Tough choices will save Nairobi River

Cleaning Nairobi River is an ambitious and difficult task, seeing as the partly-canalised main channel and some of its tributaries flow through the capital city, gathering pollution on their way east.

Thanks to hundreds of thousands of city residents living and working on their banks, the rivers are "choking with uncollected garbage, human waste from over-flowing sewers and informal settlements, industrial waste, agro-chemicals, petro-chemicals and metals from jua-kali micro-enterprises". This, United Nations Environmental Programme officers say, has led to the spread of water-borne diseases, reduced access to safe potable water, loss of livelihoods and the insidious effects of toxic substances and heavy metal poisoning on people living downstream.