D RAFT

Dune Maintenance and Management Plan – Witsand

DUNE MAINTENANCE AND MANAGEMENT PLAN - WITSAND

Prepared for:

Hessequa Municipality Van den Berg Street Riversdale 6670

Prepared by:

CAPE TOWN

Block C - The Estuaries, Oxbow Crescent, Century City, Cape Town, 7441 021 045 0900 also in Port Elizabeth, East London, Johannesburg, Grahamstown, Maputo (Mozambique) and Romsey (UK)

www.cesnet.co.za

July 2020

Dune Maintenance and Management Plan – Witsand

REVISIONS TRACKING TABLE

CES Report Revision and Tracking Schedule Document Title: Dune maintenance and management plan - Witsand

Client Name & Hessequa Municipality, Van den Berg Street, Riversdale, 6670 Address:

Status: Draft

Issue Date: June 2020

Lead Author: Dr A M (Ted) Avis

Reviewer: Ms Tarryn Martin

Study Leader/ Registered Dr A.M (Ted) Avis Environmental Assessment Practitioner – Approval: No. of hard No. electronic Report Distribution Circulated to copies copies

Hessequa Municipality

Report Version Date: July 2020 Draft 0 1

This document has been prepared in accordance with the scope of CES’s appointment and contains intellectual property and proprietary information that is protected by copyright in favour of CES. The document may therefore not be reproduced, used or distributed to any third party without the prior written consent of CES. This document is prepared exclusively for use by CES’s client. CES accepts no liability for any use of this document other than by its client and only for the purposes for which it was prepared. No person other than the client may copy (in whole or in part), use or www.cesnet.co.za rely on the contents of this document, without the prior written permission of CES. The document is subject to all confidentiality, copyright, trade secrets rules and intellectual property law and practices of South Africa.

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Contact Details: Coastal Dune Specialist and Quality Control

Name: Dr A.M (Ted) Avis Role: Lead Coastal Dune Specialist Phone: 021 045 0900 E-mail: [email protected]

CES Block C - The Estuaries, Oxbow Crescent, Century City, Cape Town, 7441

www.cesnet.co.za

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TABLE OF CONTENTS

1 INTRODUCTION ...... 13

1.1 Scope of the MMP ...... 13 1.2 Study Area and Location ...... 14 1.3 The Problem Statement ...... 15 1.4 Terms of Reference ...... 16 1.5 Brief Overview of Previous Studies ...... 16 1.6 Provincial requirements for an MMP ...... 17 1.7 Listed activities covered in the MMP ...... 17 1.8 Assumptions and Limitations ...... 18 2 APPROACH ...... 19

2.1 Vegetation Assessment...... 19 2.2 Topographical Assessment ...... 19 3 CLIMATE, CLIMATE CHANGE AND SEA LEVEL RISE ...... 20

3.1 General Climate ...... 20 3.2 Climate Change and Sea Level Rise ...... 21 4 PHYSICAL DESCRIPTION OF THE DUNE SYSTEM ...... 23

4.1 Digital Terrain Model ...... 23 4.2 Dimensional changes ...... 26 5 VEGETATION OF THE DUNE SYSTEM ...... 28

5.1 General Description of the Vegetation ...... 28 5.2 Revegetation Completed to date ...... 28 6 MANAGEMENT & MAINTENANCE PLAN FOR WITSAND ...... 31

6.1 Reforming (rebuilding & shaping) dunes ...... 31 6.2 dune stabilization ...... 32 6.3 Dune Re-Vegetating ...... 33 6.4 Specific Recommendations for the Witsand dune ...... 39 6.4.1 Overall Approach ...... 39 6.4.2 Dune Re-Vegetation – Specific Recommendations ...... 41 6.4.3 Budget Estimates ...... 43 7 CONCLUSIONS ...... 45

8 REFERENCES ...... 46

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LIST OF TABLES

Table 6-1: Suitable species to use for dune revegetation...... 35 Table 6-2: Suitable pioneer species that could be established from seed...... 42 Table 6-3: Costs for all items required to implement the rehabilitation programme ...... 43

LIST OF FIGURES

Figure 1-1: Location of the Witsand mobile dune system ...... 14 Figure 1-2: The Witsand mobile dune system in 1942 ...... 15 Figure 3-1: Graphs (from left to right) showing the average monthly rainfall; average monthly midday temperature; and average monthly night-time temperatures for Witsand (SA Explorer, 2017)...... 20 Figure 3-2: Windrose for Witsand (Meteoblue, 2020) ...... 21 Figure 4-1:Digital Elevation Model...... 24 Figure 4-2: Slope of the dunes...... 25 Figure 4-3: Transects extracted from the DEM ...... 26 Figure 5-1: National vegetation map for the Witsand site. Cape Seashore and Blombos Strandveld are both present...... 29 Figure 6-1:The area that will need to be revegetated to successfully stabilise the mobile sands at Witsand...... 39 Figure 6-2:Reduced area to be revegetated that will hopefully be sufficient to successfully stabilise the mobile sands at Witsand...... 40

LIST OF PLATES

Plate 5-1:This property, located south of the road, was under threat from sand movement. Sand was cleared and some revegetation undertaken...... 29 Plate 5-2:Wind nets and brushwood packing have been used to stabilize portions of the area. The plant in the foreground is Tetragonia decumbens...... 30 Plate 6-1: Sand that has accumulated next to the road will need to be physically removed from the site prior to revegetation...... 31 Plate 6-2: Brushwood can be placed over bare sand between the rows of wind nets...... 33

LIST OF ACRONYMS AND ABBREVIATIONS

EA Environmental Authorisation EIA Environmental Impact Assessment EMP Environmental Management Programme GIS Geographical Information System HWM High-Water Mark IDP Integrated Development Plan LAZ Littoral Active Zone LM Local Municipality NEMA National Environmental Management Act NEM:BA National Environmental Management: Biodiversity Act PA Protected Area

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WCCMP Western Cape Coastal Management Programme TOR Terms of Reference MMP Maintenance and Management Plan SA South Africa ha Hectare

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PROJECT TEAM

Dr A.M (Ted) Avis (Coastal Dune Specialist and Report Writer) Ted Avis is a leading expert in the field of Environmental Impact Assessments, having project- managed numerous large-scale ESIAs to international standards, especially those of the International Finance Corporation (IFC). From 1997 to 2005 Ted acted was principle environmental consultant to Corridor Sands Limitada, managing all environment aspects of the US$1,2billion Corridor Sands Project, including five ESIA’s, associated ESMPs, and the RAP. He has managed ESIA studies and related environmental assessments of similar scope in Kenya, Madagascar, Egypt, Malawi, Zambia and South Africa. Ted also has experience in large scale Strategic Environmental Assessments in southern Africa, and has been engaged by the IFC on a number of projects. Between 1994 and 1996 Ted was instrumental in establishing the Environmental Science Department at Rhodes University, whilst a Senior lecturer in Botany at that time. This resulted from his experience running honours modules in EIA practice and environmental management, as well as the applied research he undertook in these disciplines. He was an Honorary Visiting Fellow in the Department of Environmental Sciences at Rhodes between 1998 and 2003. He was one of the first certified Environmental Assessment Practitioner in South Africa, gaining certification in April 2002. He has delivered papers and published in the field of EIA, Strategic Environmental Assessment and Integrated Coastal Zone Management, and has been a principal of CES since its inception in 1990, and Managing Director since 1998. Ted holds a PhD in Botany, and was awarded a bronze medal by the South African Association of Botanists for the best PhD adjudicated in that year, entitled “Coastal Dune Ecology and Management in the Eastern Cape”. Ted is a Certified Environmental Assessment Practitioner (since 2002) and a professional member of the South African Council for Natural Scientific Professionals (since 1993). Summary of specific experience in coastal management, including plan and programme development:

• 1990 to 1997. Lecturing and research experience in coastal dune ecology at Rhodes University • Between 1985 and 1999 - Delivered papers and published in the field of Integrated Coastal Zone Management. • 1994 - PhD thesis entitled “Coastal Dune Ecology and Management in the Eastern Cape”. • 2010 - Presented a 5-day short course on Tools of Sustainable Coastal Zone Management (Namibia). • Four two-day short courses presented on the Integrated Coastal Zone Management Act to various Government and NGO stakeholders. • 2004 to 2005 – Developed the Integrated Coastal Zone Management Plan for the Buffalo City Municipality, Eastern Cape South Africa, including numerous Management Plans for estuaries, beaches etc. • 2002 to 2004 - The development of the Eastern Cape Coastal Management Plan, adopted as policy by the Eastern Cape Government. • 2017 to 2019 - Western Cape State of Coast report prepared for Dept. of Environmental Affairs & Development Planning (2017 – current).

