If Hurricane Sandy had hit Boston at high tide, the city would have seen 6 percent of its land underwater. That would have damaged every waterfront neighborhood and the Harbor Islands.

In a hundred years, nearly a third of Boston could see major flooding on a regular basis. Those were some of the facts shared at a climate change event at the Aquarium Tuesday, where Mayor Thomas Menino and climate change experts vowed to boost preparedness efforts.

If climate change is inevitable, then so are major storms, and Boston has to start building accordingly. That was the message at the Aquarium, where Menino and the Boston Harbor Association outlined a report on projected changes in 10 waterfront communities. David Storto, president of Spaulding Rehabilitation Network, explained that the design of his company's new Charlestown facility took into account rising sea levels.

"We built all the electrical systems not on the ground level or on the basement but one the roof of the building, on the ninth floor," Storto said.

Menino says city code and development officials are drafting design guidelines and checklists, but it's unclear how they'll be enforced in the future. The Boston Conservation Commission has also been tasked with creating a wetlands ordinance to develop new floodplain maps of the city. Report author and UMass scientist Ellen Douglas says it's not just the city of Boston that will be affected by flooding.

"Increased precipitation events means more storm water, more mosquitoes if you live out in the county, all sorts of impacts,” Douglas said. “It's pretty much a wholistic prediction and sea level rise is just one aspect of that."

With Hurricane Sandy barely in the rearview mirror, the city's office of emergency management is still reviewing response planning for storms and flooding.

But major storms such as Sandy are what have city officials and the science community concerned.

This conversation about climate change was more about logistics and urban planning than science.

"As you can see, a number of sites may be at risk of increased storm flooding soon after 2050, including Logan Airport, the Boston Convention and Exposition Center and the Baystate Expo Center site of UMass Boston," said Vivien Li, president of the Boston Harbor Association.

The BHA released a report that's really a series of case studies of those places Li mentioned, along with the UMass Boston Campus, the Aquarium and Morrissey Boulevard. What happens to residential and commercial properties during twice-daily high tides, annual storms and serious hurricanes? Maybe not much now, but that could change in the future.

"Preparedness needs to be a priority for property owners in Boston on or near the coastal flood planes,” Li said. “There are a number of things, short- and long-term, that property owners can do, including cost-effective, phased-in actions that can reduce vulnerabilities to more frequent flooding."

The report lists projected flood depths and makes recommendations such as identifying evacuation strategies, estimating clean up costs and how the city can work with developers.

Menino said he and his staff are looking into climate preparedness design requirements for new building construction.

Preparing for the Rising Tide by