Aquatic Ecological Specialist Assessment for the Proposed Upgrades to the Cape Flats Wastewater Treatment Works Including a New Access Road, Cape Town

AQUATIC ECOLOGICAL SPECIALIST ASSESSMENT FOR THE PROPOSED UPGRADES TO THE CAPE FLATS WASTEWATER TREATMENT WORKS INCLUDING A NEW ACCESS ROAD, CAPE TOWN

APRIL 2021

Prepared for:

Prepared By:

Ms Toni Belcher and Dana Grobler

PO Box 455, Somerset Mall, 7137

Tel: (021) 851 0555

Email: [email protected] Page | ii

EXECUTIVE SUMMARY

The potential for the new access road to serve as a multipurpose access road serving not only the WWTW but also the False Bay Nature Reserve (FBNR) and Pelican Park Phase 2 housing development was identified. The access road route alternatives identified are:

• Option 1 and Option 2 which share an access point with the Coastal Park Landfill site and access the WWTW from the west;

• Option 3 and Option 4 which will access the site via Strandfontein Road (from the east) and transverse portions of the FBNR;

• Option 5 which will traverse the proposed (PPP2) housing development (north-east of the WWTW) and serve as a multipurpose access road to the WWTW and FBNR; and

• Option 6 which is a refinement of Option 5 and is the final preferred route.

Access route alternatives were initially assessed for Options 1 and 2 above only (BlueScience, 2019). This freshwater assessment is an update of that original assessment report to include the additional access routes proposed to the works in terms of their potential freshwater impacts. The following aquatic features occur within the study area:

• Zeekoevlei Canal that would need to be crossed by some of the proposed access road alternatives (Options 1 and 2);

• Cape Flats Wastewater Treatment Works (WWTW) associated ponds and water bodies that would need to be crossed for all of the alternative access roads proposed; and

• Dune slack wetland areas to the north-west and east of the WWTW, along all of the alternative access roads proposed.

The entire False Bay – Zeekoevlei Nature Reserve in which the WWTW occurs is a formally protected area. The dune slack wetlands to the east and north of the WWTW are mapped as aquatic CBAs and the surrounding areas of natural vegetation cover mapped as terrestrial CBAs. The wetland habitats associated with the ponds in the WWTW are mapped as Critical ESAs. The wetlands associated with the ponds in the WWTW are also all mapped as artificial Freshwater Ecosystem Priority Area (FEPA) Wetlands while Zeekoevlei and the Zeekoevlei Channel are mapped as natural FEPA Wetlands.

The instream and riparian habitat integrity of the Zeekoevlei Canal is considered to be largely to seriously modified. This is largely due to the flow and water quality-related impacts on the watercourse. The duneslack wetland areas are in general still in a largely natural ecological state.

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The duneslack wetlands that are closer to the WWTW and the urban areas are more disturbed and range from being moderately to largely modified depending on the level of disturbance taking place.

Zeekoevlei is in a largely natural to moderately modified ecological state as a result of surrounding land use activities while the Cape Flats WWTW primary ponds which are artificial features can be considered to be seriously modified from a desired ecological state point of view. It should be noted that the ponds in the WWTW have been specifically created to treat wastewater although they do provide habitat for aquatic life.

The Zeekoevlei Canal is considered to be of moderate to low EIS. Due to its artificial and degraded condition, the watercourse is not likely to contain any intolerant species however it does provide refuge and a corridor for the movement of biota in a transformed landscape. Zeekoevlei as a large and still largely natural wetland area is of high ecological importance and sensitivity, while the largely natural duneslack wetlands are considered of Moderate to High EIS. The artificial WWTW ponds and degraded duneslack wetlands are considered of a low EIS.

The proposed BBF is likely to have a very low to insignificant impact on the adjacent degraded and artificial wetland habitat within the footprint of the WWTW, provided the construction works are contained to the indicated footprint and good housekeeping measures are implemented and monitored in terms of the Environmental Management Plan for the project.

It can be expected that the likely impacts of the proposed new access road for Options 1 and 2 would be of a limited extent and a short-term nature, occurring mostly during the construction phase. Over the longer term, one can expect a limited impact arising from the use and maintenance of the road. Longer-term impacts could also be expected as a result of increased traffic through the ponds. Some of this traffic does already make use of the existing route which occurs adjacent to the more ecologically important Zeekoevlei. This impact would, however, be more of significance for Option 1, given the higher bird populations that usually frequent the southern portions of the WWTW.

Option 3 is located in the southern end of a largely natural dune field and dune slack wetland area to the east of the WWTW. The route is proposed to be immediately north of Pelikan Heights, following the access road to the suburb and then an already modified area and jeep track to the WWTW eastern boundary fence road northwards and then into the WWTW site past some disturbed and largely artificial wetland areas. This route largely avoids any of the mapped wetlands and will have a potential low significance impact on the adjacent wetlands with mitigation.

Options 4, 5 and 6 cross several moderately disturbed and then largely natural duneslack wetlands before entering the property of the WWTW from the east and passing some disturbed and largely artificial wetland areas. These routes can be expected to have a potential high significance impact on the wetlands in the area, even with mitigation as the road will need to alter the topography and surface as well as sub-surface flow through the area as well as provide an access point for further disturbance, dumping of waste and potential development of the area. Should one of these access routes be considered, it would need to be done in conjunction with the approved development layout for Pelican Park Phase 2, given that the faunal, botanical and aquatic specialist studies for this proposed development have also identified the central dune and duneslack habitats as being of Medium to High Conservation Value.

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Summary of aquatic impact significance:

Construction Phase: Impact Consequence Probability Significance Status Confidence Without Very low Probable VERY LOW -ve High Mitigation With Very low Possible INSIGNIFICANT -ve High

Mitigation Option 1 Option

Without Very low Probable VERY LOW -ve High

2 Mitigation With Very low Possible INSIGNIFICANT -ve High

Mitigation Option Option

Without Very low Probable VERY LOW -ve High

3 Mitigation With Very low Improbable INSIGNIFICANT -ve High

Mitigation Option Option Without High Probable HIGH -ve High Mitigation With Medium Probable MEDIUM -ve High

ption 4 ption Mitigation O

Without High Probable HIGH -ve High

5 Mitigation With Medium Probable MEDIUM -ve High

ption ption Mitigation O

Without High Probable HIGH -ve High 6 Mitigation

ption ption With Medium Probable MEDIUM -ve High

O Mitigation

Operation Phase: Impact Consequence Probability Significance Status Confidence Without Very low Probable VERY LOW -ve Medium/ High Mitigation With Very low Improbable INSIGNIFICANT -ve Medium/ High

Mitigation Option 1 Option

Without Very low Probable VERY LOW -ve Medium/ High

2 Mitigation With Very low Improbable INSIGNIFICANT -ve Medium/ High

Mitigation Option Option

Without Very low Probable VERY LOW -ve Medium/ High

3 Mitigation With Very low Improbable INSIGNIFICANT -ve Medium/ High

Mitigation Option Without High Definite HIGH -ve Medium/ High Mitigation With Medium Probable MEDIUM -ve Medium/ High

ption 4 ption Mitigation O

Without High Definite HIGH -ve Medium/ High

5 Mitigation With Medium Probable MEDIUM -ve Medium/ High

ption ption Mitigation O

Without High Definite HIGH -ve Medium/ High 6 Mitigation

ption ption With Medium Probable MEDIUM -ve Medium/ High

O Mitigation Without Very low Possible INSIGNIFICANT -ve Medium/ High

Mitigation

Go With Very low Improbable INSIGNIFICANT -ve Medium/ High -

Mitigation No

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Recommended mitigation measures:

Construction Phase:

• Work within or adjacent to aquatic features should be limited as far as possible and the disturbed areas rehabilitated immediately afterwards;

• The constructed road should result in a minimal alteration to the surrounding natural topography;

• Construction within watercourses should as far as possible take place during the drier months of the year (November to March);

• Contaminated runoff from the construction site(s) should be prevented from entering the watercourses. The laydown area and main construction site should be located at least 20 m away from any aquatic features. All materials on the construction site should be properly stored and contained. Any stockpiling of material should also take place at least 20 m from any aquatic features to reduce the risk of runoff from these areas into the watercourse/wetlands. Disposal of waste from the site and the associated works should be properly managed and responsibly disposed of. Construction workers should be given ablution facilities at the construction works that are located away from the aquatic features (at least 20m) and regularly serviced. These measures should be addressed, implemented and monitored in terms of the Environmental Management Programme for the construction phase;

• The construction of the road along the section of road between the Zeekoevlei Canal and the existing access road to the works must consider subsurface flow at the road in the area of the wetlands to ensure that the road does not significantly impede this flow;

• Where the roads need to cross any of the wetland features, consideration of the surface and sub-surface flow characteristics of that aquatic feature will need to be taken into consideration and mitigated through the use of culverts or permeable road surfaces to minimise the impact of the road on flow as far as possible.

• Excess spoil material should be removed to an approved disposal site;

• Use of materials for the construction works should as far as possible be free of alien invasive plant seed;

• The materials utilised for the constructed road should be obtained from an approved source; and

• Once construction is complete, the area disturbed during construction should be rehabilitated and, where necessary, vegetated with suitable local indigenous plants.

Operation Phase:

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• Any invasive alien plants along the road should be removed on an ongoing basis according to methods as provided by the Working for Water Programme.

The new access road for all of the alternative routes is considered to pose a moderate risk to the adjacent aquatic habitats for the construction and operations phases and thus likely to require a water use licence application. The proposed upgrade for Options 2 and 3 and possibly Option 1 could potentially be reduced to a Low risk with the implementation of the recommended mitigation measures such that these route alternatives could fall within the ambit of the General Authorisations for Section 21(c) and (i) water uses. Due to the requirement to offset wetland loss for Options 4, 5 and 6, a water use licence would be required for these alternatives.

A wetland offset is proposed that would mitigate the potential loss of wetland habitat associated with Options 4. 5 and 6 that would adequately be able to mitigate the loss of wetland habitat that would occur for these proposed routes.

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TABLE OF CONTENTS

EXECUTIVE SUMMARY ...... II 1. SPECIALIST DETAILS, EXPERTISE AND DECLARATION ...... 9

1.1. BACKGROUND AND QUALIFICATIONS OF SPECIALIST CONSULTANT ...... 9 1.2. DECLARATION OF INDEPENDENCE ...... 10 2. INTRODUCTION ...... 11

2.1. BACKGROUND TO STUDY ...... 11 2.2. TERMS OF REFERENCE ...... 13 2.3. METHODS, ASSUMPTIONS AND LIMITATIONS OF THE STUDY ...... 14 2.4. USE OF THE REPORT ...... 15 3. BASELINE DESCRIPTION OF THE CHARACTERISTICS AND AQUATIC FEATURES WITHIN THE STUDY AREA 16

3.1. OVERVIEW OF STUDY AREA ...... 16 3.2. CHARACTERISTICS OF STUDY AREA ...... 18 3.2.1. Visual and Topographical Characteristics ...... 18 3.2.2. Geology and Soil ...... 18 3.2.3. Climate, Hydrology and Geohydrology ...... 19 3.2.4. Flora ...... 21 3.2.5. Aquatic Features ...... 21 3.2.6. Conservation Importance ...... 24 3.2.7. Land use ...... 29 3.3. ASSESSMENT OF FRESHWATER FEATURES AND THEIR SIGNIFICANCE ...... 30 3.3.1. Description of Aquatic Features ...... 31 3.3.2. Characterisation of Aquatic Features ...... 35 3.3.3. Present Ecological Status ...... 37 3.3.4. Ecological Importance and Sensitivity and Ecosystem services ...... 40 3.3.5. Recommended Ecological Category ...... 42 4. LEGISLATIVE AND REGULATORY REQUIREMENTS ...... 43

4.1. NEMA AND ENVIRONMENTAL IMPACT ASSESSMENT REGULATIONS ...... 44 4.2. NATIONAL WATER ACT, 1998 (ACT NO. 36 OF 1998) ...... 44 4.2.1. General Authorisation in terms of Section. 39 of the NWA ...... 44 4.2.2. Regulations Requiring that a Water User be Registered, GN R.1352 (1999) ...... 45 5. ASSESSMENT OF POTENTIAL AQUATIC IMPACTS ...... 45

5.1. DESCRIPTION AND CONSTRAINTS ASSESSMENT OF POTENTIAL AQUATIC IMPACTS OF PROPOSED ACTIVITIES ...... 45 5.1.1 Description of Potential Aquatic Impacts ...... 45 5.1.2. Consideration of the proposed route alternatives ...... 47 5.2. OVERALL ASSESSMENT OF POTENTIAL IMPACTS OF PROPOSED ACTIVITIES ...... 51 5.2.1. Aquatic Habitat Modification or Loss ...... 51 5.2.2. Water Quality Impacts ...... 53 5.2.3. Flow Modification ...... 55 5.2.4. Cumulative impacts ...... 57 5.3. CONSIDERATION OF ALTERNATIVES ...... 59 5.4. IMPACT ASSESSMENT TABLES FOR THE POTENTIAL AQUATIC IMPACTS OF THE VARIOUS PROPOSED ACCESS ROUTES..... 59

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6. RISK ASSESSMENT ...... 61 7. WETLAND OFFSET ASSESSMENT ...... 63

7.1. ASSESSMENT OF WETLAND OFFSET REQUIREMENTS ...... 63 7.2. DESCRIPTION OF PROPOSED WETLAND OFFSET ...... 65 7.3. EVALUATION OF ACCEPTABILITY OF PROPOSED WETLAND OFFSET ...... 65 8. CONCLUSIONS AND RECOMMENDATIONS ...... 66 9. REFERENCES ...... 70 ANNEXURE A: DETAILS OF SPECIALIST AND DECLARATION OF INTEREST ...... 73

DECLARATION OF INDEPENDENCE BY THE INDEPENDENT PERSON WHO COMPILED A SPECIALIST REPORT OR UNDERTOOK A SPECIALIST PROCESS ...... 73 ABBREVIATED CURRICULUM VITAE: ...... 74 APPENDIX B: IMPACT ASSESSMENT METHODOLOGY ...... 75 APPENDIX C. RISK MATRIX FOR THE PROJECT ...... 78 APPENDIX D: LOCATION OF CONTENT PRESCRIBED BY NEMA FOR SPECIALIST REPORTS: APPENDIX 6 OF GN R326 ...... 80

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1. SPECIALIST DETAILS, EXPERTISE AND DECLARATION

1.1. BACKGROUND AND QUALIFICATIONS OF SPECIALIST CONSULTANT

Organisation: BlueScience (Pty) Ltd

Contact details: PO Box 455, Somerset Mall, 7137

Names: Ms A Belcher (SACNASP No 400040/10) and Mr D. Grobler (SACNASP 002272/93)

Profession: Aquatic Ecologists for BlueScience

Expertise: BlueScience (Pty) Ltd provides water resource management services and includes the following:

• Rivers and wetlands scoping and impact assessments; • River rehabilitation plans and implementation; • Wetland rehabilitation plans and implementation; • Water use authorisation applications (WULA); • Biomonitoring or rivers (including macro-invertebrates, fish & water quality); • Water use compliance auditing (internal auditing); • Water use compliance monitoring and reporting for license holders (including water quality sampling and measurements); • Ecological Reserve determination of rivers and wetlands; • River Maintenance and Management Plans (MMP); • NEMBA – alien vegetation assessment and management plans; and • Water resources capacity building and training.

Summary of projects undertaken by BlueScience since July 2012: Type of project Number of projects undertaken Dam developments 82 Other freshwater and freshwater impact assessments 380 River reach MMP 7 ESKOM 34 Renewable energy (WEF and Solar) 30 Roads (Provincial and National roads) 48 River monitoring and rehabilitation projects 58 Water resource study 12 Water use authorisation applications (not linked to a 26 freshwater assessment study) Water use authorisation audits and licensing monitoring 7

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1.2. DECLARATION OF INDEPENDENCE

I, Antonia Belcher, as the appointed Specialist hereby declare that -- General declaration:

• 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 form 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.

Signature of the Specialist:

Name of Company: BlueScience (Pty) Ltd

Date: 16 April 2021

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2. INTRODUCTION

2.1. BACKGROUND TO STUDY

The City of Cape Town (CCT) is proposing to upgrade the sludge handling facility at the Cape Flats Wastewater Treatment Works (WWTW) in Cape Town by replacing the Thermal Drying Plant (TDP) with a Biosolids Beneficiation Facility (BBF). The BBF will treat sludge from the WWTW as well as from Athlone (transported to site via existing pipelines), Mitchells Plain and Wildevoelvlei WWTWs (transported via trucks) to recover essential nutrients and biogas (mostly methane). The biogas will be stored on-site and used to generate electricity to power the BBF and the balance to the neighbouring equipment within the WWTW. To accommodate the transport of sludge from surrounding WWTWs to the BBF, the project will include a new access road. The WWTW was originally commissioned in 1960 but has since been upgraded on several occasions. The site is located adjacent to Zeekoevlei and the False Bay Nature Reserve, as well as the Coastal Park Landfill site (Figure 1).

BBF

Alternatives Option 1 Option 2 Option 3 Option 4 Option 5 Option 6 (preferred)

Figure 1. Aerial view of the Cape Flats WWTW and surrounding land use with the proposed BBF Location and access route alternates shown

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The Cape Flats WWTW facility operates for 365 days a year and is the largest WWTW within the CCT area of jurisdiction. The BBF will beneficiate sludge from the WWTW as well as from Athlone (transported to site via existing pipelines), Mitchells Plain and Wildevoelvlei WWTWs (transported via trucks) to recover essential nutrients and biogas (mostly methane). A new access road to accommodate the transport of sludge by truck is required as the existing access road cannot accommodate this additional traffic. The City has identified the potential for the new access road to serve as a multipurpose access road serving not only the WWTW but also the False Bay Nature Reserve (FBNR) and Pelican Park Phase 2 housing development. The access road route alternatives identified (see Figure 1) are:

• Option 1 and Option 2 which share an access point with the Coastal Park Landfill site and access the WWTW from the west;

• Option 3 and Option 4 which will access the site via Strandfontein Road (from the east) and transverse portions of the FBNR; and

• Option 5 which will follow the southern boundary of the proposed (PPP2) housing development (north-east of the WWTW) and serve as a multipurpose access road to the WWTW and FBNR; and

• Option 6 which is a refinement of Option 5 and is the final preferred route. Option 6 was determined in consultation with the various specialists on the project to try and determine the route with the least potential impact.

Access route alternatives were initially assessed for Options 1 and 2 above only (BlueScience, 2019). This freshwater assessment is an update of that original assessment report to include the additional access routes proposed to the works as well as the development of the BBF in terms of their potential freshwater impacts.

Table 1: Summary of water resources information associated with the proposed activities Descriptor Name / details Notes Water Management Area Berg Olifants WMA Catchment Area Zeekoevlei Quaternary Catchment G22D Present Ecological State (PES) PES: E/F (seriously modified) Dept Water Affairs, 2000 Ecological Importance and Low Quaternary level Sensitivity assessments Water resource component Wetland areas associated with Zeekoevlei potentially impacted Latitude 34° 4'59.57"S Centre of site Longitude 18°30'46.93"E

The study area is located within a wider area considered of Very High Aquatic Biodiversity Sensitivity (Appendix D, after tables). This is due to the Aquatic Critical Biodiversity Areas (CBAs), Freshwater Ecosystem Priority Area (FEPA) Rivers, Wetlands and Estuaries as well as Strategic Water Source Areas occurring in this wider area. The Aquatic CBAs and FEPA mapped features are discussed in Section 3.2.6 of this report. While the road is located in a National Surface Water Strategic Water Source Area (Table Mountain) and a National Groundwater Strategic Water Source Area (Cape Peninsula and Cape Flats), the proposed works for the access road will not impact on these areas as strategic water source areas.

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2.2. TERMS OF REFERENCE

The original Terms of Reference for the freshwater assessment comprised of the following tasks: 1. Site visit and input to guide whether the preferred or alternative route option is more suitable from a freshwater perspective (at that stage only Option 1 and Option 2 were under consideration); 2. Freshwater Impact Assessment (FIA) to form part of the Basic Assessment Process, including a Risk Assessment to guide the Water Use Authorisation process; 3. Water Use Licence Application (WULA) and associated documentation; and 4. Any guidance or input into the project in light of the Ramsar status of the site, which includes the maturation ponds.

The following Terms of Reference apply to this Updated FIA: • Review Pelican Park Phase 2 (PPP2) freshwater ecology specialist baseline study to inform the assessment of the additional access routes; • Undertake a site visit to ground truth sensitivities not already ground-truthed by the PPP2 specialist; • Amend the FIA Report to: o Reflect the current Environmental Impact Assessment process; o Make reference to the BBF, if not already included; o Expand the baseline and impact assessment to include the additional access routes from the east (Options 3, 4 and 5); o Align with SRK’s standard reporting and impact assessment rating methodology; • Update (where relevant) the report following a single review by SRK (with input from the project team); and: • Provide high-level input into issues and responses reports compiled following the three stakeholder engagement periods (pre-application, scoping and impact assessment).

The following additional tasks were included to the appointment, following the need to include the final preferred route (Option 6) in the specialist assessment: • Update existing FIA to reflect Route 6; • Site meeting and discussion with D Gibbs (City of Cape Town Biodiversity Branch) regarding potential wetland offset; • Undertake wetland offset calculation and include wetland offset recommendations in FIA; • Manage the Water Use Licence Application process including the following tasks: o Lodge an application on the online eWULA system; o Complete online application; o Undertake a site meeting with the Department of Water and Sanitation (DWS); o Collate and upload DWS required water use application information; and o Follow up on progress with the application.

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2.3. METHODS, ASSUMPTIONS AND LIMITATIONS OF THE STUDY

Input into this report was informed by a combination of desktop assessments of existing aquatic ecosystem information for the study area and catchment, as well as by a more detailed assessment of the aquatic ecosystems on site. In particular, the Freshwater Ecology Assessment was undertaken by EverWater for the Pelican Park Phase 2 housing development in August 2018 was reviewed for consideration of the additional access route alternatives.

The site was visited in September 2019, for a single day. As the site was visited immediately following the winter season, it was possible to detect seasonal wetland areas on site. The timing of the site visit is therefore not considered to be a limiting factor of this assessment. A second site visit was undertaken for a single day in July 2020 to assess the aquatic features associated with the additional routes under consideration. This assessment was undertaken in the winter rainy season and was ideal for the delineation and assessment of the aquatic habitats. A third site visit was undertaken in January 2021 to assess Option 6 route alternative and consider the proposed wetland offset area.

During the field visits, the characterisation and integrity assessment of the aquatic features was undertaken. Mapping of the freshwater features was undertaken using a Garmin Colorado 300 GPS and mapped in PlanetGIS and Google Earth Professional. The SANBI Biodiversity GIS and CapeFarmMapper websites were also consulted to identify any constraints in terms of fine-scale biodiversity conservation mapping as well as possible freshwater features mapped in the Freshwater Ecosystem Priority Areas (FEPA) maps. This information/data was used to inform the resource protection-related recommendations.

Limitations and uncertainties often exist within the various techniques adopted to assess the condition of ecosystems. The following techniques and methodologies were utilised to undertake this study: • The guideline document, “A Practical Field Procedure for the Identification and Delineation of Wetlands and Riparian Areas” document, as published by Department of Water Affairs and Forestry (2005) was followed for the delineation of the riparian and wetland areas. • The wetlands were subsequently classified according to their hydro-geomorphic determinants based on a classification system devised by Kotze et al (2004) and South African National Biodiversity Institute (SANBI) (2009). Notes were made on the levels of degradation in the wetlands based on field experience and a general understanding of the types of systems present. • A Present Ecological State (PES) was conducted for the wetlands identified and delineated within the study area. • The functional wetland assessment technique, WET-EcoServices, developed by Kotze et al (2009) was used to indicate the ecological benefits and services provided by delineated wetland habitat. • The ecological importance and sensitivity (EIS) assessment was conducted according to the guidelines as developed by DWAF (1999).

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• Recommendations are made with respect to the adoption of buffer zones using the Department of Water and Sanitation (DWS) river and wetland buffer tool. • Lists of plants, both alien and indigenous are to describe the general and dominant habitat conditions and not comprehensive. A comprehensive botanical survey was thus not conducted as part of this freshwater assessment. • The impact assessment was undertaken as per the methodology outlined in Appendix B of this report.

The level of aquatic assessment undertaken was considered to be adequate for this study.

2.4. USE OF THE REPORT

This report reflects the professional judgment of its authors. The full and unedited content of this should be presented to the client. Any summary of these findings should only be produced in consultation with the authors.

