The quality of this digital copy is an accurate reproduction of the original print copy THE UNIVERSITY OF NEW SOUTH WALES MONITORING OF BED LOAD DISCHARGE IN N.S.W. RIVERS ANTHONY JAMES McCABE MASTER OF ENGINEERING SCIENCE DEGREE 1989 1. STUDENT'S DECLARATION a. This is to certify that I , A^JHP.'i^y , being a candidate for the degree of Master of Engineering Science am fully aware of the policy of the University relating to the retention and use of higher degree projects, namely that the University retains the copies of any thesis submitted for examination, "and is free to allow the thesis to be consulted or borrowed. Subject to the provision of the Copyright Act (1968) the University may issue the thesis in whole or in part, in photostat or microfilm or other copying medium". I also authorize the publication by the University Microfilms of a 600 word abstract in Dissertation Abstracts Intemational (D. A. I.). b. I hereby declare that none of the work in this project has been submitted to any other institution for the award of a higher degree. Signature : ' 2. SUPERVISOR'S CERTIFICATION I cenify that this project has been completed under my supervision and is in my opinion in a fonn suitable for examination as part of the requirement for admission to the degree of Master of Engineering Science. Signature : s) Project Supervisor c^ ^ ^ Q 11 ABSTRACT The lack of reliability under field conditions of existing empirical methods for predicting the transport rate of bed load material in NSW rivers has led the Department of Water Resources to implement a technique which allows direct measurement. The aim is to prevent channel degradation caused by the uncontrolled removal of sand and gravel by the extraction industry for use by the building industry. The method employs a post flood event chain/tracer technique to allow estimation of the volume of material moved during a flood. Combination with streamflow records allows calculation of the rate of movement. This report is based on the Author's involvement in the development and implementation of the program for monitoring bed load discharge. It describes the basis of the monitoring technique and discusses practical aspects of the implementation of the monitoring program. The amount of data available to date is limited, but some tentative conclusions concerning the relationship between bed load discharge and streamflow parameters are examined. Ill ACKNQWT.BDGEMEMTS The completion of this project would not have been possible without the assistance and guidance of DWR staff in the Catchment Management Unit. Thanks to Mr. Michael Eather, Engineering Assistant, for his invaluable field knowledge of each of the monitoring sites and of the procedures used in the data collection. To Mr. Bruce Coates, Scientific Officer, for his guidance on theoretical aspects of bed load movement and general stream morphology, and thanks to Ms Marie Byers for the typing of the text. IV TABLE OF CQNTENTS PAGE Student's Declaration and Supervisor's Certification i Abstract 11 Acknowledgements iii List of Figures vii List of Tables viii 1. INTRODUCTION 1 1.1 The Problem 1 1.2 The DWR's Approach 2 1.3 Location of the Monitoring Sites 3 1.4 Sites to be Examined 3 2. POST EVENT CHAIN/TRACER METHOD 6 2.1 Introduction 6 2 - 2 Theory 6 2.3 Setting Up A Monitoring Site 8 2.3.1 Survey of Site 8 2.3.2 Selection of Tracers 9 2.3.3 Tracer Preparation 12 2.3.4 Scour Chain Placement 13 2.3.5 Placement of Tracers 19 2.3.6 Monitoring of Sites Between Events 19 2.4 Resetting a Site 20 2.4.1 Location of Scour Chains 20 2.4.2 Tracer Location 22 2.4.3 Resetting Scour Chains 23 2.4.4 Placement of New Tracers 23 TABLE QF CQMTENTS (Cont.) PAGE 2.5 Analysis of Field Dat:a 24 2.5.1 Reduction of Basic Field Data 24 2.5.2 Tracer Location Data 24 2.5.3 Scour Chain Data 25 2.5.4 Bed Load Volume 26 2.5.5 Bed Load Discharge 27 WILSON RIVER 29 3.1 Site Location 29 3.2 Site History 29 3.3 Detailed Results 34 NEVER NEVER RIVER 42 4.1 Site Location 42 4.2 Site History 42 4.3 Detailed Results 49 4.3.1 Field Trip 1 - May 1988 49 4.3.2 Field Trip 2 - December 1988 54 4.3.3 Field Trip 3 - May 1989 55 4.3.4 Summary 60 5. NUMERALLA RIVER 61 5.1 Site Location 61 5.2 Site History 61 5.3 Detailed Results 68 5.3.1 Field Trip 1 - September 1988 68 5.3.2 Field Trip 2 - July 1989 70 VI TABLE OF CONTENTS (nonl:. ^ PAGE 6. CONCLUSIONS 73 6-1 General 73 