In Summary
  • The Water ministry has lined up urgent meetings with industries and polluters along the river in coming days to chart the way forward.
  • Makueni Governor Kibwana says keeping the river clean is not just about the waterway but also about the country’s own survival.

Removing the poison that lurks in the deadly Nairobi-Athi-Galana-Sabaki River will be a tough call, but it is possible.

A few years back, Kenyans would walk down the river to draw drinking water, wash clothes, bathe or just swim, but today, our investigations show that trying any of these exercises would come at a great cost to their health.

Though filthy and dead inside, Nairobi is still not as bad as some of the world’s dirtiest rivers, which were reversed.

Environmental experts and international best practices show that it is cheaper to confront the problem head-on than continue on the path of half-hearted clean-ups downstream, when polluters are still emptying their wastes upstream.

Though it will be expensive, and would take a long time to achieve full results, it is not an insurmountable problem if lawbreakers are punished and the numerous agencies paid by the taxpayer to keep them safe do their job.


River Thames, which is billed today as one of the cleanest rivers that flows through a major city, was not always among the best rivers around the world.

More than 50 decades ago, the river that passes through London was so dirty that it was declared biologically dead.

At some point in its worst days, the stench coming from its waters was so bad that the British Parliament had to soak curtains in lime to stop the odour from cutting short their sessions.

Its turning point was the building of embankments that allowed for the building of riverside roads and walkways and concealed the huge sewerage pipes.

That was not all. Treatment plants would also be built to clean dirty water from the Thames before it was pumped into homes.

The same treatment plants also cleaned dirty water from homes before it went back into the river.


But, the biggest breakthrough came when sewage found a better use. Most of London's sewage sludge today is sold in pellet form as fertiliser for agricultural use.

“There is a phenomenal resiliency in the mechanisms of the earth. A river or lake is almost never dead. If you give it the slightest chance by stopping pollutants from going into it, then nature usually comes back,” Rene Dubos says in a paper published by the National Academy of Sciences.

According to the paper that surveyed the restoration of five rivers, as settlements expand in size and become more closely spaced, the wastes start to contain a larger percentage of persistent toxicants.

As a result, the ecological damage to the streams become more severe and the possibility of self-cleansing more limited.

Though not among the rivers that illustrate the power of restoration activities on a river, the Santa Cruz River in the US is a case study of how human activities and rapid urbanisation of the floodplain can bring about irreversible changes to a stream system.


Willamette River in northwestern Oregon is one of the rivers in the US that has been described as a success story.

The restoration of the river was mainly directed towards water quality restoration, protection of beneficial uses of the river water, and management of certain species of game fish.

“The restoration also includes reservoir management and research intended to reduce ecological disturbances in the river occasioned by changes in water temperature caused by the release of water from reservoirs,” the paper reads.

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