Nehimba Seeps – a Hwange phenomenon

Nehimba Seeps – water throughout the year – naturally

Zimbabwe’s Hwange NP is known as a place with very little natural year round water; a place where pumps are needed to keep water in the pans for several months each year. But the park is not entirely without natural, year round, water sources.
During one of the game drives made from Nehimba Lodge in Hwange, I was taken to see a local phenomenon that had intrigued me since reading Ted Davison’s book.

(Ted Davison was the first warden of Wankie Game Reserve and his book “Wankie – The Story of a Great Game Reserve” gives a tremendous insight into the challenges faced in the park’s formative years.)

Nehimba Seeps is one of the only year-round, naturally occurring sources of surface water in the massive Hwange National Park. The seep is an ancient source of water that was once used by the San Bushmen and remains today a vital source of water and minerals for elephant; especially during times of drought. As 2015 is already shaping up to be a very dry year I was curious to see how the seeps worked.

Davison describes his first visit to Nehimba

“When I first visited Nehimba I was amazed to find that we left the Triga vlei and went up a gentle rise for a couple of miles and then on the top came upon this open sandy place with a depression at one side, where there was a lovely clear pool of water. The sides of the pool were sandy, with water oozing out of the sand and trickling down into the pool. There was not much game about just then as it was early in the dry season but, towards the end of the season, when all the water in the pool had dried up, the seepage continued and elephant were digging holes into the sides of the pan and getting water from them.

These buried pans, for that is what they are, form important link with the past. There are several of them of which Nehimba is the best known, but Shakawanki is the largest. Others are at ShabiShabi, Lememba, Labuti, Tamasanka, Nqwasha and, lastly, Domtchetchi.”

Different elephant behaviour

Here the elephant behaviour was much different to more conventional pans and waterholes.
For those more used to seeing elephants splashing about and spraying water this was a much more sedate spectacle; with elephants standing patiently in the wells, not wasting any of this precious water.

As we sat and watched elephant come and go from the pan it was easy to see the hierarchy amongst the herds as whilst some elephants stood patiently waiting their turn when others arrived they headed straight for their favourite part of the seep and whoever was already there, drinking, would swiftly move aside.

“Here the water oozes slowly out of the fine sand into shallow wells dug by the elephant. At each place there will only be some six to ten wells, with great competition for the water in them, and the wells will be occupied all the time during times of stress. The adults and calves tended by their mothers can get a drink, while adolescents, who have no one to fight for a place for them, are unable to get a drink and spend so much time battling to get at the water that they sometimes die of starvation and thirst. This state of affairs was very prevalent during droughts before the advent of pumps, but today the pressure on these seepage springs has been much reduced.”

I did not have the opportunity to visit any of the other seepage pans mentioned by Ted Davison but in his book he notes that they are all of a similar formation.

“The source of water, the buried pans, all have one thing in common – they are surrounded by a stretch of loose sand which supports very little vegetation, being almost devoid of trees and shrubs, while even the grass is of a tufty coarse type which is only found around these pans.
The depressions in which the water collects is in sand and not clay as in all the other pans, but four or five feet below there is the clay seal, just the same. What we really have is a natural pan covered with loose sand.”

Important to the Bushmen too

“The Bushmen know these small buried pans, as it is not difficult to detect them by the particular type of grass which grows around them. The Bushmen used to dig wells for themselves. When they moved on they filled in the wells, re-opening them when they again visited the area. At the bottom they would place a large quantity of grass covered with strips of bark which collected the moisture and made it easy to obtain water on their next visit.”

There is clear evidence of the importance of these seepage wells to the Bushmen

“When Wankie was going through one of the dry spells and water was very scarce, I made an attempt to increase the amount of water available at Nehimba by scooping out some of the sand at the bottom of the depression….

When cleaning out the pan got down to the clay line we started unearthing numerous knobkerrie heads. They had evidently been there for a long time; fifty years perhaps. They were kerries which had been used by Bushmen to kill sandgrouse as the birds came in to drink at the pan in the evenings.”

As with most waterholes in Hwange, it is the elephants that dominate. Few other animals come to drink whilst the elephants are in attendance, but the nature of the seeps creates another obstacle. The clue is in the name; Seep.

Because the water literally ‘seeps’ into the small wells, they fill very slowly and it takes quite some time for an elephant to drink its fill. They drink, then stand and wait for the well to refill before they can drink again. They need to do this several times in order to drink enough.
Therefore whereas as a normal pan a herd of elephants would march in and all drink at once, at the seeps they cannot do this and they have to queue, awaiting their turn.

With elephants occupying the seeps from mid afternoon until well after dark all the other animals must visit the wells before dawn and during the morning.
Being obliged to spend so much time at the seeps also means that the animals are particularly vulnerable to predators although the wide expanse of open ground that surrounds the seeps does offer come protection as it makes it harder for an ambush to take place.

Join us on safari in Zimbabwe to see this unique phenomenon for yourself.