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3. BASELINE DESCRIPTION OF THE CHARACTERISTICS AND AQUATIC FEATURES WITHIN THE STUDY AREA

3.1. OVERVIEW OF STUDY AREA

The Cape Flats WWTW and the proposed access routes lie within the lower reaches of the catchment of the Zeekoe/Lotus River and Zeekoevlei system which are situated in the southern region of the City of Cape Town (quaternary catchment G22D). The catchment is in general located within the low-lying Cape Flats and a large portion is underlain by the Cape Flats Aquifer. As a result, there are a large number of vleis within the catchment, including Rondevlei, Princessvlei and Zeekoevlei (Figure 2).

The Zeekoe/Lotus River consists largely of several artificially created canals which serve to drain this low-lying area. Due to the amount of high-density residential development in the upper to middle reaches of the catchment, the water quality, as well as ecosystem health of this system, is poor to very poor. Water hyacinth (an invasive aquatic weed) has invaded much of the system and clogs most of the canals as well as ponds within the Cape Flats WWTW.

The proposed project is located largely within the existing footprint of the Cape Flats WWTW which is located within the FBNR. The FBNR also includes the Zeekoevlei and Rondevlei Reserves, as well as the Strandfontein pans. Although the Cape Flats WWTW is not a natural wetland, the ponds at the Works are considered to be one of the ten most important habitats for wetland birds in South Africa. More than 200 waterbird species have been recorded at this site and include African Fish Eagles, flamingos, pelicans and many types of ducks. Up to 230 different species of birds have also been sighted at Rondevlei.

Zeekoevlei, to the north of the treatment works, was proclaimed a local authority nature reserve in June 2000 and is one of the youngest conservation areas in Cape Town. Zeekoevlei is surrounded by low coastal dunes with Cape Flats thicket on alkaline sands in the south and transitional sand plain fynbos in the north. According to the City of Cape Town’s Biodiversity Network Prioritisation Project:

• Cape Flats Sand Fynbos is critically endangered and hardly protected

• Cape Flats Dune Strandveld is endangered and poorly protected

• Cape Lowland Freshwater Wetlands are vulnerable and poorly protected and are critically endangered.

Most of the fish in Zeekoevlei are alien species, e.g. Banded Tilapia (Tilapia sparrmanii), Common Carp (Cyprinus caprio) and Sharp Toothed Catfish (Clarius gariepinus). The only indigenous fish species that remains in the Zeekoevlei is the Cape Galaxias (Galaxias zebratus). In addition, the endangered Western Leopard Toad, Bufo pantheris, Clicking Stream Frog (Strongylopus grayii), Arum Lily Frog (Hyperolius horstockii) and Common Platanna (Xenopus laevis) are known to occur in the area.

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Proposed BBF site

Cape Flats WWTW

Figure 2. Topography map (3418AB&BA) of the study area and the proposed access route alternates

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3.2. CHARACTERISTICS OF STUDY AREA

3.2.1. VISUAL AND TOPOGRAPHICAL CHARACTERISTICS

The area immediately surrounding the BBF consists primarily of the large maturation ponds associated with the WWTW. These ponds support a varied aquatic habitat depending on the level of disturbance they receive. Associated with this is the importance of that habitat for biota and in particular birdlife. The other significant features in the landscape that are adjacent to the site, are the previously mentioned Zeekoevlei and Rondevlei waterbodies to the north of the site and the Coastal Park Landfill site to the west of the WWTW. Increasing urban development at Pelican Park occurs to the east.

In the remaining open areas adjacent to the WWTW, flat or slightly undulating landscape (less than 5 m to more than 20 m above sea level), either containing vegetated dune fields from a drier, windier recent past, or a more subdued landscape further inland. The parabolic dunes tend to run northwest to southeast and are largely still vegetated with False Bay Dune Strandveld. The dune slacks often contain seasonal wetlands that are inundated to varying degrees. Where the landcover has been degraded, weedy and often alien invasive plants such as Port Jackson willows (Acacia saligna) occur.

Figure 3. A view of the landscape on the eastern side of the Cape Flats WWTW

3.2.2. GEOLOGY AND SOIL

The study area consists largely of Tertiary or Recent calcareous sands of marine origin, mainly blown in as sand dunes. These overlie mainly sedimentary deposits of Cenozoic age, deposited on impervious bedrock comprising of older granites of the Cape Granite suite and shales of the Malmesbury Group. The deposits underlying the eastern portion of the study area consist of

Aquatic Ecological Assessment: New Access Road to Cape Flats WWTW April 2021 Page | 19 calcareous sands from the Witzand formation of the Sandveld Group while the western portion comprises of aeolian quartzitic sands of the older Springfontein formation.

In the Broad Soils Classification of Environmental Potential Atlas of South Africa (ENPAT), the soils in the wider coastal zone area within which the access roads are proposed (grey area in Figure 5) consist of imperfectly drained greyish sandy soils, while further inland (brown areas in Figure 5) the soils are of restricted depth with low natural fertility, sandy texture and leached with an accumulation of organic material and aluminium.

3.2.3. CLIMATE, HYDROLOGY AND GEOHYDROLOGY

The area has a Mediterranean climate and normally receives about 600mm of rain per year, mostly during winter. It receives the lowest rainfall (16mm) in February and the highest (155mm) in June (left, Figure 4). Many of the artificial wetlands in the study area are permanently inundated but, except for the larger Zeekoevlei and Rondevlei Wetlands in the area, the wetlands are seasonally inundated wetlands that tend only to be inundated in winter, during the period April/May to October.

The winter rains are accompanied by strong north-westerly winds while winds are southerly or south-easterly in summer. The monthly distribution of average daily maximum temperatures shows that the average midday temperatures range from 15.7°C in July to 26°C in February (right, Figure 4). Prevailing winds are south-easterly during the summer and north-westerly during the winter.

Figure 4. Average monthly rainfall and temperatures (SA Atlas of Climatology and Agrohydrology (2009, R.E. Schulze) obtained from CapeFarmMapper, October 2019

The Cape Flat Aquifer that occurs within sandy deposits of the study area has been classified by the DWS as a major, intergranular aquifer with an average yield of 2 l/s to 5.0 l/s of good quality water. The groundwater quality according to the electrical conductivity (EC) for the regional aquifer underlying the site has been classified as average with an EC of 70 – 300 mS/m (increasing from east to west). The shallow, unconfined nature of the aquifer as well as a high recharge (+ 90 mm/a), make the aquifer vulnerable to contamination from surface activities, of which there are many in the area. The average depth of the aquifer is about 5 m to 5.5 m below ground level.

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Alternatives Option 1 Option 2 Option 3 Option 4 Option 5 Option 6 (preferred)

Figure 5. Soil map for the area (Source: ENPAT Soil descriptions for the Western Cape, obtained from CapeFarmMapper, July 2020)

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3.2.4. FLORA

The mapped natural vegetation type surrounding Cape Flats WWTW is broadly classified as Cape Flats Dune Strandveld (blue area in Figure 6) which is considered to be an Endangered vegetation type. The typical characteristic of the vegetation type is described by Mucina et al, 2006 as tall, evergreen, hard-leaved shrubland with abundant grasses and annual herbs in gaps. While some of the dunes surrounding the WWTW are still undisturbed, the cover vegetation within the footprint of the works as well as the adjacent developed areas have been almost completely modified and contains a moderate to a high infestation of alien plants such as kikuyu grass (Pennisetum clandestinum) and Port Jackson willows (Acacia saligna). Other natural terrestrial vegetation types in the area consist of Cape Seashore Vegetation (green area in Figure 7) which is considered a Least Threatened vegetation type. Cape Lowland Freshwater Wetland vegetation is associated with Zeekoevlei and a small estuarine area at the mouth of the Zeekoevlei Canal (grey areas in Figure 7).

Vegetation associated with the wetter areas within the study area (Zeekoevlei Canal and the ponds within the WWTW) is dominated by bulrush Typha capensis and with some arum lilies Zantedeschia aethiopica. The exotic aquatic weed, water hyacinth Eichornia crassipes, proliferates in some of the ponds of the WWTW with exotic grasses occurring along the banks (mostly kikuyu grass). Indigenous vegetation still occurring that is associated with the duneslack areas adjacent to the site comprises largely of Senecio halimifolius, Imperata cylindrica, Zantedeschia aethiopica and Ficinia nodosa with Osteospermum moniliferum, Metalasia muricata, Searsia spp., Euclea racemosa, Chondropetalum tectorum and Carpobrotus edulis occurring on the margins. Helme (2018) in a botanical study for the adjacent proposed Pelican Park 2 housing development also observed Psoralea aphylla and Cliffortia longifolia (Species of Conservation Concern, both being regarded as Vulnerable) within the duneslack wetlands to the east of the WWTW.

3.2.5. AQUATIC FEATURES

The Cape Flats WWTW and the proposed access routes lie within the lower reaches of the catchment of the Zeekoe/Lotus River and Zeekoevlei System within quaternary catchment G22D. Aquatic features in the larger study area consist of the ponds associated with the Cape Flats WWTW and the Zeekoevlei Canal to the west of the WWTW (Figure 8). Zeekoevlei is located to the north of the study area and further to the east of the WWTW are isolated dune slack wetlands within the dunes of Strandfontein.

The features within the WWTW are highly impacted or artificial. Zeekoevlei just north of the WWTW is however considered to be the largest natural inland water body in the City of Cape Town and is an important recreational area. There are however several largely natural wetland dune slack areas within the Dune Strandveld immediately adjacent to the WWTW particularly to the east of the WWTW.

These features are discussed in more detail in the following section.

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Alternatives Option 1 Option 2 Option 3 Option 4 Option 5 Option 6 (preferred)

Figure 6. Vegetation types for the study area (Source: 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, obtained from CapeFarmMapper, July 2020

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Alternatives Option 1 Option 2 Option 3 Option 4 Option 5 Option 6 (preferred)

Figure 7. Aerial imagery from 2018 with the wetland features in the study area as mapped on the City of Cape Town Biodiversity Network and the drainage through the area (City of Cape Town Map Viewer, July 2020)

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3.2.6. CONSERVATION IMPORTANCE

Three sets of conservation mapping at a local, provincial and national scale are of relevance to the identification of aquatic features of ecological and biodiversity conservation importance. These are the latest City of Cape Town Biodiversity Network (BioNet) Map, the 2017 Western Cape Biodiversity Spatial Plan (WCBSP) and the National Freshwater Ecosystem Priority Areas (FEPA).

The BioNet and the WCBSP maps aim to guide sustainable development by providing a synthesis of biodiversity information to decision-makers. The WCBSP was undertaken for the province as a whole, however, the City's BioNet maps replaced the provincial mapping as a more appropriate planning tool for the area, reconciling the BioNet categories and spatial products with the WCBSP categories and products and included therein. The maps indicate areas of land as well as aquatic features which must be safeguarded in their natural state if biodiversity is to persist and ecosystems are to continue functioning. The main map categories are Critical Biodiversity Areas (CBAs) (Terrestrial and Aquatic), Ecological Support Areas (ESAs) (Critical and Other), Other Natural Remaining Areas and No Natural Remaining Areas. The first two mentioned categories represent the biodiversity priority areas which should be maintained in a natural to a near-natural state. The last two mentioned categories are not considered as priority areas and a loss of biodiversity within these areas may be acceptable.

In the City BioNet Map (Figure 8), the dune slack wetlands to the east and north of the WWTW are mapped as aquatic CBAs and the surrounding areas of natural vegetation cover mapped as terrestrial CBAs. The adjacent more disturbed terrestrial vegetation to the east and west (at the landfill site) of the WWTW is mapped as terrestrial ESAs: Irreversibly Modified Site of Conservation Significance that should preferably not be developed but rather maintained as open space and rehabilitated where possible. The wetland habitats associated with the ponds in the WWTW are mapped as Critical ESAs. From a freshwater perspective, it is important that the proposed works do not impact on the ecological condition of the CBAs or reduce the ecological functionality of the ESAs.

The 2017 WCBSP has the entire False Bay – Zeekoevlei Nature Reserve in which the WWTW occurs mapped as a formally protected area (Figure 9). The footprint of the buildings of the WWTW and some surrounding area, extending to the east is excluded from the protected area but is mapped as a combination of terrestrial and aquatic CBA where intact dunes and duneslack wetlands occur. The landfill site and the remainder of the footprint of the WWTW excluded from the protected area are mapped as ESA that needs rehabilitation.

FEPAs are intended to provide strategic spatial priorities for conserving South Africa’s freshwater ecosystems and supporting the sustainable use of water resources. FEPAs were determined through a process of systematic biodiversity planning and were identified using a range of criteria for serving ecosystems and associated biodiversity of rivers, wetlands and estuaries. The river and wetland FEPAs are required to be maintained in a largely natural ecological state while Fish Support Areas should not be allowed to degrade from their existing ecological condition. The wetlands associated with the ponds in the WWTW are all mapped as artificial FEPA Wetlands while Zeekoevlei and the Zeekoevlei Channel are mapped as natural FEPA Wetlands (Figure 10). FEPA Wetlands were also mapped within the landfill site that was associated with the Zeekoevlei Channel but has since been lost. The site is not located within a River FEPA sub-catchment (Figure 11).

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Figure 8. City of Cape Town Biodiversity Network Mapping for the area (Source: SANBI BiodiversityGIS, July 2020)

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Alternatives Option 1 Option 2 Option 3 Option 4 Option 5 Option 6 (preferred)

Figure 9. Western Cape Biodiversity Spatial Plan mapping for the study area (Source: CapeFarmMapper, July 2020)

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Alternatives Option 1 Option 2 Option 3 Option 4 Option 5 Option 6 (preferred)

Figure 10. Freshwater Ecosystem Priority Area Wetlands in the study area (Source: CapeFarmMapper, July 2020)

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Figure 11. Freshwater Ecosystem Priority Area Rivers for the study area (Source: SANBI Biodiversity GIS, July 2020)

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3.2.7. LAND USE

The land use practice in the immediate area surrounding the Cape Flats WWTW is largely undeveloped or natural open space (light and dark green areas in Figure 12) and forms part of the False Bay Ecology Park with its permanently and seasonally inundated areas (light and dark blue areas in Figure 12). The Coastal Park Landfill site is located directly west of the Zeekoevlei Canal (red areas in Figure 12) while urban development at Pelican Park has been expanded into the natural areas, particularly to the east of the WWTW. Further to the west and north-west are the dense residential areas of Lavender Hill, Muizenburg, Retreat and Grassy Park.

Alternatives Option 1 Option 2 Option 3 Option 4 Option 5 Option 6 (preferred)

Figure 12. Land cover map for the Cape Flats WWTW and surrounding areas (Source: 2017/18 Land cover classification for South Africa, obtained from CapeFarmMapper, July 2020)

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3.3. ASSESSMENT OF FRESHWATER FEATURES AND THEIR SIGNIFICANCE

The following aquatic features (Figure 13) have been identified and are discussed further in this section:

• Zeekoevlei Canal that would need to be crossed by some of the proposed access road alternatives (Options 1 and 2);

• Cape Flats Wastewater Treatment Works (WWTW) associated ponds and water bodies that would need to be crossed for all of the alternative access roads proposed; and

• Dune slack wetland areas to the north-west and east of the WWTW, along all of the alternative access roads proposed.

Figure 13. Google Earth image indicating all the freshwater features within the greater study area

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3.3.1. DESCRIPTION OF AQUATIC FEATURES

ZEEKOEVLEI WETLAND AND CHANNEL

Zeekoevlei is classified as a Dune Strandveld depression. In terms of marginal and aquatic vegetation, the bulrush Typha capensis predominates, with a lesser contribution by sedges such as Scirpus nodosus in the deeper waters. The present condition of Zeekoevlei itself is considered to be largely to seriously modified (D/E category), which is regarded as being unacceptable. However, the vlei rates as Moderate in terms of its importance and sensitivity. This implies that efforts should be made to raise the present condition of the vlei to largely or moderately modified.

Figure 14. Downstream (top) and upstream (bottom) view of the Zeekoevlei Canal at the proposed route crossing for Option 2 (arrows indicate flow direction)

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The Zeekoevlei Canal (Figure 14) is largely a man-made canal that was constructed in 1942 to connect Zeekoevlei to the sea. Although originally concrete the canal is now largely earthen and is approximately 15m wide with steeply sloping banks of 3m to 5m. Due to the steepness of the banks and the relatively constant flows in the canal, the riparian zone is narrow and much of the vegetation along the banks is terrestrial. Some reeds and sedges grow along the water edge (Typha capensis, Scirpus spp. and Juncus spp.). Water weeds such as water hyacinth (Eichhornia crassipes) are a problem in the canal as a result of the high nutrient levels in the water body.

CAPE FLATS WWTW ASSOCIATED PONDS AND WATER BODIES

The WWTW covers an area of approximately 380 hectares that once consisted of dune-slack wetland areas. The WWTW comprises of a series of primary, secondary and tertiary ponds as well as sludge ponds (Figure 15). The WWTW was established in 1956 and has subsequently been expanded upon. The aquatic habitats consist of permanently and seasonally open ponds, canals, reedbeds and sludge beds. The ponds, in particular, are home to a large number of migrant as well as resident bird species.

Figure 15. Ponded areas within the Cape Flats WWTW (Jeffares & Green, 2013)

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Figure 16. Primary ponds of the WWTW

The proposed access road alternatives for Option 1, 2, 5 and 6 will need to pass between primary ponds within the works. These ponds comprise of large open water systems (Figure 16) with grassed banks and limited ecological value. The key ecological value being the provision of habitat for water birds.

DUNE STRANDVELD WETLANDS (DUNE SLACK WETLANDS WITH ADJACENT WETLAND FLAT AREAS)

Dune strandveld wetlands occur within depressions in the Dune Strandveld vegetation located primarily on the Cape Flats. Many of this wetland type is typical duneslack wetlands, which when unimpacted, consist of a mix of wetland grasses, sedges, asteraceous shrubs and restios. These wetlands are highly threatened by infilling and fragmentation for development, stormwater discharge and alien plant invasion. Dune strandveld wetlands make up approximately 23.5% of the total area of natural and semi-natural wetlands in the City of Cape Town.

In the area to the north-west of the Cape Flats WWTW, along the proposed alternative access road Option 2, more impacted dune slack wetlands occur that has been modified within the grounds of the WWTW to allow for the existing access road along the northern fence line down to the Zeekoevlei Canal. Figure 17 shows the remaining duneslack wetland area north of the existing access road.

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Figure 17. View of the dune slack wetland area along the alternative access road Option 2 along the northern boundary of the site

The seasonal duneslack wetlands to the east of the WWTW are more significant, covering larger areas and are less disturbed although there are several tracks through this area. Typical duneslack wetland plant species occur within these wetlands such as Senecio halimifolius, Imperata cylindrica, Ficinia nodosa and Zantedeschia aethiopica (Figure 18).

Figure 18. View of one of the duneslack wetlands in the eastern portion of the study area

Two Plant Species of Conservation Concern, Psoralea aphylla and Cliffortia longifolia (regarded as a Vulnerable species (Helme 2018) were observed in the larger wetland south of Pelican Park. This area is likely to support a number of amphibian species, including Cape Sand Frog (Tomopterna delalandii), Flat Caco (Cacosternum platys), Clicking Stream Frog (Strongylopus grayii), and Arum Lily Frog (Hyperolius horstockii) as well as possibly Endangered Western Leopard Toad (Amietophrynus pantherinus). Sword grass (Imperata cylindrica) occurring in the duneslack wetlands is also indicated to provide suitable habitat for the Critically Endangered butterfly, Kedestes barberae bunta (Barber's

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Cape Flats Ranger) and the Endangered Kedestes lenis (False Bay Unique Ranger). These wetland areas are thus deemed to be of High conservation value.

3.3.2. CHARACTERISATION OF AQUATIC FEATURES

ZEEKOEVLEI CANAL

Typically, to assess the current condition and ecological importance and sensitivity of watercourses, it is important to understand how the stream may have appeared under natural or un-impacted conditions. This is achieved through classifying rivers and streams according to their ecological characteristics and comparing ecologically similar rivers or streams. The Zeekoevlei Canal is completely an artificial channel constructed between the Zeekoevlei and the sea. It primarily receives flow from the vlei but also receives stormwater discharges as well as the final treated wastewater from the WWTW. As it has been in existence since 1942 and receives a constant flow, it has developed some natural characteristics typical to perennial watercourses in the area. One can therefore assess its ecological condition relative to other similar watercourses in the area.

River typing or classification involves the hierarchical grouping of rivers into ecologically similar units so that inter-and intra–river variation in factors that influence water chemistry, channel type, substratum composition and hydrology are best accounted for. Any comparative assessment of river/stream condition should only be done between rivers/streams which share similar physical and biological characteristics under natural conditions. The primary classification of rivers is the division into Ecoregions. Rivers within an ecoregion are further divided into subregions.

Ecoregions can be defined as groups of rivers within South Africa, which share similar physiography, climate, geology, soils and potential natural vegetation. For this study, the ecoregional classification presented in DWAF (1999), which divides the country’s rivers into ecoregions, was used. The study site falls within the South Western Coastal Belt Ecoregion (Table 2).

Table 2. Characteristics of the South Western Coastal Belt Ecoregion (bold indicates the dominant type) Main Attributes Characteristics Terrain Morphology Plains; Low Relief; Plains Moderate Relief; E: Closed Hills; Mountains; Moderate and High Relief Vegetation types Sand Plain Fynbos; Mountain Renosterveld; West Coast Renosterveld; Dune Thicket; Strandveld Succulent Karoo Altitude 0-300; 300-900 limited MAP (mm) 100 to 1000 Coefficient of Variation 20 to 39 Rainfall seasonality Winter Mean annual temp. 14 to 20 Median annual simulated runoff <5; 20 to >250

Subregions are also referred to as geomorphological zones. They represent groups of rivers, or segments of rivers, within an ecoregion, which share similar geomorphological features, of which gradient is the most important. The use of geomorphological features is based on the assumption that these are a major factor in the determination of the distribution of the biota. The geomorphological and physical characteristics of the Zeekoevlei Canal from the Site Characterisation assessment are shown in Table 3.

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Table 3. Geomorphological and Physical features of the Zeekoevlei Canal Geomorphological Zone Sandy bed lowland stream Lateral mobility Confined Channel form Moderately incised within coastal duneveld Channel pattern Single thread, very low sinuosity Channel modification Constructed channel Hydrological type Perennial Ecoregion South Western Coastal Belt Quaternary Catchment G22D Vegetation type Cape Flats Dune Strandveld Rainfall region Winter

WETLAND CHARACTERISTICS

The wetlands found within the study area can be broadly described as depression type wetlands (Table 4). This wetland type is fed from both groundwater as well as surface water, wherein the duneslack wetlands the groundwater table is a major influencing factor on the wetland health and functioning.

Table 4. Wetland hydro-geomorphic types typically supporting inland wetlands in South Africa Source of water Hydro-geomorphic types Description maintaining wetland1 Surface Sub-surface Floodplain Valley bottom areas with a well-defined stream channel, gently sloped and characterized by floodplain features, *** * alluvial transport and deposition of sediment, usually leading to a net accumulation of sediment. Water inputs from main channel and from adjacent slopes. Valley bottom with a Valley bottom areas with a well-defined stream channel but channel lacking characteristic floodplain features. May be gently *** */ *** sloped and characterized by the net accumulation of alluvial deposits or may have steeper slopes and be characterized by the net loss of sediment. Water inputs from main channel (when channel banks overspill) and from adjacent slopes. Valley bottom without a Valley bottom areas with no clearly defined stream channel, channel usually gently sloped and characterized by alluvial sediment *** */ *** deposition, generally leading to a net accumulation of sediment. Water inputs mainly from channel entering the wetland and also from adjacent slopes. Hillslope seepage linked to Slopes on hillsides, which are characterized by the colluvial stream channel movement of materials. Water inputs are mainly from sub- * *** surface flow and outflow is usually via a well-defined stream channel connecting the area directly to a stream channel. Isolated Hillslope seepage Slopes on hillsides, which are characterized by the colluvial movement of materials. Water inputs mainly from sub- * *** surface flow and outflow either very limited or through diffuse sub-surface and/or surface flow but with no direct surface water connection to a stream channel. Depression (includes Pans) A basin shaped area with a closed elevation contour that allows for the accumulation of surface water (i.e. it is inward */ *** */ *** draining). It may also receive sub-surface water. An outlet is usually absent, and therefore this type is usually isolated from the stream channel network. 1 Precipitation is an important water source and evapotranspiration an important output in all of the above Water source: * Contribution usually small *** Contribution usually large Wetland */ *** Contribution may be small or important depending on the local circumstances

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Table 5: Classification of wetland areas within the study area Dune slacks and adjacent wetland flat areas Artificial Depressions associated with the Name WWTW System Inland Ecoregion South Western Coastal Belt Ecoregion Landscape setting Flat with Depressions Depressions (excavated) On sandy well-drained soils with no channelled Excavated and filled with partially treated Drainage in or outflow - fed largely from groundwater wastewater Seasonality Seasonal Perennial to seasonal Fairly undisturbed – some roads and paths – Artificial and associated with WWTW Anthropogenic the wetlands to the west being more impacted influence by existing access roads and fencing. Geology Quaternary calcareous coastal dune sand Terrestrial Vegetation Cape Flats Dune Strandveld Wetland vegetation Imperata cylindrica Typha capensis and Phragmites australis Substrate Sand Silt, sludge and in cases lined Salinity Fresh

The geohydrological study that was undertaken as part of the Zeekoevlei/Rondevlei Rehabilitation Study Action Plan (Southern Waters, 2000) indicated that groundwater inflows contribute approximately 15% of the total inflow (4 to 5 mm per day throughout the year) into Rondevlei and Zeekoevlei and play a critical role during summer when groundwater is the sole source of supply. Groundwater likely plays a similar role for the smaller dune slack wetland areas as well.

