Ever since last week’s blog on the 7 strangest, most beautiful dams in the world (you can read it here,) I haven’t been able to get sand dams out of my mind. Sand dams are helping people all over Africa, and they can help people here, too. All over the world drought is taking its toll on resources, and with these tiny, (pretty) easily constructed dams, we could feel a whole lot better about where our water is coming from. This week we’re going to get deep into sand dams, because, let’s be honest, they’re pretty awesome.

What Are Sand Dams?

In case you missed the blog last week, sand dams aren’t your average dam. You build the structure across a stream (in the case of sand dams, a seasonal stream that only flows during rainy seasons) and wait. After one really heavy rainfall or two to four smaller rainfalls, the dam begins to fill with sand. At first the water just flows around the side or over the top, but as the sand becomes trapped behind the concrete, water becomes trapped underneath the sand. The sand that gets held back by the dam creates a new stream-bed, allowing excess water to flow over the top and not alter the flow of the stream.

What Makes Sand Dams So Great?

Why, you might ask yourself, is this such a big deal? Well, I’ll counter that with another question: Why ISN’T this a big deal? Sand dams have countless benefits to the people and ecosystems around them.

1) Endless Water: In the areas of Africa where sand dams were first built 20 years ago, there hasn’t been a single instance of the dams going dry. Not one. That means 20 years of a reliable water source right nearby. No more walking anywhere from five to 30 miles to get water for your family.

2) Endless Clean Water: The sand that piles up behind the dam acts as a filter for the water that settles underneath it. This doesn’t mean the water is 100% perfect, but sand dams almost act as a natural Brita filter.

3) Replenish Resources: When the sand dams collect enough water, they actually diffuse it out into the surrounding land and increase the water table. Because of this, plants and trees grow up around the dams. This gives communities more wood for fires and building, as well as a greater ability to grow crops and food.

4) Almost No Negative Effects on the Environment: Sand dams hardly affect the environment in the same way normal dams do. They don’t stop the river from flowing completely, they let it keep running downstream and capture whatever water the sand can hold. I know that regular dams allow water to keep running as well, but when looking at the Three Gorges dam in China, over 1 million people were displaced when its reservoir was filled. Sand dams don’t displace anyone. If anything, they allow more people to inhabit an area because they increase resources. They also allow for sediment like silt and dirt to continue down the stream along with the excess water.  This means that river deltas won’t be  as negatively affected as when larger dams are built.

5) They Help with Education: Sand dams allow for people to only spend about 30 minutes to an hour a day gathering water. This opens up immense possibilities for their children. Instead of having to stay home from school to keep an eye on their younger brother or sister for 20 hours while mom is out gathering water 10 miles away, they can now get to school and continue their education.

Sand Dams around the World

These are just a handful of reasons why sand dams are one of the greatest engineering feats of all time. Sand dams aren’t only useful in Africa, either. Just this morning, data were released that showed 70.3% of Texas is back in mild to extreme drought conditions. This is a stark contrast to July when only 4% of the state was in a drought. These massive droughts are happening all over the US, and the places that are hurting are the places where sand dams could actually help the most.

Sand Dam

Image courtesy of Excellent

All over the world, sand dams could be implemented in semi-arid to hyper-arid dry lands to help increase water tables and increase resources for communities. Multiple sand dams could be placed all along a seasonal stream-bed and replenish an entire region. All it takes is time, a little effort, and some rain, and people all across the world could have a reliable source of drinking water that could change their communities forever.


Sand dams are great for the environment, and UNINTECH cares about the environment, too. That’s why we hire LEED certified engineers to help us design structures that use less water, less energy, and are constructed using recycled materials. Click the button below to see some of UNINTECH’s LEED certified projects, and how UNINTECH is making the future of Texas a reality today.

View Our Projects