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• 2018 to 2019 – Update of the Coastal Management Plan for West Coast District Municipality and Five Local Municipalities

Ms Tarryn Martin (Botanical Specialist and Report Review) Tarryn holds a BSc (Botany and Zoology), a BSc (Hons) in African Vertebrate Biodiversity and an MSc with distinction in Botany from Rhodes University. Tarryn’s Master’s thesis examined the impact of fire on the recovery of C3 and C4 Panicoid and non-Panicoid grasses within the context of climate change for which she won the Junior Captain Scott-Medal (Plant Science) for producing the top MSc of 2010 from the South African Academy of Science and Art as well as an Award for Outstanding Academic Achievement in Range and Forage Science from the Grassland Society of Southern Africa.

Tarryn specializes in conducting vegetation assessments in Africa, specifically southern Africa and has worked in the following countries: Mozambique, Zambia, Lesotho and South Africa. She has also recently undertaken work in Cameroon. The types of projects she has worked on include mines (graphite, oil and heavy minerals), solar PV facilities and windfarms (including powerlines), bulk transportation of water and the construction of dams. A number of these projects have been to IFC standards and in addition to a botanical baseline and impact assessment, have included further reporting such as habitat assessments to determine if the site is a trigger for critical habitat, the drafting of site-specific biodiversity management plans and alien invasive species management plans and, recently, an ecosystem services assessment.

Mr Michael Johnson (GIS Specialist)

Michael holds a BSc in Geoinformatics, a BSc (Hons) cum laude in Geoinformatics and an MSc in Geoinformatics from Stellenbosch University. Michael’s Master’s thesis examined the use of Remote Sensing and computer vision technologies for the extraction of near-shore ocean wave characteristic parameters. For the duration of his Master’s, he was based at the CSIR in Stellenbosch. During this time, in addition to his Master’s studies, he conducted work in collaboration with the CSIR Coastal Systems Research Group and provided GIS and Remote Sensing tutoring and technical assistance to the junior staff and fellow students. Michael graduated in March 2018 and has been working for CES since. Since joining CES, Michael has been involved in a number of projects where his GIS and Remote Sensing skills have been utilised. These include, but are not limited to, landcover mapping for the King Cetswayo District Municipality Environmental Management Framework, the use of remote sensing to map invasive alien plant species for the Buffalo City Invasive Alien Species Management Plan and multiple Visual Impact Assessments. Michael is registered with the South African Geomatics Council as a Candidate Geomatics Practitioner: GISc Professional (CGPrGISc 0299).

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DECLARATION

Role on Study Declaration of independence Team

Report • I, Ted Avis, declare that, in terms of the National Environmental Management production Act, 1998 (Act No. 107 of 1998), as amended and the Amended Environmental Impact Assessment Regulations, 2017; • I act as the independent specialist in this application; • I will perform the work relating to the application in an objective manner, even if this results in views and findings that are not favourable to the applicant; • I declare that there are no circumstances that may compromise my objectivity in performing such work; • I have expertise in conducting the specialist report relevant to this application, including knowledge of the Act, Regulations and any guidelines that have relevance to the proposed activity; • I will comply with the Act, Regulations and all other applicable legislation; • I have no, and will not engage in, conflicting interests in the undertaking of the activity; • I undertake to disclose to the applicant and the competent authority all material information in my possession that reasonably has or may have the potential of influencing - any decision to be taken with respect to the application by the competent authority; and - the objectivity of any report, plan or document to be prepared by myself for submission to the competent authority; • All the particulars furnished by me in this report are true and correct; and • I realise that a false declaration is an offence in terms of regulation 48 and is punishable in terms of section 24F of the Act.

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EXECUTIVE SUMMARY

This Dune Maintenance and Management Plan (DMMP) has been prepared in order to facilitate the ongoing rehabilitation, management and maintenance of the dune field located at the mouth of the Breede River. The development of various properties and infrastructure has impeded the natural movement of sand, which continues to build up in the area immediately east of the river mouth. The sand is then blown inland by the dominant south and south westerly winds onto properties and roads in the area. This report has been prepared in order to cover activities primarily related to the revegetation and stabilization of the a portion of the mobile dune system, to arrest sand movement and prevent it from blowing onto roads and into properties.

Figure 1: Location of the proposed development

The study site is located at the mouth of the Breede River, which occurs on a coastal plain with a gentle gradient aligned in an east-west direction. The channel at the mouth is maintained by strong tidal erosion that extends to the boulder bed of the estuary (Figure 1). The estuary is described as a single sand spit estuary that is perennially open to the sea along the northern side of the mouth, and a sand spit or spit-bar extends across the mouth. The spit is permanent as it has been recorded in that position on a British Admiralty Chart of 1865, thane aerial photo of 1981 (CSIR, 1983) and current Google Earth Images.

Currents move sediments onto the beaches (CSIR, 1983), and sediments are deposited in the intertidal zone, and are then blown along by the prevailing south-westerly winds inland towards the residential area. Consequently, a dune field has developed on the sand spit and this provides sand that migrates inland with the winds, and has long been a problem at the Witsand resort. In the past, sand carried inland by the south and south-westerly winds would have been stored in the relic dune field. The building of the roads and houses across the connecting

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corridor has impeded the natural process of sand movement (CSIR, 1983), and this has resulted in the build-up of the sand at present. The most dominant winds at the Witsand site, both in frequency and velocity are Southerly to East-south-easterly winds (Meteoblue, 2020). For fine-grained sands, such as those at the site, a wind velocity of approximately 10km/hr is required to move sand. The Southerly to East- south-easterly winds achieve these velocities frequently, and sand is therefore blown in this direction from midwinter to spring, but generally all year round. This means that sand is constantly moving away from the HWM, where there is a constant supply on this sand spit, inland towards the houses. Areas located closer to river mouths are more susceptible, due to the possibility of higher water levels in the estuary, and foredune wash-away due to the river mouth changing direction. Changes in sea levels negatively affect coastal ecosystems indirectly by altering the saline gradient in estuaries, flooding low lying areas such as dune slacks, inducing changes to parameters such as available light, salinity, and temperature, and ultimately altering species composition. Dune Study Approach

A UAV (Drone) topographic and detail survey was conducted and the pictometry method was used to generate contours for each site. Where vegetation was too dense a conventional GPS survey method was used to fill in the missing information. The GPS was also used to capture detail such as fences and road/tar edge. This was then used to create a detailed topographical map that was used as a key data source for the project. The area is best described as a mobile dune system with small patches of vegetated hummock dunes. The mobile dunes are Transverse dunes orientated with their upwind (stoss) face orientated in a south-easterly to easterly direction, and the slip-face (down-wind face) orientated in a westerly or north-westerly direction. These slip-faces are steep (at the angle of repose – 340) which indicates active sand movement. The area has an irregular topography, including deflation basins and complex slip-faces. All of this is indicative of an area exposed to strong winds and ongoing sand movement. The entire dune system increases in elevation from the HWM, with the highest dunes associated with the vegetated ridge line on the landward edge. There are also high dunes on the west, built up as a result of sand moving west under the influence of the dominant south-easterly and easterly winds ((Meteoblue, 2020) It is difficult to identify clear dune ridges and dune patterns from the slope analysis. This is because the topography is so strongly influenced by the wind regime, and some of the higher dune ridges and associated slip-faces are orientated in a north-east direction, and others in an east-west direction. The deflection of wind off the existing dunes changes local wind conditions, and results in various wind eddies that re-orientate dune ridges as the wind is deflected off the surface. This complexity of sand movement presents challenges to the revegetation of an extensive dune system such as this. There is practically no vegetation at the Witsand site, except for a few small vegetated dune knolls and the rehabilitation site, so no transect survey or edge of vegetation survey was undertaken during the field assessment.