3.3.3. PRESENT ECOLOGICAL STATUS

ZEEKOEVLEI CANAL HABITAT INTEGRITY

Evaluating Habitat Integrity provides a measure of the degree to which a stream has been modified from its natural state. The methodology (DWAF, 1999) involves a qualitative assessment of the number and severity of the anthropogenic perturbations on a river and the damage they potentially inflict upon the system. These disturbances include both the abiotic and biotic factors which are regarded as the primary causes of degradation of a river. The severity of each impact is ranked using a scale which ranges from 0 (no impact) to 25 (critical impact). The Habitat Integrity Assessment is based on the assessment of the impacts of two components of the river, the riparian zone and the instream habitat (Table 6). The total scores for the instream and riparian zone components are then used to place the habitat integrity of both in a specific habitat integrity category (Table 7).

Table 6. The results of the Habitat Integrity Assessment of the Zeekoevlei Canal Instream Habitat Integrity Riparian Habitat Integrity Water Abstraction 0 Vegetation Removal 9 Flow Modification 16 Exotic Vegetation 7 Bed Modification 14 Bank Erosion 8 Channel Modification 15 Channel Modification 15 Water Quality 16 Water Abstraction 0 Inundation 8 Inundation 8 Exotic Macrophytes 11 Flow Modification 16 Exotic Fauna 4 Water Quality 15 Rubbish Dumping 10 Instream Habitat Integrity Class D/E Riparian Habitat Integrity Class D/E

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Table 7. Habitat Integrity categories (From DWAF, 1999) Category Description Score (%) A Unmodified, natural 90-100 Largely natural with few modifications. Small change in natural habitat and biota may have B 80-90 taken place but the ecosystem functions are essentially unchanged Moderately modified. A loss and change of natural habitat and biota have occurred but the C 60-79 basic ecosystem functions are still predominantly unchanged. D Largely modified. Large loss of natural habitat, biota and basic ecosystem functions 40-59 E The loss of natural habitat, biota and basic ecosystem functions is extensive. 20-39 Modifications have reached a critical level and lotic system has been modified completely F with almost complete loss of natural habitat and biota. At worst, basic ecosystem function 0 has been destroyed and change is irreversible.

WETLAND HABITAT INTEGRITY

The Present Ecological Status (PES) Method (DWAF 2005) was used to establish the integrity of the wetlands in the study area and was based on the modified Habitat Integrity approach developed by Kleynhans (DWAF, 1999; Dickens et al, 2003). The table below displays the criterion assessed in the habitat integrity assessment. These criteria were selected based on the assumption that anthropogenic modification of the criteria and attributes listed under each selected criterion and can generally be regarded as the primary causes of the ecological integrity of a wetland.

Table 8. Habitat integrity assessment criteria for palustrine wetlands (Dickens et al, 2003) Criteria/Attributes Relevance Hydrologic Flow Modification Consequence of abstraction, regulation by impoundments or increased runoff from human settlements or agricultural land. Changes in flow regime (timing, duration, frequency), volumes, velocity which affect inundation of wetland habitats resulting in floralistic changes or incorrect cues to biota. Abstraction of groundwater flows to the wetland. Inundation Consequence of impoundment - results in natural wetland habitat destruction & biota cues. Water Quality Water Quality From point or diffuse sources. Measure directly by laboratory analysis or assessed indirectly from Modification upstream agricultural activities, human settlements and industrial activities. Aggravated by volumetric decrease in flow delivered to the wetland. Sediment Load Consequence of reduction due to entrapment by impoundments or increase due to land use Modification practices such as overgrazing. Cause of unnatural rates of erosion, accretion or infilling of wetlands and change in habitats. Hydraulic/Geomorphic Canalisation Results in changes to wetland inundation patterns and to habitats. River diversions/drainage. Topographic Consequence of infilling, ploughing, dykes, trampling, bridges, roads, railway lines & other Alteration substrate disruptive activities that reduce/change wetland habitat directly Biota Terrestrial Consequence of encroachment of terrestrial plant species due to changes in hydrology & Encroachment geomorphology. Change to terrestrial habitat and loss of wetland functions. Indigenous Direct habitat destruction through farming, grazing or firewood collection - affects habitat and Vegetation Removal flow attenuation functions, organic matter inputs and increases potential for erosion. Invasive Plant Affects habitat characteristics through changes in community structure and water quality Encroachment changes (oxygen reduction and shading). Alien Fauna Presence of alien fauna affecting faunal community structure. Over utilisation Overgrazing, overfishing, etc.

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Table 9. Wetland habitat integrity assessment (score of 0=critically modified to 5=unmodified) Criteria & Attributes Dune slack wetland areas Duneslack areas Cape Flats WWTW Zeekoevlei adjacent to WWTW and east of WWTW (primary ponds) urban areas - to the west Hydrologic Flow Modification 2.2 3.8 1.0 2.0 Permanent Inundation 2.8 4.0 1.0 2.5 Water Quality Water Quality Modification 2.5 3.8 1.0 1.0 Sediment Load Modification 2.0 3.6 1.0 2.0 Hydraulic/Geomorphic Canalisation 3.5 4.0 1.0 3.0 Topographic Alteration 2.5 4.2 1.0 3.0 Biota Terrestrial Encroachment 2.6 3.8 1.5 2.5 Indigenous Vegetation Removal 2.4 3.8 1.5 3.0 Invasive Plant Encroachment 2.8 3.6 2.0 3.0 Alien Fauna 2.8 3.6 2.5 3.0 Over utilisation of Biota 3.2 3.8 3.0 3.0 Category C/D B E B/C

The duneslack wetland areas are in general still in a largely natural ecological state. The duneslack wetlands that are closer to the WWTW and the urban areas are more disturbed and range from being moderately to largely modified depending on the level of disturbance taking place.

Table 10. Relation between scores given and ecological categories Scoring Guidelines Interpretation of Mean* of Scores for all Attributes: Rating of Present Ecological Status Category Per Attribute* (PESC) Natural, unmodified Within general acceptable range - score=5. CATEGORY A >4; Unmodified or approximates natural condition. Largely natural - CATEGORY B score=4. >3 and <4; Largely natural with few modifications, but with some loss of natural habitats.

Moderately CATEGORY C modified- score=3. >2 and <3; moderately modified, but with some loss of natural habitats. Largely modified - CATEGORY D score=2. <2; largely modified. A large loss of natural habitats and basic ecosystem functions has occurred.

OUTSIDE GENERALLY ACCEPTABLE RANGE Seriously modified – CATEGORY E rating=1. >0 and <2; seriously modified. The losses of natural habitats and basic ecosystem functions are extensive. Critically modified – CLASS F rating=0. 0; critically modified. Modifications have reached a critical level and the system has been modified completely with an almost complete loss of natural habitat.

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3.3.4. ECOLOGICAL IMPORTANCE AND SENSITIVITY AND ECOSYSTEM SERVICES

ZEEKOEVLEI CANAL

The EIS assessment considers several biotic and habitat determinants which indicate either the importance or the sensitivity of the water resource. These determinants are rated according to a four-point scale (Table 11). The median of the resultant score is calculated to derive the EIS category of the water resource (Table 12). The EIS assessment and results are shown in Table 13.

Table 11. Scale used to assess either ecological importance or sensitivity Scale Definition 1 One species / taxon judged as rare or endangered at a local scale. 2 More than one species / taxon judged to be rare or endangered on a local scale. 3 One or more species / taxon judged to be rare or endangered on a Provincial / regional scale. 4 One or more species / taxon judged as rare or endangered on a national scale

Table 12. Ecological importance and sensitivity categories (DWAF, 1999). EISC General description Range Very High Quaternaries/delineations unique on a national and international level based on unique >3-4 biodiversity. These rivers (in terms of biota and habitat) are usually very sensitive to flow modifications and have no or only a small capacity for use. High Quaternaries/delineations unique on a national scale based on their biodiversity. These >2-3 rivers (in terms of biota and habitat) may be sensitive to flow modifications and often have substantial capacity for use. Moderate Quaternaries/delineations unique on a Provincial or local scale due to biodiversity. These >1-2 rivers, (in terms of biota and habitat) are not usually very sensitive to flow modifications and often have substantial capacity for use. Low/marginal Quaternaries/delineations that are not unique on any scale. These rivers (in terms of biota 1 and habitat) are generally not sensitive to flow modifications and usually have substantial capacity for use.

Table 13. The results of the EIS assessment Biotic determinant Zeekoevlei Dune slack Duneslack Cape Flats Zeekoevlei Canal wetland areas Wetlands WWTW east of WWTW to the west (primary (largely natural of WWTW ponds) areas) (degraded areas) Rare and endangered biota 1 2 0.5 1 2.5 Unique biota 1 2.5 0.5 1 2.5 Intolerant biota 1 2.5 0.5 1 2.5 Species / taxon richness 1.5 2 1 1.5 3 Aquatic Habitat Determinants Diversity of aquatic habitat types or 1 2.5 0.5 1 3 features Refuge value of habitat type 1.5 2 1 1.5 3 Sensitivity of habitat to flow changes 1 3 0.5 0.5 2.5 Sensitivity to flow related water 1 3 0.5 0.5 2.5 quality changes Migration route or corridor for 1.5 1 1 1 2 instream & riparian biota National parks, wilderness areas, 2 2 1 2 2 Nature Reserves, Natural Heritage Sites, Natural Areas, PNEs EIS category Moderate/Low High/Moderate Low Low High

The Zeekoevlei Canal is considered to be of moderate to low EIS. Due to its artificial and degraded condition, the watercourse is not likely to contain any intolerant species however it does provide

Aquatic Ecological Assessment: New Access Road to Cape Flats WWTW April 2021 Page | 41 refuge and a corridor for the movement of biota in a transformed landscape. Zeekoevlei as a large and still largely natural wetland area is of high ecological importance and sensitivity, while the largely natural duneslack wetlands are considered of Moderate to High EIS. The artificial WWTW ponds and degraded duneslack wetlands are considered of a low EIS.

WETLAND ECOSYSTEM SERVICES

The assessment of the ecosystem services supplied by the identified wetlands was conducted according to the guidelines as described by Kotze et al (2005). An assessment was undertaken that examines and rates the services listed in Table 14. The characteristics were scored according to the general levels of services provided. It is important to manage the wetlands to ensure that they can continue to provide valued goods and services:

Table 14. Goods and services assessment results for wetlands (where low=0; high=4) Goods and services Duneslack wetlands Duneslack wetlands Cape Flats WWTW Zeekoevlei (largely natural) (Degraded) (primary ponds) Flood attenuation 3.0 1.7 2.5 2.5 Stream flow regulation 2.0 1.0 2.0 2.5 Sediment trapping 2.5 1.8 3.5 3.0 Phosphate trapping 2.0 1.8 3.5 3.0 Nitrate removal 2.0 1.5 3.5 3.0 Toxicant removal 2.0 1.5 3.5 3.0 Erosion control 2.5 1.5 3.0 3.0 Carbon storage 1.0 0.5 2.0 3.0 Maintenance of biodiversity 1.5 1.0 2.5 3.0 Water supply for human use 0.5 0 1.0 2.0 Natural resources 2.0 1.0 0.5 1.5 Cultivated foods 0.5 0 0.5 1.0 Cultural significance 0.5 0.5 0 2.0 Tourism and recreation 0.5 0.5 2.0 3.0 Education and research 0.5 0.5 2.0 3.0

Each of the wetland areas assessed within the greater study area has valuable goods and services that they contribute. Many of these goods and services are however reduced due to existing impacts on the ecological state of the features.

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Flood attenuation Education and research 4 Streamflow regulation

Tourism and recreation 3 Sediment trapping 2 Cultural significance Phospahte trapping 1 0 Cultivated foods Nitrate removal

Natural resources Toxicant removal

Water supply for human use Erosion control Maintenance of biodiversity Carbon storage

Figure 19. Ecosystem services provided by the largely natural duneslack wetlands (top left - orange), the degraded duneslack wetlands (top right - pink), the Cape Flats WWTW primary ponds (bottom left - red) and Zeekoevlei (bottom right - green)

3.3.5. RECOMMENDED ECOLOGICAL CATEGORY

It is recommended that the wetland areas that are still largely natural remain in this ecological category while those that have been degraded be at least maintained in their current ecological condition or rehabilitated where possible. The artificial aquatic features have been constructed to provide certain services (wastewater treatment) and should at least be maintained that they can continue to provide their valued ecological services. A summary of the PES and EIS assessments are provided below, together with the recommended ecological categories. A map showing the relative aquatic ecosystem importance and sensitivity is shown in Figure 20.

Table 15. Present Ecological Status, EIS and the recommended ecological categories for the aquatic features Duneslack Duneslack WWTW Zeekoevlei Zeekoevlei wetlands (largely wetlands (primary Canal natural) (Degraded) ponds) Present Ecological Status B C/D E B/C D/E EIS High/Moderate Low Low High Moderate/Low Recommended Ecological Category B C/D D B/C D

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High EIS Moderate EIS Low EIS

Figure 20. Aquatic ecological importance and sensitivity mapping for the area

4. LEGISLATIVE AND REGULATORY REQUIREMENTS

This proposed new access road to the Cape Flats WWTW needs to take cognizance of the legislative requirements, policies, strategies, guidelines and principals of the relevant regulatory documents of the City of Cape Town area, such as the City’s Integrated Development Plan and Biodiversity Plan (Section 4.7), the River Corridor and Floodplain Management Policy, as well as the National Water Act (NWA) and the National Environmental Management Act (NEMA).

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4.1. NEMA AND ENVIRONMENTAL IMPACT ASSESSMENT REGULATIONS

NEMA is the overarching piece of legislation for environmental management in South Africa and includes provisions that must be considered to give effect to the general objectives of integrated environmental management. These provisions are contained in Section 24 (4)(a)(b) of the Act and will be considered during the EIA process. Activities listed in terms of Chapter 5 of NEMA in Government Notice No. R. 983, 984 and 985, dated 4 December 2014, as amended, trigger a mandatory Basic Assessment, or even a full scoping EIA process, before development. Many of the listed activities relate to activities within or adjacent to aquatic ecosystems. This report is intended to provide input into the Environmental Impact Assessment process being undertaken by SRK for the proposed development of the site.

4.2. NATIONAL WATER ACT, 1998 (ACT NO. 36 OF 1998)

The purpose of the National Water Act, 1998 (NWA) is to provide a framework for the equitable allocation and sustainable management of water resources. Both surface and groundwater sources are redefined by the Act as national resources which cannot be owned by any individual, and rights to which are not automatically coupled to land rights, but for which prospective users must apply for authorisation and register as users. The NWA also provides for measures to prevent, control and remedy the pollution of surface and groundwater sources.

The Act aims to regulate the use of water and activities (as defined in Part 4, Section 21 of the NWA), which may impact on water resources through the categorisation of ‘listed water uses’ encompassing water abstraction and flow attenuation within catchments as well as the potential contamination of water resources, where the DWS is the administering body in this regard. The water uses most likely to be associated with the proposed activities are as follows: Reference Description Comment in the NWA Section Impeding or diverting flow of water in a Works within the watercourses/wetlands is likely to 21(c) watercourse trigger this water use Section 21(i) Altering the bed, banks, course or Any works within or adjacent to any of the mapped characteristics of a watercourse aquatic features is likely to trigger this water use

Defined water use activities require the approval of DWS in the form of a General Authorisation or Water Use Licence authorisation if not considered an existing lawful use (a water use that was lawful 2 years prior to the promulgation of the NWA in 1998) and a Schedule 1 use (small-scale/non- commercial level use). There are restrictions on the extent and scale of listed activities for which General Authorisations apply. Section 22(3) of the National Water Act allows for a responsible authority (DWS) to dispense with the requirement for a Water Use Licence if it is satisfied that the purpose of the Act will be met by the grant of a licence, permit or authorisation under any other law.

4.2.1. GENERAL AUTHORISATION IN TERMS OF SECTION. 39 OF THE NWA

According to the preamble to Part 6 of the NWA, “This Part established a procedure to enable a responsible authority, after public consultation, to permit the use of water by publishing general authorisations in the Gazette…” “The use of water under a general authorisation does not require a licence until the general authorisation is revoked, in which case licensing will be necessary…”

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The most recent General Authorisations for Section 21 (c) and (i) water uses (impeding or diverting flow or changing the bed, banks or characteristics of a watercourse) as defined under the NWA were revised in 2016 (Government Notice R509 of 2016) and require a risk assessment of the proposed activities to be undertaken. The proposed works within or adjacent to the wetland areas and river channels are likely to change the characteristics of the associated freshwater ecosystems and may therefore require authorization. Determining if a water use licence is required for these water uses is now associated with the risk of degrading the ecological status of a watercourse. A low risk of impact could be authorised in terms of the General Authorisations (GA). A risk assessment for the proposed project has been undertaken for the proposed development of the site.

4.2.2. REGULATIONS REQUIRING THAT A WATER USER BE REGISTERED, GN R.1352 (1999)

Regulations requiring the registration of water users were promulgated by the then Minister of Department of Water Affairs in terms of the provision made in section 26(1)(c), read together with section 69 of the National Water Act, 1998. Section 26(1) (c) of the Act allows for registration of all water uses including existing lawful water use in terms of section 34(2). Section 29(1) (b) (vi) also states that in the case of a General Authorisation, the responsible authority may attach a condition requiring the registration of such water use. The Regulations (Art. 3) oblige any water user as defined under section 21 of the Act to register such use with the responsible authority and effectively to apply for a Registration Certificate as contemplated under Art.7(1) of the Regulations. Registration of the new water use activities associated with the proposed works will be included in the water use authorisation process.

5. ASSESSMENT OF POTENTIAL AQUATIC IMPACTS

5.1. DESCRIPTION AND CONSTRAINTS ASSESSMENT OF POTENTIAL AQUATIC IMPACTS OF PROPOSED ACTIVITIES

5.1.1 DESCRIPTION OF POTENTIAL AQUATIC IMPACTS

This section provides an assessment of the potential aquatic ecosystem impacts that are likely to be associated with the proposed new BBF and access road. The proposed BBF will be located within the footprint of the existing WWTW (Figure 21). While some wetland habitats are occurring in and immediately adjacent to the footprint, these wetlands are artificial and considered of low ecological importance and sensitivity and are as a result of the WWTW. Provided the construction works are contained to the indicated footprint and good housekeeping measures are implemented and monitored in terms of the Environmental Management Plan for the project, the potential impact of the proposed works on these wetland areas is considered to be very low to insignificant.

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Figure 21. Proposed layout of the works at the BBF and the associated infrastructure

A variety of route alternatives are proposed for the new access route for trucks to access the proposed Biosolids Beneficiation Facility. The route alternatives vary from being largely located along roads that are already in existence adjacent to, or within the freshwater features or within less disturbed areas that are still largely natural as described in the previous section.

Physical modifications to the freshwater features as a result of the existing land use activities have resulted in the current ecological condition of the aquatic features. Where the areas are already significantly modified, it can be expected that the likely impacts of the proposed new access road for Options 1 and 2 would be of a limited extent and a short term nature, occurring mostly during the construction phase. Over the longer term, one can expect a limited impact from the use and maintenance of the road. One also needs to compare this longer-term impact against the reduced impact associated with the sludge trucks for the biosolids facility not making use of the existing access road adjacent to Zeekoevlei (i.e. the no-go alternative). Longer-term impacts that are likely to occur as a result of the proposed activities relate to how the construction and maintenance work is undertaken for the road as well as the potential encroachment of invasive alien vegetation into the freshwater features where they have been disturbed by the construction activities. These impacts can easily be mitigated.

However, where new roads are proposed within areas that are still largely natural, more significant and longer-term impacts could be expected. This relates largely to the area east of the WWTW (Options 3, 4, 5 and 6). There is however expanding urban development occurring within this area and one needs to ensure that the new road coincides with the new development area and avoids impacting further on areas indicated as having high ecological importance and/or sensitivity that are not going to be developed. The assessment for the proposed Pelican Park housing developed expansion into Phase 2 has however only considered the northern portion in which Options 4 and 5 (and part of Option 6) are proposed. Within this proposed development, the central portion of dune and duneslack areas orientated north-south is indicated as being of medium to high ecological sensitivity and conservation value which corresponds to the aquatic EIS mapping show in Figure 16.

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5.1.2. CONSIDERATION OF THE PROPOSED ROUTE ALTERNATIVES

ROAD ALTERNATIVES WEST OF THE WWTW (OPTION 1 AND OPTION 2)

These two options entail an access road from the west of the WWTW, adjacent to the landfill site. These road options, although within the False Bay Nature Reserve (Strandfontein Birding Section), will largely be placed within disturbed areas associated with the WWTW and the adjacent landfill site. The road will need to cross the Zeekoevlei Canal and then upgrades will need to be undertaken to existing roads within the WWTW itself. These specific activities are discussed further below:

PROPOSED WORKS AT THE ZEEKOEVLEI CANAL BRIDGE

The proposed bridge over the Zeekoevlei Canal would have a limited potential impact for the proposed works in terms of the aquatic ecosystem at the proposed Zeekoevlei Canal Bridge location. The proposed bridge comprises of a single span over the canal with no proposed structure within the channel. No hydraulic impacts are thus likely to result from any structure related aspects of the crossing. The proposed works would result in a limited disturbance of the aquatic habitat on the banks of the watercourse that would be of low significance if properly mitigated.

The impact associated with the Option 1 would be more significant as the road would need to be created through relatively natural wetland habitat on the eastern bank of the canal (Figure 22) where no road currently exists before linking up with an existing road within the WWTW. The route crossing over the canal for Option 2 will be located on an existing crossing, with roads to the crossing on both the west and eastern bank (Figure 23). The bridge is however old and under-designed and will need to be replaced. The disturbance of the crossing is already in place. Thus, any potential impact to aquatic habitat at the crossing will be limited and of a low significance.

Figure 22. View of the approximate routing (pink arrow) over the Zeekoevlei Canal (blue arrow) crossing through wetland habitat on the eastern bank of the canal for Option 1

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Figure 23. View of the existing crossing over the Zeekoevlei Canal for the access road alternative Option 2 (the blue arrow shows the flow direction in the canal)

PROPOSED WIDENING OF THE PROPOSED NEW ACCESS ROUTE THROUGH THE WWTW

The proposed access road to the BBF will require widening of the existing roads within primary ponds in the WWTW for the alternative new access road Options 1, 2, 5 and 6 (Figure 24). This would require some infilling of the ponds and result in a short-term loss of aquatic habitat within the ponds. This would largely take place along a maintained pond edge with grassed banks. Over the longer-term new aquatic habitat will establish itself along the pond edge at the road. This impact would be very similar for any of road alternative routes through the ponds.

Longer-term impacts could be expected as a result of increased traffic through the ponds. Some of this traffic already makes use of the existing route, which occurs adjacent to the more ecologically important Zeekoevlei. One could thus expect that this impact would be more of significance for Option 1, given the higher bird populations frequenting the southern portions of the WWTW.

ROAD ALTERNATIVES EAST OF THE WWTW (OPTIONS 3, 4, 5 AND 6)

These route alternatives are proposed to pass through the still largely natural dunefields with their dune slack wetlands to the east of the WWTW. The duneslack wetlands within the central portion of this area are still in a largely natural ecological condition and are considered of high ecological importance and sensitivity (Figure 24). All four road alternatives would be placed within the Pelican Park section of the False Bay Nature Reserve. The duneslack wetlands, outside of the reserve are mapped as aquatic CBAs and as Natural and semi-natural wetlands in the City Wetland mapping. The wetlands are not mapped in the FEPA Wetland mapping but are in the National Wetland Map.

