Ruiru II Dam in Kenya: this major project is starting!


Egis, in consortium with the VINCI group, is starting this emblematic project with the objective of securing the drinking water supply for more than 300,000 inhabitants of Nairobi.

One ambition: to secure the drinking water supply for the capital Nairobi

Drinking water "H24" for the populations of the outskirts of Nairobi? This is the ambition of the Ruiru II project.

Launched in 2012 by the Athi Water Services Board, the organisation in charge of water management in Nairobi, Ruiru II is a major project aimed at sustainably improving the water supply in the outskirts of Nairobi, i.e. 300,000 inhabitants.

Large-scale works

A project involving the construction of large-scale works, including:

  • an embankment dam with a clay core 55 m high and 375 m long at the crest
  • a side flood channel designed for a flow of over 800 m3/s
  • a 60 m high intake tower associated with a concrete sluice allowing raw water to be drawn from the reservoir (with a capacity of 7M m3), drained and the ecological flows of the Athi River to be respected
  • a 16 km long, 1,000 mm diameter raw water gravity pipeline
  • a drinking water treatment plant with a capacity of 40,000 m3/d
  • a 9 km long, 500 mm diameter drinking water delivery pipeline
  • two storage reservoirs associated with the towns of Karuri and Kiambu of 10,000 m3 and 5,000 m3 respectively to supply drinking water to 300,000 inhabitants. The surplus supply will supply Nairobi in the early years.

More than 1 million m3 of cut and fill will be required to build the dam. The construction operations also involve temporary and permanent access, the opening and rehabilitation of borrow pits and quarries, the temporary diversion of the river through the concrete channel and the creation of cofferdams some 20 metres high upstream and downstream.

Egis' strength: multi-trade skills for major projects

Egis, as part of the consortium, is responsible for carrying out the complete design of all the project's structures, from preliminary studies to execution plans.

During the construction phase, Egis will be responsible for the integrated supervision of all works, including the management of the site laboratory, the installation of the dam's instrumentation, and the monitoring of social and environmental aspects.

"This project is a new opportunity for Egis to showcase all of its specialities in geotechnics, civil engineering, hydraulics, water treatment and the environment, and to fully exploit the synergies between our French and local teams". Frédéric Walet, Deputy CEO in charge of operations for the BU Major Structures, Water, Environment, Energy.

BIM at the heart of the project

The size and number of structures to be built, the complexity of the technical challenges and the very high level of cooperation expected between the various specialities based in several countries led Egis to design the entire project in collaborative, multi-site BIM mode.

"This working method requires a high degree of knowledge of software ranging from 3D models to electronic document management, all linked by a common data environment. The work will be carried out through two collaborative platforms (Project Wise and SGTi4); we are assisted for this project by our best "BIM by Egis" specialists."  Arnaud Le Peillet, Project Manager

It's a great adventure that's just beginning....

© Egis – Arnaud Le Peillet