Infrastructure

Northern Collector Tunnel to End Nairobi Water Woes

The tunnel stands as Kenya’s longest water diversion passageway.

Updated on

May 10, 2025

Early construction works on the Northern Collector Tunnel project. PHOTO | COURTESY

Initial construction work on the Sh8 billion Northern Water Collector Tunnel project in Murang’a has now been completed, creating Kenya’s longest water-gathering tunnel.

Drilling for the tunnel began in February 2015 and is designed to increase water levels at the Ndakaini Dam, while boosting Nairobi’s water supply by 140 million litres per day.

The Northern Water Collector Tunnel consists of a 12 km-long, 3.2m-wide water diversion tunnel from the River Maragua to the Ndakaini Dam.

This project is hailed as a pioneering endeavour in Kenya.

China Gezhouba Group Company is executing the project under the supervision of the Athi Water Services Board to address the challenge of transporting water across difficult terrain.

According to Arnold Karanja, chairman of the Nairobi City Water and Sewerage Company (NWSC), residents of Nairobi’s Utawala estate are now receiving water twice a week.

“Those who are connected are getting water for the first time,” Mr Karanja said recently.

Walter Kamau, a resident of Swan Villa, confirmed: “In the past 24 years, we’ve never had water from Nairobi Water Company. I’m happy we’re now receiving it twice a week.”

The Northern Water Collector Tunnel is seen as a solution to Nairobi’s water crisis and is expected to end water shortages in areas such as Lang’ata, Utawala, and Karen.

NWSC states that a pipeline is being extended from Karen to Lang’ata, with more than 80% of the work already completed, bringing the region closer to resolving its water issues.

According to Dong Qide, project engineer for China Gezhouba Group Company, the tunnel’s excavation involved the construction of three intakes at Maragua, Gikigie, and Irate – all of which were completed in strict adherence to Kenya’s environmental laws and policies.

Approximately 40% of floodwater from the three rivers will be captured and diverted into the tunnel, then into the Ndakaini Dam before being piped to Nairobi.

The Northern Water Collector Tunnel sparked controversy in 2016 after opposition leader Raila Odinga alleged the project would cause significant environmental damage.

Mr Odinga, who referred to the project as a “tunnel of death,” called on the government to halt development, arguing that the facility would turn seven counties into deserts.

The government dismissed the allegations, stating that the project’s integrity remained intact and that an environmental assessment had approved the World Bank-funded scheme.