The construction and operation of the railways have degraded, fragmented, and destroyed key ecosystems. Soil erosion, land degradation, flooding, and habitat destruction increased.
Kenya is building a railway line connecting the coastal port of Mombasa and the interior of the country. It is scheduled to end in Malaba, a border town with Uganda, and to link up with other railway lines under construction in East Africa. It is known locally as Standard Gauge Railway (SGR).
The passenger and freight rail line is one of the largest infrastructure investments in Kenya’s history. Construction began in 2014 at an estimated cost of $3.8 billion, 90% of which came from a loan from the Export-Import Bank (Exim) of China and 10% from the Kenyan Government.
Although the actual area affected by the railroad is small, there are elevated parts, and it traverses a wide range of ecologically fragile and important ecosystems in the country. For example, the railway runs through the Tsavo Conservation Area (which is home to around 40% of Kenya’s elephant population) and Nairobi National Park. It also traverses pasture lands in southern Kenya, which are vulnerable to the effects of climate and land-use changes.
The construction of the railway is being carried out in three phases. The first two (already completed) cover 610 km, and the third is still under construction. A study focused on the entire stretch of the first two phases, spanning eight counties from Mombasa to Narok.
The project involves many stakeholders, including various levels of government (such as the National Environmental Management Authority and the Kenya Wildlife Service), local communities, civil society organizations, and the private sector.
Investigations revealed that the construction and operation of the railways have degraded, fragmented, and destroyed key ecosystems. Soil erosion, land degradation, flooding, and habitat destruction increased. They also affected the bodies of water and the movement of fauna.
Environmental impact assessments were carried out for the railway following an international standard. The final reports, which included recommendations, were written to facilitate licensing by the National Environmental Management Authority, the government’s regulatory body. However, it has become clear that the recommendations were not fully implemented. Several observers pointed to lack of funding, technical capacity, and political interference as some of the obstacles. The project proponents must develop measures that adequately mitigate the main ecosystem challenges and ensure their compliance.
Some observers noted that the railway line had an impact on soil, water, and air pollution during the construction and operation of the line. During construction, the earth was compacted and excavated. It also moved from place to place to build embankments.
This has many effects on the environment. For example, officials from the Community Forestry Association (around Mombasa’s coastal mangroves) observed sediments eroded by road embankments, affected streams, and plants. They said that “not only did it affect the development of the mangrove seeds and their self-germination, but it also blocked streams and reduced their size.”
Another challenge was the construction of underpasses to allow circulation under the railway. This is because the railroad is elevated, but these underpasses redirected surface waters and rain courses. Narok County respondents noted that this led to erosion, leading to sedimentation of water sources, including Lake Magadi, a unique alkaline and saline lake surrounded by wildlife and a major source of trona, a sodium carbonate compound that turns into soda ash or baking soda. Another impact was the blasting of land to obtain construction material. Communities around Nairobi said this caused tremors that sometimes caused buildings to crack.
The floods have been a major challenge. To avoid cutting the railroad embankments, contractors diverted natural surface water flows (such as streams) into underpasses. But this caused the volume and velocity of the water flow to increase, which caused flooding and soil erosion. Added to this was the removal of the surrounding vegetation, which previously held back the water. In Voi, county officials explained how stormwater flooded low-lying homes and farms during heavy rains.
In addition, sediments from the construction have caused the blocking or drying of rivers, especially the Empakashe and Mbagathi rivers, around Nairobi. Most of the communities in these areas depend on rivers for domestic consumption, watering livestock, and irrigated agriculture.
Another cause for concern was oil spills. These occurred due to fuel transportation accidents and train and rail maintenance activities. For example, local Kibwezi County officials said an oil spill contaminated the Thange River. Now the river cannot be used for irrigation or for domestic purposes. Land in the affected area remains unsafe for cultivation.
Noise pollution was also reported during the construction and operation of the railway, especially in the Nairobi and Voi areas. Some communities were unable to sleep, and noise levels disrupted classes in schools. Dust contamination was an additional challenge. There were reports of coughing and chest pain.
Communities that depend on wetlands and rivers in the Voi, Kibwezi, Tuala, and Narok areas have lost access to some of these critical resources, and the long-term prospects are unclear. An additional impact of the railroad was the appearance of illegal activities, such as grazing in protected areas.
Kenya Wildlife Service officials noted that local communities were using the underpasses to move their livestock into Tsavo National Park, especially around the Buchuma gate. Livestock raids caused severe soil degradation in the southern part of Tsavo East.
Wildlife was also affected. About 120 km of the line runs through a key wildlife area, Tsavo National Park, in Kenya. The elephants showed early signs of behavior modification. Among them, aggressiveness and avoidance of the railroad zone. This is consistent with the behavioral adaptations observed in other species that change their ranges or alter their movement patterns due to infrastructures.
Linear infrastructure projects such as rail must apply sustainable and ecologically sensitive measures to mitigate these impacts. For example, underpasses must be of adequate density and size. Currently, underpasses are scarce and are located in areas not normally used by wildlife. In addition, watercourses must be channeled and redirected to avoid flooding.
Furthermore, a further comprehensive assessment, with the participation of all stakeholders, of the environmental impacts of the railroad is required. This is essential to design a sustainable railway. It must ensure that development benefits are maximized, and ecosystem impacts are minimized.