What are Sand Dams, and how do they help?

WHAT is a Sand Dam?

A sand dam is a reinforced cement wall built across a seasonal (flows after major rainfall, then dries up again) sandy river.

The dams are built by securing one or two long concrete barriers across river beds, and by placing a pipe under these barriers.

When it rains, the water carries sand downstream, depositing it against the concrete wall. Eventually, the area behind the wall becomes filled with this sand.

At the end of the rainy season, water remains trapped in this piled-up sand. This water gradually drains into the pipe and can be collected using a basic hand pump or simply by digging into the base of the dam.

WHY Sand Dams?

(Why not some "cooler" 21st century technology?)

  • Because sand dams are cheap
  • Because sand dams are easy to build.
  • Because sand dams require very little maintenance.
  • Because sand dams have no operational cost- once a dam is built, all you need is rain.
  • Sand dams are the easiest and most cost-efficient method of water conservation in water scarce environments.

HOW Do Sand Dams Help?

  • They provide a year-long local water source for communities that would otherwise suffer from water shortage.
  • They reduce the time spent collecting water and thus increase the time available to invest in working on the farms.
  • The significant reduction in the time required to collect water affords the opportunity and energy for farmers to invest in learning more sustainable innovative farming techniques.
  • Sand Dams provide access to water, which is crucial to the production of a secure and diverse supply of food, even during periods of drought.
  • Improved nutrition has a positive influence on the general health of the community.
  • Food security means farmers have surpluses that can be sold at local markets, enabling the transition from subsistence to income generation.
  • When families generate income and feel their growing independence and financial security, they are able to see their potential for a future outside of poverty.

Sand Dams are an incredible example of the huge impact small projects can have!

See for yourself how sand dams are helping farmers in Kenya’s Makueni County:

Read more about the WATER project and other LWR initiatives in Kenya