Many millions of people in the developing world do not have access to a clean, sufficient supply
of water, a resource essential to almost all aspects of life. Poor people often lack the capital or
technology to construct efficient water-supply systems, and make do with communal wells or
rivers that are easily polluted. This situation is only compounded by disasters, which can displace
populations away from infrastructure, and lead cramped, unhygienic conditions.
The concept of rainwater harvesting technology (RWH) is being developed as an affordable
alternative to traditional water supply systems, helping to give people access to a naturally clean
resource. A PCR process attempts to improve peoples’ resilience, offering the opportunity to
increase independence and participation; the planning and use of RWH within the reconstruction
process from an early stage could allow people to develop and manage their own water supplies.
Whilst it is unlikely that RWH can provide all necessary water in many cases (particularly in arid
areas that receive little rainfall), its use can at least alleviate the harshest effects of insufficient
water supply given the right conditions.
This brief will look at the basic components and functions of a RWH system, and give details of
real-world examples in practice. The relation of these different RWH technologies to the various
stages of the PCR process will be developed, assessing what solutions are practical in which
context. Please see Practical Action’s technical brief Rainwater Harvesting for original
RWH technologies can generally be divided into two categories:
Agricultural, erosion control, flood control (larger-scale)
Domestic systems can be household or community based; almost all consist of a collection
surface, a channelling device (gutter) and a storage facility. Additional filtration and first flush
devices can also be incorporated, along with post-storage water treatments described in Water
Treatment during Reconstruction.
Filtration and first-flush systems
Figure 1: Schematic of RWH System, Illustration: Martin Bounds
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