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Option 3 is located in the southern end of this area, immediately north of Pelikan Heights, following the access road to the suburb and then an already modified area and jeep track to the WWTW eastern boundary fence road northwards and then into the WWTW site past some disturbed and largely artificial wetland areas. This route largely avoids any of the mapped wetlands and will have a potential low significance impact on the adjacent wetlands with mitigation.

Option 4 will extend from Punt Road westwards, crossing several moderately disturbed and then largely natural duneslack wetlands before entering the property of the WWTW and passing some disturbed and largely artificial wetland areas. This route can be expected to have a potential medium to high significance impact on the wetlands in the area, even with mitigation as the road will need to alter the topography and surface as well as sub-surface flow through the area as well as provide an access point for further disturbance, dumping of waste and potential development of the area.

Option 5 follows a similar route to that of Option 4 and is the route initially indicated to be the preferred option by the City. The route follows a less direct route and in places avoids crossing some of the duneslack areas. Nevertheless, most of the comment given for Option 4 applies to Option 5 and it will have a potential aquatic impact similar to that of Option 4.

Option 6 largely follows the route of Option 5 and is the final preferred route. Option 6 was determined in consultation with the various specialists on the project to try and determine the route with the least potential impact.

Options 4, 5 and 6 all will result in loss of duneslack wetland habitat considered of medium to high ecological importance and sensitivity and would thus require a wetland offset to ensure that there is no net loss of wetland habitat and functionality as a result of the proposed access road. While the requirement of wetland offset areas is not desirable as a form of mitigation (it is preferred to avoid loss or disturbance of wetland habitat from the onset) it is a recognised method to ensure no net los of wetland habitat and functionality. It does however involve the risk that the rehabilitated or created habitat does not achieve the desired outcomes.

A wetland offset has specifically been determined for the preferred route alternative Option 6 that would require the recreation of duneslack wetland habitat of approx. 11 ha in extent within an area adjacent to the WWTW that was previously disturbed. It could be expected that both Option 4 and 5 would require a similar wetland offset area as mitigation. In terms of these three route alternatives, Option 6 avoids the wetland habitats considered of high ecological importance and sensitivity compared to Options 4 and 5 that would both result in some loss of high ecological importance and sensitivity.

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High EIS Moderate EIS Low EIS

Figure 24. Google Earth image showing the routes of the access road alternatives through to the WWTW from the east

The impact tables for both the preferred and alternative routes are provided in Section 7.3.

Recommended general mitigation / best practice measures for the proposed road works are as follows:

• Construction within and adjacent to the watercourses and wetland areas should as far as possible take place during the drier months of the year (November to March) and should be limited in terms of extent and duration; • Rubble and debris from the construction activities should be removed from aquatic features after construction is complete; • The constructed road should result in a minimal alteration to the surrounding natural topography; • The materials utilised for the constructed road should be obtained from a source area approved of by the project Environmental Control Officer; and

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• Ongoing invasive alien plant control should be undertaken as part of the project activities.

5.2. OVERALL ASSESSMENT OF POTENTIAL IMPACTS OF PROPOSED ACTIVITIES

This section provides an overall assessment of the potential impacts to aquatic ecosystems that are likely to be associated with the proposed new access road. The specific assessment and recommended mitigation measures were outlined in Section 7.1.

5.2.1. AQUATIC HABITAT MODIFICATION OR LOSS

Nature of Impact: The most probable impact of the proposed activities is the modification of aquatic habitats within and adjacent to the proposed works (see Section 5.1) that can be expected during the construction phase due to the fact that the activities associated with road works will need to take place within or adjacent to aquatic features. The potential loss of aquatic habitat would largely be limited to the road, with potentially new aquatic habitat forming where infilling needs to take place for the widening and realignment of existing roads. The disturbance of aquatic habitat will also provide an opportunity for new invasive alien plants to proliferate within the road reserves that are regularly maintained.

Longer terms impacts during the operations phase are also likely to take place due to the increased disturbance and access to the area along the new road as well as the need to undertake maintenance of the road.

Significance of impacts without mitigation:

Construction Phase: A localized impact of medium to low intensity in the short term that is expected to have a Very low negative significance in terms of its impact on the aquatic habitat in the study area for Options 1 and 2. This is due to the fact that the aquatic habitat at the road has already been significantly disturbed as a result of the existing road as well as the surrounding land use activities. Option 3 would also have a potential aquatic impact of Very low significance as it largely avoids any aquatic habitats and will be placed within areas that have already been disturbed. Options 4 and 5 that would be placed within or adjacent to aquatic features that are still largely natural and of high EIS would have a potential impact of high significance. This is due to the fact that the extent and duration of the still largely natural wetland areas would be permanently modified for an area that would extend wider than the road itself.

Operation Phase: Over the longer term, a negative impact of a very low significance could be expected for Options 1, 2 and 3 and of a high significance for Options 4, 5 and 6 due to ongoing disturbance that is related to the need to undertake maintenance activities on the road at the aquatic features as well as the increased access to the area.

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Proposed essential mitigation measures (measures to be implemented over and above the good housekeeping related mitigation measures listed on pages 48 and 49):

Construction Phase:

• Excess spoil material should be removed to an approved disposal site;

• Use of materials for the construction works should be free of alien invasive plant seed; and

• Once construction is complete, the area should be rehabilitated and, where necessary, vegetated with suitable local indigenous plants.

Operation Phase:

• Should the road pass through formally protected areas, the access to these areas should be restricted to prevent the roads from providing access for the dumping of waste material and increasing disturbance into these areas; • Any invasive alien plants along the road should be removed on an ongoing basis according to methods as provided by the Working for Water Programme.

Significance of impacts after mitigation:

Construction Phase: The significance of the impact on the aquatic ecosystems with mitigation is expected to be a low (negative) in the short term for Options 1, 2 and 3 and Medium for Options 4, 5 and 6. In particular, mitigation of the impacts for road Options 4, 5 and 6, within the still largely natural wetland areas would reduce the extent of the impact on the wetlands (for example from the invasion of these areas with alien vegetation) to being just localised at the road.

Operation Phase: The significance of the impact on the aquatic ecosystems with mitigation is expected to be a very low negative in the long term for Options 1 and 2; low for Option 3 and medium to low for Options 4, 5 and 6.

Impact Tables:

Construction Phase:

Significance of loss / modification of wetland habitat: Alternatives 1, 2 and 3 Extent Intensity Duration Consequence Probability Significance Status Confidence Without Local Medium Short- Very Low mitigation term Probable VERY LOW – ve High 1 2 1 4 Essential mitigation measures: Remove excess spoil and dispose to an approved disposal site. Ensure that materials utilised for the construction of infrastructure are free of alien invasive plant seed. Rehabilitate and revegetate the area with suitable local indigenous plants once construction is complete. With Local Low Short- Very Low mitigation term Possible INSIGNIFICANT – ve High 1 1 1 3

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Significance of loss / modification of wetland habitat: Alternatives 4, 5 and 6 Extent Intensity Duration Consequence Probability Significance Status Confidence Without Regional Medium Long-term High Probable HIGH – ve High mitigation 2 2 3 7 Essential mitigation measures: Remove excess spoil and dispose to an approved disposal site. Ensure that materials utilised for the construction of infrastructure are free of alien invasive plant seed. Rehabilitate and revegetate the area with suitable local indigenous plants once construction is complete. Implement a wetland offset which accounts for the residual impacts on wetland habitat. With Regional Medium Long-term High Possible MEDIUM – ve High mitigation 2 2 3 7

Operation Phase:

Significance of loss / modification of wetland habitat: Alternatives 1, 2 and 3 Extent Intensity Duration Consequence Probability Significance Status Confidence Without Local Low Short-term Very Low Probable VERY LOW – ve High mitigation 1 1 1 3 Essential mitigation measures: Restrict access to formally protected areas adjacent to the road to prevent dumping of waste material and increasing disturbance into these areas. Remove invasive alien plants along the road on an ongoing basis according to methods as provided by the Working for Water Programme. With Local Low Short-term Very Low INSIGNIFICAN Improbable – ve High mitigation 1 1 1 3 T

Significance of loss / modification of wetland habitat: Alternatives 4, 5 and 6 Extent Intensity Duration Consequence Probability Significance Status Confidence Without Regional Medium Long-term High Definite HIGH – ve High mitigation 2 2 3 7 Essential mitigation measures: Restrict access to formally protected areas adjacent to the road to prevent dumping of waste material and increasing disturbance into these areas. Remove invasive alien plants along the road on an ongoing basis according to methods as provided by the Working for Water Programme. With Local Medium Long-term Medium Probable MEDIUM – ve High mitigation 1 2 3 6

5.2.2. WATER QUALITY IMPACTS

Nature of impact: Impairment of the surface water quality from contaminated runoff and sedimentation could potentially occur, particularly during the construction phase as a result of the construction activities at the aquatic features. The potential also exists for longer-term contamination of runoff from the road impacting on the aquatic ecosystems.

Significance of impacts without mitigation:

Construction Phase: Considering the quality of these aquatic features within the study area, the potential impact is likely to be very low to insignificant for Options 1 and 2, of a low significance for Option 3 and a medium significance for Options 4, 5 and 6.

Operation Phase: A medium to low risk of water quality impacts on the watercourses and wetland areas could be expected over the longer term as a result of contaminated runoff from the road.

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Proposed essential mitigation measures (measures to be implemented over and above the good housekeeping related mitigation measures listed on pages 48 and 49):

Construction Phase:

The risk of contamination and sediment from washing into the aquatic features can be substantially reduced if the construction and maintenance activities are undertaken under dry conditions.

Contaminated runoff from the construction site(s) should be prevented from entering the watercourses. The laydown area and main construction site should be located at least 20 m away from any aquatic features. All materials on the construction site should be properly stored and contained. Any stockpiling of material should also take place at least 20 m from any aquatic features to reduce the risk of runoff from these areas into the watercourse/wetlands. Disposal of waste from the site and the associated works should be properly managed and responsibly disposed of. Construction workers should be given ablution facilities at the construction works that are located away from the aquatic features (at least 20m) and regularly serviced. These measures should be addressed, implemented and monitored in terms of the Environmental Management Programme for the construction phase.

Operation Phase:

The road should be shaped and maintained such that any stormwater runoff from the road does not discharge directly into any of the adjacent wetland areas. Drainage from the road should rather be infiltrated into the ground over the length of the road through the use of open drainage channels along the length of the road.

Significance of impacts after mitigation:

Construction and Operation Phase: Provided that the mitigation measures are effectively implemented the water quality impacts of the proposed road upgrades should be of low to very low significance.

Impact Tables:

Construction Phase:

Significance of contamination of surface water affecting aquatic biota: Alternatives 1, 2 and 3 Extent Intensity Duration Consequence Probability Significance Status Confidence Without Local Medium Short-term Very Low Probable VERY LOW – ve High mitigation 1 2 1 4 Essential mitigation measures: Undertake construction activities close to wetlands during dry seasons where possible to reduce the risk of contaminated effluent and sediment from washing into the aquatic features. Prevent contaminated runoff from the construction site(s) from entering the watercourses. Establish the site camp and lay down area at least 20 m away from any aquatic features. All materials on the construction site should be properly stored and contained. Dispose / manage waste responsibly. Locate ablution facilities at least 20 m from the aquatic features and service them regularly. With Local Low Short-term Very Low Possible INSIGNIFICANT – ve High mitigation 1 1 1 3

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Significance of contamination of surface water affecting aquatic biota: Alternatives 4, 5 and 6 Extent Intensity Duration Consequence Probability Significance Status Confidence Without Local Medium Medium- Low mitigation term Probable LOW – ve High 1 2 2 5 Essential mitigation measures: Undertake construction activities close to wetlands during dry seasons where possible to reduce the risk of contaminated effluent and sediment from washing into the aquatic features. Prevent contaminated runoff from the construction site(s) from entering the watercourses. Establish the site camp and lay down area at least 20 m away from any aquatic features. All materials on the construction site should be properly stored and contained. Dispose / manage waste responsibly. Locate ablution facilities at least 20 m from the aquatic features and service them regularly. With Local Medium Short-term Very Low Probable VERY LOW – ve High mitigation 1 2 1 6

Operation Phase:

Significance of contamination of surface water affecting aquatic biota: Alternatives 1 - 6 Extent Intensity Duration Consequence Probability Significance Status Confidenc e Without Local Medium Long-term Medium Probable MEDIUM – ve High mitigation 1 2 3 6 Essential mitigation measures: Avoid discharge of stormwater runoff from the road into any of the adjacent wetland areas. Design and maintain the road such that any drainage from the road rather infiltrates into the ground over the length of the road rather than the use of open drainage channels. With Local Low Long-term Low Probable LOW – ve High mitigation 1 1 3 5

5.2.3. FLOW MODIFICATION

Nature of Impact: While the bridge at the Zeekoevlei Canal for route options 1 and 2 is not likely to significantly alter the hydraulic capacity in the channel, the adjacent road works immediately to the west of the canal has the potential to impact on the wetlands in the area.

The proposed road within or adjacent to wetland areas also has the potential to alter the surface and sub-surface flow through the wetland areas and in so doing alter the habitat integrity of the wetlands. A longer-term modification of the flow characteristics in these wetlands at the road may thus occur as a result of the proposed works.

Significance of impacts without mitigation:

Construction Phase: For Options 1, 2 and 3, the construction activities would be expected to have a very limited impact in terms of the extent and duration that would result in an insignificant impact. For Options 4, 5 and 6, a medium to low significance impact could be expected.

Operation Phase: For Options 1 and 2, the existing road and adjacent developed areas already modified the natural flow characteristic in these wetland areas. It can be expected that the impact of the road works to this flow modification could impact on the subsurface flow at the road that would be of low significance. Option 3 is also largely located away from any natural wetland habitats and thus would also result in flow modification impacts that are of a low significance. The longer-term

Aquatic Ecological Assessment: New Access Road to Cape Flats WWTW April 2021 Page | 56 flow impacts on the natural wetland areas for Options 4, 5 and 6 would, however, be of a medium significance.

Proposed mitigation:

Operation Phase:

• It is recommended that the construction of the road along the section of road between the Zeekoevlei Canal and the existing access road to the works (for Options 1 or 2) consider subsurface flow at the road in the area of the wetlands to ensure that the road does not significantly impede this flow

• Where the roads need to cross any of the wetland features, specifically for Options 4, 5 and 6, consideration of the surface and sub-surface flow characteristics of that aquatic feature will need to be taken into consideration and mitigated through the use of culverts or permeable road surfaces to minimise the impact of the road on flow as far as possible.

Significance of impacts after mitigation:

Operation Phase: A localised impact of low intensity that is expected to have a very low negative significance in terms of its impact on the identified aquatic ecosystems in the area for Options 1, 2 and 3 and of a medium to low significance for Options 4, 5 and 6.

Impact Tables:

Construction Phase:

Significance of modification of surface and subsurface flow characteristics: Alternatives 1, 2 and 3 Extent Intensity Duration Consequence Probability Significance Status Confidence Without Local Low Short- Very Low mitigation term Possible VERY LOW – ve High 1 1 1 3 Essential mitigation measures: Ensure that construction of the road close to the Zeekoevlei Canal does not significantly impede subsurface flow. With Local Low Short- Very Low mitigation term Improbable INSIGNIFICANT – ve High 1 1 1 3

Significance of modification of flow: Alternatives 4, 5 and 6 Extent Intensity Duration Consequence Probability Significance Status Confidence Without Local Medium Long-term Medium Probable MEDIUM – ve High mitigation 1 2 3 6 Essential mitigation measures: Consider surface and sub-surface flow characteristics of the aquatic feature in detailed road design and use culverts or permeable road surfaces to minimise the impact of the road on flow as far as possible. With Local Low Long-term Low Probable LOW – ve High mitigation 1 1 3 5

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5.2.4. CUMULATIVE IMPACTS

The Zeekoevlei Canal and wetlands that are adjacent to the proposed new access road for Options 1 and 2 are either artificial or have already been modified as a result of surrounding land use activities. Within this area, the ongoing disturbance activities of the landfill site and the WWTW on the adjacent aquatic habitats in particular impact on these wetlands. Considering that the proposed new road for these options will largely be along an existing road, with a limited widening at the WWTW ponds, one can expect that the cumulative impact of this activity on these aquatic features will be of a very low significance for the proposed upgrade to the existing access road as well as the alternative new access road.

The access road for Options 3, 4, 5 and 6 is located in or adjacent to Pelikan Park and it proposed expansion areas. The proposed road would result in additional impacts to the wetland habitats along these proposed routes that are currently not impacted by any roads. For these routes, the road will need to alter the topography and surface as well as sub-surface flow through the area. The road would provide an access point for further disturbance, dumping of waste and potential development of the area. Should Option 5 and 6 be considered, it is recommended that the works be done in conjunction with the approved development layout for Pelican Park Phase 2, given that the faunal, botanical and aquatic specialist studies for this proposed development have also identified the central dune and duneslack habitats as being of Medium to High Conservation Value.

The cumulative impacts for Options 1 and 2 will largely take place during the construction phase while for Options 3, 4, 5 and 6 the cumulative impacts as discussed above will largely be associated with the operation phase. It is thus essential that the impact be adequately mitigated to minimise the potential cumulative impacts.

The Department of Environmental Affairs and Development Planning’s Maintenance Management Plan guidelines (2017) provide the following set of guiding principles for the longer-term maintenance work of the access road where it will be within or adjacent to watercourses/wetlands:

• Repairs and maintenance should be undertaken within the dry season, except for emergency maintenance works.

• Where at all possible, existing access routes should be used. In cases where none exist, a route should be created through the most degraded area avoiding sensitive/indigenous vegetation areas.

• Responsible management of pollutants through ensuring handling and storage of any pollutants is away from the watercourse. When machinery is involved, ensure effective operation with no leaking parts and refuel outside of the riparian area, at a safe distance from the watercourse to manage any accidental spillages and pose no threat of pollution.

• At no time should the flow of the watercourse be blocked (temporary diversions may be allowed) nor should the movement of aquatic and riparian biota (noting breeding periods) be prevented during maintenance actions.

• No new berms can be created.

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• In circumstances which require the removal of any topsoil, this must be sufficiently restored through sustainable measures and practices.

• Concerted effort must be made to actively rehabilitate repaired or reshaped banks with indigenous local vegetation.

• No deepening of the watercourse beyond the original, pre-damage determined thalweg, unless such deepening is directly related to the natural improved functioning and condition of such a watercourse.

• Where at all possible, limit the disturbance to the zone of the thalweg. This is due to the ecological importance of the low flow channel and respective habitat being allowed to re- establish improving the ecological condition.

• The build-up of debris/sediment removed from a maintenance site may:

o be utilised for in-filling or other related maintenance actions related to managing erosion, which form part of an adopted MMP;

o not be used to enlarge the height, width or any extent of existing berms;

o not be deposited anywhere within the watercourse or anywhere along the banks of a river where such action is not part of the proposed maintenance activity (ies). Material that cannot be used for maintenance purposes must be removed out of the riparian area to a suitable stockpile location or disposal site. Further action and consideration may be required where the possibility of contaminated material may occur, such as in urban watercourses.

• The use of foreign material, such as concrete, rubble, woody debris and/or dry land-based soil, is strictly prohibited from being used in maintenance actions, unless for the specific purpose of repairs to existing infrastructure, coupled with appropriate mitigation measures.

• On completion of the maintenance action, the condition of the site in terms of relative topography should be similar to the pre-damaged state (i.e. the shape of the riverbank should be similar or in a state which is improved to manage future damage). This ultimately dictates that the channel, banks and bed cannot be made narrower, higher or deepened respectively. Exceptions are considered for systems involved with the management of stormwater and improvements for water quality within the urban context.

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5.3. CONSIDERATION OF ALTERNATIVES

As discussed in Section 5.1, Options 4, 5 and 6 are likely to have more significant impacts on aquatic habitats as they are proposed within and adjacent to wetland areas that are still largely natural and of moderate to high EIS.

Option 3 although within an area that is less disturbed is located largely away from any aquatic habitat considered to be of moderate to high EIS and would thus have a less significant impact on the aquatic ecosystems in the area.

Option 2 will largely be located within the disturbed area at the landfill site and then cross the Zeekoevlei Canal at an existing culvert bridge. It will then follow an existing road along the northern boundary road before joining the current access road into the WWTW. This route can thus be expected to have the least potential impact on the adjacent aquatic ecosystems.

Option 1 will need to cross the Zeekoevlei at a new location that contains wetland habitat along the eastern bank at the crossing and will require widening of a second road through the WWTW to the proposed widening of the existing access road. In addition, the bird populations along this alternative route are much more. The impact of the traffic on bird life in the wetland areas would thus be more significant.

The No-Go Alternative would imply that the existing access route adjacent to Zeekoevlei continues to be utilised. As this road is within a formally protected area, the impact of increasing traffic to the WWTW would be more significant than the proposed new access road. From this assessment, there is no reason from a freshwater perspective why the proposed activities should not be approved in preference to the No-Go Alternative.

A comparison impact table for the proposed alternative access routes, as well as the No-Go alternative, is provided in the following section.

5.4. IMPACT ASSESSMENT TABLES FOR THE POTENTIAL AQUATIC IMPACTS OF THE VARIOUS PROPOSED ACCESS ROUTES

The impact assessment was undertaken as per the methodology outlined in Appendix B of this report. The below tables assess the overall impact of the proposed route alternatives on the aquatic features (i.e. the combined impact of the road on aquatic habitat, water quality and flow that have been discussed in the previous sections). For this reason, the scores reflected below may vary slightly (be slightly higher) than those mentioned in the discussions on the various types of aquatic ecosystem impacts.

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CONSTRUCTION PHASE:

Option 1 Extent Intensity Duration Consequence Probability Significance Status Confidence

Without Local Medium Short term Very low Probable VERY LOW -ve High mitigation 1 2 1 4 Essential mitigation measures: See Section 5.2 With Local Medium Short term Very low Possible INSIGNIFICA -ve High mitigation 1 4 1 3 NT

Option 2 Extent Intensity Duration Consequence Probability Significance Status Confidence

Without Local Low Short term Very low Probable VERY LOW -ve High mitigation 1 1 1 3 Essential mitigation measures: See Section 5.2 With Local Low Short term Very low Possible INSIGNIFICA -ve High mitigation 1 1 1 3 NT

Option 3 Extent Intensity Duration Consequence Probability Significance Status Confidence

Without Local Low Short term Very low Probable LOW -ve High mitigation 1 1 1 3 Essential mitigation measures: See Section 5.2 With Local Low Short term Very low Improbable INSIGNIFICA -ve High mitigation 1 1 1 3 NT Option 4 Extent Intensity Duration Consequence Probability Significance Status Confidence

Without Region Medium Long term High Probable HIGH -ve High mitigation 2 2 3 7 Essential mitigation measures: See Section 5.2 With Local Medium Long term Medium Probable MEDIUM -ve High mitigation 1 2 3 6

Option 5 Extent Intensity Duration Consequence Probability Significance Status Confidence

Option 6 Extent Intensity Duration Consequence Probability Significance Status Confidence

OPERATION PHASE: Option 1 Extent Intensity Duration Consequence Probability Significance Status Confidence

Without Local Medium Short term Very low Probable VERY LOW -ve Medium/ mitigation 1 2 1 3 High Essential mitigation measures: See Section 5.2 With Local Medium Short term Very low Improbable INSIGNIFICA -ve Medium/ mitigation 1 2 1 3 NT High

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Option 2 Extent Intensity Duration Consequence Probability Significance Status Confidence

Without Local Low Short term Very low Probable VERY LOW -ve Medium/ mitigation 1 1 1 3 High Essential mitigation measures: See Section 5.2 With Local Low Short term Very low Improbable INSIGNIFICA -ve Medium/ mitigation 1 1 1 3 NT High

Option 3 Extent Intensity Duration Consequence Probability Significance Status Confidence

Option 4 Extent Intensity Duration Consequence Probability Significance Status Confidence

Without Region Medium Long term High Definite HIGH -ve Medium/ mitigation 2 2 3 7 High Essential mitigation measures: See Section 5.2 With Local Medium Long term Medium Probable MEDIUM -ve Medium/ mitigation 1 2 3 6 High Option 5 Extent Intensity Duration Consequence Probability Significance Status Confidence

Option 6 Extent Intensity Duration Consequence Probability Significance Status Confidence

No Go Extent Intensity Duration Consequence Probability Significance Status Confidence

Without Local Low Short term Very low Possible INSIGNIFICA -ve Medium/ mitigation 1 1 1 3 NT High Essential mitigation measures: See Section 5.2 With Local Low Short term Very low Improbable INSIGNIFICA -ve Medium/ mitigation 1 1 1 3 NT High

6. RISK ASSESSMENT

The risk matrix is a tool utilised to inform Section 21(c) and (i) water uses only. The assessment indicates the level of risk certain activities pose to freshwater resources. The outcomes are used to guide decisions regarding water use authorisation of the proposed activity. Summaries of the potential risks can be seen in Table 16 where the various alternatives associated with the proposed access road are considered. The risk rating classes can be seen in Table 17.

