Sand dams
Practical Action
Figure 3: Sectional view of sand dam
Extent of use
Sand dams are not new in Kenya. Traditionally water harvesting at certain points along the dry
river has been widely practiced in ASALS with good results but on a smaller scale. Currently a
number of sand dams have been constructed to good effect in Kitui, Machakos, and West
Pokot. Practical Action EA through CORDAID funds recently built 3 sand dams along the
seasonal Baragoi River in Samburu district and both have yielded good volumes of water for
livestock and human use throughout the drought periods. (See figure 2).
Operation and Maintenance.
Once construction is complete further operation costs are negligible. Only the low riverbanks
need to be protected against erosion as this might enable floodwater to cut around the dam.
The structure’s lifespan is approximated at 30 years.
Suitability
This technique is applicable in sandy riverbeds that are seasonally dry but experiences high
siltation during water runoffs. Sites with high riverbanks and lower slopes are also desirable.
Level of Involvement
Sand dam construction is labour intensive and requires
community involvement and full participation.
Where as standardized design and wall construction
requires specialized advice to ensure it withstand the
pressure from water behind it, local materials and skills
should be preferred in order to foster community
project ownership and to reduce projects costs. Proper
consultations and consensus building among the
stakeholders are requisite for winning the commitment,
participation and contribution of the beneficiaries.
Figure 4: Community involvement in
sand dam construction
Benefits
Compared to other water harvesting techniques, Sand dams are environmentally friendly as
they control erosion and manage silt deposition within river basins. Its water is clean and of
good quality for consumption due to filtering effect of the sand. Sand dams increase moisture
infiltration within the soil profile and into the ground water providing both soil and water
conservation benefits. These sites can witness quick regeneration of indigenous trees along the
riverbanks thereby attracting other biological resources and ecosystems that hitherto faced
threats from recurring droughts. Similarly sand dams also allow for small-scale crop production
through irrigation that was otherwise not possible.
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