Forests and water - case studies
The impact of a Government-promoted settlement scheme on Mount Kenya hydrology
At 5 200 m above sea level, Mount Kenya is a prominent volcanic cone rising more than 3 000 m above the surrounding semi-arid plains of central Kenya. The upper slopes support nival, periglacial and afro-alpine vegetation, and the forest belt covers the area between about 3 000 and 4 000 m above sea level. Together, these upper belts receive copious precipitation - in excess of 2 000 mm/year - making them a vital source of water. They supply several perennial rivers and subsurface aquifers for the plains below.
The southeastern slopes of the mountain are the most humid, while the north and northwest are appreciably drier, especially at lower altitudes. In the lower northwestern forest belt, annual precipitation declines from 1 500 mm to less than 600 mm, and there is rapid transition from forest to shrub, savannah and semi-desert. Rainfed agriculture is feasible only in a relatively small area close to the lower timber line.
For centuries, this area was used mainly by Massai and Samburu pastoralists, who practised a form of nomadism adapted to the seasonal and annual variations in water availability. The colonial period witnessed a radical transition. Large areas of the plateau and mountain foothills were incorporated into ranches and large farm holdings owned by white settlers, and much of the administrative district of Laikipia became known as the ”White Highlands”. Ranching was the primary occupation and, given this very extensive form of land use, water problems were virtually non-existent.
Following independence in 1964, the Government of Kenya saw the Mount Kenya region as a vital land resource for the resettlement of landless populations from the southeast of the country. Between 1976 and 1982, the region was subject to an intensive land development scheme, which evolved into a private real estate business. Accompanying social, financial and political measures were ill-conceived, and the scheme followed an ecologically disastrous course that led to the serious water conflicts of today.
In the 1970s, the government surveyed the land and subdivided it according to a geometrical grid, regardless of soil quality, topography, vegetation cover, road access or water availability. Lots were sold or allocated by chance, some in good locations, some in bad. Settlers who found themselves in the northwestern zone were the worst off, and many survived the first years only because family members remaining in their areas of origin were able to assist. Moreover, at 0.5 to 2 ha each, most parcels were too small to support sustainable farming.
The reactions of the settled population were varied. Some survived as subsistence farmers, some sought distant off-farm labour, and others found a variety of local jobs to supplement their own unreliable food production. The forest belt was also penetrated, and illegal timber cutting and farming in the forest had further negative impacts on water availability at lower levels.
Nowadays, the entire area is affected by overgrazing, overexploitation of agricultural land, soil erosion and gullying. National parks have been established further downstream and in the Rift Valley escarpment. The ensuing development of tourism, including on the mountain itself, provides an important source of cash and employment for local settlers, but it also places additional demands on the ever-decreasing water supply.
Given the continued growth in demand for water, the pressure on perennial rivers has accelerated, leading to dramatically decreased low flows of, for example, the Ewaso Ng’iro river in the lower lands. In the 1960s, this river’s median decadal flow for February was 9 m3/second, which has since dropped to less than 1 m3/second. In low rainfall years, the lower river dries up completely, and downstream populations, as well as wildlife and tourism, face disaster.
The responsibility for this situation is shared by all stakeholders, many of whom are unaware of their downstream neighbours’ water demands. Water-related conflicts have erupted, but have been interpreted as ethnic clashes.
Between 1970 and 2000, the Swiss Development Cooperation supported a long-term applied research study. Researchers assessed the environmental and socio-economic problems facing the Mount Kenya area, and emphasized the importance of preserving the forest belt, which represents a critical buffer zone between the protected highlands above and the agricultural lands below.
Detailed investigations of water conservation in different agro-ecological zones assessed the effects of different land-use methods on water loss, soil erosion and plant productivity in both crop and grazing land. Improved farming practices were tested to find more efficient ways of using the available water. Interactions between indigenous soil and water conservation and crop protection practices were analysed by a Swedish-funded project.
These investigations clearly indicated an urgent need to develop a multi-level strategy, including sensitive political interventions to change farming practices and reduce water use, as well as efforts to achieve more effective water storage and distribution. The need for additional research in forest hydrology and for an education programme for researchers, decision-makers and water users was also identified.
This case study suggests that most of the problems currently affecting the Mount Kenya area were caused by uninformed political decision-making, including central government’s initial failure to recognize upstream/downstream linkages and the “water tower” function of this high equatorial mountain. The Mount Kenya area is a highland/lowland interactive system that involves many environmental, social, economic and political elements. Mistakes in one part of the system will have serious consequences for all other parts.
Adapted from J. Ives. 2001. Highland-lowland interactive systems.<p>Download the full-text document<br><br></p>