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Table 16. A summary of the risk assessment for the proposed new access road alternatives Phases Activity Aspect Impact Significance Risk Rating Construction Option 1 - new Bridge Construction of road will Aquatic habitat 130 M over Zeekoe Canal and require some infilling of loss/modification, widening of road in adjacent WWTW ponds and water quality and WWTW, adjacent to ponds wetland areas adjacent to flow impacts Zeekoevlei Canal Option 2 - upgrade Bridge Construction of road will 117 M over Zeekoe Canal, require some infilling of adjacent to duneslack and adjacent WWTW ponds and widening of road in wetland areas adjacent to WWTW adjacent to ponds Zeekoevlei Canal Option 3 - road away from Construction of road will 108 M duneslacks by next to require some works wetlands in WWTW adjacent to wetlands at WWTW Option 4 - road through Construction of road will 168 M duneslacks and adjacent to require some infilling within wetlands in WWTW duneslacks and WWTW wetlands Option 5 - road through Construction of road will 168 M duneslacks and adjacent to require some infilling within wetlands in WWTW duneslacks and WWTW wetlands Option 6 - road through Construction of road will 168 M duneslacks and adjacent to require some infilling within wetlands in WWTW duneslacks and WWTW wetlands Operation Operation and The potential for the Flow and habitat 126 M maintenance for Option 1 upgraded road to alter modification and Operation and flow, for contaminated run- water quality 117 M maintenance for Option 2 off from the road surface to impairment Operation and enter the aquatic features 117 M maintenance for Option 3 as well as possible Operation and increased disturbance, litter 154 M maintenance for Option 4 and alien vegetation Operation and growth impacting on 154 M maintenance for Option 5 aquatic habitat and biota Operation and 154 M maintenance for Option 6

The new access road for all of the alternative routes is considered to pose a moderate risk to the adjacent aquatic habitats for the construction and operations phases and thus likely to require a water use licence application. The proposed upgrade for Options 2 and 3 as well as potentially Option1 could potentially be reduced to a Low risk with the implementation of the recommended mitigation measures such that these route alternatives could fall within the ambit of the General Authorisations for Section 21(c) and (i) water uses.

Table 17: Risk rating classes for the Risk Assessment RATING CLASS MANAGEMENT DESCRIPTION Acceptable as is or consider requirement for mitigation. Impact to watercourses and 1 – 55 (L) Low Risk resource quality small and easily mitigated. Wetlands may be excluded. Risk and impact on watercourses are notably and require mitigation measures on a 56 – 169 M) Moderate Risk higher level, which costs more and require specialist input. Wetlands are excluded. 170 – Always involves wetlands. Watercourse(s) impacts by the activity are such that they (H) High Risk 300 impose a long-term threat on a large scale and lowering of the Reserve.

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7. WETLAND OFFSET ASSESSMENT

7.1. ASSESSMENT OF WETLAND OFFSET REQUIREMENTS

The wetland features within the site are summarised in Table 18. The potential loss of wetland areas due to the construction of the proposed access route Option 6 as the preferred alternative (Options 4 and 5 would have similar requirements) were assessed using the DWS Wetland Offset Calculator to determine the wetland targets that would need to be achieved by the proposed wetland offset. To undertake the assessment two calculations were undertaken:

• Determining the wetland offset requirements for a scenario where all the wetland areas traversed by the proposed access road (Option 6 as the preferred route was considered in the offset requirement determination) would be lost (or in the case of the wetland areas within the proposed wetland offset site, rehabilitated); and • Assessing the wetland offset that would be gained from the creation of all the wetland habitat indicated in the proposed wetland offset plan.

Figure 25 shows the proposed Option 6 route in relation to the existing wetland areas and thus areas that would be lost or partially lost and disturbed by the proposed road construction. The figure also shows the proposed focus area for the wetland offset. This area currently comprises of a mix of largely natural dunes together with highly disturbed and modified wetland habitat as a result of past activities adjacent to the WWTW. The proposal is to return this area to an area that would comprise of duneslack wetland habitat.

The wetland habitats considered in the assessment, as well as their extent, condition and importance, are provided in the table below.

Table 18: Summary of wetland features occurring on the site Wetland feature Present Ecological Ecological Importance Extent (ha) Status and Sensitivity Duneslack wetlands 1.6 B Moderate Largely artificial wetlands associated with 4.75 C/D Low works associated with the WWTW Total Extent 6.35 - -

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Figure 25. 2016 Orthophotograph of the study area with the proposed wetland offset focus area indicated by the red polygon. The existing mapped wetlands as well as the proposed access road are also indicated on the image.

A summary of the wetland offset targets for the wetland areas lost or rehabilitated, as determined by the DWS wetland offset calculator and described in more detail in the wetland offset plan for the project is provided in Table 19. The detailed assessments of the wetland offset targets are attached in the wetland offset plan for the proposed project.

Table 19: Assessed Wetland Offset Targets for wetland areas that would be lost or rehabilitated Determining wetland offset targets Dune slack wetlands Artificial wetlands Total Functional Offset Target (Functional hectare 1.1 3.2 4.3 equivalents) Ecosystem Conservation Target (Habitat hectare 6.3 5.9 12.2 equivalents) Species Conservation Target (Species measure in 140 55 - terms of habitat intactness)

The aim of the wetland offset determination is no ensure no net loss of functional and ecological value of the wetlands. The wetland offset calculator determined each of these components as hectare equivalents that should in total be exceeded by the proposed wetland offset. The species conservation target should at least equal or better on the current condition.

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7.2. DESCRIPTION OF PROPOSED WETLAND OFFSET

The rehabilitation and creation of approximately 11 ha of wetland habitat (at the location indicated in Figure 24) that would consist of a mosaic of duneslack and seasonal depression wetlands adjacent to the existing WWTW and dune slack wetland habitats within the larger site is proposed to provide a wetland offset with the following potential wetland gains. The desired condition of the proposed wetland offsets is a B/C Category (largely natural to moderately modified). The duneslack habitat recreated in this area would be intended to replace lost wetland habitat considered important for species of conservation value such as Psoralea aphylla and Cliffortia longifolia (Flora Species of Conservation Concern, both occurring in the wider area being regarded as Vulnerable) and the butterflies Kedestes barbarae bunta and Kedestes lenis lenis which are Cape Flats endemics and are listed as Critically Endangered and Endangered respectively.

A summary of the potential gains of the proposed wetland offset is provided in Table 20 below. The detailed assessment of the proposed wetland offsets is included in the separate wetland offset plan for the project.

Table 20: Potential Gains of Proposed Wetland Offsets Duneslack and Seasonal Offset Receiving Areas: Assessing potential gains wetlands

Functional Offset Contribution (Functional hectare equivalents) 5.1

Ecosystem Conservation Offset Contribution (hectare equivalents) 12.8

Final Offset Contribution (Species measure) 160

7.3. EVALUATION OF ACCEPTABILITY OF PROPOSED WETLAND OFFSET

Table 21 provides a summary of the wetland offset targets and objectives listed in Table 19 as compared to the gains associated with the proposed wetland offsets (Table 20). The proposed wetland offset will be located within the same area and is within the same vegetation type and will be of the same wetland types to the wetland areas that would be lost, except the artificial wetland habitats that have developed adjacent to the WWTW. This wetland habitat is dominated with Typha bulrush which is abundant in the area and also not desirable in terms of habitat suitability for target aquatic biota.

Table 21: Comparison of the overall wetland offset targets against the potential gains of the proposed wetland offsets Wetland Offset Target Component Proposed offset area Comment required for Option 6 The extent of the wetland habitats post- Wetland Extent 6.35 11 development would be substantially increased The wetland offset will exceed the wetland Wetland functionality 4.3 5.1 offset target as more functional wetland (Hectare Equivalent) habitat will be created Wetland offset gains would exceed the Ecosystem wetland offset target in terms of ecosystem Conservation 12.2 12.8 conservation due to the rehabilitation of more (Hectare Equivalent) ecological important wetlands.

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The wetland offset gains will exceed the wetland offset target in terms of species Species Conservation 140 160 conservation due to the proposed (% habitat intactness) rehabilitation and establishment of wetland areas

8. CONCLUSIONS AND RECOMMENDATIONS

The following aquatic features occur within the study area:

• Zeekoevlei Canal that would need to be crossed by some of the proposed access road alternatives (Options 1 and 2);

• Cape Flats Wastewater Treatment Works (WWTW) associated ponds and water bodies that would need to be crossed for all of the alternative access roads proposed; and

• Dune slack wetland areas to the north-west and east of the WWTW, along all of the alternative access roads proposed.

The entire False Bay – Zeekoevlei Nature Reserve in which the WWTW occurs is a formally protected area. The dune slack wetlands to the east and north of the WWTW are mapped as aquatic CBAs and the surrounding areas of natural vegetation cover mapped as terrestrial CBAs. The wetland habitats associated with the ponds in the WWTW are mapped as Critical ESAs. The wetlands associated with the ponds in the WWTW are also all mapped as artificial FEPA Wetlands while Zeekoevlei and the Zeekoevlei Channel are mapped as natural FEPA Wetlands.

The instream and riparian habitat integrity of the Zeekoevlei Canal is considered to be largely to seriously modified. This is largely due to the flow and water quality related impacts on the watercourse. The duneslack wetland areas are in general still in a largely natural ecological state. The duneslack wetlands that are closer to the WWTW and the urban areas are more disturbed and range from being moderately to largely modified depending on the level of disturbance taking place.

The Zeekoevlei Canal is considered to be of moderate to low EIS. Due to its artificial and degraded condition, the watercourse is not likely to contain any intolerant species however it does provide refuge and a corridor for the movement of biota in a transformed landscape. Zeekoevlei as a large and still largely natural wetland area, is of high ecological importance and sensitivity, while the largely natural duneslack wetlands are considered of Moderate to High EIS. The artificial WWTW ponds and degraded duneslack wetlands are considered of a low EIS.

The proposed BBF is likely to have a very low to insignificant impact on the adjacent degraded and artificial wetland habitat within the footprint of the WWTW, provided the construction works are

Aquatic Ecological Assessment: New Access Road to Cape Flats WWTW April 2021 Page | 67 contained to the indicated footprint and good housekeeping measures are implemented and monitored in terms of the Environmental Management Plan for the project.

It can be expected that the likely impacts of the proposed new access road for Options 1 and 2 would be of a limited extent and a short-term nature, occurring mostly during the construction phase. Over the longer term, one can expect a limited impact from the use and maintenance of the road. Longer term impacts could also be expected as a result of increased traffic through the ponds. Some of this traffic does already take place along the existing route which occurs adjacent to the more ecologically important Zeekoevlei. This impact would, however, be more of significance for Option 1, given the higher bird populations that usually frequent the southern portions of the WWTW.

Options 4, 5 and 6 cross several moderately disturbed and then largely natural duneslack wetlands before entering the property of the WWTW from the east and passing some disturbed and largely artificial wetland areas. This route can be expected to have a potential high significance impact on the wetlands in the area, even with mitigation as the road will need to alter the topography and surface as well as sub-surface flow through the area as well as provide an access point for further disturbance, dumping of waste and potential development of the area. Should one of these access routes be considered, it would need to be done in conjunction with the approved development layout for Pelican Park Phase 2, given that the faunal, botanical and aquatic specialist studies for this proposed development have also identified the central dune and duneslack habitats as being of Medium to High Conservation Value.

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Summary of aquatic impact significance:

Construction Phase: Impact Consequence Probability Significance Status Confidence

Without Very low Probable VERY LOW -ve High

Mitigation on 1 on With Very low Possible INSIGNIFICANT -ve High Opti Mitigation

Without Very low Probable VERY LOW -ve High 2 Mitigation With Very low Possible INSIGNIFICANT -ve High

Option Option Mitigation

Without Very low Probable VERY LOW -ve High 3 Mitigation With Very low Improbable INSIGNIFICANT -ve High Option Option Mitigation

Without High Probable HIGH -ve High Mitigation

ption 4 ption With Medium Probable MEDIUM -ve High

O Mitigation

Without High Probable HIGH -ve High 5 Mitigation

ption ption With Medium Probable MEDIUM -ve High O Mitigation

Without High Probable HIGH -ve High 6 Mitigation

ption ption With Medium Probable MEDIUM -ve High O Mitigation

Operation Phase: Impact Consequence Probability Significance Status Confidence

Without Very low Probable VERY LOW -ve Medium/ High Mitigation

ption 1 ption With Very low Improbable INSIGNIFICANT -ve Medium/ High

O Mitigation

Without Very low Probable VERY LOW -ve Medium/ High 2 Mitigation With Very low Improbable INSIGNIFICANT -ve Medium/ High

Option Option Mitigation

Without Very low Probable VERY LOW -ve Medium/ High 3 Mitigation With Very low Improbable INSIGNIFICANT -ve Medium/ High Option Option Mitigation

Without High Definite HIGH -ve Medium/ High

Mitigation tion 4 tion

p With Medium Probable MEDIUM -ve Medium/ High

O Mitigation

Without High Definite HIGH -ve Medium/ High 5 Mitigation

ption ption With Medium Probable MEDIUM -ve Medium/ High O Mitigation

Without High Definite HIGH -ve Medium/ High 6 Mitigation

ption With Medium Probable MEDIUM -ve Medium/ High

O Mitigation Without Very low Possible INSIGNIFICANT -ve Medium/ High

Mitigation Go - With Very low Improbable INSIGNIFICANT -ve Medium/ High No Mitigation

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Recommended mitigation measures:

Construction Phase:

• Work within or adjacent to aquatic features should be limited as far as possible and the disturbed areas rehabilitated immediately afterwards;

• The constructed road should result in a minimal alteration to the surrounding natural topography;

• Construction within watercourses should as far as possible take place during the drier months of the year (November to March);

• Excess spoil material should be removed to an approved disposal site;

• Use of materials for the construction works should as far as possible be free of alien invasive plant seed;

• The materials utilised for the constructed road should be obtained from an approved source area; and

• Once construction is complete, the area should be rehabilitated and, where necessary, vegetated with suitable local indigenous plants.

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Operation Phase:

The new access road for all of the alternative routes is considered to pose a moderate risk to the adjacent aquatic habitats for the construction and operations phases and thus likely to require a water use licence application. The proposed upgrade for Options 2 and 3 as well as potentially Option1 could potentially be reduced to a Low risk with the implementation of the recommended mitigation measures such that these route alternatives could fall within the ambit of the General Authorisations for Section 21(c) and (i) water uses.

Given the findings of this assessment, there is no reason why the proposed new access road for Options 1, 2 and 3 should not be approved from an aquatic ecosystem point of view if mitigated as recommended. Options 4, 5 or 6 would need to be adequately mitigated as recommended to reduce the potential aquatic ecosystem impacts. A wetland offset is proposed that would mitigate the potential loss of wetland habitat associated with Options 4. 5 or 6 that would adequately be able to mitigate the loss of wetland habitat that would occur for these proposed routes.

Of all the proposed access routes assessed, Option 3 would have the least potential aquatic ecosystem impacts, followed by Option 2 and Option 1 as these route alternatives all avoid the sensitive duneslack wetland areas and loss of wetland areas that would need to be offset.

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Department of Water Affairs and Forestry. (2007). River Ecoclassification: Manual for Ecostatus Determination (Version 2). Riparian Vegetation Response Index, Water Research Commission Report Number KV 168/05. Pretoria.

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Driver, Nel, Snaddon, Murray, Roux, Hill. (2011). Implementation Manual for Freshwater Ecosystem Priority Areas. Draft Report for the Water Research Commission.

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Holmes P, Stipinovich A & Purves A. (2012). City of Cape Town Biodiversity Network: Methods and Results - Technical Report (C-Plan & Marxan Analysis). City of Cape Town, South Africa.

Holmes P.M., Dorse C., Stipinovich A., Purves A., Wood J., Gibbs D., and Ernstzen R. (2012) Conservation Implementation Plan for Strandveld in The Metro South-East. Environmental Resource Management Department (ERMD), City of Cape Town.

Kotze, D., Marneweck, G.C., Batchelor, A.L., Lindley, D.S. And Collins, N.B. (2005). WET-EcoServices: A technique for rapidly assessing ecosystem services supplied by wetlands. Dept. Tourism, Environmental and Economic Affairs, Free State.

Macfarlane, D. M., Kotze, D. C., Ellery, W. N., Walters, D., Koopman, V., Goodman, P., et al. (2008). WETHealth: A technique for rapidly assessing wetland health. WRC report TT340/08. South Africa: WRC.

Marneweck, G.C. and Batchelor, A. 2002. Wetland inventory and classification. In: Ecological and economic evaluation of wetlands in the upper Olifants River catchment. (Palmer, R.W., Turpie, J., Marneweck, G.C and Batchelor (eds.). Water Research Commission Report No. 1162/1/02.

Mucina, L. and Rutherford, M. C. (eds.) (2006). The Vegetation of South Africa, Lesotho and Swaziland. Strelitzia 19. South African National Biodiversity Institute, Pretoria.

River Health Programme of South Africa (2004). State of Cape Town Rivers. Department of Water Affairs & Forestry, Pretoria.

SANBI (2009). Further Development of a Proposed National Wetland Classification System for South Africa. Primary Project Report. Prepared by the Freshwater Consulting Group (FCG) for the South African National Biodiversity Institute (SANBI).

SANBI Biodiversity GIS. http://bgis.sanbi.org

SANBI Screening Tool. https://screening.environment.gov.za/screeningtool/

Snaddon K, Turner R, Job N, Ollis D and Jones L. (2009). City Wetlands Map: Phase 5 - Ground- truthing and map update, Report submitted to the City of Cape Town.

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Snaddon K. & Day E. (2009) Prioritization of City Wetlands. Report submitted to the City of Cape Town.

Southern Waters. (2000). Zeekoevlei/Rondevlei Rehabilitation Study: Action Plan. Report submitted to the City of Cape Town.

Van Ginkel, C. E., Glen, R. P., Gordon-Gray, K. D., Cilliers, C. J., Muasya, M. and P. P. van Deventer (2011) Easy identification of some South African wetland plants. WRC Report No TT 479/10

WRC. 2011. Atlas for Freshwater Ecosystem Priority Areas – Maps to support sustainable development of water resources (WRC Report No. TT 500/11).

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ANNEXURE A: DETAILS OF SPECIALIST AND DECLARATION OF INTEREST

DECLARATION OF INDEPENDENCE BY THE INDEPENDENT PERSON WHO COMPILED A SPECIALIST REPORT OR UNDERTOOK A SPECIALIST PROCESS

I, Antonia Belcher, as the appointed Specialist hereby declare/affirm the correctness of the information provided or to be provided as part of the application, and that I:

• in terms of the general requirement to be independent:

o other than fair remuneration for work performed in terms of this application, have no business, financial, personal or other interest in the development proposal or application and that there are no circumstances that may compromise my objectivity; or

o am not independent, but another specialist (the “Review Specialist”) that meets the general requirements set out in Regulation 13 has been appointed to review my work (Note: a declaration by the review specialist must be submitted);

• in terms of the remainder of the general requirements for a specialist, have throughout this EIA process met all of the requirements;

• have disclosed to the applicant, the EAP, the Review EAP (if applicable), the Department and I&APs all material information that has or may have the potential to influence the decision of the Department or the objectivity of any report, plan or document prepared or to be prepared as part of the application; and

• am aware that a false declaration is an offence in terms of Regulation 48 of the EIA Regulations, 2014 (as amended).

Signature of the Specialist:

Name of Company: BlueScience (Pty) Ltd

Date: 29 January 2021

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ABBREVIATED CURRICULUM VITAE:

Organisation: BlueScience (Pty) Ltd

Contact details: PO Box 455, Somerset Mall, 7137

Names: Ms Toni Belcher

Profession: Senior Aquatic Ecologist for BlueScience, SACNASP No 400040/10

Expertise: BlueScience (Pty) Ltd provides water resource management services and includes the following:

Summary of projects undertaken by BlueScience since July 2012: Type of project Number of projects undertaken Dam developments 75 Other freshwater and freshwater impact assessments 364 River reach MMP 6 ESKOM 34 Renewable energy (WEF and Solar) 29 Roads (Provincial and National roads) 48 River monitoring and rehabilitation projects 58 Water resource study 12 Water use authorisation applications (not linked to a 26 freshwater assessment study) Water use authorisation audits and licensing monitoring) 7

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APPENDIX B: IMPACT ASSESSMENT METHODOLOGY

The significance of all potential impacts that would result from the proposed Project is determined in order to assist decision-makers. The significance rating of impacts is considered by decision- makers, as shown below.

• INSIGNIFICANT: the potential impact is negligible and will not have an influence on the decision regarding the proposed activity.

• VERY LOW: the potential impact is very small and should not have any meaningful influence on the decision regarding the proposed activity.

• LOW: the potential impact may not have any meaningful influence on the decision regarding the proposed activity.

• MEDIUM: the potential impact should influence the decision regarding the proposed activity.

• HIGH: the potential impact will affect a decision regarding the proposed activity.

• VERY HIGH: The proposed activity should only be approved under special circumstances.

The significance of an impact is defined as a combination of the consequence of the impact occurring and the probability that the impact will occur. The significance of each identified impact2 must be rated according to the methodology set out below:

Step 1 – Determine the consequence rating for the impact by determining the score for each of the three criteria (A-C) listed below and then adding them3. The rationale for assigning a specific rating, and comments on the degree to which the impact may cause irreplaceable loss of resources and be irreversible, must be included in the narrative accompanying the impact rating:

A. Extent– the area over which the impact will be experienced Local Confined to project or study area or part thereof (e.g. site) 1 Regional The region, which may be defined in various ways, e.g. cadastral, catchment, 2 topographic (Inter) national Nationally or beyond 3

B. Intensity– the magnitude of the impact in relation to the sensitivity of the receiving environment, taking into account the degree to which the impact may cause irreplaceable loss of resources Low Site-specific and wider natural and/or social functions and processes are 1 negligibly altered Medium Site-specific and wider natural and/or social functions and processes continue 2 albeit in a modified way High Site-specific and wider natural and/or social functions or processes are 3 severely altered

C. Duration– the timeframe over which the impact will be experienced and its reversibility Short-term Up to 2 years (i.e. reversible impact) 1 Medium-term 2 to 15 years (i.e. reversible impact) 2 Long-term More than 15 years (state whether impact is irreversible) 3

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The combined score of these three criteria corresponds to a Consequence Rating Combined 3 – 4 5 6 7 8 – 9 Score (A+B+C) Consequence Very low Low Medium High Very high Rating

Step 2 – Assess the probability of the impact occurring according to the following definitions: Probability– the likelihood of the impact occurring Improbable < 40% chance of occurring Possible 40% - 70% chance of occurring Probable > 70% - 90% chance of occurring Definite > 90% chance of occurring

Step 3 – Determine the overall significance of the impact as a combination of the consequence and probability ratings, as set out below: Probability Improbable Possible Probable Definite

Very Low INSIGNIFICANT VERY LOW VERY LOW

Low VERY LOW LOW LOW Medium LOW MEDIUM MEDIUM High MEDIUM HIGH HIGH

Consequence Very High HIGH VERY HIGH VERY HIGH

Step 4 – Note the status of the impact (i.e. will the effect of the impact be negative or positive?)

Step 5 – State your level of confidence in the assessment of the impact (high, medium or low).

Step 6 – Identify and describe practical mitigation and optimisation measures that can be implemented effectively to reduce or enhance the significance of the impact. Mitigation and optimisation measures must be described as either:

• Essential: best practice measures which must be implemented and are non-negotiable; and.

• Best Practice: recommended to comply with best practice, with adoption dependent on the proponent’s risk profile and commitment to adhere to best practice, and which must be shown to have been considered and sound reasons provided by the proponent if not implemented.

Essential mitigation and optimisation measures must be inserted into the completed impact assessment table. The impact should be re-assessed with mitigation, by following Steps 1-5 again to demonstrate how the extent, intensity, duration and/or probability change after implementation of the proposed mitigation measures. Extent Intensity Duration Consequence Probability Significance Status Confidence

Without mitigation Essential mitigation measures:

With mitigation

Best practice measures (which are assumed not to affect impact significance ratings) must be presented in the text, in bullet format.

