Boston prepares for climate change effects

Many properties in Boston may have to waterproof their buildings – raising critical electrical systems to higher levels or building barriers against storm surges — as sea levels rise from climate change.

The city is stepping up a campaign to prepare buildings for rising seas that could significantly flood neighborhoods during storms.

The public-private plan comes at the same time a Boston Harbor Association report spotlights high-risk areas, such as Long Wharf and University of Massachusetts Boston, and outlines how property owners can best protect themselves from water.

Hurricane Sandy and last week’s massive snowstorm have added new urgency to the issue, city officials say.

This “will help make our waterfront and the rest of Boston better prepared to handle future storms and get the city back in business as quickly as possible,” Mayor Thomas Menino said.

In the next six months, the Boston Conservation Commission will develop new flood-plain maps to take in to account future storm surges atop higher sea levels. A wetlands ordinance will also help guide property owners to prepare for higher sea levels, said Brian Swett, chief of Environment and Energy for the city.

The city will also conduct a detailed assessment on how individual buildings might fare in floods. For example, some may have boilers in their basements that need stronger barriers to protect against rushing waters. Meanwhile, new buildings may be required to be designed differently to take rising seas into account.

Researchers say Boston and its densely developed shoreline are extremely vulnerable to more frequent and intense storms projected from global warming. The sea level is rising here at almost four times the global rate, adding to the urgency to protect properties soon.

In its efforts to combat threats from global warming, Boston launched the “Green Ribbon Commission” in 2010, which includes more than 30 business and civic leaders, to help meet the city’s goal of reducing greenhouse gas emissions 25 percent by 2020 and 80 percent by 2050.

Much of the commission’s effort has been focused on reducing emissions, although the increasing number of storms, coupled with the realization emission reductions would not solve the problem alone, highlighted the urgent need to also protect the city against threats from the ocean. The commission recently appointed a new working group to find the best ways to do that.

“We had really been focused on the mitigation side, but we know we now have to do both,’’ said John Cleveland, executive director of the Green Ribbon Commission.

The group largely focuses on the commercial and industrial sectors, which includes health care institutions, universities, and government offices that represent 55 percent of the city’s greenhouse gas emissions. Many are in low-lying areas susceptible to coastal flooding, such as Boston University and institutions in the Back Bay. If the city is to succeed in its climate goals, he said, the question is “how do we get leadership in these sectors to make [climate preparedness] part of their business practice.”

The commission, which is funded by several foundations, also asked the Boston Harbor Association report to give case studies for individual properties. For example, the report, called Preparing for the Rising Tide, highlights UMass Boston’s entrance and the Bayside Expo Center, which the university now owns.

Based on estimations of sea level rise, the campus entrance probably will flood far more often in the future. The university could, according to the report, build a tidal control structure and wetlands to control and absorb flooding at a one-time cost of $500,000 to $750,000, with about $10,000 in yearly maintenance costs. Properties in vulnerable areas need similar assessments, city officials say.

Knowing such information — and the cost of implementing the changes — is key, said Vivien Li, executive director of the Boston Harbor Association. “It lays out in a systematic way” what needs to happen, said Li.

While many property owners say they cannot afford all the upfront costs today, “the fact is we can phase it in over two, three decades,” said Li. “It’s not that you have to do it [right now], but to think and plan for it.”

Swett said some solutions are not always difficult and pointed to New York as an example. That city added a step up to get in subway stops in places, adding 6 inches of flood protection. City officials also examined air vents, which are often at street level, and raised some of them higher.

“A critical question to understand is what is the cost of inaction,’’ Swett said. “We will never get to the point where we will say it’s flood-proof,” but buildings can be made more resilient to floodwaters.