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< prev - next > Disaster response mitigation and rebuilding Emergency relief KnO 100648_Water Supply during emergencies (Printable PDF)
Water Access in Emergencies
Practical Action
Figure 7: basic RWH
emergency collection
Source: Burt, M. and
Keiru, B. (2009)
Safe drinking and washing water can be obtained from rainfall with some of the following
Clean collecting surface regularly
Ensure storage facility is clean
Possible storage containers include:
Apply post-collection treatment such as chlorination and filtration
Encourage people to organise their own rainwater collection
Surface Water
As stated, in an emergency the available surface water is likely to be of a low quality, having a
high turbidity and level of pollution. Treatment methods such as slow-sand filters and dams are
effective, but take a long time to construct. However, it is possible to supply safe surface water by
applying basic filtration and treatment methods such as chlorination and coarse filtration.
Surface water can be abstracted by two main methods:
Flow diversion
Pumping (either direct from source or from infiltration gallery/well)
A river or stream can have its flow diverted into basic filtering devices, whereby the largest
sediments can be removed and the turbidity of the water reduced. Further treatments can then be
performed on the water supply before consumption.
Figure 8: Diversion structure
for a stream intake
Source: Davis, J. and
Lambert, R. (2002)
The quality of surface water can be improved by natural filtration processes, and accessed by
digging riverside wells. Alternatively, the construction of an infiltration gallery can be undertaken
on the bank of a river, whereby a pump is placed in an artificial gravel bed; water pulled through
the pump will be filtered by the gravel surrounding it. These solutions can be built reasonably
quickly, and could compliment other water sources soon after the impact of a disaster. WaterAid
have produced a guide on implementing infiltration galleries here. Reservoirs do not afford the
opportunity of flow diversion, but water can be pumped out and subjected to basic treatments
such as storage, chlorination and coarse filtration.