I I I I I NSW DEPARTMENT I OF PUBLIC WORKS AND SERVICES I I Manly Hydraulics Laboratory I I I I Hunter Estuary Processes Study I Summary Report I Draft Report MHL1095 March 2002 I I I I I I I I I I I I I I I I I HUNTER ESTUARY PROCESSES STUDY I SUMMARY REPORT I I Report No. MHLl095 I DRAFT I I I I NSW Department of Public Works and Services Manly Hydraulics Laboratory I I I, 1 1 I I I I I I I I I I Report No MHLl095 I DPWS Report No 01010 ISBN 0 7347 4163 4 MHL FIle No LRE6-00092 I FlfSt pubhshed (month) 2002 I © Crown copynght 2002 Th,s work IS copynght The Copynght Act 1968 penmts falf dealmg for study, research, news reporung, cnUClSm or revIew Selected I passages, tables or diagrams may be reproduced for such purposes provIded acknowledgement of the source IS mcluded Major extracts or the enUre document may not be reproduced by any process WIthout wnllen penmsslOn Enqumes should be d,rected to the Pubhcauons Officer, Manly Hydrauhcs Laboratory, I lOB KIng Street, Manly Vale, NSW, 2093 I ~ Manly Hydrauhcs Laboratory IS QUalIty System Cerufied to AS/NZS ISO 9001 1994 1 I I I I, I Foreword I The New South Wales Estuary Management PolIcy was developed to encourage the mtegrated, balanced, responsible and ecologically sustamable use of the State's estuaries The polIcy IS deSigned to reflect and promote co-operatIOn between the State Government, local I government, catchment management committees, landholders and estuary users m the development and ImplementatIOn of estuary management plans for each estuary I To assist m the development of estuary management plans, an Estuary Management Manual (NSW Government 1992) was publIshed to outlIne the processes of ImplementatIOn I Essentially, the process consists of eight steps These steps are 1) form an estuary management committee 2) assess eXlstmg data I' 3) carry out estuary processes study 4) carry out estuary management study 5) draft estuary management plan I 6) review estuary management plan 7) adopt and Implement estuary management plan, and 8) mOnItor and review management process I The Hunter Estuary Management Comnuttee was formed m 1997 and amalgamated with the I Hunter Coastal Management Committee Manly HydraulIcs Laboratory, III conjunction with The Wetlands Centre, The Ecology Lab and the Umverslty of Newcastle, was commIssIOned by Newcastle City Council to undertake I the second and third stages of the estuary management process for the Hunter estuary I I I I I I DRAFT MHL1095 - I I 1 March, 2002 I J I I I Table of Contents ,I 1. INTRODUCTION 1 1 1 AIm 1 1 2 Background 1 I 1 3 Integrated Approach 1 2. DATA INTERPRETATION 3 I, 2 1 IntroductIOn 3 2 2 PhysIcal Data 3 2 2 1 IntroductIOn 3 I 222 Clzmate 3 2 2 3 Geology and SOlis 4 2 2 4 Hydrology 4 I 2 2 5 Hydraulzcs 5 2 2 6 Geomorphology 5 I 2 2 7 Water Qualzty 8 2 2 8 Salinity Structure 10 229 Summary of Water Qualzty Vanabllzty 11 I 2 2 10 Sediment Quality 11 2 3 EcologIcal Data 12 2 3 1 IntroductIOn 12 I 232 Terrestrzal Flora and Fauna 12 2 3 3 Aquatic Flora and Fauna 14 2 4 Human Data 15 I 2 4 1 IntroductIOn 15 242 Hentage 15 I 243 PopulatIOn 16 2 4 4 RecreatIOnal 16 245 Land Use 16 I 2 4 6 RegIOnal Economy 17 247 Flood MitigatIOn Works 17 I I I I DRAFT MHLI095 - II I 1 March, 2002 J I 3. DATA GAPS AND RECOMMENDATIONS 19 3 1 IntroductIOn 19 I 32 Data, InfonnatlOn and UnderstandIng 19 3 2 1 Definmons 19 322 Scale 20 I 33 Momtonng 21 3 3 1 IntroductIOn 21 I 332 ConsideratIOns for MOnltonng In the Hunter Estuary 21 333 Complexity of the Hunter Estuary 22 34 ConslderatlOns for RecommendatIOns 28 I 34 1 Estuary Management Framework 28 3 5 RecommendatIOns for Momtonng In the Hunter Estuary 29 I 4. REFERENCES 31 I I Appendices A References from Techmcal Report. Charactenstlcs of the Hunter Estuary and I Catchment, Manly HydraulIcs Laboratory, Report No MHL1118 B References from Techmcal Report Geology and SOils of the Hunter Catchment, and EvolutIOn and SedimentatIOn of the Hunter Estuary, Dr Ron Boyd, UmverSIty I of Newcastle C References from Techmcal Report The Terrestnal Ecology of the Hunter River Estuary, Dr Tracey MacDonald, The Wetlands Centre I D References from Techmcal Report Hunter Estuary Process Study Aquatic Ecology, The Ecology Lab I E References from Techmcal Report Hunter Estuary Water Qualtty, Data Review and AnalYSIS, Dr Bnan G Sanderson and Dr Anna M Redden, Umverslty of I Newcastle I List of Tables I 2 1 Dlstance Salt Propagates Upstream at Dlfferent Flows 10 2 2 PopulatIOns and ProjectIOns 16 3 1 UnderstandIng Issues and Processes In the Hunter Estuary 24 I· 3 2 LeglslatlOn Assoclated wlth Councll Estuanne Management 29 I I DRAFT MHLI095 - III I 1 March, 2002 I I I I I List of Figures 1 1 Integrated Approach to an Estuary System 2 1 Hunter RIver Catchment 22 Hunter RIver Estuary 23 Components