Unknown to the residents of Murang’a, their town sits on top of a huge tunnel that connects two rivers — Mathioya and Maragwa — and thus the Northern Water Collector Tunnel, brought into national limelight by Cord leader Raila Odinga, will not be the first in the county; and as Nairobi expands, it will not be the last.
The building of this 63-year-old tunnel at the height of the Mau Mau emergency in 1953 was an engineering feat never accomplished before in East Africa. It was supposed to address Nairobi’s power problem.
There is something else about the tunnel: It was the first one lined with concrete to be completed in East Africa and it was a marvel then because it involved the excavation of 76,000 tonnes of rock and it consumed an estimated 6,000 tonnes of concrete to line it.
Unlike the Northern Water Collector Tunnel, the Merila Tunnel — in today’s village of Mirira in Kiharu — was built to serve the Nairobi population by supplying the city with electricity, not water.
Nairobi town had found itself at the edge of a dry nyika, thanks to railway engineers and colonial indecision.
On the afternoon of May 30, 1899, just six days after Queen Victoria’s birthday, the railway had reached this “desolate, windswept swamp”, as engineer George Whitehouse called it.
The place was useful for railway purposes and there was a feeling that nobody in his right mind would have lived here. It was hot and dusty during the dry season and muddy and swampy during the rainy season.
“The only evidence of the occasional presence of human-kind was the old caravan track skirting the bog-like plain,” wrote railway engineer Ronald Preston in his diary.
When the town was established in 1899, it was hoped that the crystal clear Nairobi River — “the place of cool waters” — would provide residents with clean water.
A small dam had been built in Chiromo that was to supply water by gravity to the residents. It was by then enough for the railway workers and traders. But the Chiromo dam, actually a check dam, became contaminated and was abandoned, forcing the city fathers to build a bigger dam in Kikuyu springs and the Kabete treatment plants in 1906.
As the Nairobi population grew, the Ruiru dam was built in 1936 and the Sasumua dam in 1945. This was to supply the mainly whites-only estates and what was known as the “African locations” of Bahati, Majengo and Pumwani.
For electricity, by this time, Nairobi was largely relying on engine oil and the need to build an underground tunnel under Murang’a towards an hydroelectricity dam arose. This was to be the first big hydropower station to supply Nairobi with cheap electricity.
When the initial application was made by East African Power and Lighting Company’s lawyers, Hamilton Harrison and Mathews, in March 1948, this area was part of the Kikuyu Native Reserve and the application indicated that they required some 25 acres for the project, built in two phases.
Engineers had said that the only nearer place where a hydropower plant could be built was in Murang’a, then known as Fort Hall, where a local chief, Joseph Wanjii, had donated part of his land for that purpose.
That is why it is known as Wanjii Power Station in the chief’s honour. (He also received a gold watch from the colonial governor when it was opened).
By then, there was a smaller hydropower station in Thika, mainly serving the sisal factories, and another 1,760KW thermal station in Ruiru that supplied Nairobi with power.
The Wanjii Power Station, still running in Murang’a, was a controversial project — and locals working on it had to be screened lest they turned out to be Mau Mau sympathisers. There were also concerns about whether Murang’a town would be safe with an underground tunnel.
More than 60 years later, it appears the engineers got it right. Taking water from the Mathioya River towards the Maragua River required engineers to blast a solid rock at a depth of 46 metres below the surface.
It was this experiment that gave engineers a chance to look again at the potential of the entire Tana Basin and it led to the development of the Seven Forks Dams that today supply Kenya with power.
Actually, the building of the Merila Tunnel happened at the same time that the city was expanding the Sasumua to a 33.5 metre high earth dam.
Despite the location problems, Nairobi had grown into a big commercial centre and, by 1950, it had an estimated population of about 118,000 people. It required an additional 8,000KW of electricity — and more water, too.
Sasumua was the second experiment with water tunnels and river diversion. It consists of a small concrete gravity weir built on the Chania River that diverts the river flows via a short channel to Sasumua stream, about 5km upstream of the dam.
Two more streams, Kiburu West and East, were diverted into this dam in 1963 and that is how Nairobi was assured of clean running water in the 1960s and 1970s. Today, Sasumua supplies 12 per cent of Nairobi’s water via a 60-kilometre pipe to the Kabete treatment plant.
Back to the new Murang’a tunnels. The problem of water in Nairobi is a result of population growth, an aging pipe network and politics, and how to navigate these problems has been a poser to leaders.
