A grant-funded engineering study proposes a variety of solutions to mitigate flooding on two low-lying roads in Harpswell, including temporary flood barriers that would narrow the roads to one lane during storms.
The study, by South Portland engineering firm Gorrill Palmer, was commissioned by the town of Harpswell and funded by a grant from the Maine Department of Transportation’s Maine Infrastructure Adaptation Fund. It proposes a range of options to address sea-level rise on Lowell’s Cove Road, on Orr’s Island, and Dingley Island Road, near Cundy’s Harbor.
The least costly of the proposed solutions for both roads would be to purchase temporary flood barriers that could be deployed ahead of major storms to block seawater from overtopping the roads. That option would cost an estimated $159,000 for Lowell’s Cove Road and between $347,000 and $473,000 for Dingley Island Road, depending on how far the barriers were extended.
Still, that option would restrict traffic to one lane during storms and require teams to work for several hours to install and later remove the barriers. Gorrill Palmer estimated the need for a crew of four to eight people working four to eight hours to set up the Lowell’s Cove Road barriers, and eight to 12 people working four to six hours to set up the barriers on Dingley Island Road.
The other option — elevating the roads — would be far more costly, the engineering firm said. It estimated raising Lowell’s Cove Road to a height that mitigates flooding would cost $779,000, and raising Dingley Island Road would cost between $2 million and $2.8 million.
Harpswell has been using state grants to fund engineering studies of major town roads that will be vulnerable to 2 feet of sea-level rise. Gorrill Palmer completed studies in January of Abner Point Road at Lubee Lane, near Mackerel Cove on Bailey Island; and Bethel Point Road at the bridge over Hen Cove, on Great Island near Cundy’s Harbor.
No funding has been allocated to perform the recommended fixes. Harpswell would need to apply for additional grants, fund the projects through bonding, or explore other local financing options such as phased budgeting or special assessments.
Local leaders have said their next priority is to facilitate engineering studies of vulnerable private roads. About two-thirds of Harpswell’s roads are privately owned, and the town isn’t responsible for climate-proofing them.
