River Water Shortage in a Highland–Lowland System
2005
Aeschbacher, Jos | Liniger, Hanspeter | Weingartner, Rolf
In the past decade, water shortage on the western and northern slopes of Mount Kenya and particularly in the adjoining lowland areas has reached a severity not experienced before. Rapid population growth and rising demand for irrigation are increasing the pressure on water resources, as can be demonstrated by an inventory of water abstractions from the Naro Moru River. A total of 98 abstraction points were documented within a river section of only 30 km, providing water to about 30,000 people. However, about 97% of the abstracted water is used for irrigation of 9% of the total catchment area. In 2002, about 30% of the annual discharge and 80 to 100% of the low flow discharge of the Naro Moru River was abstracted by furrows, gravity pipes, and pumps. The highland–lowland system of the Upper Ewaso Ng'iro Basin, with Mount Kenya functioning as a crucial water tower, has reached and repeatedly exceeded the limits of water availability in the past decade. In contrast to the heavily decreasing low flow discharge, the mean discharge does not show any decreasing tendency. This is due to higher flood flows, which may be induced by accelerated runoff generation due to land use change. The present study seeks to support Water Users' Associations (WUAs, ie self-help initiatives aiming to mitigate conflicts over the allocation of water) by providing them with up-to-date information about demand, supply and use of river water, as well as tools and methods for improving water management.
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