Sand Dams are something of a miracle. Building one, however, is nothing but hard work. Even before the first foundations are prepared, stones and rock must be wrenched from the dry river bed. By hand and by hammer, they are broken into smaller pieces and carried to the construction site, where they will eventually form the dam wall.
Foundations need to be dug deep. Where mechanical diggers might be used, hands and spades instead scrape at the earth, digging down until the bedrock is reached. Typically 2m deep, 1.5m wide and 25m long, it is tough, but essential to ensure the long term security of the dam.
Women bring water, as much as 20kg at a time, to mix the cement. With an average dam needing 21,500kg of cement, 8,000 litres of water must be transported. That may require 400 water collecting trips during the construction, with each step taken weighed under a 20kg burden.
Sand, 64,500kg of it dug from the river bed, is churned with cement by hand before being moved to the dam foundation in trays and barrows. Stone and cement come together, lifted by teams of people high over a supporting frame, and carefully placed inside to build solid foundations and strong walls. It takes days to fill the foundations enough just to reach ground level. But each dam must be raised several more metres still, sometimes eventually reaching as much as 6m from the bedrock to the dam crest.
The hard work will last weeks. Weeks of dirt, sweat and toil. But everyone will help. Often people come from neighbouring communities, ready to lend a hand in the tradition of ‘Mwethya’ (coming together to help each other), that is so representative of the spirit and determination of the people.
And it’s worth it. Once mature, a Sand Dam can conserve as much as 20 million litres of water. No small amount by any standard, but particularly in these semi-arid lands where it is most rare. Sand Dams really work. If they didn’t, who would want to build one?
The people in this part of Kenya have worked the land for generations. They know what they need. Very often that is a Sand Dam. Excellent’s role is simply to support them with existing skills and knowledge – to provide a kick start that enables people to create a future of opportunity.
Sand Dams may seem like miracles but, like all good things, they come from hard work, determination and patience.
We are planning to build a sand dam which is very hard. It's a hard job. Someone needs to be fat, energetic and strong enough to lift the stones.
Joshua, Chairman of the Kumina Wauni Self Help Group, Kenya