This was the second attack on the standby team this month, said Zahid Badroodien, member of the mayoral committee in charge of water and sanitation.
According to Badroodien the team were robbed of their personal belongings and city equipment was also stolen.
Badroodien said a case had also been opened at the Harare police station.
“The water and sanitation directorate staff and operations are heavily impacted by theft and vandalism. Earlier this year we reported the theft of more than 1 100 water meters and 4 900 manhole covers costing the city millions each year,” Badroodien said.
He said he was concerned that officials faced risks when delivering services to residents.
Residents who have more information have been asked to come forward and could possibly get a reward of up to R5 000.
Earlier this month, Eskom withdrew services in Harare, Khayelitsha, with immediate effect after workers were asked to pay a protection fee of R20 000 by alleged gangsters.
The workers were working to restore electricity in Jingi Street when they were approached by the armed men.
Meanwhile, a City of Cape Town official from the Informal Settlements Basic Services branch was shot twice while en route to respond to a burst pipe in the Klipfontein Mission Station community.
The official was a victim of an attempted robbery.
Police spokesperson colonel Andrè Traut said police were investigating a case of armed robbery.
“We can confirm that a robbery involving a fire arm was reported and a case opened. A tablet worth R2 000 was stolen. No suspects have been arrested,” Traut said.