During last season’s drought in the Kruger National Park, there were calls for park management to provide the animals with additional water. Wild asked Izak Smit, Science Manager: Systems Ecology, GIS and Remote Sensing, to shed light on the use of artificial waterholes.
Did the drought impact various parts of Kruger in different ways, and are these effects still visible?
Although the entire park received below average rainfall during the 2015/2016 rainfall season, the drought was most severe in the central and southern parts of the park where the lowest rainfall was recorded. In fact, for some rainfall stations it was the lowest rainfall recorded in history, with Skukuza receiving for the first time less than 200mm within a climatic year.
What are the current conditions in the park?
On average, most of the park experienced normal rainfall over the past rainfall season, and as such the plants that animals depend on for food (forage) have recovered well in most areas. Our intensive field monitoring data show that grasses south of the Olifants River (where the drought was most severe) have increased from on average 1,051kg/hectare during the drought to on average 3,264kg/hectare during the past season.
Nonetheless, the rainfall was very variable across the park and whilst certain rainfall stations recorded good rainfall, other stations experienced another dry year. For example, Lower Sabie Camp had more than double its average long term rainfall (1,256mm), whilst Olifants Camp had another dry year and recorded only 312mm in the past rainfall season (63% of long-term average).
The following satellite images show the difference in vegetation and greenness between the end of the growing season in 2016 and 2017. The more red an area, the lower the greenness, and vice versa for more green areas.
Surface water is widely available as pools in seasonal streams and springs, and all the perennial rivers are flowing, with good storage in upstream catchment dams.
Why did the Kruger National Park decide to close down some artificial waterholes?
When artificially provided water is widely available, it can impact the ecosystem negatively in a number of ways. Firstly, it may change the number of herbivores and their distribution. For example, if you place a waterhole in a certain area of the park where water does not occur naturally, then water dependent species like hippo, buffalo and elephant may settle in that area or visit the area more frequently. This may have knock-on effects such as a shortage of food and changes in predator behaviour. Ultimately this may disadvantage certain less water dependent species like sable and roan.
Secondly, if water attracts more herbivores into a specific area, the effect of these animals on the environment will also change markedly. If you locate a waterhole in a certain area, the grazing and browsing patterns change and will impact the environment. For example, if you place a waterhole in an area that used to be waterless, then elephant impact on trees in that area may increase. In short, artificial waterholes favour certain species (animals and plants alike). If artificial waterholes are available across the landscape, it will most likely have negative implications for other species.
Wouldn’t the waterholes have helped animals during the drought?
It’s a misconception that a high density of waterholes during droughts would be of benefit. In fact, most herbivores that die during droughts die due to the lack of food rather than the lack of water. Simply stated, if you provide a lot of waterholes, the number of water-dependent herbivores can increase unnaturally in years leading up to a drought, reducing food availability during the ensuing drought and increasing starvation-induced deaths. What’s more, veld condition is also affected as grazing is spread over a wider landscape. In short, by providing water, you can reduce the food available during droughts, which may ultimately increase the number of animals that die.
Waterholes make for great game viewing opportunities. Aren’t visitors losing out now?
We need to balance tourism and conservation objectives. At the height of the water provision programme there were more than 350 boreholes providing water for game in the park. Clearly an unnatural situation for a “semi-arid” savanna system. Many of these waterholes were not even close to tourist roads. As such, we started closing some of them since the mid-1990s when the water provision policy was changed after careful consideration and consultation and in line with scientific understanding. Although the number of artificial waterholes has been significantly reduced since then, there are still many operational waterholes available for tourists to visit and it is not our intention to remove all of them.
What’s more, in some areas we have also started to take tourist roads to (natural) water sources, instead of the other way around of taking (artificial) waterholes to tourist roads! This way we can achieve our tourism objectives without compromising our conservation mandate. In my opinion this also provides a more authentic wilderness experience – a river pool makes for much better ambience and photos than a cement trough or earthen dam. One such example is the recently opened one-way loop road (off the H1-4) next to the Ngotso Stream, where the artificial Ngotso Dam was recently breached.
Kruger is also increasingly investing energy into ensuring that the rivers flowing through the park are in a good condition and receive the water necessary to keep the system healthy. This is achieved through active monitoring of the rivers and constant engagement and interaction with our shared river users outside the park and the Department of Water and Sanitation.
These measures illustrate that we are passionate about ensuring conservation is not compromised, whilst ensuring the tourism product in Kruger remains of a high standard.
What can visitors do to be even more water wise when visiting the park?
To be honest, I think this is the wrong question – visitors should not only use water wisely when visiting Kruger, but wherever they are. The water visitors use at their homes and work, wherever that may be, a city or a town, comes from an ecosystem that sustains biodiversity… Maybe not hippos like in Kruger, but a myriad of other living things like insects, fish, plants, etc.
Modern society has become so removed from resources we often don’t realise that whenever we open the tap, the water comes from an ecosystem that is providing a ‘service’ to us. The same applies to our use of electricity – we need to be reminded that water does not come from a tap, and electricity does not come from a plug!
During the midst of the drought a remark by my five-year old son brought the message home. As we were doing the dishes, he said we should use water sparingly as the hippos have little water left in the Sabie River. I realised then that he understood something many of us adults often forget or choose to ignore for our own comfort!