From Camp Kuzama's own website:
"Camp Kuzuma, borders the Chobe National Park of Botswana and the Hwange National Park in Zimbabwe. 200 000 elephants roam in this busy corridor - including massive breeding herds, bachelor herds and lone ranging bulls. They move thousands of kilometres across the country’s wildlands, using ancient routes to pass through private farms, national parks, towns and move deep into neighbouring countries".
So it appears that the elephants move over great distances, rather than staying in one locality. Perhaps it's not surprising then that one particular watering hole isn't in use at the moment?