Aerial view of Nairobi’s Ndakaini reservoir in January 2017 - the water levels were already low then. Photo: B Bidder / The Guardian

By Cathy Watson
24 July 2017
(The Guardian) – For the team managing Nairobi’s water, the stakes have never been so high. Water-rationing has been going on in Kenya’s capital since 1 January 2017, and supplies might run dry by September. The last two rainy seasons were dismal; more rain is not expected until October and cannot be counted on.
For the city’s 3.4 million residents, the possibility of the entire city running dry is so beyond their control that most bat the thought away and soldier on, storing water in jerry cans when taps flow. But the problem is getting harder to ignore. On 14 July, Nairobi City County declared a cholera outbreak, citing among causes “irregular supply of potable water”. How bad might this get?“At the end of every rainy season I have excess water, but this year no, we’re only 37% full,” says Job Kihamba, who manages Ndakaini, the storage dam that traps three rivers that flow down from the Aberdare mountain range and releases the water in the dry season. The Ndakaini–Ng’ethu system accounts for 85% of Nairobi’s water; every day the engineer measures what comes in, what leaves, and the safety of the dam wall.For the last 12 months water has been short. The rains in October–December 2016 delivered just 268mm of water compared to about 700mm expected from rainfall patterns in recent years. Then the March–May rains this year were late. When I visited Ndakaini with colleagues from the World Agroforestry Centre in April, the reservoir was just 20% full, an unprecedented low. We gazed at the exposed mud and, looking towards the city, thought “Who down there knows?”Finally, the rains came on 1 May, but delivered just 440mm of the 1,000mm expected during the rainy season. Today the Chania and Sasumua, two rivers that supply the city, resemble streams.The water available to the city has plummeted. Nairobi’s water company is distributing 400,000 cubic metres a day, 150,000 less than it used to and 350,000 less than the city needs; 60% of the population lacks reliable water. Of 78 public boreholes, only 48 work. “Nairobi used to be a swamp but is no longer behaving like one. Our underground rivers have dried up,” says engineer Lucy Njambi Macharia, Nairobi City Water and Sewerage Company (NCWSC) environment manager. Swamps are the recharge areas, but they have been built upon. The county is attempting to address this but is “overwhelmed by urbanisation and the need for housing”. [more]

Thirsty city: after months of water rationing Nairobi may run dry