C.A.P.E. Estuary Management Programme
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C.A.P.E. ESTUARY MANAGEMENT PROGRAMME KEURBOOMS/BITOU ESTUARY MANAGEMENT PLAN VOLUME I SITUATION ASSESSMENT Final Report Produced by: Enviro-Fish Africa (Pty) Ltd 22 Somerset Street Grahamstown 6139 Produced for: C.A.P.E. Estuaries Programme Eden District Municipality Pvt Bag X29 P.O. Box 12 Rondebosch George 7701 6530 August 2010 C.A.P.E. Estuaries Management Programme; Keurbooms/Bitou Estuary Management Plan: Situation Assessment TABLE OF CONTENTS EXECUTIVE SUMMARY iii LIST OF TABLES, FIGURES & PLATES xxviii LIST OF ACRONYMS xxx CHAPTER 1 - INTRODUCTION 1 1.1 Introduction 1 1.2 Terms of reference 1 1.3 Project team 2 CHAPTER 2 - BIO-PHYSICAL DESCRIPTION 3 2.1 Introduction 3 2.2 The extent of the estuarine area 6 2.3 Physical structures 7 2.4 Physical properties 8 2.5 Floods 16 CHAPTER 3 - BIOLOGICAL DESCRIPTION 19 3.1 Flora 19 3.2 Fauna 23 CHAPTER 4 – LEGISLATION AND PLANNING & DEVELOPMENT STRATEGIES 28 4.1 International obligations 28 4.2 National legislation and policy 28 4.3 Local (Municipal) legislation 33 4.4 Existing management plans, development strategies, policies and conservation initiatives 34 CHAPTER 5 – RECREATIONAL USE 46 5.1 Exploitation of living resources 46 5.2 Tourism and non-consumptive use 49 CHAPTER 6 - WATER QUANTITY AND QUALITY 51 6.1 Introduction 51 6.2 Management of the catchment 51 6.3 Catchment description 51 6.4 Ecological status 54 6.5 Wetlands 56 6.6 Water quantity 57 6.7 Water quality 58 6.8 Ecological water requirements 59 i Enviro-Fish Africa (Pty) Ltd. C.A.P.E. Estuaries Management Programme; Keurbooms/Bitou Estuary Management Plan: Situation Assessment 6.9 Socio-cultural importance 67 6.10 Pressures/Risk/Threats 67 CHAPTER 7 – CLASSIFICATION, ECONOMIC VALUE, PROTECTION AND REHABILITATION 68 7.1 Classification 68 7.2 Economic value 69 7.3 Protected area strategy and potential 69 7.4 Restoration/rehabilitation 74 7.5 Climate change 74 CHAPTER 8 - THE WAY FORWARD: OBJECTIVE II 75 8.1 Local estuary management forum 75 8.2 The estuarine management plan 75 8.3 The stakeholder workshop 76 8.4 Issues raised by stakeholders 79 CHAPTER 9 - REFERENCES 81 APPENDIX 1 85 APPENDIX 2 87 ii Enviro-Fish Africa (Pty) Ltd. C.A.P.E. Estuaries Management Programme; Keurbooms/Bitou Estuary Management Plan: Situation Assessment EXECUTIVE SUMMARY CHAPTER 1 - INTRODUCTION Estuarine ecosystems are not isolated systems. They form an interface between marine and freshwater systems and are part of regional, national and global ecosystems either directly via water flows or indirectly through the movement of fauna. In addition to the biota that these estuaries support, they provide a range of goods and services (uses) to the inhabitants of the various regions. The interaction between estuaries and users creates a delicate balance, the sustainability of which needs to be addressed by some form of management plan. The urgent need for Estuary Management Plans (EMPs) became apparent during the development of the Integrated Coastal Management Act (Act 24 of 2008; ICMA), and are designed to help align and coordinate estuaries management at a local level. Enviro-Fish Africa (Pty) Ltd. has been contracted by the C.A.P.E. Estuaries Programme to address the development of an EMP for the Keurbooms and Bitou Estuaries. This report fulfills the requirements of Objective 1, namely a Situation Assessment. CHAPTER 2 – PHYSICAL DESCRIPTION INTRODUCTION The Keurbooms and Bitou estuaries (collectively referred to as the Keurbooms) are located close to Plettenberg Bay and both feed into what is known as the Keurbooms Lagoon, which is separated from the sea by a prominent berm, prior to it flowing out to sea. The confluence of the Bitou and Keurbooms estuaries is approximately 3.5 km from the mouth. The Bitou River is 23 km long, with its source at Buffelsnek, and is tidal for 7.2 km from the confluence to the causeway at Wittedrift. The Keurbooms River is approximately 85 km long, with its source at Spitskop in the Outeniqua Mountains, and is tidal for approximately 8.5 km from the confluence. The combined catchment has been estimated at anywhere between 1085 and 1188 km 2. The Keurbooms is a warm-temperate, permanently open, medium-large, Type F barred system (supratidal barrier), whose ichthyofauna, water quality and aesthetics are rated as good, good and moderate respectively. The Bitou Estuary above the N2 is characterized by an extensive floodplain and wetland complex, while the Keurbooms Estuary above the N2 has no floodplain and is characterized by steep gorges. Extensive intertidal areas, dominated by sandbanks, mudbanks, saltmarsh and freshwater creeks, characterize both estuaries below the N2 and the lagoon area. There are two statutory conservation areas administered by CapeNature, namely the Keurbooms River Nature Reserve and the Keurbooms