Using data from a worst-case scenario, the ocean and Duxbury Bay will be over five feet higher in 75 years and will flood low-lying areas twice every day with the incoming tides, according to a regional sea level rise study completed recently for Duxbury, Marshfield and Scituate.

Former long-time Duxbury selectman and professional engineer Andre Martecchini presented the findings of this study to the board of selectmen Monday. Martecchini is employed by the company Kleinfelder Northeast, Inc., which was hired after the three towns received a grant for the report from Gulf of Maine Council and Northeast Regional Council.

Martecchini presented highlights from the sea level rise study, which can be found on Duxbury’s town government website on the right-hand side. The 135-page document has a series of maps for Marshfield, Scituate and Duxbury that show how the ocean will rise and how it will affect coastal properties in 25, 50 and 75 years. The maps also show the effects of a storm surge coupled with sea level rise on these towns. The report notes the impacts of rising tidal waters on natural resources — tidal marshes, beaches, wildlife and shellfish; on infrastructure — roads, bridges, and sewers; and on transportation and emergency access. It also discusses “adaptation strategies” that will help lessen the impacts of long-term sea level rise and storm surges.

The study states that the primary contributors to global sea level rise are thermal expansion as a result of increases in sea surface temperature and contributions of fresh water from melting glacier ice. However, Martecchini said the report did not look at what was causing the seas to warm and the ice caps to melt.

“We did not want to get into a debate about global sea level rise – Is it man-made? Is it cyclical? It really doesn’t matter, it’s happening,” he said.

The report bases its calculations on the highest global sea level rise scenario as provided by the National Oceanographic and Atmospheric Administration.

Martecchini said that in 25 years, Duxbury can expect its tidal waters to rise by 1.08 feet. In 50 years, that will increase to 2.8 feet, and in 75 years, the ocean and bay will swell by 5.16 feet.

What does this mean for Duxbury?

“The areas that flood today are going to flood more,” said Martecchini.

He used the example of the low-lying area on Washington Street near the Bluefish River and St. George Street flagpole and the roadway at the beginning of King Caesar — both of which flood during very high tides.

“Now, during a high tide, they put up barricades,” he said. “That’s going to happen a lot more. In 75 years, it’s going to happen twice a day.”

Flooding in the Powder Point area not only prevents access to the homes there but it also cuts off Duxbury beach and the 250 houses on Gurnet/Saquish.

A low part of Washington Street in the Snug Harbor area will also see daily flooding on the road and in surrounding shops, said Martecchini. Currently, the parking lot at Blakeman’s bathhouse, the public part of Duxbury beach, floods monthly and will be subject to more flooding as the seas encroach.

Martecchini said the towns basically have four options in dealing with sea level rise: One,  do nothing; two, protection – trying to prevent flooding from happening; three, accommodation – such as raising structures and roadways; and four,  retreat.

“At a certain point, you may have to leave those areas, because you will not be able to survive in these areas,” he said.

In the back of the report, each town has its own pages that list “potential adaptation strategies” dedicated to what can be done to combat sea level rise. Some examples in Duxbury are to raise sections of roads on Washington Street, Powder Point Avenue, King Caesar Road, Bay Road, Pine Point Road, Marginal Road and Gurnet Road. The access road at Duxbury beach should also be raised and existing sea walls along the beach should be rebuilt to be at least two feet higher. Other ideas include investigating the construction of offshore floating breakwaters or other wave attenuation devices to absorb wave energy and protect sea walls, studying salt marsh health, and raising the sacrificial dune on Duxbury beach by two feet.

The report’s final page suggests that the towns should continue to follow-up with more analysis of storm surges along the coast and by creating inter-municipal groups to work together on the problem of sea level rise.

In other business, selectmen:

• Approved spending $35,960 from the Eben H. Ellison trust fund to pave a portion of the Lincoln Street field entrance and parking lot and to maintain the Ellison playgrounds. Recreation Director said the Ellison trust fund was given to the town in 1990 and contains over $300,000. The interest from the fund is used for playground maintenance and for worthy town projects. Cushing said $17,980 will be used to pave an area of the Lincoln Street fields entrance and as much of the parking lot as possible. Last year selectmen approved $3,178 for this project but this money wasn’t spent. It will be combined with the recent disbursement. Another $17,980 will go for the upkeep of the playground near the library and the one at the Chandler school. A project to power wash and paint the trim of the 14-year old town-owned North Hill Country Club clubhouse was not approved by the trustees.

• Were presented with preliminary revenue projections for fiscal year 2015 from Finance Director John Madden. Madden said he expects the town to have over $1.5 million in revenues next year from the additional 2.5 percent tax levy and new growth. This is an almost 3 percent increase. However, he projects a decrease in local receipts – as much as a $300,000 decrease in beach permit receipts – and flat state aid. Madden is holding town departments to a 2.25 percent increase in payroll and a one percent increase in expenses. Still, he faces a $450,000 shortfall at this point, however, Madden said he believes he can close that gap as the budget creation is very early in the process.

• Approved a memorandum of understanding and management plan with the Massachusetts Division of Marine Fisheries to open an area of Kingston Bay to shell fishing. The area is east of a line drawn from Peck Street in Kingston to Howland’s Landing in Duxbury and west of a line drawn from the Kingston/Plymouth town boundary at Boundary Lane to Goose Point Lane in Duxbury.

• Accepted the resignation of Ted Weihman from the Duxbury Historical Commission and appointed Frank Turner to the Sidewalk and Bikepath Committee. Both committees have vacancies on them.

• Approved three one day liquor licenses and announced a trash pickup of Duxbury Beach on September 28 and a town-wide volunteer litter sweep on October 5 from 8-4 p.m. at the Tarkiln Community Center on Summer Street.