Effects Of Land Use Encroachment On Wetlands: Case Study Nairobi Dam Area

Wetlands are ecological sites of importance as supporting bio-diversity, water purification, water storage, flow regulation, water provision, carbon sequestration and they control floods. However over the years they have faced destruction and are in the verge of distinction. The international community realized this outcry and the effects it would have to flourish of human and therefore converged in Ramsar Iran to come up with Ramsar convention on wetlands protection. Ramsar treaty highlighted major conservation measures to be undertaken to protect our wetlands through identify wetlands of international importance.

Despite this treaty there has been continued destruction of the wetlands especially through encroachment by agricultural activities, human settlements and commercial activities. This has not only been a phenomenon in Kenya rather it is a bigger picture of the impacts of encroachment of wetlands worldwide. The effects are more in urban areas due to the rapid urbanization which is estimated at an annual growth rate of 1.6 %( UN, 2009). The continued urbanization has increased the ecological footprint of the world major cities far beyond their actual geographical sizes hence complicating their ability to maintain their wetlands. In many African countries Wetlands have been drained for agricultural activities due to their fertile soils they include Uganda, South Africa, Congo, Ghana etc.

 Many wetlands in Kenya have continued to experience an array of pressures and threats emanating from both the natural events and the anthropogenic activities as 80% of wetlands occur on lands which are privately or communally owned and without any serious conservation measures. Nairobi has experienced rapid urbanization which does not resonate to infrastructural development. The city which was once refereed to  a ‘green city in the sun’ has turned to  an increasingly chocking city with uncollected garbage and overflowing sewer which have polluted the Nairobi river system and even turned it to a subject of international focus.

Nairobi Dam designed in 1946 by the Public Works Department of the British colonial government in Kenya in conjunction with the Uganda Railways and Harbours Service was to provide potable water for the residents of Nairobi City. It attracted major recreational, sporting, fishing and bird watching activities in turn being a destination for both foreign and domestic tourists.  Over the years intensive encroachment of human settlements, agricultural activities, draining of raw sewer and dumping of garbage led to eutrophication and infestation of hyacinth rendering the dam unusable. 

Destruction of the dam has both social-economic effects on the people living around the dam but also to over a third of Kenyan population within the Athi river water service board. The water demand for Nairobi is 650 000 m3/day compared to the production of 482 940 m3/day (WRMA 2010) while the dam has a reservoir of 98,000M3 which can help solve the problem of water scarcity. Nairobi dam forms part of the larger Athi river basin which has an area of 132,000KM2 representing about 23.7% of the total land area in Kenya.(Kiithia 1997). It serves a population of approximately 15 million approximately a third of Kenya population. Therefore efforts to ensure clean water in Nairobi dam will replicate a good health and access to clean water for over 15 million Kenyan hence reducing health expenditures and improving the standard of living of Kenyans.

The continued deterioration of the dam has largely been blamed on the over 77 sectoral laws and many bodies regulate and mandated to conserve the dam. There has been conflicts and duplication of roles leading to ineffective mode of cleaning and conserving the dam. Some of the statutory provisions have been conflicting in their minimum and maximum standard especially in riparian reserves.

The study has made efforts in recommending various measures which need to be undertaken to ensure that Nairobi regains its place in the socio-economic development of Nairobi and Kenya at large. The measures are as outlined below

Planting and cleaning the river at the upstream to ensure that it is clean and free from contamination. Demolition of all the structures within the riparian reserve of the dam to and replace it with green park which can be used for recreational facilities. The park enhances the aesthetics of the dam while ensuring compatibility of land-uses. The third activity to be carried out will be the dredging of the dam to remove marshes and compacted solid waste within the dam, this will ensure that the dam is retains its pristine state and increases its capacity. Solid waste management will be developed with much emphasis on the Recycle Re-use and Reduce to ensure that the waste does not contaminate the dam. It is also envisaged to create employment.

Efforts to upgrade slum and provide sustainable housing will be a remarkable effort towards cleaning the dam. The upgrading will be followed by a network of sewer system to ensure that raw sewer does not flow into the dam. There will be well planned commercial activities within the park to promote well provided recreational services while gaining revenue to protect the dam.

Nairobi dam can be protected and regain its past glory as a major sporting, fishing and recreational facilities within the city precinct but this will require concerted efforts by all stakeholders and particularly the community living around the dam. The benefits of a clean dam will not only be enjoyed by people who live around the dam rather by more than 15 million people within the Athi river basin.


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