Eastern Cape River Health Programme
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EASTERN CAPE RIVER HEALTH PROGRAMME TECHNICAL REPORT: MTHATHA RIVER MONITORING, 2004 - 2006 Prepared for: Chief Director Department of Water Affairs and Forestry: Southern Cluster Private Bag 7485 King Williams Town 5600 Prepared by: Coastal & Environmental Services PO Box 934 Grahamstown 6140 August 2006 Coastal & Environmental Services The report was prepared by: P-A Scherman (team leader and water quality), D Reynhardt (riparian vegetation)♦, S Cawe (riparian vegetation)*, A Gordon (macroinvertebrates)#, D Weeks (fish), J Kinya (fish)♣, L du Preez (geomorphology)■ , T Ntozakhe (water quality)* and N Myeko (geomorphology)* Coastal & Environmental Services PO Box 934 Grahamstown 6140 ♦ Down-to-Earth Landscape Design and Consultation 65 Garcia Street Cambridge East London 5247 * Walter Sisulu University Private Bag X1 UNITRA 5117 # Unilever Centre for Environmental Water Quality Institute for Water Research Rhodes University PO Box 94 Grahamstown 6140 ♣ University of Fort Hare Private Bag X1314 ALICE 5700 ■ Department of Geography Rhodes University PO Box 94 Grahamstown 6140 Eastern Cape River Health Programme: Mthatha River Technical Report, August 2006 i Coastal & Environmental Services The ECRHP biomonitoring team responsible for data collection and specialist workshops for the Mthatha River, was comprised of the following team members. The aerial video and data curation teams are also listed. All input is gratefully acknowledged. A special acknowledgement to Dr Kleynhans and Ms Thirion of Resource Quality Services, DWAF, for their tireless contributions to the EcoStatus workshop held in January 2006. Team member Role Ms Pumza Gasa-Lubelwana, DWAF East London Provincial RHP champion Dr Patsy Scherman, CES Team leader and water quality Dr Tando Ntozakhe, Walter Sisulu University Water quality Ms Thulani Guzana, DWAF East London Water quality – trainee + data curation Ms Leanne du Preez, Department of Geography, Rhodes Geomorphology – task leader University Mr Malixole Soviti, Walter Sisulu University Geomorphology – part time Ms Ntombi Myeko, Walter Sisulu University Geomorphology – trainee Ms Debbie Reynhardt, Down-to-Earth Consulting Riparian vegetation – task leader Dr Sizwe Cawe, Walter Sisulu University Riparian vegetation Ms Neziwe Nombekela, Walter Sisulu University Riparian vegetation - trainee Mr Dez Weeks, private Fish – task leader Ms Jane Kinya, Fort Hare University Fish Mr Eric Qonya, Nature Conservation, DEAT Fish Mr Dumisani Kali, Walter Sisulu University Fish - trainee Mr Andrew Gordon, UCEWQ, Rhodes University Macroinvertebrates – task leader Ms Ntsiki Majiza, Walter Sisulu University Macroinvertebrates – trainee Ms Kululwa Mkosan, DWAF East London Macroinvertebrates – trainee + data curation Ms Mmbatho Mampane, DWAF East London Macroinvertebrates – trainee Ms Zanele Mabaso, DWAF Cradock Macroinvertebrates – trainee Ms Bolekwa Ndeleni, DWAF Mthatha Trainee (occasional) The following specialists were also involved in the study: Specialist Task Dr Anton Bok, Anton Bok Consultants Aerial survey Dr Nikite Muller, UCEWQ, Rhodes University Data curation – task leader Dr Neels Kleynhans, RQS DWAF Aerial survey + EcoStatus specialist Ms Christa Thirion, RQS DWAF EcoStatus specialist First Draft: March 2006 Second Draft: August 2006 Eastern Cape River Health Programme: Mthatha River Technical Report, August 2006 ii Coastal & Environmental Services COPYRIGHT INFORMATION This document contains intellectual property and propriety information prepared at a cost to Coastal & Environmental Services, and is therefore protected by copyright in favour of Coastal & Environmental Services. No portion of this document may therefore be reproduced, or used without the prior written consent of Coastal & Environmental Services. This document is prepared exclusively for the Department of Water Affairs and Forestry, and is subject to all confidentiality, copyright, trade secrets, and intellectual property law and practices of SOUTH AFRICA. Eastern Cape River Health Programme: Mthatha River Technical Report, August 2006 iii Coastal & Environmental Services EXECUTIVE SUMMARY The National Aquatic Ecosystem Biomonitoring Programme was set up in South Africa in 1994. The aim of this programme was to monitor the health of aquatic ecosystems using biological organisms. The first focus of the programme was on rivers, with the River Health Programme (RHP) adopted on a national level and framework documents for implementation being produced in 1996. The programme aims to promote standardised and continuous monitoring and reporting on river health, and is operated at both national and provincial level. This report provides the technical input which will underlie the State-of-Rivers