Water Supply in Africa

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WATER SUPPLY BY RURAL BUILDERS

A charco dam being constructed by contractors and a community during training in Kitui

A subsurface dam being built of soil.

A handdug well being sunk.

Erik Nissen-Petersen for Danish International Development Assistance (Danida) 2007

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WATER SUPPLY BY RURAL BUILDERS

A charco dam being constructed by contractors and a community during training in Kitui

A subsurface dam being built of soil.

A handdug well being sunk.

Erik Nissen-Petersen for Danish International Development Assistance (Danida) 2007

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Chapter 1.
1.1

Introduction

Purpose of this publication

Builders in rural areas have for many years constructed water supply systems, such as roof gutters and water tanks for catchment of rainwater, handdug wells, subsurface dams, weirs, sand dams, ponds and small earth dams. The clients have either been individuals, non-governmental organizations (NGOs), government ministries, or donors such as Danida, Sida and UNDP. Many of these water projects function well and supply water, and, according to the waterusers, do so without problems. However, some water projects do not function very well, while others are complete failures, and the reasons are a mixture of insufficient knowledge about surveying, design drawings, estimating bills of quantities, and costing accurately, as well as inadequate training of technicians and contractors, and improper operation and maintenance by the water users. This handbook, Water Supply by Rural Builders, is the 8th in a series of handbooks that gives guidelines on how to carry out simple, yet adequate, surveys, designs and construction of basic water projects. It is the popular belief that deep boreholes and large earth dams, built by heavy machinery, are the only two solutions to get water in arid and semi-arid lands (= the ASALs). The fact is, that a subsurface dam, built cheaply of soil in a riverbed and with a handdug well in the riverbank, can supply much more water and at a fraction of the cost compared to e.g. a deep borehole equipped with a submersible pump powered by a diesel generator. It is hoped that this handbook, and the whole series of 8 handbooks, will reduce the number of failed and under-performing water projects, and will reduce the significant amounts of money and man-hours wasted on costly, over-designed water projects, whose yields of water could be achieved by applying simple, low-cost, design and construction criteria, with lower operation and maintenance costs. Engineers do not learn the simple techniques required for low-cost water structures, such as they are described in these handbooks. It is therefore very timely that two university lecturers now produce textbooks, for use at universities and colleges, on community water projects. The world is running out of fresh water, partly due to over-exploitation of ground water resources by boreholes, and by contamination of the water in rivers and lakes. In the very near future, the only fresh water source may be the rains, at least where it is not acid due to pollution. Rainwater harvesting is a viable, sustainable and long-term solution, if applied properly, and it is hoped that this series of handbooks can also assist in promoting education on rainwater harvesting and self-reliance in water supply systems, while also improving the environment.

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1.2

Rural water projects

People living in the ASAL areas of the world must fetch water from the nearest water source, perhaps being 10 to 15 km away. Where water sources are further away than that, it may take several days to transport water by donkey or camel. Individuals and communities therefore find it very frustrating when they have worked hard and contributed cash to build a water project, and then find that it cannot supply sufficient water to cover the demand, or even worse, that it cannot supply any water at all. The Ministry of Water...
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