Harvesting icebergs and learning from forests on how to run a city were offered as solutions for Cape Town’s water woes at the African Utility Week Conference held in Cape Town in May.
Salvage expert Nick Sloane addressed delegates at the Conference during a keynote session on Wednesday, May 16, where solutions from nature were explored to address increasing energy and water constraints. “It sounds like a crazy idea but if we break it down, it is not so crazy after all,” Sloane said.
Millions of litres to go to keep Day Zero at bay
Director of water and sanitation in the City of Cape Town, Peter Flower, told delegates at the Conference that the city still needs to reduce consumption to 450 million litres of water per day to keep Day Zero at bay. With the current usage at 500 million litres per day, the situation remains dire despite measures employed by the city to reduce consumption.
Answer to Day Zero could be Icebergs!
According to Sloane, the answer may just be in icebergs, or a total of 140 000 icebergs to be specific, drifting in the southern oceans. Harvesting icebergs, he said, can help provide at least 20 percent of Cape Town’s water needs. Icebergs creak off in Antarctica, containing some of the purest quality water and drift into the ocean, melting away.
Tonnes of the purest water you’ll ever drink!
“About 2000 million tonnes of ice are breaking off every year,” he said. The idea is to use the current system to guide these icebergs towards the Cape. Sloane said the iceberg can be captured in the area round Gough island and will ultimately have to be guided and moored about 40 km offshore from St Helena island to be harvested.
Up to 60 million litres of iceberg water a day
He said they will then have to “create a saucer to capture the melting water that can deliver up to 60 million litres per day”. This volume can increase to 150 million litres a day if it is pumped into tankers and ferried to land where it will be treated before it goes into the water system.
“So, with four to six of these tankers 150 million litres can harvested per day for one year. We are looking into the viability of this approach,” Sloane stated.
Copying nature’s wisdom
Director of BiomimicrySA Claire Janisch also shared case studies on how nature’s “wisdom can be copied” to help with the increasing pressure on and challenges with natural resources. “Solutions to our problems already exist in nature. We can improve our physical world by following nature’s example,” she said.
One such an example is emulating the humpback whale’s attack manoeuvre in wind turbines to increase efficiency and learning about desalination through the example of the mangrove trees that use sea water to survive.
Janisch also told delegates humankind can learn from termites on how to design buildings with efficient energy use for air-conditioning. She referred to the Eastgate building in Harare that is built on the model of termite nests that mimic the self-cooling nature of these nests. By simply looking at the world around us, we might solve some of our most complex daily challenges!