DATE: 2015-2017

TYPE OF PROJECT: Modular Steel Truss Bridges​​

CLIENT: Kenya National Highways Authority (KeNHA)

SUMMARY: From 2015 to 2017, Centunion implemented a contract for the design, fabrication, supply and Erection Supervision of Modular Steel Truss Bridges in Kenya. In total, 6 bridges from 60 to 120 m length were installed along the Loruk – Barpelo (B4) and Homa Bay – Mbita (C19) Roads. The main goal was to promote socio-economic development with climate-resilient infrastructures, providing isolated communities with access over impassable landscapes to essential services and ensuring social inclusion and networking. The bridge design was consistent with the climate and environmental conditions and considered the diversity of the climate within the country, ranging from coastal climate (high humidity and salty conditions) and highlands (low temperatures and high rainfall intensity) to the semiarid and desert conditions (wide temperature ranges). The bridges are designed for both vehicles and pedestrians. CENTUNION provided the corresponding transfer of technology by means of a technical assistance for the erection and maintenance of steel bridges and the introduction to a bridge management system.

Mbita Causeway Bridge, a history of success: Goodbye to causeway as modern, fly-over bridge, was installed: The Lake Victoria, with a surface area of about 68,800 km2, is the second largest freshwater body in the world. It is a transboundary resource shared by Kenya, Tanzania, and Uganda. From 1960 to 1983 a manual ferry operated to enhance movement through the channel from Mbita to Rusinga Island but was susceptible to accidents that led to losses. The construction of Mbita Causeway in 1983 was a response to immense loss of lives and property within the channel during transit, but it did not consider environmental impacts at all. The Causeway affected the alternative exchange pathway between the gulf and the open lake, impacting on the hydrology of the gulf. The causeway was constructed to link Rusinga Island to the mainland to enhance trade and human traffic between the two zones, but it essentially blocked a natural channel with dimensions of 250 m in length and 10 m in depth through earth filling with a road overlain to Rusinga Island. Due to the impact of the causeway, the water quality declined significantly, mainly due to increased sedimentation, as well as pollution and eutrophication. A remarkable result was achieved in 2018 joining Mainland Mbita to the Rusinga Island with a bridge designed and supplied by Centunion. The bridge replaced the causeway, thereby restoring the lagoon life, lagoon transport and having a positive impact on the hydrology of the gulf. The opening of the Mbita channel helped the dynamics of nutrient movements in the gulf to bring a visible change in the species diversity and species abundance in the gulf. Besides, the conflict between Kenyan and Uganda fishermen, due to a shortage of fish on the Kenyan side of the lake, is set to end following the opening of the bridge. Vehicles and pedestrians use the upper side of the 160 meter bridge, while allowing navigability of larger boats at the lower side.