More Projects

Northern Collector Tunnel

Our Role

SMEC completed detailed design and tender documentation under Phase I of the project, and is currently providing construction supervision under Phase II.

SMEC’s scope of works includes:

  • Detailed design
  • Preparation of tender documents
  • Review and approval of work materials
  • Project monitoring
  • Construction supervision.

Project Overview

The Northern Collector Tunnel is part of a master plan development strategy for new water sources for Nairobi and 13 satellite towns up to the year 2035.

The project includes construction of a 12 km long water transfer tunnel which will intercept three rivers to the north of Nairobi and transfer the intercepted water to the existing Thika Dam, the main water source for Nairobi.

The project, undertaken in two phases, includes:

  • A 12 km long, 4 m diameter, bulk water transfer tunnel from Maragua, Gikigie and Irati rivers
  • Three run-of-river intake weirs with an outlet to Thika Dam
  • Associate stilling and de-silting basins
  • Fish ladders at Maragua, Gikigie and Irati Rivers
  • An outtake sluice and stilling basin at Githika Outfall.
Technical Area:
Athi Water and Water and Environment Services Board

Learn More

To learn more about our Tunnels capabilities please fill out the form below and one of our team will be in touch.