In the semi-arid area of Makueni County in Kenya, Just a Drop works with community self-help groups to build sand dams, which provide a natural and sustainable solution to capturing the biannual rains that fall so quickly and heavily that very little water is captured for drinking, washing, or other needs.

Sand dam walls are built across a dry riverbed. As rain falls it is captured behind a sand dam wall, where it is naturally filtered and stored by the sand in the riverbed. As the river flows it brings more sand along with it, which collects upstream of the dam, in turn creating more water storage capacity. The water is safely stored in the sand where it is protected from evaporation. A hand pump next to the river enables the community to extract the water stored in the sand dam.

Sand dams provide a reliable year-round supply of safe water for communities near to their homes. Sand dams raise the water table of the local area, meaning they are a very effective way of regenerating land and enabling vegetation to grow. Alongside sand dams, Just a Drop establishes food security programmes. Communities are trained in sustainable agricultural practices such as terracing and tree planting; and taught how to grow drought resistant crops which ensure a sustainable, nutritious source of food, improving the health of the whole community. Excess crops can be traded to provide an income, transforming a community's prospects.

Here's the story of the Kwa Voki Self-Help Group's sand dam:

The Kwa Voki Self-Help Group in Makueni County, Kenya, build their sand dam.
Communities are always involved with the planning, construction and maintenance of their sand dam.
This creates ownership and ensures the sustainability of the project.

Left: Cement is mixed and carried to the sand dam in pails.
Right: Stones and rocks are carried to the sand dam structure.

To construct a sand dam, a deep trench is first dug across the valley wall, reaching the bedrock.
A concrete or masonry wall is then built on the underlying rock bars across the river channels so that
it can trap and hold back the sand brought by the river during the rainy season. 

The community work together to build the sand dam wall before the rains come.
Rocks are lifted into the middle of the structure, the cement will then be poured in afterwards.

The Kwa Voki Self-Help Group are all farmers by trade. The sand dam will increase the yield of their crops and bring in more income.

Everyone helps out and takes turns with rock carrying, cement mixing and construction of the wall.

Jackson Jumakasoo (left), Chair of the Kwa Voki Self-Help Group and Samuel Katiku (right),
Vice Chair of the Self-Help Group, stand in front of the drought resistant crop seedlings they are soon to plant.
The crops will survive thanks to the extra water from the sand dam.

Elizabeth Munyao waters the seedlings ahead of planting.

Sharon Nyamai is happy with the mango, jacaranda, papaya and moringa plants.
The community have been trained in growing and cultivating the plants as part the food security programme.

A hand pump is used to collect the water stored in the sand dam.

Elizabeth walks among her seedlings. 

Photography: Sophie Green