Those of our social media following that our local to Kenya will know that the much awaited rains have finally come. It’s great news for all of us and, at the Tsavo Trust, we know how important this precipitation is to both the animals we look out for and our human neighbours.
If you missed our previous article on how Kenya is affected by the seasonal rains, you can access it here.
This year’s rains are especially exciting because they give us a chance to assess the success of one of our latest projects. Over the last couple of months, we’ve been building sand dams over some of the then dried-up river beds.
With the rains here, we’re hoping, those dams can now start filling up. The idea is that water will get trapped in the sand. This will create underground deposits of water that may help the elephants we monitor make it through the next dry season.
Sand dams: how do they work?
Most drylands, much of Tsavo included, are not visited by rainfall for long periods of the year. When it does come, as it is doing now, it falls quickly and heavily. So quickly, in fact, that the water often slides atop the surface of the earth. Often, it will wash away loose topsoil which is essential for new plant growth.
The water enters into established rivers and other waterways, quickly leaving the areas that need it and, eventually, entering the oceans.
Sand dams are very simple constructions often built of concrete. They aren’t designed to stop the water’s natural course, merely to slow it down. Here in the Tsavo Conservation Area, we’ve put them at various catchpoints over our regionally filled riverbeds.
When the rains come, the water, with silt and sand mixed in, meets with these dams and quickly builds up. The sand, which is heaviest, gets caught behind the barrier. A layer of sand builds upstream of the dam and, when that layer is tall enough, the water and silt simply flows over it and the dam, continuing on downstream.
That layer, however, remains when the rains leave. And within that thick blanket of sand, large quantities of water are trapped, protected from evaporation, filtered clean and kept for when is needful.
What is the significance of these projects?
Sand dams are an incredible invention. The trapped water is often good enough for humans to drink right away. And, if there is real need, and pipes are lain before the sand accumulates, sand dams can become a staple source of water for humans in areas that lack regular rainfall.
The sand dams built by our team at the Tsavo Trust are, however, not designed for human use. We’ve built ours within the national park, where humans are not allowed to wander, and we’re hoping to see a whole host of changes brought about by their creation.
Elephants can drink up to 200 litres of water a day. Their huge bodies and active lifestyles require quite a bit of hydration. They will often keep a catalogue of known watering holes, and herds are known to travel miles from one to the other.
In times of scarcity, however, elephants have developed the habit of digging for water in dry river beds. With their tusks and trunk, they’re quite capable of digging deep holes where other animals cannot.
It is this useful skill of theirs that prompted our creation of these sand dams. It is our hope that, if their need is great enough, elephants will always be able to locate a protected store of water behind the dams we have built.
Furthermore, we expect that these additions to the Tsavo National Park will benefit others as well. Once elephants have dug their watering holes and drunk their fill, other animals are known to take advantage of the wells created by those useful tusks.
We also believe that the sitting water will encourage plant life to take root and hopefully rejuvenate the flora around Tsavo. This, in turn, is likely to shore up and stabilise the topsoil that heavy rain tends to wash away. All in all, we expect that these sand dams could have a huge impact on the area.
Other effects of these great inventions
Providing a stable and accessible source of water to the elephants that we have made it our mission to conserve is, at the Trust, our principle aim. Our sand dams are designed for elephant conservation. However, we just wanted to take a little time to talk about the huge, and potentially life-changing application of this invention in human lives.
Very often, in dryland areas, local human inhabitants can find it very difficult to access drinking water. Often, members of a family are forced to walk miles in the search for it.
Sand damns, as we touched on above, can be piped and protected for human use. Incredible organisations such as The Water Project consider the sand dam as one of the best weapons at humanity’s disposal in the battle to provide clean drinking water to all.
We hope you this news has found you well. Stay tuned for an update on how our sand dams are working out in a couple months’ time!