Spurs and dykes
Practical Action
The community based risk reduction programme comprises of a number of elements.
flood warning - strengthening the capacity of communities to manage early warning
systems (EWS)
flood proof housing
flood rehabilitation
income generating activities for families living in areas of risk
bioengineering. fruit and fodder tree planting to stabilise hillsides
flood resistant crops
evacuation
relief distribution
food storage
immunisation of people and their animals
spray of insecticides after flood to prevent epidemic waterborne diseases like diarrhoea,
dysentery, cholera, typhoid, pneumonia, etc.
risk mapping – mapping out the flood areas and its effects on those areas
structural measures for diverting and checking flood water through the use of spurs and
dykes
In Nepal, the community, through the CFMC, was able to ask for technical support from the
various division or sub-division offices of the Department of Water Induced Disaster Prevention.
These offices often also provide material support such as gabion boxes and sand bags. There are
many other organisations that may provide technical as well as financial support to carry out
these works. Therefore the CFMC needs to be well informed of the options.
The CFMC also coordinates activities during flooding. These include; filling the breaches of the
embankment, deflecting river flow, isolating water wells. Preventing provision stores, health
centres and other structures from being flooded may become an essential activity. Adequate
provision of materials for these tasks should be obtained and stored at convenient places.
Structural Options
Various structural measures can be used depending on the particular requirements of an area.
Material like loose stones, bricks, bamboo piles, bamboo mats, stone filled gabions, and sand
filled bags are all used. With appropriate support the community can do the bulk of the work
including collecting stones, filling the gabions, and earthworks etc.
Dykes run along the side of river rather
than protruding into the river. They
protect the river bank from erosion but
do not redirect the river.
Embankments are constructed along
the river bank to raise the bank level
and stop the water spilling over. The
embankments are made of earth and
are sometimes additionally protected
with revetments.
Revetments are structures placed on
banks in such a way as to absorb the
Figure 2: Section through a gabion dyke. Illustration:
energy within the moving water
Practical Action / Neil Noble
therefore protecting the land behind
them from erosion. In Nepal they are
often porous and will allow water to filter through.
Spurs are structures that protrude into the river. Small spurs know as studs help keep the flood
water away from venerable banks.
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