in Nakuru, Nyeri, Kisumu, Eldoret and Kitale.

Even the smaller towns such as Siaya and Kericho instituted similar efforts to green through planting trees along the streets.

Fast forward ten years later and the unintended consequences have kicked in.

Whether by omission or otherwise, every single town has the same problem – the uncontrolled action by the tree roots. 

The choice of trees and shrubs to be planted was, I believe, based on how the planted items would present themselves on the above ground but without little consideration on what would happen below ground.

The above ground intent has been realised.

There is a lot more green in the central parts of the urban areas mentioned above.

Wananchi who frequent the central parts appreciate the greenery both for the shade it provides and also the aesthetics that it enhances.

The pictures taken along the streets look better and also the air one breathes is better due to the amount of carbon dioxide that the foliage absorbs thus reducing the impact of the increasing number of motor vehicles on the roads.

However, the plants do not remove the sulphur and nitrogen based gases that are a lot more toxic and can cause illnesses to pedestrians as well as inner city workers.

The below ground impact is the unintended consequence.

A lot of utility infrastructure is also laid underneath the pedestrian paved areas as well as along the verges of the roads.

The most common is drainage and sewerage infrastructure.

Both of these contain water and this is an attraction to the tree roots.

Depending on the root systems, the attack by the plant roots could be quite damaging to eth infrastructure.

The presence of the infrastructure close to the surface or sometimes on the surface causes the root systems to spread horizontally.

This causes the pedestrian area paving to bulge upwards as the root systems grow in size leading to unevenness and a safety hazard or eventually a break in the paving or displacement of the paving blocks depending on the construction style.

The damage could also extend to the breaking up of the road surface as the root systems spread in their incessant search for water and nutrients.

This is happening in almost all the urban centres in Kenya and it is not only here.

The city authorities in many countries have made and continue to make the same mistakes.

The knowledge about what to plant or not plant is getting more common but somehow, within the bureaucracy of urban management the selection of the right foliage does not receive the amount of attention it should.

It requires very little to carry out a check on what the plants that are to be introduced could do to the adjacent constructions.

This small pause will result in the reduction of the unintended impacts of greening of cities.

It would stop the flooding of cities due to the restrictions created in drainage that is caused by inundation by root systems.

It will cause a reduction in the amount of sewage that is released to open drainage systems as a result of the sewer pipes being blocked and then broken by the roots that invade the infrastructure and then thrive on eth nutrients that the sewage provides so they grow almost exponentially in size and coverage.

The simple thing that our county governments can do at this point in time is to create a small team that will go round the cities, towns, municipalities and whatever urban centres exist to map out locations of the infrastructure and whatever was added to beautify the urban areas.

This will allow then to quickly assess what threats there are to the infrastructure and take very simple remedial action.

This will reduce the flooding that we saw during the recent rains and also reduce the amount of raw sewage that is flowing in open systems and along roads that now create health hazards in our towns.

As Kachumbari says, a stitch in time saves nine!




The Law Of Unintended Consequences And Unexpected Paternity In A Foreign Country!

Our Policy Heads Need To Fully Consider The Human Cost to Continuing Coast Demolitions

Corruption: Only Time Will Tell Who The True Sons Of This Nation Are?

An Unlucky Visitor Caught Up In The CBD, Hard To Find A Toilet

Business of Public Lavatories leaving a bad smell in the air

We Need A Radical Changes To How We Manage The Important

We Need To Completely Re-Examine How We Manage Our Public Transport

‘Boda Boda’s Done Right Could Be An Important Carriage System

Anarchy Is Never Solution To The Very Real Danger From Massing

Gazzillions - There Was Probably Some 100 Plus Million Shillings Involved Here

Where To Park Cattle, Horses, Donkeys, Yaks, Llamas, And So Forth ...

Most Drivers Treat Matatus With Caution And Daring Matatu Drivers Love This!

Even Seemingly Difficult Interventions Can Often Reap Welcome Results

Agencies Who Manage Disaster Need To Seriously Review Both Operations

Motorists Must Face Up To Dangers Of Submerged Hazards

Flooding: The Drainage Is Clogged - Most Have Not Been Cleaned For Years!

Creative Painters Have Turned Kenya Vehicle Art Into A Sophisticated Industry

Most Of The Coastal Tribe Of Matatu Is Of The 14 Seater Body Type

Matatu Apps. No Longer Act As Exhaust Brake Components

SACCOs were seen as a first step in getting sanity back

In Western: Matatus Driven Mainly By Function

Just Focussing On Enforcing Existing Laws For Six Months - Major Change?

My Adventure In A Busia Matatu On its Way To ‘Kisumu International’ Airport!

Some One Hundred Plus Officers Taking Bribes Were ‘Sacked’

Popular Slogan Harambee Is Always About Raising Money

Visitors Marvel At The Cleanliness Of Kigali City and even over Rwanda

Police Appear To Recognise Motoring Novices Breaking The Law!

Kenyan Traffic Bribes: System Should Begin To Operate Smoothly

Road accidents cost us three hundred billion Kenyan shillings yearly

Authorities Should All Jump In To Solve Driving Woes In This Country

Drivers Who Fail To Remove Road Rubbish Once Vehicle Is Repaired

Examination Methods Now Used To Teach Driving Needs an Overhaul

Most Sane Drivers Fear Every Time A PSV Appears Near Their Vehicle

Attempt To Level Playing Field During Political Campaigns Rubbished

Kenya Bus Service Went Bust Due Onslaught Of The Matatu Industry




Remember: you read it first at !

  This year’s rally will be
flagged off at Sarova
Whitesands on November
23rd and finish at the same
venue on December 1st.


Please contact

MOMBASA - GULSHAN JIVRAJ, Mobile: 0722 775164,
Tel: 0731 099309 / (+254) (41) 2230130 / Wireless: 020 3549187

NAIROBI - ANJUM H. ASODIA, Mobile: 0733 775446 / 0773 468786

    © Coastweek Newspapers Limited               Tel: (+254) (41) 2230130  |  Wireless: 020 3549187  |  E-mail: