• The Nairobi City Water and Sewerage Company on Thursday said Ndakaini Dam, the main source of water supplied to the capital city, is 72.6 per cent full.
• With the dismal performance of short rains, many city residents are worried that the taps will soon dry.
Image: ALICE WAITHERA
Nairobi residents have been assured of a steady supply of water until the start of the long rains.
The long rains usually begin in March or early April.
With the dismal performance of short rains, many city residents are worried that the taps will soon dry.
However, the Nairobi City Water and Sewerage Company on Thursday said Ndakaini Dam, the main source of water supplied to the capital city, is 72.6 per cent full.
“There is no cause for alarm as we have 50.6 million cubic metres of water in the dam,” Nairobi City Water and Sewerage Company managing director Nahashon Muguna told the Star on the phone.
He said the amount of water in the dam is enough to sustain 63 per cent of the city’s demand.
Nairobi Water Sewerage Company receives a supply of 525 million litres per day from Ndakaini.
The demand in the city is 830 million litres per day, leaving a shortfall of 305 million litres.
As of December 12, the capacity of the dam in Murang'a county was 69.8 per cent full.
This means the dam then had slightly above 48 million cubic metres of water.
According to the 2019 census, Nairobi has a population of 4.3 million people and statistical projections estimate the number will hit 10 million by 2030, further straining the water supply.
Water rationing in Nairobi has been associated with the failure by authorities to upscale services to meet the demands of the rapidly growing population.
Experts say Nairobi ought to have had its first water collector tunnel in 2005. The second tunnel was to have been completed and operational by 2015.
Nairobi's water infrastructure has also been crumbling. The city does not have used water treatment plants.
Authorities say the dilapidated water pipes are a major reason for the shortage.
It is estimated that the city loses non-revenue water valued at Sh3.7 billion per year due to broken pipes, leakage and vandalism as well as illegal connections.
This is equivalent to 40 per cent of the total water supply. Non-revenue water is that which is produced but lost through leakage or theft.
Muguna said they have a problem transmitting water into the city as there has been no expansion in the last 23 years.
The Nairobi Water Sewerage Company is banking on the ongoing construction of a multibillion-shilling Northern Collector Tunnel.
The tunnel, which is set to be completed by April, will help boost the water supply to the city by 140 million litres.
The tunnel has been under construction since 2015 and is more than 91 per cent complete.
It will draw water from rivers Gikigie, Iratu and Maragua and channel it to Ndakaini Dam.
NWSC is also banking on the Kariminu II Dam in Gatundu North to ease the water woes in the city.
Upon completion, the dam will be 59 metres high, with a 26.5 billion-litre volume and produce 70 million litres of water a day.
Residents of Kiambu will be the major beneficiaries as 80 per cent of the water will go to Thika, Juja and Ruiru, with the remaining 20 per cent being pumped to Nairobi.
But even as the project is being implemented, the NWSC has been planting bamboo along the Ndakaini dam.
Authorities said the bamboo helps as windbreakers to prevent water from evaporating.
The Ndakaini Dam has a storage capacity of 70,000,000m3 (70 billion litres) at a full storage level and is 2,041 metres above sea level.
It has a depth average of 65 metres.
It consists of Kimakia and Gatare Natural forest which forms Aberdare Ranges. The main rivers that drain into the dam from this catchment are Thika, Githika and Kayuyu.
The area receives ample rainfall of between 2000–2500mm annually.
The dam is owned by Athi Water Works Development Agency and operated by the Nairobi City Water and Sewerage Company.
Its construction started in the year 1988 when the government compulsorily acquired approximately 1,200 acres to create space for the facility to supply portable water to Nairobi residents and its environs.
Water from the dam is conveyed through a system of tunnels running from the dam, tapping Kiama River and Kimakia River and diverting the flows to Chania River at the Mwagu Outfall.
Water is tapped from Chania River at Mwagu and conveyed via a tunnel to the Mataara chamber from where it’s conveyed by pipelines to Ngethu water production plant.