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Management & Maintenance Plan for Witsand Experience gained from the rehabilitation of the Hout Bay dune system (van Eeden, pers com.) indicates that a phased approach is unlikely to work, due to constant variations in surface wind patterns, a shift in dominant summer wind direction towards the north-west, and the sheer expanse of the system. All these factors ensure that there will be continuous sand movement, and in a single strong wind event the volumes of sand moved can be sufficient to cover wind nets by over 1m (van Eeden, pers com.) Furthermore, the maintenance is too difficult and costly if only sections of an area are covered with wind net, as they cannot be lifted in time after strong wind events, and can become completely buried with sand. It is therefore recommended that the entire site be covered with wind nets in late autumn, just before the winter rains. Before the area has been covered with wind nets, consideration must be given to establishing a borehole, consisting of a pump, tanks, electrical supply and other infrastructure required for the implementation of an irrigation system. Ideally an irrigation system will need to be established along the seaward edge of the rehabilitation area, where allowance must be made to irrigate a 20m wide strip of vegetation. These areas will be exposed to the most sand movement as they take the brunt of the SE winds, and successful plant establishment will require irrigation. An allowance of 1ha under irrigation is required. After wind net establishment, the entire site must be seeded with cheap agricultural seed in May or June. Rye grass is recommended, as it has been used successfully elsewhere, is able to bind the sand, and increases nutrients and soil mycorrhiza in the sand. This all improves the success of indigenous seeding and planting. As Rye grass is an annual it will die back in the summer. It is further recommended that Marram Grass is not used, as it needs to be planted at a density of 6 plants per m2, and this comes with significant costs. The sand movement in the area will hopefully not require an aggressive pioneer species such as Marram, as the indigenous plants under irrigation should cope. Marram is also a Category 3 plant under NEM:BA Alien and Invasive Species List and a permit for its use is required. The following activities will be required prior to initiating any actual rehabilitation or revegetation activities on the dune field: ➢ Construct a plant nursery ➢ Construct a site office ➢ Establish a borehole ➢ Install irrigation infrastructure (pumps, tanks, electrical supply etc.) ➢ Establish a secure area at site with security fencing, guard hut and toilet.

It is recommended that the propagation nursery be established on land close to the only house located to the east of Galjoen Street. A containerised site office and store area will be required and this should be contained together with the irrigation infrastructure and water tanks within a fenced secure area. A borehole will need to be established close to this site office, or access to the main water supply is a further source of irrigation water. Preferred Option: It is concluded that rehabilitation of the dune system will only be successful if the entire area is stabilised en-bloc, and not in a piecemeal fashion, in order to achieve a sustainable and self-perpetuating ecosystem. Thus, the overall approach is to stabilise the entire site in year 2, with year 3 focusing on intensive maintenance and year 1 on site and nursery establishment. This will be an expensive exercise, and although not part of the Terms of Reference, a budget to achieve successful rehabilitation is provided.

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Rationalised Option: due to the costs of dune rehabilitation a further option would be to only stabilise the vegetation that is close to the existing Blombos Strandveld thicket The same approach would be adopted in both options. The total cost for the preferred option is R2,908,258.00, and the total cost per hectare, including all CAPEX items, preliminaries & general and a 5% contingency is R714,599.00. These costs are accurate to within 25%. If the reduced area of 1,77ha is rehabilitated the total cost will be R1,948,941.00, and the total cost per hectare R1,101,096.

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1 INTRODUCTION

1.1 SCOPE OF THE MMP

This Dune Maintenance and Management Plan (DMMP) has been prepared in order to facilitate the ongoing rehabilitation, management and maintenance of the dune field located at the mouth of the Breede River. The development of various properties and infrastructure has impeded the natural movement of sand, which continues to build up in the area immediately east of the river mouth. The sand is then blown inland by the dominant south and south westerly winds onto properties and roads in the area. The location of the sites covered by the DMMP are presented in Section 1.2. This report has been prepared in order to cover activities primarily related to the revegetation and stabilization of the a portion of the mobile dune system, to arrest sand movement and prevent it from blowing onto roads and into properties. This is likely to require the following activities, as and when necessary (CoCT,2017):

• Mechanical movement of sand that may have accumulated on, against or near coastal infrastructure. • Bulk movement of sand to repair blow-outs and reshape compromised dune profiles. • “Topping”, reshaping and re-vegetating dunes that have grown too tall, or which have a very irregular topography due to erosion and blow-out development. • Clearing access paths from sand build-up and re-distribution of the sand on the beach, dunes or intertidal areas. • Returning clean sand that might have accumulated on roads and other built infrastructure to suitable areas on the beach or dunes. • Planting vegetation and installing irrigation systems as part of dune rehabilitation projects. • The stabilisation of sand with brushwood, netting, Kelp or mulch. • Installation of post and rail fencing and barriers to prevent public from walking over sensitive dune systems. • Installing wooden or Pollywood raised boardwalks and walkways to improve access control. • Removal or repair of irrigation systems as and when required. • Maintaining and repairing storm-water outlets along beaches in dune systems. • Installing refuse bins, benches, signage, fencing and bollards as and when required, and • Removal of broken benches, fencing, signage, bollards, rubble and poles.

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1.2 STUDY AREA AND LOCATION

The study site is located at the mouth of the Breede River, which occurs on a coastal plain with a gentle gradient aligned in an east-west direction. The channel at the mouth is maintained by strong tidal erosion that extends to the boulder bed of the estuary (CSIR, 1983). The estuary is described as a single sand spit estuary that is perennially open to the sea (CSIR, 1983). Along the northern side of the mouth a sand spit or spit-bar extends across the mouth. The spit is permanent as it has been recorded in that position on a British Admiralty Chart of 1865, the aerial photo of 1981 (CSIR, 1983) and current Google Earth Image. The north-easterly longshore surf-zone currents that move sediments onto the beaches occur 20% of the time (CSIR, 1983), and sediments are deposited in the intertidal zone, and are then blown along by the prevailing south-westerly winds inland and towards the residential area. Consequently a dune field has developed on the sand spit and this provides sand that migrates inland with the winds and has long been a problem at the Witsand resort. The report of the CSIR (1983) points out that the aeolian transport of sand inland is by south-easterly, southerly and south-westerly winds. The less frequent north-westerly winds would carry some sand back towards the shore but the dominant winds are southerly and south-westerly and the sand migration is thus north-eastwards.

Figure 1-1: Location of the Witsand mobile dune system

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1.3 THE PROBLEM STATEMENT

An extensive dune field has developed on the sand spit to the east of the river mouth, which provides a source of sand that constantly migrates inland under the influence of the prevailing south-westerly winds. This has been a problem at the Witsand village for many decades. A report of the CSIR (1983) pointed out that the aeolian transport of sand was inland due to the south-easterly, southerly and south-westerly winds. The less frequent north-westerly winds would carry some sand back towards the shore, but as the dominant winds are southerly and south-westerly sand migration is north-eastwards. The inland edge of the mobile dune field is defined by a relic dune field that was part of the ancient vegetated coastal dune belt that is typical of the south Cape coast. The CSIR (1983) state that the area was probably de-vegetated by burning or overgrazing by earlier inhabitants of the region, but this situation is widespread along this coast and it is doubtful if the human influence could have been consistently destructive. However, in the recent past (last 75 years) the dune system has consisted of a mobile dune field, as seen from earliest 1942 aerial photograph (Figure 1-2). The mobile dune field across the sand spit is clearly visible, and only patches of vegetation are located in the north east. The aeolian transport of sand was inland due to the south-easterly, southerly and south-westerly winds. Roads and houses have now been established in this area (Plate 1-1).

Figure 1-2: The Witsand mobile dune system in 1942

In the past, sand carried inland by the south and south-westerly winds would have been stored in the relic dune field. The development of various properties and infrastructure has impeded the natural movement of sand, which continues to build up in the area immediately east of the

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river mouth. The sand is then blown inland by the dominant south and south westerly winds onto properties and roads in the area.

1.4 TERMS OF REFERENCE

The Terms of Reference (ToR) set out for this study included the following:

• Engage with the local authority and Witsand residents • Provide a comprehensive topographical survey of the site • Quantify the dimensional changes that have occurred at the site since the initial study for the development of a Basic Assessment for the Witsand Dune System in 2008/9 in 1993. This included the direct comparison between the two surveys as well as an analysis of available aerial imagery. • Re-assess the design parameters considering future Sea Level Rise (SLR) scenarios and the effects of climate change. This included the parameters associated with three future climate change scenarios. • Assess the beach and foredune integrity in terms of the revised design requirements • Update the EMP Addendum to include the development of an annual maintenance plan.

