Even as the rain pours, we are beset with warnings that as soon as the rain stops we shall return to drought and water shortages. In Nairobi, the tap water rationing still continues. The problem, says UNEP, is not the rainfall, but the water waste. If we harvested the rainfall, we would have plenty of water, and water harvesting isn’t even expensive.
Across Africa, the ongoing water crisis has been exacerbated, says the United Nations Environmental Programme, by the low investment in water projects, even where water resources are plentiful. A UNEP report in November 2006 showed Kenya wouldn’t even rank as water stressed if rain water harvesting became commonplace.
Nairobi, alone, could support six to ten million people with 60 litres a day if rain water harvesting techniques were implemented, reported the organisation, with the supply potential of the city running at 460,000 cubic metres - but only 50 per cent of that currently reaching consumers.
In March this year for World Water Day, UNEP sent the same message again, with a report showing that investing $20m in low cost water technologies globally, including drip irrigation and treadle pumps, would lift 100 million families out of extreme poverty.
In Kenya, local organisations are now working hard to achieve take-up and offer new water solutions for Kenyan families and farmers alike. Leading in the mission has been the Kenya Rainwater Association (KRA), which has now developed a set of simple water harvesting blueprints, for city residents and for farmers.
According to Jackson Kariuki, a technical officer for KRA, water run offs during the rains around homes can be redirected and stored in specially constructed underground tanks.
The tanks have a silt trap that sieves the silt. “In arid Gansu China, they use run off for drinking and farming,” said Kariuki. Road run offs can also be trapped in trenches and directed to underground tanks.
The organisation also gives information on ways of collecting rainwater using guttering around roofs, and draining the water down to storage tanks.
In arid Mwingi, in Eastern province, concrete guttering has even been put in on huge rocks: guttering can capture run-off from any large run-off area. The run off and rain water trapped on the rocks is being directed to dams and underground tanks, and has meant that villagers who previously walked long distances for water now have it within 500m, and small scale commercial farming has thrived.
In a place with average annual rainfall of 300mm a roof of 30 square meters can provide a home with 9000 litres of safe drinking water. A family of five each using 20 litres daily will see the guttered water reservoir last them for 3 months.
A new water conservation farming trend now common in China, is also now gradually gaining a following in Kenya where the farming area is covered with a nylon sheet that has holes, through which seeds are planted, and the crop grows through.
In rainy seasons, rain drops pass through open pores in the sheet to the ground. But when it’s sunny, the sheet stops water from evaporating. According to Kariuki, this technique also hampers weeds from flourishing. “It’s even practical on small gardens at homes” he said.
More ambitious rural water harvesting projects include the building of shallow pits lined with plastic dam liners. These are being used to construct farm pods that trap either run offs or rain water and are ideal for growing vegetables in close proximity to the pods. The water in the pods is connected to an irrigation drip kit. The drip kit sees the same amount of water achieve far more irrigation than conventional overhead irrigation methods.
A drip kit for a small vegetable garden costs from Sh2000.
In places where there are soils like clay or black cotton soil, such as Narok and Mwingi, KRA is now overseeing the construction of earth dams. The fenced dams hold 150,000 litres of water being used by residents to farm. The earth wall holds stagnant run off water trapped during rainy spells and costs around Sh80,000 to build.
For more details of water harvesting options, the Kenya Rainwater Association can be contacted on:
Kenya Rainwater Association,
P.O. Box 10742-00100, Nairobi, Kenya
Tel./fax: +254 (0) 20 2710657
Hurlingham, Rose Avenue, Off Argwings Kodhek Road, Rose Avenue Flats (next to Kwality Hotel), Block B, Office No. 4.
Written by Bob Koigi for African Laughter
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