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Via The Guardian, a report on the critical state of Nairobi’s water supplies, clear evidence of a broken loop between how a city reconciles its thirst for water and its hunger for food:
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, 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”.
Njambi and other experts have plenty of possible solutions. There are things that can be done in the city, such as rainwater harvesting from buildings and “deliberate efforts to cause groundwater recharge”. The 115,000 cubic metres of wastewater, that the company treats daily, could be pumped back into the ground for eventual re-use.
But the most important route, they all say, is to care for the land. “The catchment is my ‘next God’,” says Kihamba. “Without it, I’m done.” The total catchment spans 970,000 hectares and, besides the city, must supply water to millions more within it and along the Tana River which wends down to the Indian Ocean. It consists of small towns, tea estates and an estimated 300,000 small farms, many of which supply food to the city.
“What we are seeing here is a broken loop between how a city reconciles its thirst for water and its hunger for food,” observes resilience expert Arturo Getz Escudero. “Cities can reward farmers for behaviours such as preventing erosion.” There are signs that this is already happening – such as the work of Fred Kihara and the Nairobi Water Fund which encourages landowners to conserve slopes.
“Working with 15,000 farmers, we’ve increased water to Nairobi by 27,000 cubic metres a day,” says Kihara. “Most is terracing, sediment trapping, 200,000 trees a season. The deal is you can keep the soil on your land with this good quality Napier grass that we supply you. We aim for three metres of permanent vegetation on banks. What you want is to reduce the pace of the water, get the rivers clean and improve flow.”
But the multiplicity of challenging trends – climate change (which intensifies floods), the needs of a city expected to double by 2030, a growing rural populace and hundreds of thousands of still unreached farmers – means the crisis is still not being addressed in its full gravity. “People are farming without soil and water conservation structures. Restoration of lands outside forests is a must,” says Oscar Simanto of the Kenya Forest Service.
“It needs more than we are doing,” says Njambi. “It is time for best practices. But the land is mostly private, which is difficult. Farmers look at economic benefits. When it rains, the water gushes down, causing damage. We can’t dictate what to do.”
Besides small farmers, estates must step up. Tea is promoted as a perennial that benefits farmers and keeps the ground covered. “But under the tea, the soil is panned,” says Njambi. “This can be managed by growing legumes or planting on contours,” says Ravi Prabhu, deputy director general of the World Agroforestry Centre, which is measuring the relationship between soil carbon and infiltration capacity in the valleys and hills.
The centre has also promoted financial incentives to nudge sustainable land management. With Jomo Kenyatta University of Agriculture and Technology, it found that “40% of water users in the city of Nairobi were willing to pay an incremental $1.25 (£1) over their tariffs for watershed management”. This could go to pay farmers for the “environmental services” they generate like increased water supplies.
Loans incentivise too. Nine years ago Peter Karanja, 70, received one for a cow. The centre helped him grow fruit trees and Napier grass; fed on the grass, the cow produced offspring and years of manure. Lying deep and rich behind bunds, little soil erodes from his land; his income has grown. But he needs better markets for his pears and plums. “It’s finding the high-value tree species that have the hydrological properties you want,” says Fergus Sinclair.
Back in Nairobi, an often fractious city that abounds with the energy of entrepreneurs, from the jua kali (“hot sun”) workers, to the digital global trendsetters in their air-conditioned offices, the lack of water is everyone’s crisis. It won’t be easy to replenish this essential resource, but Prabhu says that if the people of Kenya pull together the issue can be solved: “There is growing political will, and investments have started to flow. What is required is social capital from watershed to water user, and this situation could be turned around.”