Today's Decisions,
Shape Tomorrow's Shorelines
Shoreline erosion is one of the greatest long-term challenges facing Great Diamond Island and the Casco Bay islands.
As sea levels rise and coastal conditions continue to change, understanding how shorelines respond has never been more important. Through collaborations with neighboring islands, the City of Portland, state agencies, regional organizations, and coastal engineering professionals, the GDI Partnership has helped bring together the latest research, practical field experience, and educational resources to support informed shoreline management.
THE RESOURCES below explore the processes driving coastal erosion, highlight emerging approaches to shoreline and upland management, and share the research, reports, webinars, and case studies developed through these collaborations.
ANATOMY AND LIFE-CYCLE OF MAINE'S COASTAL BLUFFS. Learn how Maine's shoreline is classified and the forces that drive coastal erosion. Developed by the GDI Partnership and the Long Island Civic Association, with guidance from the Maine Geological Survey, this webinar provides a practical foundation for understanding shoreline change and coastal management.
WATCH ON YOUTUBE
2024 CALLING YOUR BLUFF SYMPOSIUM VIDEO SERIES. Hear from coastal scientists, engineers, and practitioners as they discuss bluff erosion, shoreline stability, and practical management approaches during the Calling Your Bluff Symposium held at the Gulf of Maine Research Institute.
WATCH SERIES ON YOUTUBE
CALLING YOUR BLUFF TOOLKIT. More than 20% of Casco Bay's coastal bluffs have been armored—often with riprap. As base-line sea levels rise and coastal conditions change, these hard structures will require ongoing maintenance and repairs. This toolkit provides educational resources, lessons learned, and practical guidance to help coastal communities and property owners better understand shoreline processes, explore more sustainable approaches, and plan for long-term shoreline resilience.
VISIT THE TOOLKIT WEBSITE
GDI OUR SHORE REPORT. This comprehensive report documents the April 2026 OUR SHORE assessments completed at three Great Diamond Island properties. Prepared through the Maine Department of Environmental Protection's OUR SHORE program, it includes site observations, shoreline conditions, upland factors, and recommendations based on current best practices for shoreline and upland management.
READ THE COMPREHENSIVE PDF
GDI OUR SHORE GRAPHIC SUMMARY. Looking for a quicker overview? This illustrated summary highlights the key findings and recommendations from the Great Diamond Island assessments and. You can also watch the accompanying Island Institute webinar, which features a Great Diamond Island site alongside additional OUR SHORE assessments completed on Portland's other three islands.
VIEW THE GRAPHIC PDF
DEMYSTIFYING NATURE-BASED STRATEGIES. This workshop explores how nature-based strategies can help island communities prepare for coastal change while protecting infrastructure and natural resources. Presenters from the Maine Coastal Program, The Nature Conservancy, and the Maine Department of Environmental Protection discuss green infrastructure, wetland restoration, flood adaptation, and nature-based approaches to shoreline erosion, supported by practical case studies from Maine communities. Materials include video, slides and workshop overview.
VIEW IN MIP's GOOGLE DRIVE