River Seagull Breeding Colony. In addition to this, there are significant areas of private land that are managed for conservation purposes and the Eden to Addo Corridor Initiative is looking to protect plant and animal habitats through establishing biodiversity corridors on privately owned land between formally protected areas. Land iii Enviro-Fish Africa (Pty) Ltd. C.A.P.E. Estuaries Management Programme; Keurbooms/Bitou Estuary Management Plan: Situation Assessment use in the Keurbooms catchment comprises approximately 15% commercial agriculture and 85% natural shrubland, bushland and forest. Very little (<1%) is degraded or developed. The upper Bitou catchment comprises mostly State owned indigenous forests; with the rest of the catchment comprising privately owned land with indigenous forest and cultivated lands. The lower Bitou catchment comprises mostly farmland, urban settlements and a sewage treatement works at the head of the Gansevallei. THE EXTENT OF THE ESTUARINE AREA The Keurbooms Estuary extends approximately 1.5 km upstream from Whiskey Creek and the Bitou Estuary extends as far as the causeway over the Wittedrift road. These are the generally accepted limits, but the exact upper limit of each estuary at any one time will vary depending on tidal flows in relation to the volume of freshwater entering from upstream. The seaward extent of the Keurbooms Lagoon is located at the mouth, which varies according to the location where floods breach the barrier and the subsequent rate of migration in a SW direction. With regards the terrestrial boundaries, there are several options commonly used to define the area, namely: • Floodlines – either the 1:50 or 1:100 year floodlines. These provide a good indication of the historical extent of floods and therefore areas that pose a risk for developments and infrastructure. • 5 m contour – this may be useful in the context of the projected sea level rise and increase in the severity of floods and storm events due to climate change. • Coastal protection zone – this zone is defined as a 100 or 1 000 m buffer zone measured inland from the high water mark and also makes provision for any land located within the 1:50 year floodline. Essentially, the 100 m zone is defined for areas zoned as urban and the 1 000 m zone is defined for rural (agricultural) areas. It must be made clear that these zones are designed to restrict certain activities that may interfere with the estuary and its sensitive riparian areas, but it does NOT mean that no activities may take place. Activities that should be restricted, or at least assessed prior to authorization are those listed in the National Water Act (NWA) that require a license (e.g. water use), the EIA Regulations and those affecting sustainable development and sensitive ecosystems These zones do NOT indicate that landowners may not operate within their boundary, i.e. they do not lose this land, but they must adhere to sound environmental principles when conducting any activities. • EIA regulations – although not used to specifically define the estuary area, the 100 m buffer zone also provides an indication of the area in which listed activities are regulated relative to the high water mark in accordance with the EIA Regulations. PHYSICAL STRUCTURES The road bridge over the Bitou Estuary at Wittedrift and the old causeway immediately downstream act as obstructions to water flow and essentially form the upper limit of tidal exchange in the estuary. The existing N2 bridge and embankment obstructs more than 45% of the river width of the Bitou Estuary. A low causeway is present across the Bitou Estuary approximately 1.5 km upstream of the N2 Bridge. This causes some constriction iv Enviro-Fish Africa (Pty) Ltd. C.A.P.E. Estuaries Management Programme; Keurbooms/Bitou Estuary Management Plan: Situation Assessment to tidal flows especially at low tides. The N2 bridge over the Keurbooms Estuary does not appear to affect the orientation of the channel, but may contribute to increased sediment deposition immediately downstream. There are three picnic sites, administered by CapeNature, one on the eastern bank and two on the western bank of the Keurbooms Estuary above the N2 bridge. There is one slipway above the N2 bridge on the Keurbooms Estuary and seven below the N2 bridge. There are no slipways upstream of the N2 bridge on the Bitou Estuary and no jetties upstream of the N2 on either the Bitou or Keurbooms Estuaries. There are two jetties and one boathouse/jetty on the western side of the Bitou channel below the N2 and a slipway on the eastern side. A single long jetty extends from Stanley’s Island and a further 4 jetties exist on the eastern side of the eastern Keurbooms channel below the N2. A small-boat harbour, comprising mooring facilities for over 100 boats and a slipway are located on the western side below the N2 at the Plettenberg Bay Angling Club.