Thwake Multipurpose Water Development Project

Nation

defining

water

project

to

supply

renewable

energy

and

tackle

water

insecurity

Thwake multipurpose water development is a priority project in the Government of Kenya’s Vision 2030 strategy. It is the largest water conservation and hydropower project ever to be undertaken by the government of Kenya. The works will combine a new dam reservoir and hydropower facility with enhanced water supply and irrigation that will impact 1.3 million people.

Currently under construction, SMEC is leading the design and engineering of the dam, spillway, and powerhouse. SMEC is also undertaking investigations and developing designs for two new water treatment facilities and sanitation infrastructure for the projects later phases.

Integrated design and management

As part of the dam design, SMEC has delivered advanced hydraulic modelling to test and optimize flow rates across the 422km distribution network. The team also developed a miniature physical model of the site area to clearly articulate the interfacing components of the dam’s infrastructure.

Sedimentation of the dam was a major problem which was overcome using sediment modelling. Based on SMEC’s recommendations, a multi-agency government committee has been established to spearhead catchment protection and prevent buildup of sediment. This includes upgrading sewerage infrastructure in Nairobi City to control pollution to Athi River.

Late in December 2021, engineers successfully managed to divert the Athi river into the dam’s two mega tunnels, marking a significant milestone in the project’s implementation.

Location

Kenya

Client

Ministry of Water and Irrigation (Kenya)

Expertise

Hydropower & Dams Water Supply

668

mega cubic m

water storage capacity

40000

of irrigated land

of electricity to the national grid