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Step 7 – Summarise all impact significance ratings as follows in your executive summary: Impact Consequence Probability Significance Status Confidence

Without Mitigation With

Option 1 Option Mitigation

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APPENDIX C. RISK MATRIX FOR THE PROJECT

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ASPECTS AND IMPACT REGISTER/RISK ASSSESSMENT FOR WATERCOURSES INCLUDING RIVERS, PANS, WETLANDS, SPRINGS,DRAINAGE LINES PROJECT: PROPOSED NEW ACCESS ROAD TO CAPE FLATS WWTW COMPILED BY: Toni Belcher, BlueScience (SACNASP 400040/10) DATE: July 2020

Severity Nr. Phases Activity Aspect Impact Flow Physico & Habitat Biota Severity Spatial Duration Consequence Frequency Frequency Legal Detection Likelihood Significance Risk Control Measures Confidence Type Watercourse; Regime Chemical (Geomorph+ scale of activity of impact Issues Rating PES and EIS (Water Vegetation) Quality) 1 Construction Option 1 - new Construction of road Aquatic habitat 5 5 5 5 5 3 2 10 1 4 5 3 13 130 M Construction Phase: Bridge over Zeekoe will require some loss/modification • Work within or adjacent to aquatic features should be Canal and infilling of adjacent , water quality limited as far as possible and the disturbed areas widening of road in WWTW ponds and and flow impacts rehabilitated immediately afterwards; WWTW, adjacent to wetland areas • The constructed road should result in minimal ponds adjacent to Zeekoevlei alteration to the surrounding natural topography; Canal • Construction within watercourses should as far as 1 Option 2 - upgrade Construction of road 5 5 5 5 5 2 2 9 1 4 5 3 13 117 M possible take place during the drier months of the year Bridge over Zeekoe will require some (November to March); Canal, adjacent to infilling of adjacent • Contaminated runoff from the construction site(s) duneslack and WWTW ponds and should be prevented from entering the watercourses. widening of road in wetland areas The laydown area and main construction site should WWTW adjacent to adjacent to Zeekoevlei be located at least 20 m away from any aquatic ponds Canal features. All materials on the construction site should 2 Option 3 - road Construction of road 5 5 5 5 5 2 2 9 1 3 5 3 12 108 M be properly stored and contained. Any stockpiling of away from will require material should also take place at least 20 m from any duneslacks by next someworks adjacent aquatic features to reduce the risk of runoff from these to wetlands in to wetlands at WWTW areas into the watercourse/wetlands. Disposal of WWTW waste from the site and the associated works should be properly managed and responsibly disposed of. Construction workers should be given ablution Option 4 - road Construction of road 5 5 5 5 5 3 4 12 1 5 5 3 14 168 M facilities at the construction works that are located through duneslacks will require some away from the aquatic features (at least 20m) and and adjacent to infilling within regularly serviced. These measures should be wetlands in WWTW duneslacks and addressed, implemented and monitored in terms of WWTW wetlands the Environmental Management Programme for the construction phase; • The construction of the road along the section of road between the Zeekoevlei Canal and the existing access 2 Option 5 - road Construction of road 5 5 5 5 5 3 4 12 1 5 5 3 14 168 M road to the works must give consideration to through duneslacks will require some Zeekoevlei Canal - subsurface flow at the road in the area of the wetlands and adjacent to infilling within PES=D/Eand to ensure that the road does not significantly impede wetlands in WWTW duneslacks and EIS=Moderate to this flow; WWTW wetlands Low; Duneslacks • Where the roads need to cross any of the wetland High PES=B / C and features, consideration of the surface and sub-surface EIS=High to flow characteristics of that aquatic feature will need to 4 Operation Operation and The potential for the Flow and habitat 5 5 5 5 5 2 2 9 2 4 5 3 14 126 M Moderate; WWTW be taken into consideration and mitigated through the maintenance for upgraded road to alter modification and ponds PES=E and use of culverts or permeable road surfaces to Option 1 flow, for contaminated water quality EIS=Low run-off from the road impairment minimise the impact of the road on flow as far as surface to enter the possible. aquatic features as • Excess spoil material should be removed to an well as possible approved disposal sites; Operation and increased 5 5 5 5 5 2 2 9 2 3 5 3 13 117 M • Use of materials for the construction works should as maintenance for disturbance, litter and far as possible be free of alien invasive plant seed; Option 2 alien vegetation • The materials utilised for the constructed road should growth impacting on be obtained from an approved source area; and aquatic habitat and • Once construction is complete, the area should be biota rehabilitated and, where necessary, vegetated with suitable local indigenous plants. Operation and 5 5 5 5 5 2 2 9 2 3 5 3 13 117 M Operation Phase: maintenance for • Should the road pass through formally protected Option 3 areas, the access to these areas should be restricted to prevent the roads from providing access for the dumping of waste material and increasing disturbance into these areas; Operation and 5 5 5 5 5 2 4 11 2 4 5 3 14 154 M • Any invasive alien plants along the road should be maintenance for removed on an ongoing basis according to methods Option 4 as provided by the Working for Water Programme.

4 Operation and 5 5 5 5 5 2 4 11 2 4 5 3 14 154 M maintenance for Option 5

* Risks although greater than 56 are still deemed to be low

Signed: Aquatic Ecological Assessment: New Access Road to Cape Flats WWTW April 2021

Date: 23 July 2020 Page | 80

APPENDIX D: LOCATION OF CONTENT PRESCRIBED BY NEMA FOR SPECIALIST REPORTS: APPENDIX 6 OF GN R326

Table 22: Minimum Requirements for Aquatic Biodiversity Specialist Assessment as per Protocol for the Specialist Assessment of Environmental Impacts on Aquatic Biodiversity (GN 320 of 20 March 2020) Protocol ref Aquatic Biodiversity Specialist Assessment Section / Page / Included 2.3. The assessment must provide a baseline description of the site Section 3 which includes, as a minimum, the following aspects: 2.3.1. a description of the aquatic biodiversity and ecosystems on the site, including; 2.3.1. (a) aquatic ecosystem types; and Section 3.3 2.3.1. (b) presence of aquatic species, and composition of aquatic species Section 3.3.1 communities, their habitat, distribution and movement patterns; 2.3.2. the threat status of the ecosystem and species as identified by the Section 2.1 screening too11; 2.3.3. an indication of the national and provincial priority status of the Section 2.1 and 3.2.6 aquatic ecosystem, including a description of the criteria for the given status (i.e. if the site includes a wetland or a river freshwater ecosystem priority area or sub catchment, a strategic water source area, a priority estuary, whether or not they are free-flowing rivers, wetland clusters, a critical biodiversity or ecologically sensitivity area); and 2.3.4. a description of the ecological importance and sensitivity of the Section 3.3.4 aquatic ecosystem including: 2.3.4. (a) the description (spatially, if possible) of the ecosystem processes Section 3.2 that operate in relation to the aquatic ecosystems on and immediately adjacent to the site (e.g. movement of surface and subsurface water, recharge, discharge, sediment transport, etc.); and 2.3.4. (b) the historic ecological condition (reference) as well as present Section 3.3 ecological state of rivers (in-stream, riparian and floodplain habitat), wetlands and/or estuaries in terms of possible changes to the channel and flow regime (surface and groundwater). 2.4. The assessment must identify alternative development footprints Section 5.1 within the preferred site which would be of a "low" sensitivity as identified by the screening tool and verified through the site sensitivity verification and which were not considered appropriate. 2.5. Related to impacts, a detailed assessment of the potential impacts Section 5.1, 5.2, 5.3 and 6 of the proposed development on the following aspects must be undertaken to answer the following questions: 2.5.1. is the proposed development consistent with maintaining the priority aquatic ecosystem in its current state and according to the stated goal? 2.5.2. is the proposed development consistent with maintaining the resource quality objectives for the aquatic ecosystems present? 2.5.3. how will the proposed development impact on fixed and dynamic ecological processes that operate within or across the site? This must include: 2.5.3. (a) impacts on hydrological functioning at a landscape level and across the site which can arise from changes to flood regimes (e.g. suppression of floods, loss of flood attenuation capacity, unseasonal flooding or destruction of floodplain processes); 2.5.3. (b) will the proposed development change the sediment regime of the

1 These ecosystems include the National Environmental Management Biodiversity Act. 2004(Act No. 10 of 2004) listed ecosystems.

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Protocol ref Aquatic Biodiversity Specialist Assessment Section / Page / Included aquatic ecosystem and its sub-catchment (e.g. sand movement, meandering river mouth or estuary, flooding or sedimentation patterns); 2.5.3. (c) what will the extent of the modification in relation to the overall aquatic ecosystem be (e.g. at the source, upstream or downstream portion, in the temporary / seasonal / permanent zone of a wetland, in the riparian zone or within the channel of a watercourse, etc.); and 2.5.3. (d) to what extent will the risks associated with water uses and related activities change; 2.5.4. how will the proposed development impact on the functioning of the aquatic feature? This must include: 2.5.4. (a) base flows (e.g. too little or too much water in terms of characteristics and requirements of the system); 2.5.4. (b) quantity of water including change in the hydrological regime or hydroperiod of the aquatic ecosystem (e.g. seasonal to temporary or permanent; impact of over-abstraction or instream or off-stream impoundment of a wetland or river); 2.5.4. (c) change in the hydrogeomorphic typing of the aquatic ecosystem (e.g,change from an unchannelled valley-bottom wetland to a channelled valley-bottom wetland); 2.5.4. (d) quality of water (e.g. due to increased sediment load, contamination by chemical and/or organic effluent, and/or eutrophication); 2.5.4. (e) fragmentation (e.g. road or pipeline crossing a wetland) and loss of ecological connectivity (lateral and longitudinal); and 2.5.4. (f) the loss or degradation of all or part of any unique or important features, associated with or within the aquatic ecosystem (e.g. waterfalls, springs, oxbow lakes, meandering or braided channels, peat soils, etc.); 2.5.5. how will the proposed development impact on key ecosystems regulating, and supporting services especially: 2.5.5. (a) flood attenuation; 2.5.5. (b) streamflow regulation; 2.5.5. (c) sediment trapping; 2.5.5. (d) phosphate assimilation; 2.5.5. (e) nitrate assimilation; 2.5.5. (f) toxicant assimilation; 2.5.5. (g) erosion control; and 2.5.5. (h) carbon storage? 2.5.6. how will the proposed development impact community composition (numbers and density of species) and integrity (condition, viability, predator-prey ratios, dispersal rates, etc.) of the faunal and vegetation communities inhabiting the site? 2.6. In addition to the above, where applicable, impacts to the frequency Not applicable of estuary mouth closure should be considered, in relation to: 2.6. (a) size of the estuary; 2.6. (b) availability of sediment; 2.6. (c) wave action in the mouth; 2.6. (d) protection of the mouth; 2.6. (e) beach slope; 2.6. (f) volume of mean annual runoff; and 2.6. (g) extent of saline intrusion (especially relevant to permanently open systems),

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Table 23: Minimum Content Requirements for Aquatic Biodiversity Specialist Reports as per Protocol for the Specialist Assessment of Environmental Impacts on Aquatic Biodiversity (GN 320 of 20 March 2020) Aquatic Biodiversity Specialist Assessment Report Protocol ref Content requirement Section / Page in Report 2.7.1. contact details of the specialist, their SACNASP registration number, Section 1.1 their field of expertise and a curriculum vitae; 2.7.2. a signed statement of independence by the specialist; Section 1.2 2.7.3. a statement on the duration, date and season of the site inspection Section 2.3 and the relevance of the season to the outcome of the assessment; 2.7.4. the methodology used to undertake the site inspection and the Section 2.3 specialist assessment, including equipment and modelling used, where relevant; 2.7.5. a description of the assumptions made, any uncertainties or gaps in Se4ction 2.3 knowledge or data; 2.7.6. the location of areas not suitable for development, which are to be Section 5.1 avoided during construction and operation, where relevant; 2.7.7. additional environmental impacts expected from the proposed Section 5.2 development; 2.7.8. any direct, indirect and cumulative impacts of the proposed Section 5.2 development on site; 2.7.9. the degree to which impacts and risks can be mitigated; Section 5.1 and 5.3 2.7.10. the degree to which the impacts and risks can be reversed; Section 5.1 and 5.2 2.7.11. the degree to which the impacts and risks can cause loss of Section 5.1 and 5.2 irreplaceable, resources; 2.7.12. a suitable construction and operational buffer for the aquatic Section 5.1 and 5.2 ecosystem, using the accepted methodologies; 2.7.13 proposed impact management actions and impact management Section 5.1 and 5.2 outcomes for inclusion in the Environmental Management Programme (EMPr); 2.7.14. a motivation must be provided if there were development footprints Section 7 identified as per paragraph 2.4 above that were identified as having a 'low" aquatic biodiversity sensitivity and that were not considered appropriate; 2.7.15. a substantiated statement, based on the findings of the specialist Section 7 assessment, regarding the acceptability or not of the proposed development and if the proposed development should receive approval or not; and 2.7.16. any conditions to which this statement is subjected. Section 7

Aquatic Ecological Assessment: New Access Road to Cape Flats WWTW April 2021

WETLAND OFFSET PLAN FOR THE CAPE FLATS WASTEWATER TREATMENT WORKS NEW

ACCESS ROAD, CAPE TOWN

JANUARY 2021

Prepared By: Toni Belcher Email: [email protected] Cell: 082 883 8055

TABLE OF CONTENTS

KEY DEFINITIONS AND CONCEPTS ...... 1 1. INTRODUCTION ...... 3 2. DESCRIPTION OF EXISTING AQUATIC FEATURES ON AND ADJACENT TO THE WETLAND OFFSET SITE ...... 4 3. WETLAND OFFSET TARGET DETERMINATION ...... 7 4. PROPOSED WETLAND OFFSET ...... 7 5. DESCRIPTION OF DRIVERS OF THE WETLAND HABITAT FORMATION ...... 8 6. WETLAND OFFSET PLAN SCOPE AND ASSUMPTIONS ...... 9 7. WETLAND OBJECTIVES AND RECOMMENDATIONS ...... 9

LOCATION AND EXTENT ...... 9 RECOMMENDED ECOLOGICAL CONDITION ...... 1112 WETLAND CREATION OBJECTIVES ...... 1112 GUIDING PRINCIPLES ...... 1213 KEY RECOMMENDATIONS ...... 1213 8. IMPLEMENTATION PLAN FOR ESTABLISHMENT OF THE WETLAND OFFSET AREA ...... 1314 9. METHOD STATEMENTS ...... 1617

CREATION OF NEW WETLAND AREAS ...... 1617 PLANTING OF THE WETLAND OFFSET AREA ...... 1617 CONTROL OF ALIEN AND INVASIVE VEGETATION ...... 1718 10. RECOMMENDED PLANT LIST ...... 1819 11. OPERATION PLAN ...... 1819 12. MONITORING PROGRAMME ...... 1819

MONITORING OF THE WETLAND OFFSET CREATION WORKS ...... 1920 MONITORING OF GROUNDWATER, FLOW AND WATER QUALITY ...... 1920 MONITORING OF AQUATIC ECOSYSTEM HEALTH IMPROVEMENTS ...... 1920 FREQUENCY, INTERVAL AND TIMING OF MONITORING ...... 2021 13. DECLARATION ...... 2223 APPENDIX A: WETLAND OFFSET TARGETS AND POTENTIAL GAINS ...... 2324 APPENDIX B: RESOURCE QUALITY OBJECTIVES FOR THE WETLAND OFFSET ...... 2728 APPENDIX C: DEA&DP GUIDELINES FOR MAINTENANCE WORKS IN WATERCOURSES AND WETLANDS ..... 2829 P a g e | 1

Key Definitions and Concepts

Biodiversity is the variety of plant and animal life in a particular habitat. The term incorporates species, ecological communities and ecosystems; their composition and the ecological and physical processes and function.

Ecological Category is used to define and type the ecological condition of a water resource in either the present, past or future in terms of the deviation of biophysical components from the natural state or Reference Condition.

Ecological Importance and Sensitivity (EIS) indicates the presence of rare and/or sensitive species and sensitive habitats within an aquatic ecosystem. The ecological importance is an expression of its importance to the maintenance of biological diversity and ecological functioning on local and wider scales. Ecological sensitivity (or fragility) refers to the system’s ability to resist disturbance and its capability to recover from disturbance once it has occurred.

Indigenous plants are plants that occur under natural conditions in a particular area and have evolved to cope with particular conditions, circumstances or situations.

Aquatic habitat includes the physical structure of a watercourse or wetland and the associated vegetation in relation to the bed and banks of the watercourse/wetland.

Invasive alien plants are plants that have been introduced to an ecosystem (and are thus not indigenous) and spread such that they may cause economic or environmental harm.

Present Ecological Status (PES) of a water resource refers to the current ecological condition of the resource or a component of the resource, derived from, or described as a change for the worse from a described Reference Condition, which ideally relates to the historically natural condition.

Recommended Ecological Category is the desired ecological condition of an aquatic ecosystem that is recommended a water resource be managed at that allows for a certain level of ecosystem function and supports certain habitats and biota.

Rehabilitation (ecological) refers to measures taken in the process of returning an impacted area to a condition ecologically similar to the desired ecosystem structure, function, biotic composition and associated ecosystem services. Rehabilitation thus entails undertaking certain remedial action to minimise the adverse impacts on the environment and to prevent further environmental degradation from occurring, continuing or recurring.

Restoration (ecological) is the practice of renewing and restoring degraded, damaged, or destroyed ecosystems and habitats in the environment back to their former (‘pre-development natural state’) by active human intervention and action.

Watercourse and wetland rehabilitation refers to the process of assisting the recovery of a degraded watercourse or wetland in terms of the condition, function, and associated biodiversity, or in maintaining the health of that aquatic ecosystem that is threatened by degradation, through the implementation of remedial interventions or proactive preventative measures. It involves the manipulation of the physical (e.g. blocking drainage canals), chemical, or biological characteristics (e.g. assisting the regeneration of the natural vegetation P a g e | 2

and/ or clearing of invasive alien species on the wetland site or in its buffer zone) of a degraded wetland system to repair or improve wetland integrity and associated ecosystem services.

Watercourse'' means - (a) a river or spring; (b) a natural channel in which water flows regularly or intermittently; (c) a wetland, lake or dam into which, or from which, water flows; and (d) any collection of water which the Minister may, by notice in the Gazette, declare to be a watercourse, and a reference to a watercourse includes, where relevant, its bed and banks (National Water Act 36 of 1998).

Wetlands are defined as “land which is transitional between terrestrial and aquatic systems where the water table is usually at or near the surface, or the land is periodically covered with shallow water, and which land in normal circumstances supports or would support vegetation typically adapted to life in saturated soil” (National Water Act 36 of 1998).

Wetland Offset, as for a biodiversity offset, provides a measurable conservation outcome that results in actions designed to compensate for significant residual adverse biodiversity or, in this case, wetland impacts arising from a development after appropriate prevention and mitigation measures have been taken. The goal of the offset is to achieve no net loss but rather a net gain of biodiversity/wetland with respect to species composition, habitat structure, ecosystem function and ecosystem goods and services.

P a g e | 3

1. INTRODUCTION

The City of Cape Town (CCT) is proposing to upgrade the sludge handling facility at the Cape Flats Wastewater Treatment Works (WWTW) in Cape Town. The proposed new Biosolids Beneficiation Facility (BBF) will be constructed within the footprint of the WWTW and will replace the existing Thermal Drying Plant. The BBF will treat sludge from the WWTW as well as other WWTW that will need to be transported to the BBF. The project thus includes consideration of a new access road. A number of route alternatives were considered that would access the WWTW from either the west and from the location of the adjacent landfill site or from the east, along Strandfontein Road. Only the route alternatives from the east will result in the loss of wetland habitat that will require offsetting. This wetland offset has been determined for the preferred access route from the east of the WWTW (Option 6). The wider area assessed to the west and the east of the WWTW between the landfill site and Strandfontein Road is referred to as the study area in this document.

This document comprises of the proposed wetland areas that would be created to meet the determined offset requirements for the following wetland habitat that would be lost on the Remainder of Farm 829 on the Cape Flats in Cape Town (Figure 1):

• Wetland habitat lost as a result of the road construction along the preferred route, and • Wetland habitat modification within the proposed offsite wetland area (existing largely artificial reedbeds that would be filled to re-establish natural duneslack wetland habitat in the offset area).

Figure 1. 2016 Orthophotograph of the study area with the proposed wetland offset focus area indicated by the red polygon. The existing mapped wetlands as well as the proposed access road are also indicated on the image. P a g e | 4

Included in the wetland offset plan is:

• A proposed programme for the establishment and management of the proposed wetland offset area; • The flow requirements for the wetland offset area; • Recommended Plant Species for the wetland offset area; • A recommended environmental assessment and monitoring programme of the established wetland offset area; and • An Operational Plan to implement the wetland offset requirements.

Routine maintenance activities that would be required within the wetland areas have been included in a separate approved Maintenance Management Plan (MMP) for the site and would include aspects such as alien invasive plant species control in the wetland offset area.

2. DESCRIPTION OF EXISTING AQUATIC FEATURES ON AND ADJACENT TO THE WETLAND OFFSET SITE

The area in which the access road is proposed to be constructed is to the east of the WWTW. This area is flat or slightly undulating landscape (less than 5 m to more than 20 m above sea level), either containing vegetated dune fields from a drier, windier recent past, or a more subdued landscape further inland. The parabolic dunes tend to run northwest to southeast and are largely still vegetated with False Bay Dune Strandveld. The dune slacks often contain seasonal wetlands that are inundated to varying degrees. Where the landcover has been degraded, weedy and often alien invasive plants such as Port Jackson willows (Acacia saligna) occur.

The soil in the area consists of imperfectly drained greyish sandy soils, while further inland the soils are of restricted depth with low natural fertility, sandy texture and leached with an accumulation of organic material and aluminium. Indigenous vegetation still occurring that is associated with the duneslack areas adjacent to the site comprises largely of Senecio halimifolius, Imperata cylindrica, Zantedeschia aethiopica and Ficinia nodosa with Osteospermum moniliferum, Metalasia muricata, Searsia spp., Euclea racemosa, Chondropetalum tectorum and Carpobrotus edulis occurring on the margins. Psoralea aphylla and Cliffortia longifolia (Species of Conservation Concern, both being regarded as Vulnerable) have also been identified within the duneslack wetlands to the east of the WWTW.

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Below is a description of the wetlands currently occurring along the proposed route of the access road:

Cape Flats WWTW associated ponds and water bodies

The WWTW covers an area of approximately 380 hectares that once consisted of dune-slack wetland areas. The WWTW comprises of a series of primary, secondary and tertiary ponds as well as sludge ponds. The WWTW was established in 1956 and has subsequently been expanded upon. The aquatic habitats consist of permanently and seasonally open ponds, canals, reedbeds and sludge beds. The ponds, in particular, are home to a large number of migrant as well as resident bird species.

Figure 2. Primary ponds of the WWTW

The proposed access road for Option 6 will need to pass between primary ponds within the works. These ponds comprise of large open water systems with grassed banks and limited ecological value. The key ecological value being the provision of habitat for water birds.

Dune Strandveld Wetlands (Dune slack wetlands with adjacent Wetland Flat Areas)

The seasonal duneslack wetlands to the east of the WWTW are more significant, covering larger areas and are less disturbed than other duneslack wetlands that lie to the west of the WWTW. There are however several tracks through this area. Typical duneslack wetland plant species occur within these wetlands such as Senecio halimifolius, Imperata cylindrica, Ficinia nodosa and Zantedeschia aethiopica. P a g e | 6

Figure 3. View of one of the duneslack wetlands in the eastern portion of the study area

Two Plant Species of Conservation Concern, Psoralea aphylla and Cliffortia longifolia (regarded as a Vulnerable species (Helme 2018) were observed in the larger wetland south of Pelican Park, within the False Bay Nature Reserve (FBNR). This area is likely to support several amphibian species, including Cape Sand Frog (Tomopterna delalandii), Flat Caco (Cacosternum platys), Clicking Stream Frog (Strongylopus grayii), and Arum Lily Frog (Hyperolius horstockii) as well as possibly Endangered Western Leopard Toad (Amietophrynus pantherinus). Sword grass (Imperata cylindrica) occurring in the duneslack wetlands is also indicated to provide suitable habitat for the Critically Endangered butterfly, Kedestes barberae bunta (Barber's Cape Flats Ranger) and the Endangered Kedestes lenis (False Bay Unique Ranger). These wetland areas are thus deemed to be of High conservation value.

The typical characteristics and classification of the wetland areas occurring in the area directly to the west and east of the Cape Flats WWTW (the study area) are provided in Table 1.

