Marine salvage expert Nick Sloane said he was looking for investment to guide huge chunks of ice across the ocean and melt them down into millions of litres of drinking water.
South Africa has declared a national disaster after two of its driest years on record in 2015 and 2016.
Authorities have warned that taps could run dry next year if rains do not come to the rescue of Cape Town’s four million residents.
Mr Sloane, who led the re-floating of the Costa Concordia cruise liner in 2014, said his team could wrap passing icebergs in fabric skirts to protect them and reduce evaporation.
“We want to show that if there is no other source to solve the water crisis, we have another idea no one else has thought of yet,” he said.
Large tankers would guide the blocks into the Benguela Current that flows along the west coast of southern Africa, before a milling machine would cut into the ice.
A single iceberg “could produce about 150 million litres per day for about a year,” around 30% of Cape Town’s needs, Mr Sloane said.
The director of the marine salvage firm Resolve Marine said he was planning to hold a conference later this month to try and sell the $130m (£95m) project to officials and investors.