My recommendations to you. Plan the work and work the plan. Get many opinions and create the best affordable plan for your community.
Potential resource to generate a plan.
1 - Josh Platt - MES Maine. Private consultant based in Hallowell Area. I highly recommend his work. I used him in Harpswell, Maine.
https://mesmaine.com/about
2 - Cumberland County Soil Conservation District: For a Fee, they have generated plans for erosion control and green storm run-off measures. In the last few years they completed an erosion control plan for a populated island in Casco Bay. I have not used them. I have seen a few presentations and plans.
https://www.cumberlandswcd.org/documents-1
Look at the Coastal Bluffs Plan.
I know you are not in Cumberland Co. I do not know anything about the Androscoggin Co. organization.
https://www.androscogginswcd.org/technical-services.html
Consulting firms - more expensive, but may be necessary to get plans approved
3 - GEI Consultants in Portland. GEI completed a "climate resilient" boat ramp plan for Garrison Cove in Harpswell. The cost is estimated at over $300k. It has not been installed, but some of the same measures might be useful for a coastal private road. I have attached the Powerpoint presentaion shared with the town in 2022. There were actually 3 boat ramps in 3 different communities. Contact info in presentation.
4 - Ransom Consultants in Portland, Maine. They helped several coastal towns in York and Cumberland County with flood plain map appeals (my experience). The have a coastal engineering section.
Good luck with your project.
Lee