Winyah Bay, Georgetown, South Carolina, Data Collection Survey Report 12
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iHNICAL REPORT HL-89-23 PROPERTY OF BUREAU OF RECLAMATION LIBRARY EORGETOWN, SOUTH CAROLINA, DATA COLLECTION SURVEY REPORT by Timothy L. Fagerburg Hydraulics Laboratory DEPARTMENT OF THE ARMY Waterways Experiment Station, Corps of Engineers 3909 Halls Ferry Road, Vicksburg, Mississippi 39180-6199 November 1989 Final Report Approved For Public Release; Distribution Unlimited Prepared for US Army Engineer District, Charleston Charleston, South Carolina 29402-0919 LIBRARY MAR 7 '90 Bureau of feciamaffon Denver, Cuforado Destroy this report when no longer needed. Do not return it to the originator. The findings in this report are not to be construed as an official Department of the Army position unless so designated by other authorized documents. The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. ÏRARY b u r e a u o f RECLAMATION 92003996 TSOOBTTb .i/ o - Unclassified SECURITY CLASSIFICATION OF THIS PAGE* Form Approved REPORT DOCUMENTATION PAGE O M B No. 0704-0188 la. REPORT SECURITY CLASSIFICATION 16. RESTRICTIVE MARKINGS Jnclassified_______ 2a. SECURITY CLASSIFICATION AUTHORITY 3. DISTRIBUTION/AVAILABILITY OF REPORT 2b. DECLASSIFICATION /DOWNGRADING SCHEDULE Approved for public release; distribution unlimited. 4. PERFORMING ORGANIZATION REPORT NUMBER(S) S. MONITORING ORGANIZATION REPORT NUMBER(S) rechnical Report HL-89-23 6a. NAME OF PERFORMING ORGANIZATION 6b. OFFICE SYMBOL 7a. NAME OF MONITORING ORGANIZATION USAEWES (If applicable) SjrdraulJL^ CEWES-HE-P 6c ADDRESS (Gty, State, and ZIP Code) 7b. ADDRESS (C/ty, State, and ZIP Code) 3909 Halls Ferry Road Vicksburg, MS 39180-6199 8a. NAME OF FUNDING/SPONSORING 8b. OFFICE SYMBOL 9. PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER ORGANIZATION (If applicable) USAED, Charleston 8c ADDRESS (City, State, and ZIP Code) 10. SOURCE OF FUNDING NUMBERS PROGRAM PROJECT TASK WORK UNIT PO Box 919 ELEMENT NO. NO. NO. ACCESSION NO. Charleston, SC 29402-0919 11. TITLE (Indude Security Classification) Winyah Bay, Georgetown, South Carolina, Data Collection Survey Report 12. PERSONAL AUTHOR(S) Fagerburg, Timothy L. 13a. TYPE OF REPORT 13b. TIME COVERED 14. DATE OF REPORT {Year, Month, Oay) 15. PAGE COUNT Final report FROM__________TO November 1989 130 16. SUPPLEMENTARY NOTATION Available from National Technical Information Service, 5285 Port Royal Road, 17. COSATI CODES 18. SUBJECT TERMS (Continue on reverse if necessary and identify by block number) FIELD GROUP SUB-GROUP Boundary layer profiling Density gage Core samples Suspended sediments 19. ABSTRACT (Continue on reverse if necessary and identify by block number) Water levels, current speeds and directions, salinities, suspended sediment concen trations, bed sediment characteristics, and densities were measured in Winyah Bay, SC, in January 1989. The prototype data were collected as part of a study to evaluate the effects of a dredged material placement operation to create a wetland marsh in the bay. The report describes the equipment and procedures used in the data acquisition and presents tables, plots, and summaries of all the data collected. 20. DISTRIBUTION/AVAILABILITY OF ABSTRACT 21. ABSTRACT SECURITY CLASSIFICATION E UNCLASSIFIED/UNUMITED □ SAME AS RPT. Q prie USERS Unclassified 22a. NAME OF RESPONSIBLE INDIVIDUAL 22b. TELEPHONE (Include Area Code) | 22c. OFFICE SYMBOL OD Form 1473. JUN 86 Previous editions are obsolete. SECURITY CLASSIFICATION OF THIS PAGE Unclassified SECURITY CLASSIFICATION OF THIS PAGE PREFACE The field investigation reported herein was conducted by the US Army Engineer Waterways Experiment Station (WES), Vicksburg, MS, during the period 1 October 1988 through 8 March 1989 to provide the necessary data for support of the Georgetown Harbor Channel Project, Georgetown, SC. This effort was funded by the US Army Engineer District, Charleston, under the project management of Messrs. Braxton Kyzer and Steve Morrison. Personnel of the WES Hydraulics Laboratory (HL) performed the work under the general supervision of Messrs. F. A. Herrmann, Jr., Chief, HL; R. A. Sager, Assistant Chief, HL; W. H. McAnally, Jr., Chief, Estuaries Division; and G. M. Fisackerly, Chief, Estuarine Processes Branch (EPB). The data col lection program was designed by Messrs. G. M. Fisackerly, T. L. Fagerburg, H. A. Benson, and J. W. Parman, EPB. Data reduction was performed by Mr. Fagerburg and Ms. C. J. Coleman, EPB. Laboratory analyses of water sam ples were performed by Mr. L. G. Caviness, EPB. The in situ sediment density profiles presented in Appendix A were prepared by Dr. Andrew P. Salkield, Sediment Instrumentation Research and Development, Moline, IL, for WES under Contract No. DACW 3989 M0913. This report was prepared by Mr. Fagerburg and edited by Mrs. M. C. Gay, Information Technology Laboratory, WES. Commander and Director of WES during preparation of this report was COL Larry B. Fulton, EN. Technical Director was Dr. Robert W. Whalin. 