In 2002, when Sasumua Dam was destroyed by floods, the city was left with only Ndakaini as its main supplier of water and had to go through a water-rationing programme.
When there was a drought in 2009 and Ndakaini’s volume fell below 26 million cubic metres from the regular 70 million, the city was forced to adopt rationing and drill boreholes.
That is how vulnerable Nairobi remains even as the debate on the impact of the Murang’a tunnel enters its second week.
Lost in this political debate is perhaps the long relationship between Nairobi, Murang’a and Nyandarua in the provision of water and electric power — and what options the city has. Also lost in the debate is how counties can share resources.
Perhaps because of its location, Nairobi will continue to rely on Murang’a, Kiambu and Nyandarua counties for water.
Besides the colonial projects of Sasumua and Ruiru, Nairobi had two more water projects in 1972-1978 and 1978-1984 — both mooted to supply the city with enough water until 1987. But these fell short of expectations as Nairobi was put under an inept Nairobi City Commission from 1983 to 1990.
The Ndakaini dam was to be the third phase and the third experiment with water tunnels. Unknown to many, Ndakaini has its own concrete tunnels that transfer water from the dam passing by the Kiama and Kimakia rivers and feeding into the Chania River, where a weir is built in Mwagu Village before it enters into yet another tunnel that runs to the Mataara intake in Gatundu North — the place where the piping of Nairobi water starts to the Ngethu treatment plant and Gigiri reservoirs.
Part of the Third Nairobi Water Supply Project financed by the African Development Bank, the World Bank, the European Investment Bank and Japan’s Overseas Economic Co-operation Fund, the tunnels at Ndakaini had also been the subject of scrutiny.
Actually, the World Bank had to send an independent team to review the tunnel’s design. (It found them acceptable). It was also a highly expensive project.
Initially, the project was supposed to cost $33.5 million but it ended up consuming $57 million — a 70 per cent increase — because donors fell out with President Moi’s government over human rights and democracy and delayed disbursement of funds. In 1993, the contractor almost pulled out due to non-payment.
“The issue of resettlement and compensation created problems between land owners and the government, who resorted to forced evictions in the end,” according to the final project report.
Also, the final report says “the contractor’s claims were generally higher than could be substantiated … and his variation of prices was not always well supported.”
Besides that, and on a positive side, Ndakaini has its own underground power station designed to generate 2MW of power.
It was hoped that since Ndakaini would meet Nairobi’s water requirements up to 2005, the city was to have finished the now controversial Northern Water Collector Tunnel project.
That Nairobi is in a water crisis is because it has only enough of it to serve its 2005 population. A World Bank appraisal report of Ndakaini had warned that this dam would not meet the 2010 Nairobi water demands of 746,000 cubic metres per day.
The current total supply to Nairobi — from all its water sources — is 540,000 cubic metres a day against a demand estimated at about 750,000 cubic metres a day. Thus we have a daily shortfall of 210,000 cubic metres.
And that is where debate on the Northern Water Collector Tunnel comes in and what to do with Nairobi’s population of 6 million people.
For its part, Ndakaini is facing a lot of pressure as deforestation in Aberdares threatens the water sources. More so, the rise of new Nairobi estates and industrial complexes — Mlolongo, Ruai, Syokimau and Athi River Export Processing Zones — will see water demand rise.
At the time of its construction, the locals were promised that they would benefit from Ndakaini water. They didn’t, and that has left a lot of bitterness from Murang’a leaders.
That matter was first raised in Parliament in 1995 by then Kigumo MP Kirore Mwaura and later by Juja MP Stephen Ndichu, all demanding that Murang’a and Thika residents should get a fraction of the money that Nairobi gets from the sale of Ndakaini water.
It is the same argument that was put forward recently by Murang’a Senator Kembi Gitura that water is a shared resource and both Nairobi and Murang’a should find a formula for sharing the revenue.
But centrally to what Senators James Orengo and Johnson Muthama said recently that the water was to feed some elite projects, the Northern Tunnel is derived from the Nairobi Water Master Plan that is supposed to address the needs of Nairobi and its satellite towns by 2035.
The 13 towns that are to benefit from the entire scheme are Kikuyu, Ruiru-Juja, Kiambu, Karuri, Githunguri, Mavoko Municipality, Ngong Township, Ongata Rongai, Thika, Gatundu, Limuru, Lari and Tala-Kangundo.
How these water problems will be sorted out is the big question. But Nairobi, with its shortfall of 210,000 cubic metres a day, will be hit hardest.