1.5 BRIEF OVERVIEW OF PREVIOUS STUDIES

An environmental management and rehabilitation plan was drafted as part of the Environmental Impact Assessment process for the Witsand site in 2012 (CES, 2012). Environmental Authorisation was received for the proposed dune stabilisation program for the site on the 26 November 2013. Because of the urgency of the need to remove the sand, stabilization of the site was started in January 2009. The method used was to flatten to portion of the dune field by removing and bull dozing the sand. The recommendation in the EMP was to then consolidate the brushwood and plant the dunes with indigenous dune plants. The study conducted in 2012 (CES, 2012) and the Addendum to the EMP (Hessequa, 2014) recommended the following measures for the site:

➢ Stabilize the drift sands in front of (south of) the region where the sand has been removed. As these will be migratory dunes it may be necessary to erect fences to limit the movement of sand. ➢ Use marram Grass in this region, planted in tufts at 30cm intervals. ➢ Use brushwood to limit sand movement while dune plants become stabilised. ➢ The dunes should be fenced during stabilisation to prevent access onto the dune. Information boards to explain the importance and sensitivity of the dunes and the reason for the fence were recommended. ➢ In order to restrict trampling of dunes, access for pedestrians should be restricted, and confined to wooden walkways. Only one boardwalk will be constructed and this will be done once the dune system has been stabilized. The exact location of the boardwalk could not be determined as it would be dependent on the success of the revegetation programme. ➢ The monitoring programme should be continued for some 3 to 5 years.

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➢ On-going maintenance and control of access will be required indefinitely.

1.6 PROVINCIAL REQUIREMENTS FOR AN MMP

The Department of Environmental Affairs and Development Planning (DEA&DP) produced an information document for the development of maintenance management plans (MMP) for water courses (DEA&DP, 2017). In the absence of a specific guideline document, this report has been used to ensure that the content of this Dune MMP is aligned to DEADP requirements.

The MMP must be submitted with a signed declaration for the MMP to be adopted in terms of the National Environmental Management Act. It must provide a strategic overview of the need for its development, and how the plan aims to contribute to sustainable practices and reducing and/or mitigating the need for maintenance. Details on the responsible party who will implement the MMP must also be included.

Engagement for this MMP with the following authorities was undertaken:

➢ Department of Environmental Affairs and Development Planning ➢ Hessequa local municipality

Details of the interaction with the authorities must be provided, and comments received must be submitted and referenced within the MMP. Interested and affected parties must be notified that an MMP is to be prepared, and afforded an opportunity to comment on the document. In terms of the actual maintenance plan method statements, providing a step-by-step plan must be included for the various activities that will be required. The time period should be provided within which the maintenance actions need to be implemented, and an indication as to whether certain maintenance actions will be repeated must be given.

1.7 LISTED ACTIVITIES COVERED IN THE MMP

This report has been produced in accordance with the National Environmental Management Act, 1988 (NEMA Act No. 107 of 1998), as amended and the Environmental Impact Regulations of 2014.

The following listed activities contained in NEMA 107 of 1998, as defined in Government Notice (GN) No. R 983, R. 984 and R. 985 of 4 December 2014 are likely to be trigged, and this DMMP applies for authorisation to undertake the below activities:

1. Activity 18 of GN No. R. 983 – the planting of vegetation or placing of any material on the dunes were exposed said services of more than 10 m² with in the little active site for the purpose of preventing the free movement of sand erosion or accretion excluding where – i. The granting of vegetation placement of material relates to restoration and maintenance of indigenous coastal digitation undertaken in accordance with and maintenance management plan, or ii. Such planting of vegetation or placing of material will occur behind a development setback”.

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2. Activity 19 of GN No. R. 983 – the infilling or depositing of any material of more than 5 m³ into, or the dredging, excavation, removal or moving of soil, sand, shall great, pebbles all rock of more than 5 m³ from – i. A watercourse; ii. The seashore; or iii. The littoral active zone, an estuary or a distance of 100 m inland of the high- water mark of the sea or an estuary, which ever distance is the greater – But excluding where such infilling, depositing, dredging, excavation, removal or moving- a. Will occur behind a development setback. b. Is for maintenance purposes undertaken in accordance with a maintenance management plan; or c. Falls within the ambit of activity 21 in this notice, in which case that activity applies.

3. Activity 14 (xi) of GN No. R. 324 – the development of boardwalks exceeding 10 m² in size in the (i) Western Cape (i) outside and urban area; or in (ff) Critical biodiversity areas or ecosystem service areas as identified in systematic biodiversity plans adopted by the competent authority or in bioregional plans.

The DMMP also covers the following activity, in accordance with the Integrated Coastal Management Act (Act 36 of 2014) - Section 15: measures affecting erosion and accretion – Subsection (2): “no person may construct, maintain, or extend any structure, or take other measures on coastal public property to prevent or promote erosion or accretion of the seashore except as provided for in this Act, the National Environmental Management Act or any other specific environmental management Act”. It also covers regulations relating to the control of the use of vehicles in the coastal area known as the off-road vehicle regulations. Section 3(1)(d) make provision for permissible activities which include “the use of a vehicle by any employee or agent of an organ of state acting in the course and scope of their employment of mandate, or by any person contracted by an organ of state, for the purposes of performing the public duties of that organ of state mandated by law”.

1.8 ASSUMPTIONS AND LIMITATIONS

This report is based on the information available at the time of the compilation and as such, the following assumptions and limitations are implicit:

➢ This report is based on best available information gained from the site surveys and desktop research ➢ No historical quantitative data on changes to the dune system were available.

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2 APPROACH

2.1 VEGETATION ASSESSMENT

There is practically no vegetation at the Witsand site, except for a few small vegetated dune knolls and the rehabilitation site, so no transect survey or edge of vegetation survey was undertaken during the field assessment.

2.2 TOPOGRAPHICAL ASSESSMENT

A UAV (Drone) topographic and detail survey was conducted and the pictometry method was used to generate contours for each site. Where vegetation was too dense a conventional GPS survey method was used to fill in the missing information. The GPS was also used to capture detail such as fences and road/tar edge. The survey included the following:

➢ A drone survey to capture aerial imagery of each site; ➢ Calculation and capture of cadastral data; ➢ In fill survey of basic detail (i.e. fences, roads and Services); and ➢ Processing of data, generation of elevation contours and completion of final drawings.

This was then used to create a detailed topographical map that was used as a key data source for the project.

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3 CLIMATE, CLIMATE CHANGE AND SEA LEVEL RISE

3.1 GENERAL CLIMATE

The information provided here is based on the climate data for Witsand – the nearest urban area located adjacent to the Breede River estuary mouth. Witsand boasts a Mediterranean climate typical to that of the Western Cape Province of South Africa, with warm, dry summers and mild, moist winters. Average daily temperatures for Witsand range from 25.7°C in February to 17.9°C in July. The coldest temperatures are recorded during the month of July when temperatures drop to a low of 6.4°C during the night. Rainfall typically occurs throughout the year, receiving an average of 279 mm of rain per annum (SA Explorer, 2017) (Figure 3.1).

Figure 3-1: Graphs (from left to right) showing the average monthly rainfall; average monthly midday temperature; and average monthly night-time temperatures for Witsand (SA Explorer, 2017).

Along South Africa’s southern coast, westerly to south-westerly winds occur throughout the year. The main seasonal difference occurs during the spring and summer months, when there is a high frequency of easterly winds. Along the south coast there is also a slight sea breeze throughout the year with a moderate to strong north-west land breeze component. The windiest time of the year is from midwinter to spring (Tinley, 1985). The most dominant winds at the Witsand site are Southerly to East-south-easterly winds (Figure 3.2). This is both in terms of frequency and velocity. For fine-grained sands, such as those at the site, a wind velocity of approximately 10km/hr is required to move sand. The Southerly to East-south-easterly winds achieve these velocities frequently, and sand is therefore blown in this direction from midwinter to spring, but generally all year round. This means that sand is constantly moving away from the HWM, where there is a constant supply on this sand spit, inland towards the houses.

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Figure 3-2: Windrose for Witsand (Meteoblue, 2020)

3.2 CLIMATE CHANGE AND SEA LEVEL RISE

Climate variability and change is becoming an increasing threat to both natural and man-made assets along the coastline and coastal management needs to more carefully consider the effects of this. The main pressures on the coast as a result of climate change are sea level rise together with increasing storm frequencies, intensities and storm surge events. Infrastructure located in low lying coastal areas are particularly vulnerable to damage and destruction during extreme natural events that have become more frequent and intense due to climate change.

