Much of the focus on the proposal for four residential towers in Portland’s Bayside neighborhood has been on the height of the buildings, which would be as tall as 165 feet.

But some interesting changes could soon take place at the street level.

The ground floor of the new project, which is called “midtown,” would be built 2 feet above street level to protect against frequent flooding in the neighborhood. And because the buildings are proposed to be built closer to the street than normal, city officials are planning to raise a section of Somerset Street by up to 2 feet to meet the building – a project expected to cost millions of dollars.

Raising the elevations of streets and buildings is an issue that will likely resurface whenever new developments are proposed in Bayside and East Bayside – two burgeoning neighborhoods with a history of flood problems that will only get worse if sea levels rise and storms become more extreme because of climate change.

The Portland Planning Board is expected to vote on the first phase of midtown next month. It held a 2½-hour public hearing on the project last week and much of the public’s concerns focused on the height and size of the buildings.

One neighbor of the proposed project is concerned about the ground-level changes.

The Noyes family worries that the elevated street and curb will create a water problem for its nearby storage facility on Somerset Street. The 75,000 square feet of ground-floor storage accounts for about half of the business.

“The Noyeses are a little bit in the cross fire on this one,” said Nathan Smith, the family’s attorney.

Will and Brent Noyes said the current street-raising plan, which includes an additional 6 inches of curbing for a sidewalk, would leave almost no buffer before water pools up around a Somerset Street side building, where it could degrade and penetrate the old brick.

“Right now we have 3 feet of buffer,” Will Noyes said.

The midtown elevations are being driven by federal insurance guidelines, according to Greg Shinberg, the local representative of the Miami-based developer, The Federated Cos. Those guidelines require the ground floor to be 12 feet above the average sea level. Currently, the street is roughly 10 feet above that level.

The street raising would also make the retail spaces more marketable, Shinberg said, because it would eliminate a potentially steep drop-off from the sidewalk as it reduces the flood hazard. The parking garage, the first floor of which would house most of the retail space, is being built on Somerset Street because the lot is so narrow.

Shinberg also said he believes the street can be raised in a way that protects the Noyes family’s property. Grading and design details could direct water away, he said.

The Bayside neighborhood has long suffered from chronic flooding.

Until 1850, much of the 100-acre neighborhood was part of Back Cove. It was filled in over the years with gravel from Munjoy Hill and debris from the Great Fire of 1866.

During heavy rains or extraordinarily high tides known as “King Tides,” water rises through storm drains and pools up on Somerset Street and Marginal Way, a phenomenon that has earned them the nicknames “Somerset Lagoon” and “Knudsen Pond” among area residents.

Cattails can be found growing on the city-owned parcel on Somerset Street where the midtown project is planned.

“What we see with the Somerset Lagoon is the Back Cove trying to reclaim its edge,” said East Bayside resident and University of Southern Maine professor Jan Piribeck.

Piribeck is an art professor who specializes in digital mapping. She is part of “Envisioning Change,” an effort to raise awareness about sea level rise by using art. The group recently began holding events focused on King Tides – where tides can rise 11.6 feet or higher – to highlight the potential effects of sea level rise.

If sea level rise occurs as predicted, even more of the neighborhood could find itself underwater at the highest tides.

New flood maps released by the Federal Emergency Management Agency place most of Bayside from Lancaster and Kennebec streets to Back Cove in the new flood plain.

In 2011, a group of academics, scientists and city officials studied possible long-term economic impacts of a 3-to-6-foot sea level rise and storm surges along Back Cove.

The 2012 “COAST in Action” report, by Catalysis Adaption Partners, found that Back Cove is already vulnerable to large storms – as evidenced by the frequent flooding. The report noted the “enormity of potential impacts from storm surge flooding even in low (sea level rise) scenarios.”

Ambitious proposals to deal with water problems included building a $103 million hurricane surge barrier at the mouth of Back Cove and a $40 million levee system around Back Cove. If no action is taken, the report says, the city could suffer up to $447 million in real estate losses by 2050 and up to $3.7 billion in losses by 2100.

City officials say they are still developing long-range plans to address flooding and sea level rise not only in Bayside, but along Commercial Street as well.

The city does not have any plans to raise other streets in Bayside, according to Greg Mitchell, the city’s economic development director. Decisions about other streets will be made in response to specific development proposals, as with midtown, he said.

The city would not provide a cost estimate for raising the roughly 1,110-foot section of Somerset Street, from Pearl to Elm streets. But it is likely to be a significant investment, involving city funds, since electrical wires and transformers would be placed underground – a standard change with new developments.

Mitchell said he will recommend that the city pay some of the cost, because the road is a public amenity and other property owners could benefit. The exact amount is still being negotiated with The Federated Cos., he said.

Randy Billings can be contacted at 791-6346 or at:

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Twitter: @randybillings