Kenya – Upper Tana basin

Caring for Kenya’s largest river

Tana River, Kenya’s largest river, plays a vital role in the country’s economy.

A household survey by a PRESA researcher (right) at the Kapingazi River basin. PHOTO: Miika Mäkelä

A household survey by a PRESA researcher (right) at the Kapingazi River basin. PHOTO: Miika Mäkelä

The Tana begins in the central Kenya highlands, flowing 800 kilometres to the Indian Ocean. The Tana River basin is divided into two distinct ecosystems. The Upper Tana basin, in the central part of

Kenya, receives more rainfall and is the source of most of the water. Then there is the lower, drier and flatter Lower Tana which is completely dependent on the river’s water.

Tana River is used to produce hydroelectricity and it supplies irrigation water to the some of the largest public schemes in Kenya. However, the reservoirs in the middle part of the river are threatened by sediments generated from the intensively farmed areas in the upper Tana catchment.

Ecosystem degradation has resulted in unpredictable flows of water amidst rising demand. The degradation is caused by deforestation, and the expansion of commercial and subsistence farming activities especially in the upper catchment area.

PRESA focuses on the Upper Tana, where ecosystem degradation has the highest impact on the river’s life supporting functions.

In the upper Tana catchment, PRESA is at the Kapingazi River – a tributary of the Tana – to generate knowledge on the potential of payments for environmental services. The Kapingazi catchment area is 61.2 square kilometres. The cropping pattern is stratified, with a tea zone in the upper part, especially around Kiriari, a transition zone at Kairuri where both coffee and tea are dominant, and a coffee zone in the lower catchment.

Some farmers are receiving premium prices for coffee and tea from eco-certification programmes by UTZ and Rainforest Alliance. Soil and water conservation practices, including tree planting, are part of the certification requirements.

We found that the Kapingazi River carries a high sediment load during the wet season due to soil erosion from exposed farming areas before crop vegetation cover is sufficient. Other bare spots include roads, footpaths, homesteads, market centres and other public areas. The flow of the river during the dry season is becoming unreliable.

The factors driving land use change are: population increase, need for income diversification, fluctuation in prices of cash crops, climate variability and displacement of people due to political violence.

PRESA is working with the Mount Kenya East Pilot Project for Natural Resource management (MKEPP), the Green Water Credits project of the World Soil Information Centre (ISRIC) and the Jomo

Kenyatta University of Agriculture and Technology to explore a rewards-based approach to address degradation at the upper Tana catchment.

Farmers’ capacity to estimate opportunity costs is limited. Although our surveys show that land owners are willing to accept US$93 a year to adopt improved land use practices, models indicate that the more realistic figure should have been US$232 per hectare per year.

Another important finding was that people already involved with MKEPP were willing to get into contracts for relatively lower pay, possibly because of other benefits such as free training.

Next steps

  1. Developing a technology targeting tool with Green Water Credits.
  2. An analysis of local by-laws and institutions that may constrain environmental service rewards.
  3. Roundtable discussions with private sector buyers, including the direct beneficiaries of environmental services.

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Environmental service

Watershed services

Potential provider of environmental services

Owners of agricultural land and farmers in the upper and middle catchment areas.

Potential buyers