The following climate change related impacts are relevant to the study area:

➢ Changes in sea level; ➢ Occurrence of severe storms; ➢ Extreme sea levels, and ➢ Wind and waves;

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In particular, the first two will have a significant effect on foredune integrity, and are discussed further. Changes in sea level pose a significant risk to coastal systems and coastal development. It can lead to beach and dune erosion resulting in shoreline retreat, as well as salt water intrusion into freshwater coastal aquifers, negatively affecting the quality of water used for human consumption and irrigation (Nicholls and Cazenave, 2010, 2010). Over the 20th century, mean sea-level has risen an average of 0.17 metres (0.12 metres – 0.22 metres) (Cartwright, 2008). In South Africa, the first detailed analysis of all tide gauge sites along the southern African coastline was conducted in 2009. The analysis shows that over the past 50 years, sea level rise along the southern African coastline has not been constant, varying between 0.42 mm/year (West Coast) to 3.55 mm/year (East Coast) (with a rise of 1.57 mm/year along the southwestern and southern Cape coastline) (Mather et al. 2009). This equates to a mid- scenario for SLR due to climate change of 1m by 2100, and 0.35m by 2050 (CSIR, 2014). Along the coastline around Pringle Bay, and assuming a planning horizon of 2050, the extreme future scenario for a coastal low pressure system occurring during spring high tide could resulting in flooding levels of about 1.84 m above mean sea level (MSL) (Barwell, 2015). In the absence of site specific data, a similar event in Stillbaai needs to be catered for. The 1.84m refers to the still-water level. The dune system must also be able to withstand the additional effects of wave setup and wave run-up. (Wave setup is the effect of water build-up against the shore due to waves breaking and wave run-up is the rush of water in the swash zone up the beach slope of the still water level). This can add an additional 4,3m to the still water level, meaning that the foredune height needs to be at least 6m above MSL to accommodate the compounding effects of SLR.

Changes in sea levels negatively affect coastal ecosystems indirectly by altering the saline gradient in estuaries, flooding low lying areas such as dune slacks, inducing changes to parameters such as available light, salinity, and temperature, and ultimately altering species composition.

Severe storms, such as tropical cyclones and extratropical cyclones, can result in storm surges that affect coastal areas. The severity of the storms depends on the storm’s projected path, the regional bathymetry, near shore hydrodynamics and the contribution from waves (Wong, et. al. 2014). On short time scales (order of hours to days), tides and weather contribute to a sudden rise in sea level. This is because variations in wind and atmospheric pressure can raise sea levels by up to forty centimetres, and during extreme storms waves can increase sea level by several metres. These variations are more significant due to climate change. With a rise in sea-level and increase in frequency and intensity of sea storms, accompanied by an increase in wave heights, the coastline is expected to experience a greater risk of damage by storm surge; increased exposure to more intense and more frequent extreme events; increased flooding, with greater extent and frequency, and ultimately more frequent destruction of foredunes, coastal property and infrastructure (Goschen, 2011).

Coastal erosion, including the removal of dunes and subsequent under-scouring of foundations are important consequences. Areas located closer to river mouths are more susceptible, due to the possibility of higher water levels in the estuary, and foredune wash- away due to the river mouth changing direction.

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4 PHYSICAL DESCRIPTION OF THE DUNE SYSTEM

4.1 DIGITAL TERRAIN MODEL

The area is best described as a mobile dune system with small patches of vegetated dunes. The mobile dunes are Transverse dunes orientated with their upwind (stoss) face orientated in a south-easterly to easterly direction, and the slip-face (down-wind face) orientated in a westerly or north-westerly direction (Figure 4.1). These slip-faces are steep (at the angle of repose – 340) which indicates active sand movement. The area has an irregular topography, including deflation basins and complex slip-faces. All of this is indicative of an area exposed to strong winds and ongoing sand movement. The entire dune system increases in elevation from the HWM, with the highest dunes associated with the vegetated ridge line on the landward edge. There are also high dunes on the west, built up as a result of sand moving west under the influence of the dominant south-easterly and easterly winds (Figure 4.1). It is difficult to identify clear dune ridges and dune patterns from the slope analysis (Figure 4.2). This is because the topography is so strongly influenced by the wind regime, and some of the higher dune ridges and associated slip-faces are orientated in a north-east directions, and others in an east-west direction. The deflection of wind off the existing dunes changes local wind conditions, and results in various wind eddies that re-orientate dune ridges as the wind is deflected off the surface. This complexity of sand movement presents challenges to the revegetation of an extensive dune system such as this.

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Figure 4-1:Digital Elevation Model

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Figure 4-2: Slope of the dunes.

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4.2 DIMENSIONAL CHANGES

Seven transects where extracted from the digital elevation model and are presented in Appendix 1, as Figure A2. The location of these transects is presented on Figure 4.3 below. Transects 1 to 5 are in approximately the same location as Transects 1 to 5 in the Environmental Management and Rehabilitation Plan prepared by CES in March 2012. However, this report only discusses the changes that took place to transects 1 and 4 (Figures 4.2.1a 4.2.1b – CES 2012), as only these two transects are available in the 2020 CES report. These are presented in Appendix 1 as Figure A1.

Figure 4-3: Transects extracted from the DEM

General observations: The first 50 to 60m of Transects 1 to 4 slope gently upwards, and this level area represents the beach and upper beach area. Thereafter the dune rises steeply up towards the vegetated dune system and houses, reaching heights of between 13m to 16m. The overall topography of these four transects are similar. Transects 5 to 7 start further inland and away from the HWM, and the dunes rapidly obtain heights of 8m to 10m, and continue to rise to elevations of 13m. Deflation basins are evident in Transects 6 and 7.

The scope of work asked for a quantification of dimensional changes that have taken place since the 2012 survey, but this is not possible because no digital elevation model and 3-D survey was completed in 2012, so there is no quantitative baseline. Rather, a comparison of Transects 1 and 4 is presented below. However, it must be noted that the system is so mobile and dynamic that there is no real benefit to this exercise.

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A comparison of Figure 1 from CES (2012) (Appendix 1, Figure 1A) indicates that the overall profile of the transect has not changed noticeably. Although the length of the 2012 transect is longer, this is simply because the transect line started approximately 30m closer to the HWM. The same small dune ridge is visible at 110m (2012) and 90m (2012), and the overall shape of the transect is very similar. The height of the transect at its termination point in both transects is 16m, so if the sand was cleared in the area indicated as “dune sand to be removed”, it has reaccumulated. The clearing of sand at the end of transect 2 is however evident.

A comparison of Figure 4 from CES (2012) also indicates that the overall profile of the transect has not changed noticeably. Although the length of the 2012 transect is 280m, this is because the transect line started at the HWM (Figure 1A, Appendix 1), with the 2020 line starting almost 100m from the HWM. The small dune ridge at 120m (2012) and 20m (2020) supports this. The height of the transect at its highest point in both transects is 14m, so if the sand was cleared in the area indicated as “dune sand to be removed”, it has reaccumulated.

These observations indicate that generally the profile of the dune system remains similar over time, which suggests that although there is active sand movement across the dune system, there is not a large amount of sand accumulation. However, sand moves across the system and tends to accumulate against the vegetated dune ridge and houses on the northern and western edges of the site.

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5 VEGETATION OF THE DUNE SYSTEM

5.1 GENERAL DESCRIPTION OF THE VEGETATION

The South African Vegetation Map (SA VEGMAP) of 2018 is an important resource for biodiversity monitoring and conservation management in South Africa. Under the custodianship of the South African National Biodiversity Institute (SANBI) the SA VEGMAP, (2018) was updated in order to ‘provide floristically based vegetation units of South Africa, Lesotho and Swaziland at a greater level of detail than had been available before’. The map provides a detailed description of each of South Africa’s unique vegetation types along with a comprehensive list of the important species associated with each, including endemic and biologically important species. According to the SA Veg Map (2018), the following vegetation type is found within the dune system of Areas 1 and 2: Cape Seashore Vegetation Cape Seashore Vegetation typically occurs on recently deposited coastal sandy sediments forming dunes and beaches, along the Eastern and Western Cape Provinces of South Africa. It stretches along the temperate coasts of the Atlantic and Indian Ocean, from Olifants River mouth to Cape Agulhas in the south west and from Cape Agulhas to East London in the south. This vegetation type is characteristic of beaches, coastal dunes, dune slacks and coastal cliffs. It ranges from open grassy and herbaceous vegetation to dwarf-shrubby vegetation, often dominated by a single pioneer species. The age of the substrate and natural disturbance regime (moving dunes), coupled with the distance from the upper tidal mark and the exposure of the dune slope (leeward verses seaward), influences the composition of the plant communities present (Muncina et al., 2006). Cape Seashore Vegetation is classified as Least Concern, with a conservation target of 20% (Figure 4.1). Almost half of the area is statutorily conserved in formal protected areas, including national parks and Nature Reserves, while a considerable portion is protected in a number of private conservation areas. Only 1.7% of this vegetation type has been transformed, mainly as a consequence of urban development (Mucina et al., 2006). Blombos Strandveld Further inland the vegetation becomes more woody, and is dominated by evergreen, sclerophyllous shrubs with a poorly developed undergrowth, and is classified by Mucina et al., (2006) as Blombos Strandveld. This is the woody vegetation that exists on the landward edge of the mobile dune, but in places it has been invaded by the exotic Acacia cyclops. Blombos Strandveld is listed as Least Threatened with a conservation target of 36%. More than 20% is statutorily conserved and 11% is conserved privately.

