Cultural Resources Survey of the New Savannah Bluff Lock and Dam Fish Weir Tract Richmond County, Georgia

Between December 9 and 20, 2019 and January 13 and 17, 2020, Brockington and Associates, Inc. (Brockington) conducted a Phase I cultural resources survey and Phase II trench excavations on the New Savannah Bluff Lock and Dam tract in Richmond County, Georgia. This survey was conducted incompliance with Section 106 of the National Historic Preservation Act of 1966 (as amended). The survey was performed to determine if cultural resources are located within the project Area of Potential Effects (APE) in preparation for the construction of a proposed fish passage. The Water Resources Development Act (WRDA) within the Water Infrastructure and Improvements for the Nation Act of 2016 (2016 WIIN Act) deauthorized the New Savannah Bluff Lock and Dam and requires modifications to the original 2014 fish passage design in the authorized Savannah Harbor Expansion Project (SHEP). The SHEP fish passage mitigation feature must allow safe passage over the structure to historic spawning grounds of the endangered shortnose sturgeon (Acipenser brevirostrum), Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus), and other native migratory fish, while maintaining the functionality of the pool for navigation, water supply, and recreational activities. The navigation deepening project, SHEP, was authorized in the Water Resources Reform and Development Act (WRRDA) of 2014. The project contained a mitigation feature to provide fish passage at the New Savannah Bluff Lock and Dam. The fish passage feature was designed to keep the existing lock and dam in place, while building a bypass channel for fish migration to Augusta Shoals, the historic spawning grounds for sturgeon. The Augusta Shoals is also important for other fish, including the Georgia state-listed robust redhorse. However, this original design is not consistent with the 2016 WIIN Act. The U.S. Army Corps of Engineers (USACE), Savannah District has extensively studied the effects of multiple alternatives which satisfy the 2016 WIIN Act. Alternative 2-6d was selected as the recommended plan. The modified fish passage would include the design of a weir. This design is for a constructible, nature-like fishway (NLF) at the New Savannah Bluff Lock and Dam with fixed crest weir elevations and a floodplain bench. This includes a rock ramp sloping upstream from the existing dam location and a low-lying floodplain bench in the right overbank to provide additional flow conveyance. The lock and dam would be removed. A floodplain bench would be on the Georgia side of the existing dam location.

The bench would act as additional conveyance area for flood waters to pass. The 60-acre (24.2 hectare [ha]) fish passage APE includes an approximately 50-acre (20.2 ha) federally owned tract located immediately east of the New Savannah Bluff Dam on the Georgia side of theSavannah River. Most of the land is currently part of the New Savannah Bluff Lock and Dam Park. Additionally, the USACE will be constructing a new boat ramp on a 10-acre (4 ha) privately owned property. Cultural resources investigations covered both the 50-acre (20.2 ha) and 10-acre (4 ha) tracts. Brockington performed the tasks for this survey while under contract with Tetra Tech, Inc. (Tetra Tech), which is the technical lead organization for the project design. Geomorphological investigations were conducted for this survey by Dr. John Foss while under contract with Brockington. A Submerged Cultural Resources Investigation was not required for this investigation.