Where water is a benevolent mistress

IN Kariba, water is worthy benevolent mistress, kissing the sky with all the love of nature and providing the much-needed life, comfort and business.

Where the land meets the water, in swash and backwash, silky white coves hem in the azure bays, overlooked by a chain of wild jungle-draped rolling hillocks and mountains.

It is from the peaks that wild animals streak to the lake-shore to quench their thirst, bath and feed on the lush green vegetation. From the shaggy water buck to the nimble-footed duiker, the spindle-legged impala to the boisterous jumbo and sluggish hippo, the lake is a source of life.

From leafy suburbs and sprouting settlements dotted around the shoreline to the rest of Zimbabwe and beyond, Kariba has become a tourist resort of repute and a source of fish. It is an attraction of repute.

Lake Kariba is fed from rainfall in a catchment area of 1 352 000 square km, more than half the size of South Africa and larger than France.

The Zambezi River rises in north western Zambia and its catchment area covers eight countries, namely Angola, Botswana, Malawi, Mozambique, Namibia, Tanzania, Zambia and Zimbabwe. It enters the Indian Ocean in Mozambique at Quelimane.

It flows for some 2 650 kilometres from its source to the Indian Ocean. It is the fourth largest river in Africa after the Congo, the Nile and the Niger and it is the largest river in Africa flowing into the Indian Ocean.

Kariba Dam is located approximately halfway down the Zambezi River, which is divided into four distinct sections, namely; Upper Catchment Level (Northern Highlands); High Level Plateau, north of Lukula, the Zambezi River’s source.

Middle Catchment, (Central Plains), stretching from source to Victoria Falls.

Lower Catchment, (Northwestern drainage area of the Zambezi); Lake Kariba lies within this area in the Gwembe Valley.

Lake Kariba is the beast of burden, carrying water for leisure, tourism and hospitality as well as electricity generation for Zambia and Zimbabwe. The average annual rainfall varies from 1,5 metres in the North to 0,7 metres in the South, with the run-off factors varying generally from 0 to 16 percent and reaching 100 percent on the 1,3 sq km surface of the Lake.

The entire catchment area is generally difficult to access and in some cases its watershed boundaries are indeterminate.

But Kariba is not alone as world climate change bites. The world over, climate change is sapping hydropower’s dependability as rivers that once ebbed and flowed with seasonal regularity have grown erratic.

In full capacity or at its lowest, Kariba dam still commands a lot of attraction from the tourism industry.

In Brazil, record drought triggered blackouts in 2015. In California, output from dams has swung wildly from year to year. And in Europe, Spanish utility giant Iberdrola SA’s hydro output reached a record high in 2016, then plunged 57 percent the following year.

The shift in climate is sending shivers in countries that depend on dams for power and is prompting utilities and investors to more closely and re-look at what has of been one of the largest sources of carbon-free electricity.

“Hydropower is going to be less effective,” says Jenny Kehl, a professor at the University of Wisconsin-Milwaukee’s School of Freshwater Sciences.

“As the water levels decline, the capacity for hydropower plants to generate electricity will decrease.”

“The industry has had an awakening,” said Mike Haynes, COO of Seattle City Light, which gets 90 percent of its power from hydroelectric dams. While Zimbabwe and Zambia are planning another dam upstream on the Zambezi to address electricity shortages, it might be time to pause and think again.

The river, meanwhile, is near its lowest level in half a century. The dam which usually overspills during the rainy season into winter when the Zambezi is in full flow, may not experience any over spill this year, authorities said.

While expectations are high that the river and dam will record inflows, water levels dropped by three metres between October 2018 and February this year. The levels further dropped to five metres above minimum operating level. And, while droughts may come and go, the river’s future looks grim. The lethargy of climate change is real and will be with us for long.

Whichever way, Kariba holds its own and fishing of kapenta has become a mainstay.