The City of Johannesburg has lost more than R300-million due to theft and vandalism of its properties.

Mayor Herman Mashaba said the amount could escalate further.

"Yesterday [Tuesday], I was alerted by council members, during our visible service delivery committee meeting, of the concerning upward trend of vandalism and theft of City Power infrastructure.

"This was cited as the biggest reason to the slowness in delivering electrification of streets in some areas of our city.

"I have been made aware that the cost of this all, including the value of all the material that has been stolen, surpasses R300-million and continues to rise," he said.

Mashaba blamed criminals for repeatedly vandalising street poles and stealing supply cables and newly-installed equipment, such as Aerial Bundle Conductors.

Areas affected by criminal incidents include the Crown Interchange, the Heidelberg and Joe Slovo interchange, and the Grayston pedestrian bridge lights.

"There has also been a high number of illegal connections, which result in street light sections being cut off by Eskom, because illegal connections damage the supply transformers. All of this is having an impact on the quality of service the City is trying to deliver," he said.

Some substations have been robbed and valuable equipment stolen.

"It means, while we’re busy with major and necessary upgrades, we’re also faced with work being undone and millions from our budget going down the drain. There are thugs who want to see us fail, those who think of nobody else but themselves and their selfish gains.

"We cannot allow these brazen criminals to threaten the delivery of services in our city. It must not happen at all. Having working streetlights aids with prevention of night-time accidents and crime," he said.

The mayor pleaded with residents to report theft and vandalism, as well as defective street lights in their communities.