Vapour vision City reviewing fog harvesting plan for Table Mountain

THE City of Cape Town is reviewing its fog harvesting plans, which was first initiated amid the panic of the City and province's water crisis.

- THEOLIN TEMBO

Back in December 2020, the City announced that as a result of the drought shock, the implementation of desalination, water reuse and aquifer abstraction had been implemented at an accelerated rate.

One of the projects they investigated looked into the potential of using fog to directly or indirectly augment the drinking water supply.

The principle of fog harvesting is based on the fact that air contains a certain amount of water vapour, originating from ocean evaporation.

At higher temperatures, air contains a larger volume of water vapour than at lower temperatures.

As air is transported up a gradient by wind, it interacts with colder air and is condensed into fog.

“Key ingredients to the favoura-ble formation of fog are high altitude mountains (> 800m above sea level) within close proximity to the coastline.