The recent directive by the President to the authorities to take action to stop effluent draining into rivers has resulted in them tearing down various buildings and imposing arbitrary setbacks along canalised streams and storm water channels through Nairobi.
Nairobians are still left with open sewers running through their midst. A walk through the City Park clearly demonstrates this. Residents of Lavington have been forced to cover the rivers through their neighbourhood because of the stench they give off. The Nairobi River is another example as it flows through Westlands and Kilileshwa.
In medieval times London covered the River Fleet to become Fleet Street because it was an open sewer flowing into the River Thames. It was only in the 19th century that sewers were built along the Thames to form the Embankment that allowed the great river to recover.
From early days, the engineers in Nairobi constructed storm water channels and sewers along the rivers but these have not kept pace with the city’s growth. Steps must be taken to improve the system.
In particular, the role of the canalised conduits and storm channels must be fully understood. They are not rivers with riparian reserves, they are engineered waterways which only require way leaves either side to allow for maintenance access. Typically the city planners required surveyors to provide three metres wide way leaves for these waterways since Nairobi was first established.
In particular, the industrial area has a number of drainage channels, some of which are canalised streams that connect to rivers downstream. Along the channels there are numerous go-downs and factories. If riparian reserves are incorrectly applied, then owners will be forced to demolish valuable assets for no useful reason.
The same applies to the stream that flows from Kyuna through Brookside and ultimately joins the Mathare Valley after passing through City Park. This stream was famously built in the 1990s along Brookside Drive although the land had been reserved as a park.
Further down the stream was canalised between Peponi Road and Mpaka Road. It was famous for flooding, not because of the canalisation but because the culverts under the bridge carrying Mpaka Road were undersized. The Visa Oshwal Centre is on the other side of the road but it has never been an impediment to the river flow. Properties upstream of the bridge have had to deal with the stench of sewerage in their gardens after the flooding subsides.
Where rivers flow through areas such as Lavington, Kilileshwa, Westlands and Parklands, they should be cleaned using technology like tangential flow separators to remove the effluent which can be redirected to the sewers which already exist in the same river valleys. This system has been proposed to the City Engineers in the past but ignored.
Perhaps now is the time to readdress the problem. This will do far more to meet the aims of the presidential directive than incorrect rulings concerning setbacks from canals and channels that do not hinder the flow of rivers through the city.
Architect working for DMJ Architects