Report to be produced for the Mthatha River, Eastern Cape, in 2006. This forms a product of Phase II of the Eastern Cape River Health Programme (ECRHP), initiated in July 2002. The report provides results and recommendations for three monitoring surveys (March, July and October 2005) of 9 Assessment Units (AU) and 10 sites spread throughout the upper, middle and lower Mthatha River catchment, including selected tributaries. Field indices used for data collection included the South African Scoring System version 5.0 (SASS5) for macroinvertebrates, the Fish Assemblage Integrity Index for fish (FAII), the Integrated Riparian Vegetation Index (IRVI) developed during the Buffalo River programme of the ECRHP, the Geomorphology Assessment Index (GAI) and a water quality assessment using information from DWAF gauging weirs and data collected during field surveys. Habitat integrity was assessed using a video produced for the Mthatha River and the Index of Habitat Integrity (IHI; both instream and riparian assessments were conducted). All data were analysed through the use of associated EcoStatus models per index, to arrive at an integrated EcoStatus per Assessment Unit. The output of the EcoStatus assessments are shown below: ASSESSMENT DESCRIPTION OF LOCATION ECOSTATUS RIVER HEALTH UNIT CATEGORY CLASS 1 Upper catchment to the confluence of the C (68.40) Fair Qelana and Mthatha rivers 2 Below the Qelana tributary to the Langeni C – C/D (62.01) Fair sawmills 3 Langeni sawmills to Mthatha Dam (but C (62.69) Fair excluding Mthatha Dam) 4 Downstream Mthatha Dam to Mthatha C (69.69) Fair town (no data; qualitative assessment based on aerial video only) 5 Below Mthatha town to First Falls Dam E (38.23) Poor 6 Below First Falls Dam to Ngqungqu River D – D/E (52.74) confluence 7 Ngqungqu River confluence to Mthatha C (69.43) Fair estuary 8 Cicira River D (43.74) Fair 9 Ngqungqu River C (66.19) Fair Eastern Cape River Health Programme: Mthatha River Technical Report, August 2006 iv Coastal & Environmental Services TABLE OF CONTENTS page Project team and authors i Executive summary iv Abbreviations and acronyms vii CHAPTER 1: RIVER HEALTH AND BIOLOGICAL MONITORING 1 1.1 Introduction: South African River Health Programme 1 1.2 River health classification 2 1.3 Indicators and EcoStatus models used in the RHP 3 1.4 The Eastern Cape River Health Programme: Mthatha River 6 CHAPTER 2: THE MTHATHA RIVER CATCHMENT AND STUDY SITES 7 2.1 General description 7 2.2 Site selection for river health monitoring of the Mthatha River 12 CHAPTER 3: MACROINVERTEBRATES 15 3.1 Introduction 15 3.2 Materials and methods 16 3.3 Results 17 3.4 Conclusions and recommendations 26 CHAPTER 4: ASSESSMENT OF FISH ASSEMBLAGE INTEGRITY 27 4.1 Introduction 27 4.2 Materials and methods 28 4.3 Results 29 4.4 Conclusions and recommendations 33 CHAPTER 5: RIPARIAN VEGETATION ASSESSMENT 35 5.1 Introduction 35 5.2 Materials and methods 36 5.3 Results 38 5.4 Conclusions and recommendations 46 Eastern Cape River Health Programme: Mthatha River Technical Report, August 2006 v Coastal & Environmental Services CHAPTER 6: GEOMORPHOLOGICAL CLASSIFICATION AND ASSESSMENT 48 6.1 Introduction 48 6.2 Materials and methods 51 6.3 Results 52 6.4 Conclusions and recommendations 57 CHAPTER 7: WATER QUALITY 59 7.1 Introduction: Water quality status of the Mthatha River 59 7.2 Materials and methods 61 7.3 Results 62 7.4 Conclusions and recommendations 65 CHAPTER 8: HABITAT INTEGRITY AND ECOSTATUS 66 8.1 Introduction 66 8.2 Habitat Integrity Assessment 67 8.3 Assessment of integrated EcoStatus 70 CHAPTER 9: FINAL DISCUSSION AND CONCLUSION 89 9.1 Management Plan for the Mthatha River catchments 89 9.2 Summarized results of the Mthatha River RHP study 91 REFERENCES 93 APPENDICES 96 Appendix 1 – Photographic record of monitoring sites 96 Appendix 2 – Macroinvertebrates 103 Appendix 3– Fish assessment 111 Appendix 4 – Riparian vegetation assessment 120 Appendix 5 – Geomorphology assessment 141 Eastern Cape River Health Programme: Mthatha River Technical Report, August 2006 vi Coastal & Environmental Services ABBREVIATIONS AND ACRONYMS ASPT Average Score Per Taxon DO Dissolved Oxygen DSS Decision Support System DWAF Department of Water Affairs and Forestry EC Ecological Category ECRHP Eastern Cape River Health Programme EIS Ecological Importance and Sensitivity EWR Ecological Water Requirements EVC Extent of Vegetation Cover FAII Fish Assemblage Integrity Index FRAI Fish Response Assessment Index GAI Geomorphological Assessment Index HAI Hydrological Driver Assessment Index IHAS Integrated Habitat Assessment System IAP Invasive Alien Plants IHI Index of Habitat Integrity IRVI Integrated Riparian Vegetation Index MAR Mean Annual Runoff MIRAI Macroinvertebrate Response Assessment Index NAEBP National Aquatic Ecosystem Biomonitoring Programme