Table 1: Classification of wetland areas within the study area

Dune slacks and adjacent wetland flat areas Artificial Depressions associated with the Name WWTW System Inland Ecoregion South Western Coastal Belt Ecoregion Landscape setting Flat with Depressions Depressions (excavated) On sandy well-drained soils with no channelled Excavated and filled with partially treated Drainage in or outflow - fed largely from groundwater wastewater Seasonality Seasonal Perennial to seasonal Fairly undisturbed – some roads and paths – Artificial and associated with WWTW Anthropogenic influence the wetlands to the west being more impacted by existing access roads and fencing. Geology Quaternary calcareous coastal dune sand Terrestrial Vegetation Cape Flats Dune Strandveld Wetland vegetation Imperata cylindrica Typha capensis and Phragmites australis Substrate Sand Silt, sludge and in cases lined Salinity Fresh P a g e | 7

The present ecological status (PES) and ecological importance and sensitivity (EIS) assessment of the aquatic features are summarised in Table 2.

Table 2. Summary of present ecological condition and ecological importance and sensitivity of the wetland areas within the proposed new road servitude that will be impacted or lost as a result of the road construction

Wetland Dune slacks Artificial Depressions Extent (ha) 1.6 0.25 PES Largely natural Seriously modified EIS Moderate – high EIS wetlands are avoided Low Functionality Habitat/maintenance of biodiversity Associated with the WWTW Recommended Ecological Largely natural Largely modified Category Recommended buffer Topography critical factor – must - incorporate dunes

3. WETLAND OFFSET TARGET DETERMINATION

The wetland offset calculator of the Department of Water and Sanitation (DWS) was designed to guide the functional as well as ecological and species conservation importance of wetland areas and indicates each of these aspects as hectare equivalents that would be required as an offset. The wetland offset calculator was used to determine the offset requirement for the potential wetland loss associated with the construction of the new access road to the Cape Flats WWTW (Option 6). Detailed calculations are presented in Appendix A.

Table 3. Summary of wetland detail and offset requirements for the proposed road servitude

Wetland Dune slacks Artificial Depressions along the proposed road and in the wetland offset area Extent (ha) 1.6 5.85 PES Largely natural Seriously modified EIS Moderate – high EIS wetlands are avoided Low Functional Wetland Target (ha 1.1 3.2 equivalents) Ecosystem Conservation Target (ha 6.3 5.6 equivalents) Species Conservation Target 140 55 according to a species impact measure (habitat intactness)

From the wetland offset assessment, it was determined that a functional offset of 4.3 ha equivalents and an ecosystem conservation offset of 12.2 ha equivalents was required to offset the wetland areas that would be lost.

4. PROPOSED WETLAND OFFSET

The rehabilitation and creation of approximately 11 ha of wetland area (See Figure 4 for the proposed wetland offset areas) that would consist of a mosaic of duneslack and seasonal depression wetlands adjacent to the existing WWTW and dune slack wetland habitats within the larger wetland offset site indicated in Figure 1 is proposed to provide a wetland offset with the following potential wetland gains (Appendix A):

• 5.1 ha functional equivalents; P a g e | 8

• 12.8 ha ecosystem conservation equivalents; and • 160 Species Conservation Target.

Thus, exceeding the wetland offset target requirement outlined above and allows for the inclusion of adequate buffers within the wetland mosaic that would be created.

The larger focus wetland area shown in Figure 1 contains the required dune and duneslack topography that result in the formation of duneslack wetland habitat. Within the focus area, the dune topography is largely still intact with approx. 2 ha of intact dunes covered with relatively natural vegetation. The duneslack areas have been excavated and modified with a resultant loss of that natural duneslack wetlands and their replacement with reedbeds and disturbed areas. This area comprises of two focus areas in which the wetland offset has been identified are approx. 11 ha area in total. The offset area is largely located upslope of the WWTW ponds and with filling and shaping of the area, an area that is only inundated seasonally as a result of localised rainfall could be created in these target areas. The proposed area lies to the south of the proposed access road in an area that would potentially remain as an important conservation area within the protected FBNR.

5. DESCRIPTION OF DRIVERS OF THE WETLAND HABITAT FORMATION

Topography: The site is located on the Cape Flats which is typically a flat, low-lying area with a high water table that is conducive to the formation of wetland areas. Much of the area through which the road will be constructed is still largely natural and displays this typical characteristic, with the only elevation changes on the site as a result of low coastal dunes. The duneslack and seasonal wetlands on the site occur within shallow depressions while the more permanently wet areas along the eastern boundary of the WWTW occur mostly the result of past excavations and seepage from the WWTW. This has resulted in the Typha dominated wetland habitat in this area. A couple of smaller dunes occur within the focus areas that still contain good indigenous vegetation cover. Thus, with relative ease one can rehabilitate the dune slack areas to comprise of the duneslack wetlands that would naturally have occurred in the depressions adjacent to the dunes.

Soils: The soils observed east of the WWTW consist of calcareous sands from the Witzand formation of the Sandveld Group. Where wetlands occur on deep, well-drained sands such as in the duneslack wetlands, the typical signs of seasonal wetness such as gleying, are not as evident as in wetlands with soils of a higher clay and organic content.

Hydrology: The general drainage at the site is towards the south and False Bay. Under natural conditions, the level of wetness within the soils of a wetland is largely due to interaction with the groundwater table and as a result of the topography on the site. It is expected that flow would, under natural conditions take place through the sandy soils rather than on the surface, and in a diffuse manner rather than within a distinct channel. Areas within and immediately adjacent to the WWTW are more permanently wet as a result of seepage from the WWTW. Management of the seepage from the WWTW ponds will need to be addressed in the rehabilitation measures for the wetland offset areas.

Geohydrology: Indications from the DWS National Groundwater Database are that the average groundwater level at the site is about 4 to 5 meters below ground level. The water level is likely to be higher in winter and to support seasonal wetland habitats and plant species in this time. The aquifer is a major intergranular type aquifer P a g e | 9

with average yields of 2.0 to 5.0 l/s pf good quality water (Electrical conductivity of 150 to 370 mS/m). The shallow, unconfined aquifer has a very high vulnerability/sensitivity, with recharge occurring across the surface of the aquifer via infiltration of rainwater through the overlying sand. General flow groundwater direction is towards False Bay.

Water quality: The general groundwater quality of the area is indicated to be of relatively low electrical conductivity (150 to 370 mS/m). The impact of the adjacent WWTW and the surrounding urban development areas could however be expected to impact on this vulnerable aquifer.

6. WETLAND OFFSET PLAN SCOPE AND ASSUMPTIONS

Key elements that should form part of a wetland offset plan, according to the DWS Wetland Offset Guidelines (Macfarlane et al, 2014), are the following:

• Outline of the assumptions and limitations associated with the wetland creation; • Description of the desired outcomes and objectives for the wetland offset area; • Wetland offset layout, indicating the location and extent of wetland habitat to be created; • Plant species list for the wetland habitats; • Methods for the establishment of the wetlands; • Operation Plan for the Wetland; • Maintenance Plan for the wetland; and • Monitoring and auditing of the wetland areas.

These aspects are addressed further in the following sections of this wetland offset plan.

7. WETLAND OBJECTIVES AND RECOMMENDATIONS

Location and extent

The wetland offset site is located within the larger Zeekoeivlei Catchment to the east of the Cape Flats WWTW (Farms 837, RE/829 and 1/840). The proposed wetland offset area will be located south of the proposed access road to be offset and east of the WWTW in an area that has been significantly disturbed as a result of past activities at the WWTW. The proposal is to rehabilitate these areas and re-establish and enhance the duneslack wetland areas that would naturally have occurred in this area.

The wetland offset calculator (Macfarlane et al, 2013) was utilised to ensure that the objectives and targets set for the wetland offset area would be met in terms of functionality and ecosystem conservation. No species of special concern were identified within the wetland area that needed to be offset. The new duneslack wetlands that would be established as part of the wetland offset would, however, provide habitat for species of conservation concern such as Psoralea aphylla and Cliffortia longifolia (Flora Species of Conservation Concern, both occurring in the wider area being regarded as Vulnerable) and the butterflies Kedestes barbarae bunta and Kedestes lenis lenis which are Cape Flats endemics and are listed as Critically Endangered and Endangered respectively. P a g e | 10

The wetland offset area is proposed to be created adjacent to still largely natural dunes but where the duneslack areas have been significantly modified (approx.13ha focus area shown in Figure 5), where the final offset area will still change slightly as a result of possible onsite constraints such as the presence of any terrestrial vegetation to be avoided. The project botanist has been consulted with regards to the suitability of the site but will need to do a walk down of the site before construction to make sure there are no terrestrial plant communities that should be avoided. Should any sensitive areas be identified these will be integrated into the wetland offset mosaic. Mr Dalton Gibbs of the City of Cape Town has also been consulted on the proposed wetland offset area and agrees with the proposed area. His input into the detailed wetland design and implementation of the wetland offset area, should it be approved, is seen as essential.

In terms of the proposed future development of the area, the proposed access road to the WWTW lies to the north of the site while the WWTW is located to the west. Phase 2 of Pelikan Park that is currently undergoing an Environmental Impact Assessment process, is proposed to be located to the north of the access road, with the access road forming an important management edge between urban development to the north of the road and conservation areas to the south. Figure 5 shows the location of the proposed wetland offset area in relation to the access road and Pelikan Park Phase 2. A Nature Reserve is central to the proposed layout plan for Pelikan Park and would be located to the north-east of the proposed wetland offset area. The area to the east of the offset area and south of the proposed Nature Reserve would remain as an intact and important conservation area as part of the FBNR.

Pelikan Park Phase 2

Pelikan Park Phase 2 proposed Nature Reserve

Proposed access road

Target area for potential onsite offset wetland requirement

P a g e | 11

Figure 4. Google Earth image of the area east of the WWTW with the proposed wetland offset indicated, together with the proposed access road alignment and the extent of the Pelikan Park development, with its proposed Nature Reserve area.

Figure 5. View of the general area where the wetland offset is proposed

Recommended Ecological Condition

The recommended ecological category that should guide the proposed wetland offset creation and maintenance is B/C Category (largely natural to moderately modified).

Resource Quality Objectives associated with the above recommended ecological conditions determined to inform the monitoring and assessment of the aquatic ecosystems are included as Appendix B.

Wetland Creation Objectives

Key wetland creation objectives that relate to the goods and services provided by the wetland to be created within the site are to increase the naturally occurring aquatic habitat and biodiversity within the site. By rehabilitating the area within which the wetland offset is proposed, the connectivity between wetlands within the site would also be improved. This can be achieved through clearing of dense alien vegetation in the area; reshaping of the area and removal of rubble and waste dumped into this area. Access to the offset site should also be monitored and controlled to prevent future dumping and disturbance of this area. P a g e | 12

Guiding Principles

The following principles should guide the wetland creation process to ensure the functionality provided by the wetland offset is such that it would assist in the enhancement of biodiversity within the site:

• Optimising biodiversity within the wetland should be a goal, that is to prevent single species, or a limited number of species, from dominating the wetland area; • Plant species used in the wetlands should as far as possible be based on what would naturally have occurred in the area; • Runoff to the wetland area should resemble the natural seasonal flow patterns as far as possible; and • The point of departure should be to create the wetland actively (clearing of alien vegetation, infilling of excavated areas, shaping of the new wetland habitat and vegetating the areas with indigenous wetland vegetation) and then allowing the development of the wetland to continue passively, to monitor and intervene where necessary and minimise the need to undertake maintenance activities within this area. Topsoil and plant material for the offset areas should be obtained from the proposed access road corridor.

The main drivers (or principle elements) that will determine the establishment of the wetland area is the water supply (depth and duration of saturation) as determined by the groundwater level at the site and seasonal fluctuation, topography, soil types and water quality within the wetland area. All other biological aspects will be a response to these drivers.

Key Recommendations

Key recommendations to ensure the desired ecological condition of the aquatic ecosystems would be achieved are as follows:

• The area for the proposed wetland offset should be clearly demarcated to ensure that disturbance of the area and its surroundings do not occur. Only rehabilitation activities should be undertaken in this area until the required approvals are in place for the remainder of the development with which this offset is associated; • Shaping and revegetation of the wetland areas should be according to the advice of a suitably qualified aquatic ecologist with the specialist being on-site when shaping takes place; • Infilling of the current excavated areas and the creation of shallow seasonally wet areas take place to allow for the naturally occurring wetland habitats and biota in the wetland offset area; • The wetland areas within the site should comprise of suitable local indigenous vegetation as provided in the plant list for the wetlands (Section 10); • The propagation and or supply of vegetation for the wetland areas should be overseen by a wetland horticulturalist; • Cultivation/propagation of indigenous wetland plants occurring in the existing wetland areas within the site that can be utilised in the newly created wetland area should be undertaken before the shaping of the landscape. These plants should be removed in sods that not only transfer plant material but also the associated topsoils to the newly created wetland areas; P a g e | 13

• Once created, the wetland offset area should form part of the larger conservation area to the north and east and should be formally protected to ensure that it is not allowed to form part of any proposed development of the area; • Limited disturbance of the wetland areas should take place once the initial rehabilitation and creation of these areas should be undertaken. The creation of roads through the offset area should not take place. Access should only be for maintenance purposes; • No sewage or solid waste should be disposed of in the wetland offset area; • A detailed and adaptive programme of monitoring of inundation patterns, groundwater levels; water quality and the vegetation and biotic responses should take place from the onset; • Ongoing monitoring and removal of invasive alien plants within the wetland offset area should be undertaken in accordance with the Maintenance Management Plan (MMP) approved for the site; • Should the need for control of nuisance growth of bulrushes or any other indigenous or exotic aquatic vegetation within the wetland offset area arise, it should be undertaken in accordance with the MMP approved for the site; and • Any other maintenance activities within the wetland area, such as the need to remove sediment, should also be undertaken in accordance with an approved MMP for the site to ensure long term management of the wetland area.

8. IMPLEMENTATION PLAN FOR ESTABLISHMENT OF THE WETLAND OFFSET AREA

This section comprises of those actions required in the creation of the wetland offset area to achieve the recommended ecological condition of B/C Category (largely natural to moderately modified). The establishment plan is divided into two phases:

• Pre-construction phase that comprises of the feasibility and approval stages for the wetland offset; • Construction phase that is to commence with the measures to create the wetland offset area; and • Operation phase that lists the actions that would need to continue after the wetland creation measures are complete to ensure the aquatic feature achieves the defined resource quality objectives.

Implementation Plan: Pre-Construction Phase

ACTION RESPONSIBLE BODY (S) TIMING DELIVERABLE Pre-Construction Phase (currently underway to assess the feasibility of a wetland offset and will require the necessary approvals in terms of the wetland offset proposal itself as well as the associated environmental and water use authorisations – this will form part of the approvals process for the access road) Investigate suitable wetland offset Aquatic ecologist with 2021 Implementation plan for wetland input from the project offset team Obtain DWS approval for proposed Toni Belcher 2021 DWS Approval of Wetland Offset wetland offset and implementation plan Implementation Plan and Water Use Authorisation Obtain necessary environmental SRK 2021 Environmental Authorisation for the authorisations wetland offset

P a g e | 14

Implementation Plan: Construction Phase

ACTION RESPONSIBLE BODY (S) TIMING DELIVERABLE Construction Phase (to be undertaken from the commencement of construction until completion of initial construction works within the site -approximately 24 months for creation and satisfactory establishment of vegetation) Undertake an assessment of suitable Suitably qualified On approval of the Collection and cultivation vegetation in wetland areas on-site that wetland horticulturalist Implementation Plan, of local indigenous plant can be cultivated and used for vegetating and/or rehabilitation before the shaping of material for vegetating the created wetland areas as per method specialist team wetland the created wetland statements in the following section offset areas Investigate the wetland areas that will be Suitably qualified On approval of the Collection of local lost to provide a source not only for wetland horticulturalist Implementation Plan, indigenous plant material wetland plants that could be utilised and/or rehabilitation before the shaping of and wetland soils for the within the wetland offset area but also specialist team, with wetland created wetland offset for a potential wetland soil source for the input from Kedestes areas offset butterfly specialist Investigate the most appropriate timing Kedestes butterfly On approval of the Collection of host plants for introduction of Kedestes host plants specialist preferably Implementation Plan, as per the from the Kedestes before the shaping of recommendations of the Butterfly Conservation wetland Kedestes butterfly Project specialist Demarcate the working area required for Wetland horticulturalist On approval of the Defined working area for the wetland offset /aquatic ecologist Implementation Plan, wetland creation activities before the works for the site Prepare the site in and immediately Wetland horticulturalist On approval of the Rehabilitation of wider adjacent to the wetland offset area – this /aquatic ecologist Implementation Plan, area at the wetland offset would comprise of alien invasive plant before the works for clearing, removal of litter etc, clearing the site and setting aside / stockpiling of soil and indigenous vegetation. Undertake infilling and shaping of Appointed contractor On approval of the Creation of the shaped wetland offset area under the guidance of Implementation Plan, areas for the wetland the Wetland during the offset horticulturalist /aquatic construction works ecologist for the site Ongoing collection and propagation of Wetland horticulturalist Ongoing Wetland plant material to local indigenous wetland plant material team / aquatic ecologist, be used in the required for the implementation of the with input from establishment phase wetland creation works. Suggested Kedestes butterfly wetland plants are included under specialist Section 3. A suitably qualified wetland horticulturalist and/or rehabilitation specialist should be appointed to guide this process. Prepare topsoil in newly created areas for Appointed contractor Following shaping and Prepared areas for seeding and planting by scarifying the under the guidance of preparation of planting surface of the shaped areas that are to be the Wetland wetland area planted in a direction that is horticulturalist perpendicular to the runoff direction Seed and plant the prepared areas with Wetland horticulturalist Following shaping and Vegetated wetland areas the cultivated plants and seed collected team / aquatic ecologist preparation of for this purpose. wetland area Irrigate where necessary, drier planted Wetland horticulturalist As and when required Establishment of areas to ensure that they properly team / aquatic ecologist vegetated areas established Control alien and invasive vegetation Wetland horticulturalist Ongoing Aquatic features with no within the wetland and buffer area team / aquatic ecologist invasive alien vegetation according to the Maintenance Management Plan for the site Undertake monitoring and assessment of Appointed Ongoing as per Construction and the works as laid out in the Environmental Control requirements of the rehabilitation works are P a g e | 15

Environmental Monitoring and Officer and Aquatic Construction EMP and monitored and assessed Assessment section of this document Specialist appointed to Environmental and where necessary monitor Monitoring and adjusted to ensure implementation of the Assessment section of compliance defined wetland offset this document objectives implementation plan Monitor and respond to any aspects of Wetland Ongoing during Ensured the sustainability concern such as poorly covered areas as horticulturalist team / rehabilitation of rehabilitated areas a result of plants not establishing and aquatic ecologist invasion with alien vegetation Control alien and invasive vegetation Wetland Ongoing Aquatic features with no within wetland areas according to the horticulturalist team / invasive alien vegetation Method Statements in the following aquatic ecologist section and the Maintenance Management Plan for the site Undertake performance monitoring to Appointed riparian and Two monthly Performance assessment gauge the success of rehabilitation Wetland monitoring after of wetland creation measures against recommended horticulturalist rehabilitation is measures in terms of objectives. The monitoring should complete for 24 objectives set for the area comprise of regular visual inspections, at months until wetland least 6 fix point photography points and established collect images quarterly and an annual assessment of the wetland integrity and functionality Undertake an annual audit of wetland Appointed auditors July / August An annual audit offset until the wetland offset is well undertaken for wetland established offset area Wetland Offset Plan: Operation Phase

ACTION PERSON(S) TIMING DELIVERABLE Operation Phase Undertake wetland management Maintenance staff of Ongoing Managed and maintained monitoring to inform the maintenance the property wetland area and management of wetland Respond to outcomes of the monitoring Maintenance staff of Ongoing Responsive management of the property created wetland area Continue to manage the wetland area Maintenance staff of Ongoing Wetland offset area that meets under the guidance of the approved the property objectives set Maintenance Management Plan for the site Control alien and invasive vegetation Maintenance staff of Ongoing Aquatic features with no within the wetland area according to the property invasive alien vegetation the Maintenance Management Plan for the site Monitor main drivers of wetland Appointed Aquatic Ongoing as per Drivers of the wetland area are characteristics – in particular, Specialist appointed requirements of the monitored and assessed to inundation patterns and quality of to monitor Environmental better understand the water in the wetland during inundation implementation of Monitoring and functioning of the created the wetland offset Assessment section wetland and how this influences plan of this document monitored responses in wetland and meeting of defined objectives for the wetland Monitor success of Kedestes butterfly Kedestes Butterfly Ongoing establishment annually Conservation Project Undertake annual assessments of the Appointed Aquatic Ongoing as per Operation of the wetland offset success of the works over the longer Specialist appointed requirements of the works are monitored and term to monitor Environmental assessed and where necessary implementation of Monitoring and adjusted to ensure compliance the wetland offset Assessment section with water use licence plan of this document requirements

A programme of the sequence in which the above actions need to be implemented is attached as Appendix D. P a g e | 16

9. METHOD STATEMENTS

The key activities that need to take place for the creation of the wetland area comprise of the following:

1. Creation of the new wetland areas through infilling and shaping of the landscape and bringing in suitable topsoil where necessary; 2. Planting of the wetland with local indigenous wetland plants; and 3. Removal of invasive alien vegetation in the immediate area (approx. 50 m) of the wetland offset.

A concept level of detail on the methods that would be used to undertake these activities are provided below. A more detailed suite of method statements for the various activities associated with the creation of the wetland offset area will need to be compiled between the appointed specialists and contractors for the works before commencement.

These activities would be followed by longer-term maintenance and management of the wetland area should be addressed in an approved Maintenance and Management Plan for the larger area that would include the new access road. Note should be taken of the mitigation measures that have been provided by the Department of Environmental Affairs and Development Planning (2017) for works within watercourses and wetland areas that have been included as Appendix C.

Creation of new wetland areas

• The wetland offset areas are proposed to comprise of a mosaic of shallow seasonal wetlands and duneslack areas. This would allow for a diversity of wetland habitats and associated biota within the wetland offset area. • The methods proposed for the creation of this wetland corridor is to infill and shape the landscape to create depressions that will facilitate some inundation during winter. • Any existing excavated areas and channels will be filled to prevent the ingress of water from the WWTW. • Vegetation for these areas will primarily be obtained from the other wetland areas within the larger study area that would be collected in sods together with topsoil or propagated from seed. The opportunity also exists to introduce other local indigenous wetland plants and in particular geophytes into this area. • Inundation of these areas would largely be associated with groundwater levels and increased surface moisture levels created as a result of surrounding dune areas.

Planting of the wetland offset area

• Planting of the wetland areas within the site should preferably be undertaken using local indigenous wetland plants (Suggested plant list provided in Section 10). • A survey of the other wetland areas within the site will be undertaken to harvest seed and other plant material suitable for cultivation purposes. • In addition, investigate the access road route in the wetlands that will be lost and could provide a source of wetland plants and wetland soil source for the offset; P a g e | 17

• Follow up seed collection trips are likely to be required to collect sufficient seed and diversity for cultivation when that seed and plant material is available to be able to plant the wetland offset area. These trips will be undertaken by a freshwater specialist and horticulturalist. • Where necessary (due to removal of topsoil) available stockpiled topsoil will be spread over the reshaped surface to a depth of 250mm. The soil will then be ripped and scarification to 250mm and prepared with gypsum, calcitic lime and compost as required. • A succession of the planting of the wetland area can then take place that is responsive to the establishment of the wetland areas. This could entail the direct replanting of in situ material as well as the sowing of seed collected. Planting should take place at the start of winter to enable plants to establish during the winter.

Control of alien and invasive vegetation

• Identify alien plants to be removed within the focus wetland offset area. The key invasive alien plants to be removed are displayed in the table below. If unsure, please contact the Department of Agriculture or CapeNature for assistance.

Table 4. Invasive alien species identified within the study area

Species Legislation Photograph

Rooikrans NEMBA category 1b Acacia cyclops

Port Jackson willow NEMBA category 1b Acacia saligna

• Regular monitoring and control of alien vegetation should be undertaken to ensure that the plants are removed while still young saplings that can more easily be removed (usually pulling of seedlings by hand is possible when the soil is wet). This also prevents the spread of the alien plants once seeds have been produced. • Avoid trampling or clearing indigenous vegetation by using established paths where possible. • Clear alien vegetation according to the described alien vegetation removal methods for each invasive species as provided in the detailed method statements or with the methods and herbicides/biological control recommended on the Working for Water website: http://www.dwaf.gov.za/wfw/. P a g e | 18

• Clear felled alien vegetation from the wetland offset area and use an acceptable method of handling biomass that does not promote fires and seed spreading. Stockpiling of cleared material will pose a fire hazard and has a risk of resulting in intense fires that will sterilise the underlying soil of seed. • Where necessary revegetate cleared areas with suitable indigenous vegetation as suggested under the recommended plant list in the following section. Planted areas will require irrigation and care for 1-2 years following planting. Planting of the new vegetation at the start of the wet season can assist to ensure that the new vegetation is kept wet. • Ongoing monitoring and clearing of regrowth of alien plants within these areas will be required.

