The project restored critical marsh habitat for this National Wildlife Refuge while improving navigation in the river. Thin layer deposition of dredge material allows for the beneficial use of sediment that in the past was treated as a waste and disposed of as “dredge spoils.“ It also keeps the sediment resource within the ecosystem while providing enhanced storm protection for adjacent communities. Lastly, the project provided the ecological base for later stage planting, enabling the community to participate in the restoration and learn firsthand about the ecosystem that helps protect them.
SumCo implemented a cutting edge coastal resilience strategy to address salt marshes impacted by sea level rise on Rhode Island’s Narrow River where it flows through the John H. Chafee National Wildlife Refuge. Working with The Nature Conservancy in partnership with USFWS and the Rhode Island Coastal Resources Management Council, SumCo used the innovative technique of thin-layer deposition of dredge material to create and enhance the eroding and “drowning” marsh resources of this tidal estuary while increasing climate resilience for Narragansett communities.
Through the use of low flow dredging equipment, barges and other specialized equipment, SumCo increased the elevation of the sinking wetlands of this wildlife refuge by hydraulically dredging the Narrow River and carefully depositing 30,000 CY of material which was spread over the marsh. A project component included the installation of stone sills along Sedge Island and shell bag groins to capture sediment and stabilize the toe. Stone was barged in from Boston Post Road through the shallow and fast moving currents of this river stretch.