Power utility Eskom on Wednesday called on consumers to switch off geysers, pool pumps and all non-e.
The signs come after at least 8 people were mugged in separate incidents at the beach since February, the Cape Times reported.
Community Safety MEC Dan Plato said tourists were most vulnerable.
“Specifically tourists don’t know the dangers of the area. What we will have to do is put up signboards that say: 'Only walk in these designated areas' or 'Please don’t go beyond this point’,” he said.
Plato was also looking at the possibility of installing quad bike patrols but said this would not solve all crime.
“Attacks are happening almost any time of the day. If criminals want to attack, they attack.”
Table Mountain National Park spokeswoman Merle Collins warned people to walk in groups of four or more and not to carry valuables.