In the Hunter Estuary System 24 Geology of the Hunter Catchment I 26 SOlI Types of the Hunter Catchment 26 Summary of SedIment Budget 27 Water Quahty Momtonng SItes I 28 Sahmty Structure of the Hunter RIver Estuary 29 Normahsed Values Dunng HIgh and Low Flow CondItIOns I 210 Land Cover Lower Hunter Estuary 211 Change In DlstnbutlOn of Saltmarsh WIthin the Hunter RIver Estuary 1954-1994 212 Change In DlstnbutlOn of Open Water WIthin the Hunter RIver Estuary 1954-1994 213 Change In Mangrove DlstnbutlOn WIthin the Hunter RIver Estuary 1954-1994 I 214 Cadastre Newcastle CIty 2 15 Cadastre Maitland Area 2 16 Newcastle Land Use I 217 Maitland Land Use 218 The EvolutIOn of Structures Restnctlng TIdal Flow WIthin the Hunter RIver DeltaIc Islands and Subsequently, Kooragang Island I 3 1 LocatIOn of Issues 32 Temporal and Spatial Scales In an EcologIcal Process I 33 ConceptuahsatlOn of 'Loss of HabItat' I I I, I I I I, DRAFT MHLl095 - IV I 1 March, 2002 I I I I 1. Introduction I 1.1 Aim The aim of this report IS to analyse whether the eXlstmg data for the Hunter estuary~r sufficient to be able to define the 'baseline' conditions of the estuanne processes In a I subsequent phase of the Estuary Management Process For that purpose the current report summarises and synthesises a senes of Techmcal Reports that together provide a comprehensive overview of the estuary characteristics The Techmcal Reports have been I mcluded as a senes of separate reports that address the I) geomorphology, II) terrestrial ecology, III) aquatIc ecology, IV) water quality, and V) other characteristics (mcludmg hydrologylhydraullcs) of the Hunter estuary The compilatIOn and review of eXlstmg data IS a I vital component of the project as work Items may be refmed followmg the review In short, I this synthesIs alms to • provide an overview of data collected, analysed and mterpreted m the context of the Hunter Estuary Processes Study and assess the eXlstmg data gaps I, • address the ImplicatIOn of the data gaps for management Issues • advise on future data collectIOn Issues I 1.2 Background This report uses the Hunter Estuary Data CompilatIOn Report (DLWC 1999) as a startmg I pomt The data sources documented m the data compilatIOn study are not necessanly repeated here Based on the observatIOns m the aforementIOned report, additional data has been collated and analysed The 'assembly of eXlstmg data' IS the second step of the Estuary I Management Process as formulated by the Estuary Management Manual (1992) It forms an I essential prerequlSlte to a successful Estuary Processes Study (step 3) 1.3 Integrated Approach I The pnmary goal of the NSW Estuary Management Pohcy IS to encourage the mtegrated, balanced, responsIble and ecologIcally sustamable use of the State's estuanes (1992) This reqUIres an mtegrated approach to the estuary system m which the estuanne processes are I analysed m then mteractlOn Yet, due to the compleXity of estuary systems, It IS difficult to accurately descnbe the mtegrated functlOnmg of such a system and ItS response to changes Numerous mteractlOns and feedback mechamsms between the varIOus subsystems can be I Identified For mstance, the economic activIties, geomorphological processes and the ecological health of an estuary are tightly coupled and their mterrelatlOns need to be I understood The estuary IS a dynamic system, which will change over time due to the vanous I DRAFT MHLl095 - 1 I 1 March, 2002 I I I feedbacks Apart from these Internal dynamIcs, the estuary IS also Influenced by certain external Influences These external Influences wIll affect the indIvIdual elements as well as I the interactIOns between them In the lIght of sustainable estuary management, a full understanding of the processes In the estuary and of external Influences, IS indIspensable I In general, a physIcal, ecologIcal and human system can be dIstIngUIshed In an estuary These Interact In varIOus ways The total estuary system IS also under Influence of, for Instance, clImatIc change, polItIcal or instItutIOnal changes and changes In the world economy ThIs IS I schematlsed In FIgure 1 1 The physIcal system represents the natural a-bIOtIc system and addresses physIcal and I chemIcal processes that are relevant to the estuarIne system ThIs Includes Issues regarding clImate, sOIls, hydrology, morphology, nutrIent and sedIment flows In the estuary The ecologIcal system represents the natural bIotIC system It concerns flora and fauna In the I estuary and addresses Issues of bIOdIversIty, habItat loss etc The human system represents the total human actIvIty In the estuary ThIS Includes all soclo-economlc actIvIty, such as resIdentIal, tOUrIst and IndustrIal use of land It also Includes less tangIble aspects, such as I herItage and the use of the estuary