1 CONTENTS Page PREFACE...................................... ........................ 1 CONVERSION FACTORS, NON-SI TO SI (METRIC) UNITS OF MEASUREMENT........ 3 PART I: INTRODUCTION............................................... 5 Project Description............................................ 5 Purpose and Scope of Work...................................... 5 PART II: EQUIPMENT DESCRIPTION, PROCEDURES, MEASUREMENT LOCATIONS, AND CONDITIONS............................................ 7 Data Collection Equipment...................................... 7 Procedures..................................................... 14 Postsurvey Measurements........................................ 17 PART III: DATA PRESENTATION.......................................... 21 Tide Data....................................................... 21 Velocity Data.............................................. 21 Salinity Data.................................................. 22 Suspended Sediment Data......... 22 Bottom Sediment Classification................................. 23 Gamma Backscatter Density Gage Measurements.................... 24 Boundary Layer Automated Profiling System................. 24 PART IV: SUMMARY ................. 26 TABLES 1-22 PLATES 1-35 APPENDIX A: IN SITU SEDIMENT DENSITY PROFILES, WINYAH BAY (GEORGETOWN), SOUTH CAROLINA, 21-23 JANUARY 1989.......... A1 Introduction................................................... A2 General Comments............................................... A2 TABLE A1 FIGURES A1-A22 2 CONVERSION FACTORS, NON-SI TO SI (METRIC) UNITS OF MEASUREMENT Non-SI units of measurement used in this report can be converted to SI (metric) units as follows: _____Multiply_____ By To Obtain cubic feet 0.02831685 cubic metres feet 0.3048 metres gallons (US liquid) 3.785412 cubic decimetres inches 25.4 millimetres miles (US statute) 1.609347 kilometres ounces (US fluid) 0.02957353 cubic decimetres 3 4 WINYAH BAY, GEORGETOWN, SOUTH CAROLINA DATA COLLECTION SURVEY REPORT PART I: INTRODUCTION Project Description 1. Winyah Bay is an irregularly shaped tidal estuary extending about 16 miles* from the ocean to the confluence of the Pee Dee and Waccamaw Rivers near Georgetown, SC, as shown in Figure 1. The bay width is about 0.75 mile at the entrance between the North and South Islands, 4.5 miles in the middle section as it widens into a shallow expanse known as Mud Bay, and 1.25 miles in the upper section. Freshwater inflow into the bay is contributed by the Pee Dee, Waccamaw, Black, and Sampit Rivers. The total mean freshwater inflow into the bay is approximately 13,000 cfs. The existing navigation project provides a 27-ft-deep channel from the Atlantic Ocean to the turning basin in the Sampit River near Georgetown. The route of the Atlantic Intracoastal Waterway also passes through Winyah Bay. Over the past 14 years, the material from annual maintenance of the channel has been disposed at locations along the northern side of the Western Channel Island in an attempt to create marsh lands for habitat development. Purpose and Scope of Work Purpose 2. The US Army Engineer District, Charleston, was concerned about the loss of sediment material from the marsh-creation site and needed a means of quantifying the transport pathways of the material. The purpose of this report is to present the data that were collected during a comprehensive field survey for the Charleston District. The data from this report are to be used by the District to support the Georgetown Harbor Channel Project. * A table of factors for converting non-SI units of measurement to SI (metric) units is found on page 3. 5 Scope 3. One 13-hr (tidal cycle) survey was conducted to collect synoptic field data during peak tidal flow periods within the Winyah Bay study area. Data were also collected for longer term conditions that covered the period prior to the start of dredging operations, during dredging, and for several weeks following the completion of the dredging. Measurements consisted of the following: a. Current speed and direction at three ranges. b. Tide levels recorded at three locations. £. Suspended sediment and salinity samples at each range, d. Automatic water samplers at three locations. e. Core samples of bottom material at 13 locations for material classification. if. Wind speed and direction in the study area. Postsurvey deployment of a SIRAD B.S.G. 1 Gamma Backscatter Density Gage. Density profiles are shown in Appendix A. h. Postsurvey deployment