5.2 REVEGETATION COMPLETED TO DATE

Very limited revegetation has been undertaken at the site, with activities having focused on the north-eastern portion where a property to the south of the road was under immediate threat from sand movement (Plate 4-1), and where continuous sand movement blows sand onto the road. This area is visible in Figure 1-1.

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The main approach to the current revegetation includes the installation of the wind nets, brushwood packing and planting indigenous pioneer species. Arctotheca populifolia seems to have been the preferred species.

Figure 5-1: National vegetation map for the Witsand site. Cape Seashore and Blombos Strandveld are both present.

Plate 5-1:This property, located south of the road, was under threat from sand movement. Sand was cleared and some revegetation undertaken.

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Plate 5-2:Wind nets and brushwood packing have been used to stabilize portions of the area. The plant in the foreground is Tetragonia decumbens.

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6 MANAGEMENT & MAINTENANCE PLAN FOR WITSAND

6.1 REFORMING (REBUILDING & SHAPING) DUNES

No physical reshaping or re-forming of dunes will be required. However, the removal of sand that has accumulated next to the road as well as close to some of the properties will be required (Plate 5.1). Removed sand could be deposited on sections of beach that show signs of erosion, should they be close enough, or it will need to be taken to a landfill site. Selling the sand is possible, but then in term of Section 27 of the Mineral and Petroleum Resources Development Act (MPRDA) 29 of 2002 (and subsequent amendments) a mining permit will be required, which may be issued if- a. The mineral in question can be mined optimally within a period of two years; and b. The mining area in question does not exceed 5.0 hectares in extent

The definition of ‘mining area’ in the MPRDA “in relation to a mining right or mining permit, means the area on which the extraction of any mineral has been authorised and for which that right of permit is granted”. Therefore, as the area from which sand will be removed is less than 5 ha a mining permit is required. Once this sand has been removed the resultant level area must be vegetated, and wind nets established up-wind to prevent further sand movement. Shrubs and not herbaceous pioneer species must be used in this area (see Table 5.1 for recommended species).

Plate 6-1: Sand that has accumulated next to the road will need to be physically removed from the site prior to revegetation.

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6.2 DUNE STABILIZATION

The following interventions are required: • Wind-nets: dune forming fences will be required across most of the site. They have the advantage of preventing people from walking through the rehabilitation area. These wind-nets should be approximately 15 to 20m apart, in rows perpendicular to the dominant winds. The wind-nets should be constructed from porous materials such as shade cloth. • Brush matting: This involves placing a layer of branches over the sand surface. As wind passes over the brush, velocities are reduced and this allows the sand surface to remain stable, and sand movement is reduced. Windblown sand drops through the brush to settle underneath (Plate 5.2). Branches should be spread sparsely, with 650 cubic metres per hectare being a good rule of thumb. This is labour-intensive as it involves the cutting, transporting and spreading of brush, but funds could be obtained from the Extended Public Works Program. It is restricted to areas where brush is readily available, and brush could be obtained from the areas being cleared of Rooikrans, provided those branches are sterile (do not carry any seed). • Irrigation: Irrigation is required to assist with the watering of plants in the early stages of their establishment, so they can evade moisture stress during their establishment period. It greatly increases the survival rate of planted seedlings. Typically, irrigation will be required during the hot and dry summer months, and for the first two years only. Portable irrigation systems, such as draglines, could be used. The following guidelines are provided, but the landscape contractor will need to develop a more detailed irrigation schedule, as this will be dependent on many factors, especially the success of plant establishment: o During periods of drought use of water for irrigation must be limited. o If possible use non-potable water for irrigation. o Insure the correct amount of water is provided. Besides being wasteful, excessive irrigation results in root rot, and root growing too close to the surface, resulting in plants being drought intolerant. o Irrigation must take place at weekly intervals. To reduce water loss, this should ideally be done in the early mornings or late afternoons. o The irrigation system must be designed to ensure that all plants receive 100% irrigation coverage. o Weeds and alien vegetation should be removed on an ongoing basis. o The irrigation system must be checked frequently to identify leaks.

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Plate 6-2: Brushwood can be placed over bare sand between the rows of wind nets.

6.3 DUNE RE-VEGETATING

The most effective long-term method of dune stabilisation is through the planting of vegetation. It is the least expensive and most durable cover lens and blends into the natural setting. It is generally self-maintaining as coastal vegetation is adaptive to the harsh conditions it is exposed to, and plays a very important role in binding the sand, thus creating dune systems. Ultimately a self-sustaining ecosystem, with minimal maintenance requirements is created, and this should be the goal. Establishing vegetation can be achieved by using nursery-raised seedlings, in-situ cuttings and seeding the area with indigenous species. The following conditions are applicable when using vegetation to stabilise the dune system:

• Planting must only occur once the dune has been profiled and/or the sand surface has been stabilised. • Locally indigenous species must be used. Recommended species are provided in Table 7-1. • When using seed it is advised that a seed mulch be used, whereby the seed is mixed with straw or grass and broadcast across the site. This must only be done once the area has been packed with brushwood and the sand surface is stable. • Successional processes should be mimicked, meaning that pioneer species are planted close to the high-water mark, and then as one moves further inland, pioneer woody species are planted, and later more climax shrubs and small trees. • Because the combination of high temperature, low soil moisture and strong winds are the major causes of poor establishment of dune vegetation, the timing of planting is critically important. In the Western Cape planting must take place in the growing season, which is generally between May and August.

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• If required, mulch or fertiliser should be added to improve the chances of survival. As mentioned above, irrigation systems will improve plant survival, but even if an irrigation system is installed it is recommended that planting occurs between May and August. • Improved survival rates are achieved if hardy indigenous dune plants are used. These can be raised in nurseries and when ready, planted on the dunes. As it is difficult to obtain dune plants from commercial nurseries it might be necessary to establish a small nursery to propagate the species required. • In bare and open areas set-back from the HWM, where dune scrub is found, woody vegetation must be planted. However, to ensure their survival it will be necessary to use fertiliser or sterile compost in order to increase the nutrient level for these later successional species. • Organic matter generated by garden refuse may be used as compost. • Care must be taken when using fertiliser products near sensitive areas such as wetlands, to avoid contamination of these areas. • Organic fertilisers should be used in preference to inorganic fertilisers. • Fertilizer must not be used to establish vegetation on undisturbed coastal dunes. • It is preferable to apply fertilizer during favourable weather and not when heavy rainfall is anticipated, as the nitrogen and phosphate can leach out the soil and contaminate adjacent areas. The fertilizer is also leeched out the root zone of these young plants. .

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Table 6-1: Suitable species to use for dune revegetation.

Moisture Months Common Means of Species Picture require- to be Habitat Notes name planting ments collected GRASSES

Lolium Rye grass H P - All mobile This is a widely grown grass used for pastures, perenne sands as a sports fields etc. To be used as an initial cover cover crop crop, which will improve soil nitrogen levels, but will die out in the first year.

Ehrharta Pipegras L P, S Oct-Dec Foredunes; Good in mobile sands. Indigenous equivalent to villosa areas with Marram grass but not as aggressive. More mobile sand. common in the Eastern Cape. In the Western Blowouts. Cape Elymus distichus seems to occupy its niche more effectively, but the species is still suitable. Will die out once sand becomes stabilised.

Elymus Sea L S Sep-Nov Foredunes; As above, but in addition this species is very distichus wheat areas with common in the study site. It appears to be one mobile sand. of the most aggressive pioneers, and is able to Blowouts. colonise disturbed areas. It is therefore highly suitable to use for revegetation.

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Moisture Months Common Means of Species Picture require- to be Habitat Notes name planting ments collected Sporobolus Dune M P - Areas of A low growing sprawling grass similar to kweek. virginicus kweek mobile sand. More suitable in rear dune areas, lower lying Not restricted areas. Suitable to use in parking areas provided to foredunes. it is irrigated. Can tolerate tramping and vehicle movements better than most species. Fairly easily propagated by planting runners.

HERBACEOUS SPECIES Arctotheca Dune L P, S Jan-Dec Incipient In areas close to the high-water mark. This plant populifolia pumpkin foredunes is able to tolerate severe salt spray and sand and movement, and is able to establish incipient hummock foredunes immediately above the high-water dunes mark. It can also be used as a pioneer in open sandy areas within existing vegetation, but will die out once sand become stabilised.

