Deer Isle and Stonington Causeway Project

The Stonington Causeway connects Little Deer Isle to Deer Isle and Stonington. This causeway and the causeway between the Deer Isle-Sedgwick Bridge and Little Deer Isle support the only roadway link between these islands and the mainland. Therefore, providing for a continued safe and reliable connection is vital for emergency services, tourism and the local and regional economy. Due to factors such as deterioration and erosion overtime as well as the potential for increased extreme weather events and sea level rise, MaineDOT, residents and municipal governments have expressed concerns about the need to make considerable improvements to the causeways. MaineDOT has been asked to allow for considerable public input and to consider the history, ecological and environmental significance of the causeways as part of this project.

Collectively these causeways span over 2,000 feet generally with two travel lanes and minimal shoulders. They are constructed upon a natural sand/gravel bar of earthen fill, rubble with rip-rap and metal barriers. Alternatives under consideration are expected to include but not necessarily be limited to rehabilitation, reconstruction including raising the roadway surface by several feet and increasing the frequency and methods of maintenance. MaineDOT’s study will also consider related efforts underway evaluating the benefits and feasibility of providing openings to improve tidal flow between the Penobscot and Eggemoggin Reach sides of the Stonington Causeway such as a bridge. This study is limited to the causeways and does not include an evaluation of the Deer-Isle Sedgwick Bridge.

Presentation from the August 1, 2023 Initial Project Meeting (PDF)