• Once done Maragua dam will produce 120,000 cubic meters per day with a storage capacity of 64 million cubic meters.
• National government is planning dam but it should be expedited to solve city's water problem.
The controversial Sh6.8 billion Northern Water Collector Tunnel will not solve water shortages in Nairobi, a city official has said.
Nairobi City Water and Sewerage Company acting managing director Nahason Muguna said another dam is needed in Maragua to improve the reliability of Thika dam and the Northern Water Collector Tunnel.
"Without Maragua dam, the Northern Collector Tunnel will be producing water more less five months in a year. It may not be producing adequate water for the city. So there is a need to have Maragua dam constructed as soon as possible," Muguna said.
Once done Maragua dam will produce 120,000 cubic meters per day with a storage capacity of 64 million cubic meters, Muguna said.
He said the national government was planning for it but wished it could be expedited to solve the problem of water supply in Nairobi.
The Northern Collector Tunnel during its inception caused furore after leaders expressed concerns about its construction.
Raila Odinga accused the government of being “secretive” about the project and said it would “turn counties into deserts”.
He called it a “tunnel of death”. The Tunnel is set to be completed mid next year.
Raila said the project would lead to the drying up of rivers in Murang’a county and elsewhere.
“It will be collecting water from the rivers at their source in the Aberdares and diverting the water to Thika’s Ndakaini Dam for use in Nairobi,” he said.
Muguna said the project will improve water supply in Nairobi by 140,000 cubic meters per day.
Nairobi gets 580,000 cubic metres of water daily, against a demand of 750,000 cubic metres, leaving a deficit of about 200,000 cubic metres.
Muguna said the Thika dam was at 43 percent full, an equivalent of 30 million cubic meters.
The acting MD said they have harvested two million cubic meters of water in Thika dam, an equivalent of four days full production.
Muguna said most of water catchment areas have badly been degraded leading to erratic rains.
"We must plant a lot of trees from the current 7.2 per cent to 15 per cent. If we can reach 15 percent, I believe there will be a change in the river flows to our dams,"he said.
Muguna assured Nairobi residents that the production will last up to October, short rains are expected.
He dismissed leaders who have been agitating for water supply to residents of areas where dams supplying Nairobi are located.
"You cannot give water just from where the dam is situated because of hydraulics. For instance, if you want to give Githunguri residents water from Ruiru dam, it will require a lot of pumping which is very expensive," he said.
Leaders from Kiambu have been up in arms agitating for residents to benefit from water.
Muguna said there are two dams that are being developed to serve Kiambu.
"There is Karimenu dam which has just been commissioned. It is going to produce 47,000 cubic meters of water for Ruiru, Juja area and Kiambu town. There is Ruiru II which will be used in Kiambu."
Muguna said that by the time the two dams are completed and commissioned in 2022, the whole of Kiambu will have around 92 per cent of water coverage.