Tunnel to ease Nairobi water woes nearly done

Tunneling experts at Makomboki site in Kigumo. [Boniface Gikandi, Standard]

Plans to inject an additional 140,000 cubic metres of water supply to Nairobi will soon be realised following completion of a tunnel tapping water from three rivers.

On Friday there was celebration in Makomboki, Kigumo constituency, after the contractor announced completion of drilling and parallel reinforcement of the tunnel.

The tunnel will empty water sourced from rivers Gikigie, Irati and Maragua into Ndaka-ini dam for onward transmission to Nairobi through the newly constructed Kigoro Treatment Works and a new steel pipeline.

Athi Water Service Board CEO Thuita Mwangi said the demand for water in Nairobi stands at 770,000 cubic metres against a much lower supply of 525,000 cubic metres.

David Kimingi, a lead consultant of the project, said the excavation works have been completed and the edges of the tunnel lined, to prevent leaking of water from the surface or inside along the 11.7-kilometre path.

Complaints

The excavation started four years ago amid complaints from locals that the project could dry up local rivers.

The project funded by World Bank at Sh21 billion is earmarked to inject the additional volume of water to consumers to end perennial shortage.

According to the design, the tunnel will only collect flood water from the three rivers and weirs (barriers), rather than dams, will be built at the tapping points.

Eng Alphaxard Kitheku from Athi Water yesterday told Murang’a County Development Implementation Coordination Committee that the contractor is currently working to reinforce lining of the tunnel after completion of excavation works.

Kitheku said the construction of two weir intakes at Maragua and Irati are ongoing, while the third at Gikigie will start next year.

“Construction at Irati River intake is 98 per cent complete and at Maragua River intake is at 20 percent,” said Kitheku.

Construction of raw and treated water transmission pipelines from Ndaka-ini Dam to Kirogo water treatment plant and to Nairobi is also ongoing.

Pipes laid

He told the committee, chaired by County Commissioner Mohamed Barre, that 15.5 kilometres out of the total 54 kilometres of steel pipes have been laid.

“The treated water from Kirogo will be channelled to the Gigiri reservoir for distribution in Nairobi,” explained Kitheku.

He further said that the laying of the pipes, especially between Ndaka-ini dam and Kirogo water treatment plant, has faced obstacles as some families objected the compensation given.