10. RECOMMENDED PLANT LIST

Suggested wetland and marginal plant species for the created wetland habitats are as follows:

• Imperata cylindrica, Searsia laevigata, Searsia glauca, Salvia africana lutea, Chrysanthemoides monifera, Senecio halimifolius, Nylanria spinosa, Zantedeschia aethiopica, Chasmanthe aethiopica, Carpobrotus edulis, Metlasia muricata, Psoralea aphylla and Cliffortia longifolia.

Invasive alien grasses such as Pennisetum clandestinum should not be planted in this area and any growth of the grass should be removed

11. OPERATION PLAN

The operation plan relates specifically to how the drivers of the wetland habitats rehabilitated or created within the site will be operated/ maintain. As stated previously in this plan, the key drivers of wetland formation are topography, soils, geohydrology, hydrology and water quality.

The topography and soils associated with the wetland offset area will be established when the wetland offset areas are created. These should not be altered during the operation phase. Nevertheless, monitoring for signs of sedimentation within the wetland areas should remain an ongoing element of the wetland monitoring programme as laid out in the following section.

The hydrology, geohydrology and water quality may alter significantly as a result of the surrounding activities and should also form part of the ongoing monitoring for the site as described in the following section.

12. MONITORING PROGRAMME

This monitoring programme includes the following information:

• indicators to be measured; • frequency, interval and timing of monitoring; and • evaluation procedure.

P a g e | 19

Monitoring of the wetland offset creation works

During implementation/construction, the monitoring of the rehabilitation works should form part of the activities of the appointed wetland horticulturalist / freshwater specialist and should be conducted together with their supervision activities. The frequency is likely to depend on the programme of activities for the wetland offset creation. Monitoring should include, but not be limited to, the following parameters:

• Monitoring for signs of increased sedimentation or erosion within the wetland areas; • Monitoring of alien vegetation regrowth within the disturbed area; • Visual monitoring for any issues of concern within the aquatic habitats and surrounding areas; and • Ensuring that any activities not related to the wetland offset creation measures do not encroach into the wetland offset area.

Upon completion of the initial wetland creation works on site, the appointed specialist should continue to monitor the works for every month until it can be established that the wetland vegetation within the offset is adequately established. Thereafter, one monitoring site visit is recommended after 6 months from completion of wetland creation works and final sign-off of then works should take place after one to two years.

Monitoring of groundwater, flow and water quality

It is recommended that at least two to three piezometers be installed within the wetland offset area that can facilitate monthly monitoring of groundwater levels and basic water quality (electrical conductivity can be used as an indicator for groundwater quality and the potential for ecological impact to the wetland habitat). Should a significant increase in the electrical conductivity and change to the groundwater level at the site be observed, a more detailed assessment should be undertaken.

Similarly, it is recommended that visual surface water level and inundation observations/measurements be undertaken within the wetland areas. This can be done as part of the fixed point photography exercises. If the water level in the wetland allows for the collection of a water quality sample, a water quality sample should be taken monthly within the wetland and analysed for electrical conductivity, pH, dissolved oxygen and total suspended solids. These measured parameters can then be assessed against the resource quality objectives recommended in Appendix B.

Monitoring of Aquatic Ecosystem Health Improvements

Fixed-point photography

To illustrate the improvement in the wetland habitat associated with the wetland offset created area, fixed- point photography monitoring should be used. The following guidelines should be followed when locating photographic points for fixed-point photographs:

• photo-points should be selected at various locations throughout the wetland offset site and at points that will be easily accessible at all times; P a g e | 20

• record the geographical coordinates of each point using a GPS, preferably accurate to within 3m. This provides any individual with the information required to navigate to the exact location of each photo point; and • a permanent field marker should be placed in the ground at each point, to ensure that photos are always taken from the same point. If possible, the orientation of the photo at the point should be recorded on the marker.

The following guidelines should be followed when implementing fixed-point photography for monitoring purposes:

• the orientation of the photograph should be recorded; • use of the same zoom ratio each time. If this is not possible, record the settings used. The camera should preferably be located at a fixed height; • when the frequency of monitoring decreases to an annual interval that is undertaken in the spring, photographs should be taken at roughly the same time of year and at the same time of the day, and under similar weather conditions. This would limit the variability of the wetland habitat associated with vegetative and hydrological changes linked to seasons; • a standard object, such as a metre rule should be included in the photograph as a reference for scale; and • record relevant information about factors that may influence features in the photograph (e.g. a recent fire, late or early rains, etc.), especially those relating to the appearance of the site.

Wetland Health Monitoring

The wetland health assessments should be undertaken a year, and then two and three years after the completion of the wetland offset area. The assessment of the wetland unit's health should be undertaken using the WET-Health tool developed by Macfarlane et al (2009).

Frequency, Interval and Timing of Monitoring

Monitoring should take place during the initial construction stages of the wetland as well as in the operational phase. During the construction phase, monitoring should be more regular to identify issues quickly and have them remedied. Once excavation and construction activities are complete in the wetland, and the area has been replanted, then assessments can become less frequent as distinct changes will take longer to manifest. In addition, monitoring during the establishment phase will make sure that there are no fundamental flaws in the wetland establishment process. The final, long term monitoring will assess the overall success of the wetland offset, once the system has had time to stabilise. A monitoring framework is provided in the following table. P a g e | 21

Monitoring Framework for the wetland offset

Phase Frequency Assessment Duration Responsible Construction Phase Daily to weekly depending Visual and photography monitoring – Aquatic specialist For the + 2 month construction Aquatic specialist and wetland on the intensity of and/or wetland horticulturalist should be onsite during period horticulturalist construction activities the shaping and preparation of wetland offset areas

Weekly extending to two Visual inspections of: Duration of implementation Aquatic specialist and wetland monthly once initial • Intervention construction management monitoring activities horticulturalist rehabilitation works • Alien plant removal (two monthly report) completely • Re-vegetation Operational Phase Monthly (until the wetland Groundwater level monitoring Ongoing until the wetland habitat Aquatic specialist and wetland habitat established to the Inundation monitoring established to the satisfaction of horticulturalist satisfaction of aquatic Water quality monitoring aquatic specialist then annually as specialist then annually as part of the annual assessment part of the annual Visual inspections of: Monthly brief internal report with Aquatic specialist and wetland assessment) • Structural integrity (erosion and sedimentation) photographs until the wetland horticulturalist monitoring habitat established to the • Alien plant re-emergence monitoring and removal satisfaction of aquatic specialist • Re-vegetation success monitoring then annually as part of the annual assessment Annual WET-Health Assessments as measured against the Annual visits Aquatic ecologist recommended resource quality objectives for the (Full report that would include the wetland (Appendix B) internal monthly monitoring and inspection reports with photographs per visit)

P a g e | 22

13. DECLARATION

This confirms that the author of this Wetland Offset Implementation Plan is independent and does not have any vested or financial interests in the project under consideration. The report reflects the professional judgment of its author. The full and unedited content of this should be presented to the client and the authorities. Any summary of these findings should only be produced in consultation with the authors.

Toni Belcher (P. Sci. Nat. 400040/10)

P a g e | 23

APPENDIX A: WETLAND OFFSET TARGETS AND POTENTIAL GAINS P a g e | 24

Determining wetland offset targets: Duneslack wetlands on road

Wetland Functionality Targets

Wetland size (ha) 1.6 Prior to development Functional value (%) 70 Functional value (%) 0 Post development Change in functional value (%) 70

Key Regulating and Supporting Services Identified Biodiversity maintenance

Impact Assessment Development Impact (Functional hectare equivalents) 1.1

Triggers for potential adjustment in exceptional circumstances None Offset Ratios

Functional Importance Ratio 1.0 Offset

calculation Functional Offset Target (Functional hectare equivalents) 1.1

Have other key Provisioning or Cultural Services Identified that require compensation? No

s Additional compensatory

Further Further None

mechanisms proposed consideration

Ecosystem Conservation Targets

Wetland size (ha) 1.6 Prior to development Habitat intactness (%) 70 Habitat intactness (%) 0 Post development Change in habitat intactness (%) 70

Development Impact (Habitat hectare equivalents) 1.12 Impact Assessment Wetland Vegetation Group (or type based on Cape Flats Dune Strandveld - Duneslack vegetation local clasification) Threat status EN Threat status of wetland Ecosystem Status Threat status Score 7.5 Moderately Protection level Protection level of wetland Protected Protection level Score 0.75 Ecosystem Status Muliplier 5.625

Priority of wetland as defined in Regional and High Importance 1 Regional and National National Conservation Plans Conservation context

Regional & National Context Multiplier 1.0 Determining offsetDetermining ratios Uniqueness and importance of biota present in the wetlandHigh biodiversity value 1

Buffer zone integrity (within 500m of wetland) Buffer compatability score 1 Local site attributes Local connectivity Good connectivity 1 Local Context Multiplier 1.0 Ecosystem Conservation Ratio 5.63 Development Impact (Habitat hectare equivalents) 1.1

Ecosystem Conservation Ratio 5.6 Offset

Calculation Ecosystem Conservation Target (Habitat hectare equivalents) 6.3

Species Conservation Targets

Species Name Desktop Evaluation: Species flagged as potentially occurring Imperator cylindrica - other vegetation includes Searsia laevigata, Senecio halimifolius, Zantedeschia at the site aethiopica, Stenotaphrum secundatum, Chasmanthe aethiopica, Psoralea aphylla and Cliffortia longifolia .

Specialist assessment: Species Species Selected Rationale for species selection selection of conservation concern Imperator cylindrica - Habitat for Kedestes bararae identified as requiring offset Species review and Species review bunta, K lenis lenis and Pelopidas thrax Species dominating duneslacks activities inconspicua

Target Species 1: Imperator cylindrica - Habitat for Kedestes bararae bunta, K lenis lenis and Pelopidas thrax inconspicua

Selected species impact measure Habitat measure Selected unit of measurement Habitat intactness Impact measure Description and rationale for species impact measure selected Overall habitat integrity more applicable for site

Prior to development Species impact measure 70 Species impact measure 0 Post development Impact Assessment Change in species impact measure 70

Development Impact (Species impact measure) 70 Offset Ratio 5.0

Offest Ratios Description and rationale for offset ratio selected

Wetlands in area more degraded and fragmented but still of moderate to high ecological importance offset ratios Determining Determining Species Conservation Ratio 2.0

Development Impact (Species impact measure) 70.0

Species Conservation Ratio 2.0 Offset Calculation Species Conservation Target (Species measure) 140.0 P a g e | 25

Determining wetland offset targets: Depressions on road

Wetland Functionality Targets

Wetland size (ha) 0.25 Prior to development Functional v alue (%) 55

Functional v alue (%) 0 Post development Change in functional v alue (%) 55

Key Regulating and Supporting Services Identified Associated with WWTW Impact Assessment Impact

Development Impact (Functional hectare equivalents) 0.1

Triggers for potential adjustment in exceptional circumstancesNone Offset Ratios

Functional Importance Ratio 1.0 Offset Offset

calculation Functional Offset Target (Functional hectare equivalents) 0.1

Have other key Provisioning or Cultural Services Identified that require compensation? No

Additional compensatory

Further None

mechanisms proposed considerations

Ecosystem Conservation Targets

Wetland size (ha) 0.25 Prior to development Habitat intactness (%) 55

Habitat intactness (%) 0 Post development Change in habitat intactness (%) 55

Impact Assessment Impact Development Impact (Habitat hectare equivalents) 0.1375 Wetland Vegetation Group (or type based on Cape Flats Dune Strandv eld - transformed local clasification) Threat status EN Threat status of wetland Ecosystem Status Threat status Score 7.5

Protection lev el of Protection lev el Moderately Protected

wetland Protection lev el Score 0.75

Ecosystem Status Muliplier 5.625 Priority of wetland as Not specifically identiifed defined in Regional and 0.5 Regional and National as important Conservation context National Conserv ation

Determiningratios offset Regional & National Context Multiplier 0.5

Uniqueness and importance ofLow biota biodiv present ersity in v the alue wetland 0.5

Buffer zone integrity (within 500mBuffer of compatability wetland) score 1 Local site attributes Local connectiv ity Good connectiv ity 1

Local Context Multiplier 0.7 Ecosystem Conservation Ratio 1.83

Development Impact (Habitat hectare equivalents) 0.1

Ecosystem Conservation Ratio 1.8 Offset Offset

Calculation Ecosystem Conservation Target (Habitat hectare equivalents) 0.3

Species Conservation Targets

Desktop Evaluation: Species Name Species flagged as potentially occurring at Typha capensis and Zantedeschia aethiopica

Species Selected Rationale for species selection

Senecio halimifolius, Specialist assessment: Imperata cylindrica, Species of conserv ation Zantedeschia aethiopica and Ficinia nodosa with These are currently transformed areas that should be concern identified as Osteospermum moniliferum, rehabilitated were possible back to seasonal and requiring offset activ ities Metalasia muricata, Searsia duneslack wetlands

Speciesreview selection and spp., Euclea racemosa, Chondropetalum tectorum and Carpobrotus edulis

Senecio halimifolius, Imperata cylindrica, Zantedeschia aethiopica and Ficinia Target Species 1: nodosa with Osteospermum moniliferum, Metalasia muricata, Searsia spp., Euclea racemosa, Chondropetalum tectorum and Carpobrotus edulis

Selected species impact measure Habitat measure

Selected unit of measurement Habitat intactness Impact measure Description and rationale for species impact measure selected

Overall habitat integrity more applicable for site

Prior to development Species impact measure 55

Species impact measure 0 Impact Assessment Impact Post development Change in species impact measure 55

Development Impact (Species impact measure) 55

Offset Ratio 1.0

Offest Ratios Description and rationale for offset ratio selected Wetlands in area moderately to largely modified and of moderate to high ratios ecological importance

Determining offset Species Conservation Ratio 1.0

Development Impact (Species impact measure) 55.0

Species Conservation Ratio 1.0

Offset Offset Calculation Species Conservation Target (Species measure) 55.0 P a g e | 26

Offset Receiving Areas: Assessing potential gains - Cape Flats WWTW Access Road Offsite Offset Note: Cells where information must be entered are highlighted in grey Contribution Towards Wetland Functionality Targets

Wetland attributes Wetland Reference Cape Flats WWTW Wetland Offset Area

Acceptability Criterion Relevance Site attributes Guidelines Targeted wetlands should typically be of the same type to ensure Wetland type that similar serv ices to those impacted are improv ed through offset Wetland is of the same type as the impacted wetland. Ideal activ ities. Alignment with site Targeted wetlands should be prioritised and selected based on their Selected wetland is well placed to contribute selection Key serv ices targeted ability to compensate for key regulating and supporting serv ices meaningfully towards improv ing key regulating and Ideal guidelines impacted by the proposed dev elopment. supporting serv ices identified. Offset site location relativ e to Targeted wetlands should ideally be located as close to the Selected wetland is located within the same local Ideal impacted wetland impacted site as possible. catchment as the impacted wetland. Overall comment on Wetland areea will be located directly adjacent to wetland areas to be lost and will aim to re-establish wetlands in an area where similar wetland alignment with site selection habitat prev iously occurred but as been lost as a result of works at the Cape Flats WWTW guidelines Wetland size (ha) 11 Prior to offset activities Functional v alue (%) 0 Preliminary Offset Following sucessful offset Functional v alue (%) 70 Calculation implimentation Change in functional v alue (%) 70 Preliminary Offset Contribution (Functional hectare equivalents) 7.7

Criterion Relevance Offset activity Adjustment factor The risk of offset failure is linked to the type of offset activ ity planned Final Offset Types of offset activ ities with wetland establishment considered less preferable and more risky Rehabilitation & Protection 0.66 Calculation proposed than rehabilitation or av erted loss activ ities. Final Offset Contribution (Functional hectare equivalents) 5.1

Contribution Towards Ecosystem Conservation Targets

Wetland Reference Cape Flats WWTW Wetland Offset Area

Wetland attributes Wetland Vegetation Group (or type based on local clasification) Cape Flats Dune Strandv eld

Threat status of wetland Threat status EN

Acceptability Criterion Relevance Site attributes Guidelines Targeted wetlands should be aligned with "like-for-like" criteria to Wetland is of the same wetland type within the same Like for Like ensure that gains associated with wetland protection are Ideal wetland v egetation group commensurate with losses. To what degree is wetland selection aligned with Regional and Wetlands hav e been identified as being of high Landscape planning Ideal National Conserv ation Plans importance in landscape planning The habitat condition of the wetland should ideally be as good / Final habitat condition is likely to be better than that of Alignment with site Wetland condition better that that of the impacted site prior to dev elopment (or at Ideal the impacted wetland. selection least B PES Category in the case of largely un-impacted wetlands) guidelines Wetlands that are unique or that are recognised as hav ing a high The wetland is charachterised by habitat and / species Local biodiv ersity v alue Ideal local biodiv ersity v alue should be prioritised for wetland protection. of high biodiv ersity v alue.

Connectiv ity and consolidation with other intact ecosystems Viability of maintaining The offset prov ides an opportunity to consolodate / together with the potential for linkage between existing protected Ideal conserv ation v alues expand existing protected areas areas is preferable. Overall comment on Wetland areea will be located directly adjacent to wetland areas to be lost and will aim to re-establish wetlands in an area where similar wetland alignment with site selection habitat prev iously occurred but as been lost as a result of works at the Cape Flats WWTW guidelines

Wetland size (ha) 11.0

Wetland areas to be secured Habitat intactness (%) 75

Wetland habitat contribution (hectare equivalents) 8.3 Preliminary Offset Area of wetland buffer zone included in the wetland offset site Calculation 1 Integrity of buffer zone 1 Buffer zones to be secured Buffer zone hectare equiv alents 0.3

Buffer zone contribution (hectare equivalents) 0.3

Criterion Relevance Site attributes Adjustment factor Offset activ ities that formally secure offset sites for longer than the Minimum acceptable security of tenure for a longer Security of tenure minimum requirement are more likely to be maintained in the long- 1.5 period Final Offset term and are therefore preferred. Calculation Wetland habitat contribution (hectare equiv alents) 12.4

Offset Contributions Buffer zone contribution (hectare equiv alents) 0.4

Functional Offset Contribution (hectare equivalents) 12.8

Contribution Towards Species Conservation Targets

Imperator cylindrica, Searsia laev igata, Searsia glauca, Salv ia africana lutea, Chrysanthemoides monifera, Senecio halimifolius, Nylanria spinosa, Target Species 1: Zantedeschia aethiopica, Chasmanthe aethiopica, Carpobrotus edulis, Metlasia muricata, Psoralea aphylla and Cliffortia longifolia .

Description of offset activ ities Proposed offset proposed The wetland area should comprise of a mix of shallow seasonal wetland areas and duneslacks activities Rationale for proposed offset activ ities

Selected species impact measure Habitat measure

Preliminary Offset Species impact measure Selected unit of measurement Habitat intactness

Calculation Species impact measure (secured) 80.0

Preliminary species contribution 80.0

Criterion Relevance Site attributes Adjustment factor Offset activ ities that formally secure offset sites for longer than the Security of tenure minimum requirement are more likely to be maintained in the long- Highest possible lev el of protection permanently secured 2 term and are therefore preferred. Final Offset The risk of activ ities potentially failing to deliv er desired outcomes Calculation Risk of proposed activ ities should be taken into accont when assessing the potential offset Low Risk 1 contributions. Species Adjustment Factor 2 Final Offset Contribution (Species measure) 160.0 P a g e | 27

APPENDIX B: RESOURCE QUALITY OBJECTIVES FOR THE WETLAND OFFSET

This appendix to the Wetland Offset Plan for The Cape Flats Wastewater Treatment Works New Access Road on Farms 837, RE/829 and 1/840 in Cape Town is intended to provide the resource quality objectives to be achieved within the created wetland on the properties. These resource quality objectives must be read in conjunction with the monitoring plan provided to facilitate the assessment of the established measures to determine whether the recommended objectives are being achieved and improvement of the health and functionality of the system is taking place over time. Regular monitoring also allows one to identify the need for corrective action for problems that may arise.

Wetland Offset Objectives: The recommended ecological category that guides the proposed establishment measures for the wetland offset area within the site is as follows: B/C Category (largely natural to moderately modified). Key wetland creation objectives that relate to the goods and services provided by the wetland to be created within the site. That is to increase the aquatic habitat and biodiversity within the site. By rehabilitating the area within which the wetland offset is proposed, the connectivity between wetlands within the site would also be improved. This can be achieved through the clearing of dense alien vegetation in the area; reshaping of the area and removal of rubble and waste dumped into this area. Access to the site is also being monitored and controlled to prevent future dumping and disturbance of this area.

Resource Quality Objectives for the Wetland Offset - The Cape Flats Wastewater Treatment Works New Access Road on Farms 837, RE/829 and 1/840 in Cape Town):

Component Objective Comments Water Quantity Hydrology PES Component of the WET-Health (Hydro Module) Score > 70% Hydrological input into the wetlands is largely associated with groundwater levels which are likely to be impacted by the adjacent WWTW and existing urban Partial inundation of the wetland habitat should take place during the rainfall period development in the catchment. of June to September. Water Quality Water Quality PES Component of the WET-Health (Wetland IHI WQ Module) > 70% Water quality in the wetland will also be driven by the quality of the groundwater which is likely to be impacted by the adjacent WWTW and existing urban Nutrients: development in the catchment. Orthophosphates < 0.125 mg/l (50 %ile) Total Inorganic Nitrogen < 1.5 mg/l (50 %ile) Salts: Electrical Conductivity < 300mS/cm (95 %ile) System Variables: pH range of 6.5 to 8.5 ( 5 and 95 %iles) Dissolved oxygen > 4 mg/l (5 %ile) Toxins: Ammonia < 0.075 mg/l (95 %ile) Habitat Geomorphology, Vegetation and Overall Wetland PES > 70% No invasive or alien (exotic) or terrestrial woody plants should occur within the wetland and its adjacent buffer area of 30 m, where feasible. P a g e | 28

APPENDIX C: DEA&DP GUIDELINES FOR MAINTENANCE WORKS IN WATERCOURSES AND WETLANDS

The DEADP MMP guidelines (DEADP 2017) provide the following set of guiding principles for maintenance work in water courses that are of relevance to this site:

• Repairs and maintenance should be undertaken within the dry season, except for emergency maintenance works. • Where at all possible, existing access routes should be used. In cases where none exist, a route should be created through the most degraded area avoiding sensitive/indigenous vegetation areas. • Responsible management of pollutants through ensuring handling and storage of any pollutants is away from the watercourse. When machinery is involved, ensure effective operation with no leaking parts and refuel outside of the riparian area, at a safe distance from the watercourse to manage any accidental spillages and pose no threat of pollution. • At no time should the flow of the watercourse be blocked (temporary diversions may be allowed) nor should the movement of aquatic and riparian biota (noting breeding periods) be prevented during maintenance actions. • No new berms can be created. • In circumstances which require the removal of any topsoil, this must be sufficiently restored through sustainable measures and practices. • Concerted effort must be made to actively rehabilitate repaired or reshaped banks with indigenous local vegetation. • No deepening of the watercourse beyond the original, pre-damage determined thalweg, unless such deepening is directly related to the natural improved functioning and condition of such a watercourse. • Where at all possible, limit the disturbance to the zone of the thalweg. This is due to the ecological importance of the low flow channel and respective habitat being allowed to re-establish improving the ecological condition. • The build-up of debris/sediment removed from a maintenance site may: o be utilised for the purpose of in-filling or other related maintenance actions related to managing erosion, which form part of an adopted MMP; o not be used to enlarge the height, width or any extent of existing berms; o not be deposited anywhere within the watercourse or anywhere along the banks of a river where such action is not part of the proposed maintenance activity (ies). Material that cannot be used for maintenance purposes must be removed out of the riparian area to a suitable stockpile location or disposal site. Further action and consideration may be required where the possibility of contaminated material may occur, such as in urban watercourses. • The use of foreign material, such as concrete, rubble, woody debris and/or dry land based soil, is strictly prohibited from being used in maintenance actions, unless for the specific purpose of repairs to existing infrastructure, coupled with appropriate mitigation measures. • On completion of the maintenance action, the condition of the site in terms of relative topography should be similar to the pre-damaged state (i.e. the shape of the riverbank should be similar or in a state which is improved to manage future damage). This ultimately dictates that the channel, banks and bed cannot be made narrower, higher or deepened respectively. Exceptions are considered for systems involved with the management of stormwater and improvements for water quality within the urban context.