Felicia Blue M P Foredunes Useful groundcover in fairly stable areas. Not aethiopica daisy and rear necessarily suitable on foredunes. Useful dunes ground cover towards the rear of the dunes. Suitable to be planted between woody shrubs as ground cover.

Gazania Daisy M P,S Foredunes Good in foredune areas, but plant behind the rigens var. and rear Arctotheca zone and in slightly more stable uniflora dunes sands. Suitable to plant together with Elymus distichus and Ehrharta villosa.

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Moisture Months Common Means of Species Picture require- to be Habitat Notes name planting ments collected Senecio Dune L S Sep-Jan Foredunes As above, But also suitable in the rear dunes elegans Senecio and rear and as an alternative to Felicia aethiopica. Bi- dunes annual plant

SUCCULENTS

Carpobrotus Hottentot L P, S Foredunes A very good, hardy pioneer groundcover plant edulis fig and rear that is suitable on foredunes and rear dunes dunes alike. Easily propagated from cuttings.

Tetragonia Klappiesb L P - Foredunes A very good, hardy pioneer plant that is also decumbens rak and rear suitable on foredunes and rear dunes alike. It or Tetragonia dunes can be propagated from cuttings. It dominates sp. the foredune in the study area and is regarded as one of the most suitable species to use.

SHRUBS

Osteospermu Bitou L P, S Jun-Jul Rear dunes Excellent shrub that grows well from seed and m monolifera spreads rapidly in open areas. Grows (previously extensively in the study area. Chrysanthem oides monolifera)

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Moisture Months Common Means of Species Picture require- to be Habitat Notes name planting ments collected Myrica Waxberry L P,S - Rear dunes Shrub that can be germinated from seed, but is cordifolia slow growing. The horizontal stems grow along the surface of the dunes.

Searsia Dune L P - Rear dunes Shrub that can be germinated from cuttings. The crenata crowberry horizontal stems grow along the surface of the (previously dunes, and the shrub is very effective at Rhus covering large areas. Grows extensively in the crenata) study area.

Passerina Dune- L S Dec Rear dunes Very good in open areas and as a pioneer dune rigida string forest species, but seeds are slow to germinate.

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6.4 SPECIFIC RECOMMENDATIONS FOR THE WITSAND DUNE

6.4.1 Overall Approach

Preferred Option: It is concluded that rehabilitation of the dune system will only be successful if the entire area is stabilised en-bloc, and not in a piecemeal fashion, in order to achieve a sustainable and self-perpetuating ecosystem. Thus, the overall approach is to stabilise the entire site in year 2 with year 3 focusing on intensive maintenance and year 1 on site and nursery establishment. This will be an expensive exercise, and although not part of the Terms of Reference, a budget cost to achieve successful rehabilitation is provided.

Figure 6-1:The area that will need to be revegetated to successfully stabilise the mobile sands at Witsand.

Rationalised Option: Due to the costs of dune rehabilitation a further option would be to only stabilise the vegetation that is close to the existing Blombos Strandveld thicket (Figure 7.2). The same approach would be adopted in both options.

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Figure 6-2:Reduced area to be revegetated that will hopefully be sufficient to successfully stabilise the mobile sands at Witsand.

Experience gained from the rehabilitation of the Hout Bay dune system (van Eeden, pers com.) indicates that a phased approach is unlikely to work, due to constant variations in surface wind patterns, a shift in dominant summer wind direction towards the north-west, and the sheer expanse of the system. All these factors ensure that there will be continuous sand movement, and in a single strong wind event the volumes of sand moved can be sufficient to cover wind nets by over 1m (van Eeden, pers com.) Furthermore, the maintenance is too difficult and costly if only sections of an area are covered with wind net, as they cannot be lifted in time after strong wind events, and can become completely buried with sand. It is therefore recommended that the entire site must be covered with wind nets in late autumn, just before the winter rains. Before the area has been covered with wind nets, consideration must be given to establishing a borehole, consisting of a pump, tanks, electrical supply and other infrastructure required for the implementation of an irrigation system. Ideally an irrigation system will need to be established along the seaward edge of the rehabilitation area, where allowance must be made to irrigate a 20m wide strip of vegetation. These areas will be exposed to the most sand movement as they take the brunt of the SE winds, and successful plant establishment will require irrigation. An allowance of 1ha under irrigation is required. After wind net establishment, the entire site must be seeded with cheap agricultural seed in May or June. Rye grass is recommended, as it has been used successfully elsewhere, is able to bind the sand, and increases nutrients and soil mycorrhiza in the sand. This all improves the success of indigenous seeding and planting. As Rye grass is an annual it will die back in the summer.

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It is further recommended that Marram Grass is not used, as it needs to be planted at a density of 6 plants per m2, and this comes with significant costs. The sand movement in the area will hopefully not require an aggressive pioneer species such as Marram, as the indigenous plants under irrigation should cope. Marram is also a Category 3 plant under NEM:BA Alien and Invasive Species List and a permit for its use is required.

6.4.2 Dune Re-Vegetation – Specific Recommendations

Construct plant nursery and site establishment: The following activities will be required prior to initiating any actual rehabilitation or revegetation activities on the dune field:

➢ Construct a plant nursery ➢ Construct a site office ➢ Establish a borehole ➢ Install irrigation infrastructure (pumps, tanks, electrical supply etc.) ➢ Establish a secure area at site with security fencing, guard hut and toilet.

It is recommended that the propagation nursery be established on land close to the only house located to the east of Galjoen Street. A containerised site office and store area will be required and this should be contained together with the irrigation infrastructure and water tanks within a fenced secure area. A borehole will need to be established close to this site office, or access to the main water is a further source of irrigation water. Wind-nets will need to be placed across the entire site, as the entire area is exposed to strong winds and active sand movement. Ongoing maintenance of wind nets will be required until adequate vegetation cover is achieved. Wind-nets must be constructed from porous materials such as shade cloth and be orientated parallel to the HWM in a NE SW orientation. They need to be placed at 5m intervals, and the budget allows for this. The nets, supplied by both Alnet (Pty) Ltd and Knittex (which is part of the Multiknit (Pty) Ltd group of companies), come in 225 m long rolls, are 750 mm high, and have stitched sleeves spaced every 2.5 m for 1.2 m x 10 mm steel droppers1 to be inserted and pushed into the ground. These can be lifted and maintained after major wind storms and routinely on a 14 day cycle. Seeding: Seeding with indigenous grasses and herbaceous species can be undertaken once the wind nets have been established, but only if the sand surface is sufficiently stable. Table 6-1 list all potentially suitable species that could be used at Witsand, and Table 6-2 provides a list of suitable pioneer species, including grasses, herbs and a few shrubs, that could be established from seed. Seeding at the rate of 50 kg per hectare is required. The seed mix needs to be locally collected, contain no more than 10% of a single species, and no less than 15 species listed in the specifications. In difficult areas, where there is active sand movement and salt spray, the diversity can be reduced and the mix changed to include only the hardy species, as it will take time to establish diversity in these areas.

1 This is the only cost-effective option to use under these circumstances; the droppers are easy to erect and to maintain.

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Planting: Once the sand surface is stable enough, pioneer herbaceous species and woody pioneer shrub species grown in the nursery can be planted out. These plants should be large enough to have been planted up into 4kg bags. This is required to improve vegetation cover and diversity. These must be planted at a density of at least 1 plant per 6,25m2 or 1600 plants per hectare. Suitable species are presented in Table 6-2. If smaller eco-tray plants are used they need to be planted at a density of 1 plant per m2 but due to the active sand movement, it is anticipated that these smaller seedlings will not be suitable. Table 6-2: Suitable pioneer species that could be established from seed

Species kg / ha Amellus tenuifolius 3 Anthospermum aethiopicum 2 Arctotheca populifolia 2 Athanasia trifurcata 3 Carpobrotus edulis seeds 3 Cadoraphis cyperoides 3 Didelta camosa var. tomentosa 1 Disphyma crassifolium 1 Ehrharta villosa 5 Helichrsum revolutum 2 Jancus kraussii 2 Lycium ferocissimum 1 Metalasia muricata 2 Oncosiphon grandiflorum 3 Oncosiphon suffruticosum 3 Pelargonium sp 1 Searsia glauca 3 Tetragonia decumbens 2 Thinopyrum distichum 3 Trachyandra ciliafa 2 Osteospermum moniliferum (was Chrysanthemoides monolifera) 3 Total per hectare 50

Brushwood packing: Brushwood packing is not recommended for this site as the branches get entangled with the nets, it is more costly than wind nets and is not required if wind nets are used. Irrigation: To improve the success of vegetation establishment and rehabilitation an irrigation system should be established. It is recommended that the seaward 20m strip be irrigated, as it will be too costly to irrigate the entire site. A permanent borehole will need to be sunk on the site which will provide adequate and suitable water for this project. Irrigation is required to assist with the watering of plants in the early stages of their establishment, so they can evade moisture stress during their establishment period. It greatly increases the survival rate of planted seedlings.

