The Nyami Nyami of Zimbabwe.

The descriptions of African water monsters vary, probably a bit like the Loch Ness Monster’s descriptions vary, but they all have body parts belonging to different animals stitched together to make them fearsome looking.

Zimbabwe’s river denizen is the Nyami Nyami, which is also regarded as a river God by the Tonga People. It has rarely been seen, but when it swims past you, the water turns red.

Nyami Nyami lives under a rock, named Kariwa, ‘the trap’ in the Zambezi River. That stone is now 30m under water in what is now Lake Kariba, a dam built in the 1950s. Supposedly, Lake Kariba is named for Kariwa.

The Tonga People, believe that Nyami Nyami is married, and that his wife is trapped on the other side of the dam wall, which understandably makes him angry, and when angry, he unleashes powerful and deathly forces, such as earth tremors and floods.

Lake Kariba, or more correctly: Kariba Dam, is man made. It is surrounded by African wildlife, and is a huge tourism attraction.

He did not appreciate that Lake Kariba was built, and unleashed floods of magnitudes never seen before in the area. The first was in 1950, when the dam was still just a plan on a piece of paper – a cyclone from the Indian Ocean swept up the Zambezi valley, causing the river to rise 7 metres, leaving death and destruction when the waters subsided.

The second flood was on Christmas Eve 1955, washing away the newly built coffer dam foundations and pontoon bridge.

The third flood happened in 1956, when exceptionally heavy rains fell in the Zambezi River’s catchment area. The mass of water in the tributary, the Sanyati River entered the Zambezi just above the new dam wall, and the water having risen over 6 metres, surged over the coffer dam. It took six months before work on the dam could be properly resumed.

In 1958, Nyami Nyami was really cross and missing his wife, and unleashed a ‘thousand year’ flood of Biblical proportions, killing many people and doing untold damage. The Tonga elders believed that the deaths of the European engineers were in lieu of sacrifices demanded by Nyami Nyami.

Nyami Nyami has a serpentine body and a horse like head, with enormous Sabre -Tooth Tiger type fangs. He has tiny wings, maybe fins, or possibly gills, and a dinosaur-like crest runs down his spine.

A giant fish, the Vundu Catfish (Heterobranchus longifilis) lives in these waters, and the legends may have originated from sightings of this fish. The Vundu is prized as a sport angling fish, and can grow to 1.5m in length, and weigh 55kg. It has long whiskers (also called barbels) on their upper lips, which could easily have become sabre teeth as the fish got taken into Tonga folklore.

The Vundu catfish has long whiskers which could have become sabre-like teeth as the legend grew.

The Tonga believe that one day, the Nyami Nyami will restore their flooded lands to them, by causing a flood which will wash the dam wall away.

An interesting fact is that the Kariba dam wall has some serious cracks in it, and speculation that it could collapse has been rife for years. Scientifically, the cause is that the bedrock is unstable and has been eroded over the years. Rehabitation of the cracks has been affected, as should the wall collapse, a disaster would enfold: 3.5million people living downstream of it would be at serious risk.

But has this instability been caused by Nyami Nyami’s earth tremors created when he is missing his wife?