"Can water flow uphill?" asked a member of our paddling group, peering at his GPS. We were two days into a four-day canoe trip in Botswana. "Yes," someone replied, "but only if it's in a Roman aqueduct, or a pipe." "Well," he said, "my Garmin says we've gained two metres since we stopped to swim at the elephant carcass."
Apparently we were paddling uphill. No wonder our arms were taking such strain. Later investigation proved this reading was due to random error built into the GPS by the US military, which runs this satellite-based triangulating system.
But uphill flow wouldn't have been entirely surprising: we are in a place where water does strange things.
Between the Okavango Delta and Savute Marsh in Chobe National Park is a body of water with a name that sounds like a Sri Lankan spin bowler. Reed-lined Lake Zibadianja is little known, because for decades it was part of a hunting concession.
It is also mysterious, in that it can be full for many years, then drain away in one direction or another, dry up, then suddenly fill again. It is fed from its western Okavango side by a channel called the Selinda Spillway, and from the north by the Linyanti River, an offshoot of the Kwando River, which flows into the Chobe River, which in turn flows into the Zambezi.
Lake Zibadianja empties along the Savute Channel into the Savute Marsh, a once-abundant wetland that has been bone dry for decades. Then it gets a little weird: when the Zambezi is very full, it flows backwards into the Chobe, then into the Linyanti, into Lake Zibadianja, and from there into the Savute Channel and "backwards" up the Selinda Spillway towards the Okavango Delta. It will do that for any number of years, then stop, then reverse.
During the early to mid-90s, wildlife movie-making mavericks Dereck and Beverly Joubert were living on Lake Zibadianja, having filmed, among other epics, Zebras: Patterns in the Grass and Eternal Enemies: Lions and Hyenas. They were tenants in the concession run by Hunters Africa and the wildlife was getting hammered all around them - especially the lions they were filming. These glamorous bush babies - teenage sweethearts who decided they would spend their lives together in the African bush - were despondent.
Over the next few years things would get worse. All the big male lions had been shot for trophies, the hyenas were beating the crap out of the female-led prides, and even the sub-adult males were being hunted. Then the lake - the last "permanent" water in the region - started drying up. By 2000 it was reduced to a puddle of chocolate mousse, with hippos lying motionless in the last dribbles of sludge.
But then the hunters lost the concession and things started to look up. By 2003, the lake had become a fertile grazing paddock for zebra, wildebeest and tsessebe. Still, at its centre was a stinking star-shaped cesspool with dead and dying hippos packed nose to tail. With permission from the authorities, an emergency channel was opened from the Linyanti into the lake, which just managed to keep the hippos alive. The years 2004 and 2005 saw terrible drought grip the land, but seasonal flood waters - miraculously - kept flowing into the lake.
Whether there is a link or not, exactly one week after the Indian Ocean tsunami at the end of 2004, water started coursing down from Linyanti to refill Lake Zibadianja. Water also flowed, for the first time in more than 30 years, from the Okavango down the Selinda Spillway towards the lake.
By 2007, water from the Okavango side had reached well down the channel, while water from the Linyanti side had pushed far beyond the lake and down the Selinda Spillway. The following year, the delta water came within 15km of reaching the darker, peaty water from Lake Zibadianja.
This year, they were expected to meet, and that is why we were there, hoping to be the first people to paddle the entire spillway since mokoro-poling Bayei boatmen had used it for hippo-hunting expeditions in the early '70s.
We got further down the spillway than any paddlers since that time, but had to walk about 10km between the two sections. When we left, though, water was still flowing strongly from both directions, with a heavier than usual annual flood expected to come down from Angola. The gap became 2.5km, and by the time you read this the waters will, in all likelihood, have met.
While the lake was beginning its renaissance, Colin Bell was having a midlife crisis. The co-founder of Wilderness Safaris had decided to up and off. No one knew quite where for a while, until he pitched camp with the Jouberts as the new concession-holders of the Selinda Reserve: a 150 000ha eco-reserve that straddles the Selinda and Zibadianja waterways.
It's a new level for ecotourism. Camps are being converted to solar power and waste is minimised, as is any other kind of human impact on the natural environment. This doesn't come cheap, but then neither does a plum safari concession in northern Botswana.
One of Selinda Reserve's exciting ecofriendly offerings is a seasonal canoe safari down the Selinda Spillway, so long as the rains, annual floods and seismic activity deep beneath the Kalahari sands permit.
The tours will run at least till the end of this month, when the Ngamiland floodwaters start to recede, and probably for another three years, until the rains slow, the Selinda's mysterious waterways retreat and the thin skein of water that brings life to north-eastern Botswana flows away. Uphill, perhaps.
"We'd all just turned 50," recalls Colin. "We realised our planet was getting really screwed. What we were doing seemed like putting a Band-Aid on a severed artery. We felt we had to do something extraordinary with the time we had left." So they dreamed up a conservation organisation that would do some tourism, rather than a tourism operation that did some conservation. They formed Great Plains, which has projects across Africa and around the Indian Ocean.
And whether you're in a canoe or staying at rustic mopane pole and canvas Motswiri camp or opulent Zarafa (voted by international travel magazines as one of the top eco-lodges and small hotels in the world), you'll be treated royally.
Selinda Reserve is mostly about protecting the elephants of the greater Chobe region, the Jouberts' other great love after lions. The long-term dream is to save some of the last great wildlife of the world. At Selinda and its sister projects elsewhere, Great Plains is developing the gold standard - or carbon standard, if you like - for balancing the needs of conservation, governments and local communities in threatened wildlife areas.
Just as water can sometimes turn and flow the opposite way up a river, the course of an aspect of history can be changed by something as random as three individuals having a simultaneous midlife crisis. Life is wild that way.
- This article was published with permission from GQ magazine