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6.4.3 Budget Estimates

The budget is based on current costs obtained from the rehabilitation programme at Hout Bay, and considers all costs to achieve the rehabilitation programme explained in Sections 5.3 above. The rates used are commercial rates that include overheads and profit, and assume that no work will be done internally by the municipality, or from the Working for the Coast programme. The costs are detailed in Table 6.3 below. The total cost for the preferred option is R2,908,258.00, and the total cost per hectare, including all CAPEX items, preliminaries & general and a 5% contingency is R714,599.00. These costs are accurate to within 25%, and this cost per hectare is on the high side as the stabilisation of an active dune field in an area exposed to strong winds requires a concerted effort and the installation of an irrigation system. The hectare rate is also elevated because the site is relatively small and the capital costs are significant. If the reduced area of 1,77ha is rehabilitated the total cost will be R1,948,941.00, and the total cost per hectare R1,101,096. Any successful rehabilitation of the Witsand dune system will therefore require expenditure well in excess of R2m, with approximately 25% this amount being spent annually on maintenance for the first few years. Table 6-3: Costs for all items required to implement the rehabilitation programme

Activity Unit Unit rate Area Quantity Cost Rehabilitation & revegetation costs Provide and install wind nets Meters R12,78 4,07 2250 R117 032,85 Ongoing maintenance of wind nets year 1 Meters R2,50 4,07 2250 R22 893,75 Provide and spread suitable dune seed mixture hectare R42 780,00 4,07 R174 114,60 Provide suitable dune plants in 4 kg bags Plants R32,00 4,07 1600 R208 384,00 Plant out dune plant Number R3,60 6512 R23 443,20 Irrigation reticulation (southern edge of site only) sqm R35,00 10 000,00 R350 000,00 Security guards Month R66 000,00 2 R132 000,00 Labour to propagate and stage plants (10 labourers, 12 mnths) man- months R7 087,50 120 R850 500,00 Horticulturist Man- days R4 000,00 20 R80 000,00 Restoration ecologist Hrs R1 250,00 80 R100 000,00 Sub-total R2 058 368,40 Cost per hectare R505 741,62 Once-off CAPEX costs. Year 1 only Establish borehole sum R120 000,00 Security fencing, guard hut and toilet Sum R100 000,00 Electrical installation Power point R75 000,00 1 R75 000,00 Cable to well field 1 m deep installation meter R375,00 50 R18 750,00

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Activity Unit Unit rate Area Quantity Cost Install 10,000l Jojo Tanks No R22 000,00 4 R88 000,00 Nursery set-up costs sum R125 000,00 Sub-total R526 750,00 Total R2 585 118,40 Add Contingency 5% Sum R129 255,92 Add Preliminaries and Generals (7,5%) Sum R193 883,88 TOTAL R2 908 258,20 Total cost per hectare (including CAPEX and P&G's) R714 559,75

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7 CONCLUSIONS

The following main conclusions are drawn: ➢ The dune system is supplied by sand from the river mouth and the sand spit and there is active sand movement all year round. ➢ The area has consisted of mobile dunes for at least the last 75 years. ➢ The dominant winds are southerly and south-westerly, and sand migration is north eastwards. ➢ Properties and infrastructure have been established north-east of the dune field, and hence these areas are subject to the negative effects of this natural sand movement, as there are located in a sand corridor. ➢ The area has an irregular topography, including deflation basins and complex slip- faces, which is indicative of an area exposed to strong winds and ongoing sand movement. ➢ This complexity of sand movement presents challenges to the revegetation of an extensive dune system such as this. ➢ Two transects from 2012 were compared to the same two transects from 2020, but the variability in sand movement does not allow for quantification of sand movement. However, generally the transects have retained a very similar profile. ➢ The dune is unvegetated, with only a few vegetated hummock dunes and a well vegetated dune edge. Which is part of the relic dune system. This is vegetated with Blombos Strandveld. ➢ Limited revegetation has taken place but sand has been removed from critical areas in the site. ➢ To be successful then entire area defined in the study should be revegetated after the sand has been removed from certain areas. ➢ Wind nets should be used to temporality stabilise the sand and the area planted with the cover crop of rye grass, and then sown with indigenous seeds. ➢ It should also be planted with indigenous vegetation at the density of that least 1600 is plants per hectare. ➢ The outer southern boundary of the revegetation site should be irrigated, as this area will be subject to the greatest amount of sand movement. ➢ Owing to the costs, consideration can be given to stabilising a smaller area as described in the report (Figure 6-2).

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8 REFERENCES

Barwell, L & Associates. 2015. Updated management plan for the Pringle Bay beach and adjacent dune area. Prepared for Overstrand Municipality and the Pringle Bay Ratepayers Association. October 2015.

CES 2012 Environmental Management and Rehabilitation Plan for the Stabilisation of the Witsand Dunes, Breede River Mouth. Coastal and Environmental Services, Gramhamstown 2012.

City of Cape Town (2017) Maintenance Management Plan: Dune and Beaches, Environmental Management Department. CSIR (1983). Estuaries of the Cape. Part 2. Synopses of available information on individual systems. Breë (CSW 22). Stellenbosch, South Africa. CSIR Report No 21. 58pp. CSIR, 2014. Updated Management Plan for Lappiesbaai Beach and adjacent area at Stillbaai. CSIR Contract Report. January 2014. Goschen, 2011 Goschen, W. (2011). Coping with sea level rise and storm surges. South African Environmental Observation Network: eNewsletter April 2011. http://www.saeon.ac.za/enewsletter/archives/2011/april2011/doc08. Government Gazette Republic of South Africa. National Environmental Management: Biodiversity Act, 2004 (Act No. 10 Of 2004) Alien and Invasive Species Lists, 2016 Government Gazette Republic of South Africa. Vol. 401: National Environmental Management Act 107 Of 1998. Government Gazette Republic of South Africa. Vol. 524. National Environmental Management:Integrated Coastal Management Act, No. 24 Of 2008 Hessequa 2014. Addendum to the Environmental Management Plan: Witsand Dune Stabilisation Program Mather AA, Garland GG and Stretch DD, 2009. Southern African sea levels: corrections, influences and trends. African Journal of Marine Science 2009, 31(2), ISSN 1814–232X EISSN 1814–2338 Meteoblue, 2020. Witsand Weather, Climate and Wind Data. Online: www.meteoblue.Com Mucina L, Rutherford MC, eds. 2006. The vegetation of South Africa, Lesotho and Swaziland. Pretoria, South Africa: SANBI Nicholls RJ and Cazenave A, 2010. Sea-Level Rise and Its Impact on Coastal Zones. Science 328, 1517 (2010);DOI: 10.1126/science.1185782 SA Explorer, 2017.Weather and Climate of Witsand. Online: Www.saexplorer.Co.Za/South- Africa/Climate/Witsand_Climate.Asp South African National Biodiversity Institute (2006-2018). The Vegetation Map of South Africa, Lesotho and Swaziland, Mucina, L., Rutherford, M.C. and Powrie, L.W. (Editors), Online, http://bgis.sanbi.org/Projects/Detail/186, Version 2018

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Tinley, KL. 1985. Coastal dunes of South Africa. National Scientific Programmes Unit: CSIR, SANSP Report 109. Wong, et. al. 2014 Wong, PP; Losada, IJ; Gattuso, JP; Hinkel, J; Khattabi, A; McInnes, KL; Saito, Y and Sallenger, A. (2014) Coastal systems and low-lying areas. In: Climate Change 2014: Impacts, Adaptation, and Vulnerability. Part A: Global and Sectoral Aspects. Contribution of Working Group II to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Field, CB; Barros, VR; Dokken, DJ; Mach, KJ; Mastrandrea, MD; Bilir, TE; Chatterjee, M; Ebi, KL; Estrada, YO; Genova, RC; Girma, B; Kissel, ES; Levy, AN; MacCracken, S; Mastrandrea, PR and White, LL

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APPENDIX 1 – Transects

Figure 1A: Elevation profiles of transects 1 and 4 from the 2012 CES study.

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Figure 1B: Elevation profiles of each transect, extracted from the 2020 digital elevation model

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