A report commissioned by the City of Victoria says 4,000 buildings could be destroyed if a catastrophic earthquake hits.

That means nearly 40 per cent of the city's buildings, as well as much of the water and sewage infrastructure, could be destroyed in a magnitude 9 megathrust earthquake.

Victoria is only the second city in the province to commission a study like this. The District of North Vancouver did one in 2008.

According to the study, the likelihood of that scenario occurring in Victoria in the next 50 years is five per cent.

Carlos Ventura is the director of the Earthquake Engineering Research Facility at the University of British Columbia in Vancouver.

For this study, he says they made an inventory of all the buildings in Victoria.

"You catalogue the buildings mainly through visual surveys, Google searches and also information that is available in databases, like property assessments," said Ventura.

"The focus is to identify the areas in the city where the risk of damage from an earthquake could be significant and start developing policies to minimize the risk."

The City of Victoria can use the study to start creating strategies it can use in the aftermath of an earthquake.

Ventura says it's not necessarily only about buildings that might collapse, but, "being damaged enough that they could not be occupied."

"If those are residential buildings, then where do you put those families until you are able to repair or replace that building."

The detailed data on the vulnerability of specific buildings in the City of Victoria is expected to be released soon.

Report: Citywide Seismic Vulnerability Assessment of the City of Victoria