6.2 Recommenda-tions for Future Development 73 6.3 Further Analysis 77 REFERENCES 79 APPENDICES Appendix A Field Sheets 80 Appendix B Programs 85 Vll LIST OF FTCnWES PAGE 1.1 Location of Monitoring Sites 4 2.1 Idealised Illustration of the Transported 7 Volume of Bed Material 2.2 Wilson River - Particle Size Distribution 11 2.3 Principal Axes of a Rock Particle 12 2.4 Illustration of Scour Chains in Different 14 Conditions During A Flood Event 2.5 Chain Placement by Excavator Method - 16 Wilson River Site 2.6 Chain Placement by Star Picket Method - 17 Wilson River Site 2.7 Steel Plate Used in Star Picket Method 18 2.8 Scour Chain Elbow Illustrating Scour 21 and Fill 3.1 Wilson River Locality Plan 30 3.2 Wilson River Base Plan 31 3.3 Wilson River Monitoring Site 33 3.4 Wilson River - Location of Series 1 35 Tracers - June 1988 3.5 Wilson River - Transect Movement 37 - Trip 1 3.6 Particle Size v Distance Moved - Wilson 40 River - Series 1 - Trip 1 4.1 Never Never River Locality Plan 43 4.2 Never Never River Base Plan 44 4.3 Never Never River Monitoring Site 46 4.4 Never Never River - Transect Movement 52 - Trip 1 4.5 Duration Above A Base Flow Rate 59 - Floods in Never Never River 5.1 Numeralla River Locality Plan 62 5.2 Numeralla River Base Plan 63 5.3 Numeralla River Monitoring Site 65 vili LIST OF TART.ES PAQE 1.1 Monitoring Site Details 5 3.1 Wilson River - Series 1 Tracers 36 - Located June 1988 3.2 Wilson River - Scour and Fill - June 1988 38 3.3 Duratio- Apriln 198and8 VolumFloode -Abov Wilsoe an BasRivee rFlo w Rate 41 4.1 Never Never River - Series 1 Tracers 51 - Located May 1988 4.2 Never Never River - Scour and Fill 51 - May 1988 4.3 Duration Above a Base Flow Rate - April 53 1988 Flood - Never Never River 4.4 Never Never River - Series 1 Tracers 54 - Located December 1988 4.5 Never Never River - Series 2 Tracers 55 - Located December 1988 4.6 Never Never River - Series 1 Tracers 56 - Located May 1989 4.7 Never Never River - Series 2 Tracers 57 - Located May 1989 4.8 Never Never River - Series 3 Tracers 58 - Located May 1989 4.9 Flood Details for Never Never River 56 Between Trips 2 and 3 4.10 Duration and Volume Above Threshold of 60 Motion for Floods in Never Never River - Trips 2 to 3 5.1 Flood Details for Numeralla River Site 68 5.2 Numeralla River - Series 1 Tracers - 69 Located September 1988 5.3 Duration Above A Base Flow Rate - 69 Numeralla River Floods From Set-up to Trip 1 5.4 Duration and Volume Above Threshold of 70 Motion - Numeralla River - Trip 1 5.5 Numeralla River - Series 1 Tracers 71 - Located July 1989 IX LIST OF TABI^ES icont:. > PAGE 5-6 Numeralla River - Series 2 Tracers 72 - Located July 1989 A.l Tracer Measurement Sheet 81 A-2 Tracer Location Sheet 82 A.3 Scour Chain Details Sheet 83 A.4 Tracer Recovery Sheet 84 B.l ROCKID Program Listing 87 B.2 REDUCTN Program - Sample Input and Output 89 B.3 Listing of XSECT Program 91 B.4 Sample Output from XSECT Program 92 B.5 Data Entry Requirements for TRANS Program 92 B.6 TRANS Program Listing 93 B.7 Listing of RATE Program 98 # I INTRODUCTTQN The ProblQin The extractive industries of this State depend heavily on it's rivers for the supply of sand and gravel for subsequent use in the construction industry. Problems occur however, if the rate of removal by the extractors equals or exceeds the long term natural replenishment rate. River degradation can result, and this in turn can cause river bank instability and lead to a decline in water quality. The Department of Water Resources (DWR) is the State Authority responsible for the formulation of policies and environmental options for gravel extraction in all non- tidal sections of the rivers in NSW. Appropriate legislation is under the Rivers and Foreshores Improvement Act (1948). The DWR has recognised that its policies are currently inadequate and this, in combination with the extractive industries insatiable demand for gravel, has lead to river degradation problems throughout NSW. For example, in the Cockburn River near Tamworth, channel degradation of up to 2 metres has been experienced over the last ten years. During this period, some 160 000 tonnes per year of gravel has been extracted from the river without control. Problems such as these could be avoided if the natural rate of replenishment could be scientifically determined before an extractor was allowed to remove any material from a site.