Rainwater Harvesting for Reconstruction
Practical Action
Figure 15: Plan of Shangili
Tobaya Dam Project in
Western Sudan
Photo: Practical Action
Projects are large-scale community investments, requiring planning, labour, materials, training
and maintenance. It is highly unlikely that there will be sufficient resources in an emergency or
transitory stage of reconstruction to consider the construction of a dam. Additionally, the benefits
would not be experienced until a rainy season has arrived.
However, it is clear from the experience of Practical Action’s work in Western Sudan that a
sensibly sited and correctly maintained dam can revitalise agricultural land for a community. A
consideration early on in the reconstruction process could be to site redevelopment close to an
area where construction of a water harvesting damn could be possible. The inclusion of local,
displaced people in the process is essential, and adequate training could be provided over time to
ensure they can take charge of the project.
Sand Dams
High water flows in such areas often carry large quantities of sand downstream, which can get
trapped behind rocks and act as a natural water filter; the water which is ‘cleaned’ by this
occurrence is usually safe for drinking. It is possible to artificially enhance this process with a
‘Sand Dam’, which increases the amount of water filtered and trapped for consumption.
The concept involves creating a
concrete wall across a river path,
which directs and traps the sand;
this creates a sub-surface water
bank for harvesting.
Despite the technology being lower
cost than normal rainwater
harvesting dams and easier to
implement in the reconstruction
process, sand dams can only be
constructed in areas where sandy
riverbeds receive seasonal
floodwaters. The level of labour
required for their construction is still high, and to involve
local populations will involve training if new to the
concept.
Figure 16: Diagram of Sand Dam
Photo: Practical Action
Practical Action’s East Africa office has produced a technical brief detailing the basics of the
technology; refer to Sand Dams.
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