South Manitou Island Boat Dock Extension Environmental Assessment
This document provides alternative approaches to providing boat dock access to South Manitou Island.
The National Park Service at Sleeping Bear Dunes National Lakeshore (National Lakeshore) prepared an Environmental Assessment (EA) that examines alternatives for an extension of the South Manitou Island boat dock that would result in meeting the desired future conditions for access to South Manitou Island. The South Manitou Island boat dock lies in shallow water in an area subject to sediment accumulation. Eventually, this buildup of sediment forms a sandbar beneath the boat dock that extends out into open water, blocking access to the dock.
The South Manitou Island boat dock, located on the southeast shore of South Manitou Island bay, is the only manageable access point to the island for public visitors and National Park Service staff. From the dock, visitors have a short walk to the lighthouse, a U.S. Life-Saving Service and Coast Guard Station that now serves as a ranger station, and several historically preserved 19th century farm buildings. The island's many trails begin from the dock landing and allow visitors a scenic hike to the high perched dunes overlooking the island's western shore, a natural inland lake (Florence Lake), three designated backcountry campgrounds, and numerous other natural features.
Under the "No Action" Alternative, the proposed dock extension would not be constructed. The existing dock facility would continue to operate. There would be a continued need for ongoing maintenance dredging to support ferry operations. This dredging would be conducted as needed and would result in the removal of materials from the dock area and the disposal of such materials in nearshore aquatic habitats.
Under the Preferred Alternative, the existing dock would be extended further into Lake Michigan. This extension would allow boat access in deeper waters and would minimize or eliminate the need for future maintenance dredging at South Manitou Island. Construction of this facility could be completed in a three to four week timeframe. The structure would be constructed out of wood and steel connectors. Wood pilings would be driven into the lake bottom to form the basis of the structure and would be of a similar type as the existing dock facility.
A Finding of No Significant Impact (FONSI) was signed in August 2012. The complete South Manitou Island Boat Dock Extension EA, Finding of No Significant Impact and Errata Sheet documents may be found on the National Park Service Planning Environment and Public Comment (PEPC) website (documents can be found by clicking on the Document List link found on the left side of the PEPC webpage for this EA).