It was a warm and sunny day, perfect for visitors to soak-up the world-renowned wildlife sightings of the Kruger National Park. But not everybody enjoyed what the wilderness put on display. It was a hippopotamus. She was stuck in the mud left behind in the wake of the river’s retreat. Too hot, she lay panting under the brutal sun. Too dry, she could not wrestle free. Too wild, she could not count on the mercy of men for help.
Like a bad tune stuck in your head, drought has been humming in the background of the history if the Kruger National Park for almost as long as the park exists. Serious droughts flared up in the sixties and early seventies, and then again, on-and-off, from 1982 to 1997. The most severe on record were the droughts of 1982/83 and of 1991/92.
But, then 2015 arrived.
Before I dig into that, let’s take a sec to confirm why you are reading about the wild, a hippo, and the history of drought on a blog dedicated to cities.
Well, before cities were built; before the building where you are sitting now reading this existed, it also used to be wild. Depending on where you are, your sitting room could have been savanna, or scrubland, or jungle. Maybe the soft grunt of a kudu bull was once common in your backyard. Perhaps the comforting whisper of leaves, from a shady and dense riparian forest, was once the tune that accompanied the stream that now runs polluted and bare through your neighbourhood.
Nevertheless, though we have changed, built, and developed a mind-boggling amount of stuff on the planet, we can still look at wilderness areas to teach us how the same system that still affects us, ticks. In this case, it teaches us why drought happens and, that it will come again. That’s why I first wrote about it, digging into the details of that early-nineties drought and why it matters.
Back to that 2015 drought then.
A chart topping drought
It was a record-breaker. For some areas in the Kruger National Park it developed into the most extreme on record yet. This drought was dryer, and swept through the area with soaring temperatures – higher than before (see ‘notes’ below). It wreaked havoc outside the park. Farmers were brought to their knees and towns to the brink of running out of water.
Yet, inside the fences, a different story was unfolding. “This time, we emerged from the drought much healthier,” says Danie Pienaar, head of SANParks Scientific Services. Dr Eddie Riddell, the park’s manager for water resources and aquatic biodiversity and SANParks river bio-technician, Jacques Venter, also reports “significantly improved performance” of the five perennial rivers that run through the park, in comparison to the droughts of the early eighties and nineties. This is a big thing. In the 1991/92 drought the Sabie River, the country’s most biodiverse, almost stopped running.
That drought also saw masses of animal deaths – tens of thousands. Yet, this time around, not as many died.
So, how did they do it? The answer is: not easily, not overnight and, not alone.
The basis for this success story was laid decades ago and was hard won. The park was testing ground for groundbreaking management strategies. These were applied, tested, fine-tuned and applied again. Rigorous scientific testing took place in the background. Tourists, and the public, did not always approve, and announced their displeasure widely. Constant, intensive collaboration took place with stakeholders upstream and downstream of the park, and across the border with Mozambique.
It was worth it. By the looks of it, the strategies are working.
Water is what makes our country tick
Many rivers run through Kruger. But, five retain flow throughout the year, flowing through Kruger into Mozambique: the Crocodile; Sabie; Olifants; Letaba; and, Luvhuvhu rivers. These rivers work hard. Commercial foresters and farmers tap them extensively before they reach the haven that is Kruger. Then, mines and other industries also take their bits. In fact, the rivers are used so much, they cannot really be developed any further.
This is not unusual in South Africa. Rivers oil the machinery that makes South Africa tick. We are intensely dependent on them for survival and economic development. Water is an incredible valuable resource in South Africa, especially since we are a relatively dry country. If people had their way, we would use much more than we already have; more than the rivers can afford.
Because of this, they are protected by law. Rivers have the right to a sufficient amount of water, and quality of water, to keep them alive. It’s called the ecological reserve. It’s also referred to as environmental water requirements (EWR) and is encapsulated in the National Water Act of 1998. A beautiful law, it is sadly, not enforced very well in many parts of South Africa.
In one place, at least, it is: The Kruger National Park.
Using the law to help rivers
The EWR of the five mentioned perennial rivers have been figured out by researchers, and is being monitored and implemented. “Over the past ten years or so the Kruger National Park, along with upstream stakeholders had been implementing draft ecological reserve targets, which assisted with the co-operative arrangements required during the time of crisis,” says Eddie.
Park management thus had a legal standing when they asked for more water to be released into some rivers. This was granted, even though it meant less water to upstream farmers and foresters. The water, and the suffering was shared, and divided by law. In general, the 2014/16 hydrological cycle is described as a “considerably trying time for river operations for all users in the Lowveld region”.
Still, they were able to maintain flows in the rivers, and were mostly successful, says Jacques. “In some cases the absolute minimum flows were reached but the rivers never went below that or stopped flowing during the drought,” he says.
Releases from the Tzaneen, De Hoop, Blyde, Kwena and Inyaka dams were also essential during the height of the drought. Though unlikely allies to conservation, dams played an important role during the drought. “If dams are managed according to proper operating rules it can actually be an asset,” says Jacques.
