The Challenge

Since the 1970s, forests on steep hillsides and areas of wetlands around Nairobi have been converted to agriculture. As a result, sedimentation is becoming a serious problem, reducing the capacity of reservoirs and increasing the costs for water treatment. Today, 60% of Nairobi’s residents are water insecure. The challenges to water security will likely grow as climate change brings increasingly unpredictable rainfall.

CIAT’s Role

A public-private steering committee including CIAT, WLE, and other partners, commissioned a study to assess  the economic viability of a water fund in the Upper Tana River basin. CIAT used its expertise in detecting and mapping land use change to inform targeted investments for preventing major ecosystem damage. The study evaluated the impact of conservation interventions to reduce suspended sediment in waterways and increase dry season water flows; two of the key issues affecting water supply and community sustainability. CIAT and The Nature Conservancy provided scientific and project management support to ensure the overall success of the study.

What has changed?

The Kenyan Government, businesses, conservation groups, and utilities, launched Africa’s first water fund. The Upper Tana-Nairobi Water Fund supports improvements in how land and water are managed upstream to benefit farmers, businesses, and Kenyans throughout the watershed. Working in partnership with Kenya’s Water and Resources management authority, CIAT plans to measure water quality in real time at specific points along the watershed. CIAT scientists will also inform decisions about land management options by measuring the effectiveness of different interventions.


Fred Kizito

Fred Kizito

Senior Scientist, Soils Research Area

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