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THE KENYA

  • 14/10/1998

Captured rainwater has regenerated degraded lands in Kenya. Eroded grazing areas have been rejuvenated by building mini-catchments using a 'pitting and ridging technique' known as katumani. This is accompanied by re-seeding of native grasses and legumes. Pits are dug at the top of an eroded slope below a cut-off drain, which intercepts run-off.

This creates an interlocking system of catchments extending down the slope and final embankments (30 cm high) are built around the crescent shaped trenches. Cow peas and other groundcover crops are sown on the ridges. Grazing cattle is banned to allow vegetation cover.

Though easy to construct and maintain, pitting is labour- intensive, requiring community involvement. Harvesting of the surface run-off increases the moisture content of the soil, enhancing the yield of grains and legumes. Total dry matter production on these lands increases by a factor of 5 to 10 compared to untreated land.

Community-based organisations have shown the way by developing rainwater harvesting practices at the grassroots level. The Laikipia district provides an instance of how rainwater harvesting can even alleviate poverty. Water, a key ingredient in poverty alleviation, can greatly increase food and livestock production. A decade ago, the Anglican Church of Kenya made a small start with an ordinary 200-litre oil drum and a few one metre by three metre galvanised iron sheets.

The outcome has been the Kenya Rainwater Association, set up to coordinate individuals and institutions interested in utilising rainwater. The programme has introduced 2.5-cufaic metre jars to harvest and store rainwater, apart from introducing run-off farming.

Ten years down the road, the crop yield has increased immensely. Yields of maize - the region's staple food - have increased by more than 200 per cent and crop failures are less frequent. Diseases from unsafe water have declined, while the extra income has enhanced living standards.

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