CIVIL WORKS

THE BASIS OF DESIGN DESCRIBED HEREIN IS FOR THE MCCOY’S CUT FLOW DIVERSION STRUCTURE. THE DESIGN TEAM COMPLETED THE FINAL DESIGN. THE SUBMITTAL INCLUDED THE DESIGN (PLANS & SPECIFICATIONS), QUANTITY AND COST ESTIMATES, AND STUDY REPORTS FOR THE SAVANNAH HARBOR EXPANSION PROJECT (SHEP) MITIGATION FEATURE DESIGN OF THE DIVERSION STRUCTURE ON THE SAVANNAH RIVER AT MCCOY’S CUT. THE PLANS AND SPECIFICATIONS WERE ONLY PREPARED FOR THE DIVERSION STRUCTURE. THE TASK DOES NOT INCLUDE PLANS AND SPECS FOR THE MCCOY’S CUT OR RIFLE CUT CLOSURE STRUCTURES, OR THE BACK RIVER/MIDDLE RIVER DREDGING.THE FINAL DESIGN SUBMITTAL IS PRESENTED IN FOUR VOLUMES:

 VOLUME 1 – BASIS OF DESIGN INCLUDES THE HYDRAULICS MODELING REPORT, GEOTECHNICAL

INVESTIGATIONS REPORT, STRUCTURAL AND CIVIL DESIGN, SURVEY INFORMATION, AND

ENVIRONMENTAL STUDY REPORTS.

 VOLUME 2 – SPECIFICATIONS

 VOLUME 3 – DRAWINGS

 VOLUME 4 – COST ESTIMATE

BASED ON EFDC HYDRODYNAMIC MODELING, THE PROPOSED DEEPENING OF SAVANNAH HARBOR WILL INCREASE SALINITY CONCENTRATIONS IN THE UPPER REACHES OF THE SAVANNAH RIVER ESTUARY, INCLUDING BACK RIVER. TO MITIGATE FOR THAT INCREASED SALT CONTENT IN BACK RIVER, WHERE THE SAVANNAH NATIONAL WILDLIFE REFUGE INCLUDES SIGNIFICANT AMOUNTS OF TIDAL FRESHWATER WETLANDS, DIVERSION OF ADDITIONAL FRESHWATER FROM THE SAVANNAH RIVER, THROUGH MCCOY’S CUT, INTO BACK RIVER IS DESIRED. ONE OF THE MITIGATION FEATURES PLANNED TO ACHIEVE THAT IS TO CONSTRUCT A DIVERSION STRUCTURE AT THE CONFLUENCE OF THE SAVANNAH RIVER AND MCCOY’S CUT TO INCREASE THE FRESHWATER FLOW INTO BACK RIVER WHEN THE FLOW AT THE USGS GAUGE AT CLYO IS 5000 CFS.