However, when not managed correctly, the hoarding of water can have far-reaching consequences. Since the nineties, many man-made waterholes in the park were closed, and dams in rivers dismantled. This decision ensured the survival of much of the park’s wildlife.
Letting nature do its work
During drought, animals mostly die due to a lack of food, not water. Where waterholes are ample, vegetation is not. Vegetation close to water is trampled and grazed. In a landscape where water is evenly provided, vegetation is thus also uniformly degraded.
When Kruger was established, people thought the landscape was ‘drying out’. In response, as many as 300 borehole-fed waterholes were opened from 1911 to the 1990s. Various dams built were also built in rivers. When the early-nineties drought hit, this landscape benefited some animals, to the detriment of many others.
Plains game such as zebra and blue wildebeest, who graze shorter grasses did well. Long grass feeders such as buffaloes and the rare roan, tsessebe and reedbuck suffered greatly. Thousands of hippos, warthogs, kudus, impala and bushbuck also died.
Since the early nineties, many of the artificial waterpoints have been closed down. Fences separating the park from some neighbouring protected areas have been dropped, enlarging the areas available to animals to roam. Now waterholes are spread unevenly across the landscape. This allows for natural plant and animal distribution patterns. And, vegetation far from waterpoints is allowed to recover from trampling and grazing.
Effectively broken when the region received average rainfall again in the 2016/17 hydrological year, park management has since had time to take stock of what happened.
Post-drought census counts show that the park did not experience the previous mass deaths of animals. “This time, the buffalo population, for example, only fell with around 12 000,” says Danie. Buffalo numbers dropped in Kruger between 2015 and 2017 by 26% in comparison to 48% during the previous drought. These are also fewer losses than was reported from fenced, private game-reserves in the 1982/83 drought.
This result has been put down to grazing that accumulated in areas far from water, or so-called “buffer” forage areas. Analysis of rainfall and grass biomass indicated less severe drought condition in the north of the park, in combination with larger distances between rivers and other water sources, resulted in greater grass forage reserves. Buffalo also appear to have migrated from the south of the park to make use of these reserves. “We also did not see the large-scale deaths of impala, warthogs and bushbuck,” says Danie. “We had more herbivore biomass, but fewer animal losses.”
A number of elements have been highlighted as key to the park’s achievements, especially to keep the rivers flowing.
First, it is essential to have a proper communication system with all role players involved, says Jacques. Second, flow data must be available, and accessible. Hydrological modelling and water resources accounting systems to inform decisions are necessary. Last, there must be a system to evaluate the result of the decisions.
Though the severe drought is officially broken, the area is still in a dry cycle. “At present, we are borderline drought again, says Eddie. About 70% of average annual rain graced the park in the 2017/18 cycle. This would be classed as a hydrological drought according to the regional definition,” he says.
Though not technically a severe drought, this time, there was already less water in the dams than before the severe drought. Forecasts by the South African Weather Service indicate that the area is likely to experience a hot, dry spring with a short rain season into early 2019.
This means the park’s resilience will still be put to the test. Will management be able to continue to protect the rivers? And inside the park, how will animals respond to continued pressure on the environment?
Once again, only time will tell.
- Rainfall in Kruger varies a lot in any year. A drought technically takes place when there is only 70% of the average annual rainfall in an area. When less than 50% of the annual average amount of rain falls, this is defined as extreme drought.
- At Skukuza (in the south of the park) the average rainfall within a hydrological year is 558 mm. Double this amount fell in 1999/00 (leading to floods). During the hydrological years of 1982/83 the area received 51% less than the average rainfall (extreme drought).
- In 1991/92 the area received 58% less rain than the usual yearly average (extreme drought, compounded by below average rainfall for the two previous years). The 2015/16 hydrological cycle notched only 35% of the annual rainfall (severe drought) strengthened by a dry 2014/15 (only 64% average rainfall). From a rainfall perspective, the 2014 to 2016 hydrological cycle is considered the most extreme drought on record (for Skukuza).
- During 2015/16 a “significant” number of days pushed the quicksilver over 40, as compared to other drought years. These temperatures aggravated water stress due to considerably higher evapotranspiration rates.
- This articles has been adapted from a version that appeared in The Water Wheel magazine, published by the Water Research Commission
• Testing Strategic Adaptive Management during crisis: management of the perennial rivers of the Kruger National Park during drought by ES Riddell, S Pollard, H Retief, B Jackson and S Mallory. 14th International Water Association Specialist Conference on Watershed and River Basin Management, Skukuza, Kruger National Park, 2017
• The ecology of drought, a workshop report by Anthony Swemmer, William J. Bond, Jason Donaldson, Gareth P. Hempson, Johan Malherbe and Izak Smit (South African Journal of Science, September/October 2018)
• Drought – nature’s lessons in overdrive in Kruger National Park by Lani van Vuuren (The Water Wheel, September/October 2016)
• Kruger getting house in order for severe drought by Petro Kotze (The Water Wheel, September/October 2015)