Surface Water Assessment for the Gamma-Kappa Power Line Environmental Screening Study

REPORT Surface Water Assessment for the Gamma-Kappa Power Line Environmental Screening Study Client: MDT Environmental Reference: MD4703-RHD-ZZ-XX-RP-Z-0001 Status: S0/D02 Date: 9/23/2020 Project related ROYAL HASKONINGDHV (PTY) LTD 21 Woodlands Drive Building 5 Country Club Estate Woodmead Johannesburg 2191 Transport & Planning Reg No. 1966/001916/07 +27 87 352 1500 T +27 11 798 6005 F [email protected] E royalhaskoningdhv.com W Document title: Surface Water Assessment for the Gamma-Kappa Power Line Environmental Screening Study Document short title: Gamma-Kappa Surface Water Reference: MD4703-RHD-ZZ-XX-RP-Z-0001 Status: D02/S0 Date: 9/23/2020 Project name: Environmental Screening Study for the Proposed Development of the Gamma- Kappa Power Line Project number: MD4703 Author(s): Paul da Cruz Drafted by: Paul da Cruz Checked by: Date: Approved by: Date: Classification Project related Unless otherwise agreed with the Client, no part of this document may be reproduced or made public or used for any purpose other than that for which the document was produced. Royal HaskoningDHV (Pty) Ltd accepts no responsibility or liability whatsoever for this document other than towards the Client.Please note: this document contains personal data of employees of Royal HaskoningDHV (Pty) Ltd. Before publication or any other way of disclosing, this report needs to be anonymized. 9/23/2020 GAMMA-KAPPA SURFACE WATER MD4703-RHD-ZZ-XX-RP-Z-0001 i Project related Table of Contents 1 Introduction 7 1.1 Aims of the Study 7 1.2 Assumptions and Limitations 8 1.3 Site Location and Description 8 1.4 Expertise of the author to compile this specialist assessment 9 1.5 Adherence to Appendix 6 of the EIA Regulations 12 1.6 Definition of Surface Water Features, Wetlands and Hydric Soils 14 1.6.1 Definition of Surface Water Features 14 1.6.2 Definition of Wetlands 15 1.6.3 Definition of Riparian Zones 16 2 Legislative Context 18 2.1 The National Water Act 18 2.2 The National Water Act and Riparian Areas 19 2.3 International Policy Framework and Guidelines 20 2.3.1 The World Bank Policies 20 2.3.2 The International Finance Corporation (IFC) Performance Standards 20 2.3.3 Equator Principles 21 3 Methodology for Assessment 22 3.1 Field Assessment and Riparian Zone Delineation 22 3.2 Prioritisation of Riparian Areas 22 3.3 Identification of Surface Water and Riparian Zone Impacts and Mitigation Measures 23 4 Findings of Assessment 23 4.1 Macro-Drainage Context 23 4.2 Surface Water Typology and Occurrence 28 4.2.1 Riparian Zones 29 4.2.2 Wetland Occurrence 30 4.2.3 Riparian Zone Delineation 31 4.3 Freshwater Hydrology 43 4.4 Groundwater-surface water interactions and implication for riparian zone delineation 48 4.5 Fluvial Morphology 50 4.5.1 Vegetation Composition and Lateral Zonation 55 4.6 Water Quality 60 9/23/2020 GAMMA-KAPPA SURFACE WATER MD4703-RHD-ZZ-XX-RP-Z-0001 ii Project related 5 Freshwater Prioritisation 61 6 Impacts and Mitigation associated with the proposed power line 66 6.1 Impacts associated with placing towers within a surface water feature 66 6.2 Potential Impacts of the construction and operation of the Proposed Power Line on Surface Water Features in the Study Area 67 6.3 Impacts of power line servitude clearing on Riparian Zones 67 6.3.1 Potential Impacts specific to priority riparian areas in the study area 68 6.4 Mitigation Measures 71 6.4.1 General Mitigation Measures related to surface water features and riparian zones 71 6.4.2 Recommended Walk Down 71 6.4.3 Alien Invasive Plant Management within servitudes during operation 72 6.4.4 Recommended areas within corridors in which the proposed power line should not be routed 72 6.5 Impact Rating Matrix 84 7 Water Use Authorisation Implications 86 8 Comparative Assessment of Corridors 87 9 Conclusions and Recommendations 89 10 References 90 Table of Tables Table 1 – Findings of Compliance with Appendix 6 of the EIA Regulations 12 Table 2 – Tiered classification for aquatic environments in the study area 28 Table 3 – Comparative Assessment of Corridors in the South-western part of the Study Areas 87 Table 4 – Comparative Assessment of Corridors1&2 in the remainder of the Study Areas 88 Table of Figures Figure 1 – Locality 9 Figure 2 - Schematic diagram indicating the three zones within a riparian area relative to geomorphic diversity (Kleynhans et al, 2007) 17 Figure 3 – Drainage and Quarternary Catchments in the South-western Part of the Study Area 25 Figure 4 - Drainage and Quarternary Catchments in the Central of the Study Area 26 Figure 5 - Drainage and Quarternary Catchments in the North-eastern Part of the Study Area 27 Figure 6 – Riparian Areas in the Study Area – Groot River Area 32 Figure 7 - Riparian Areas in the Study Area – Muishond River Area 33 9/23/2020 GAMMA-KAPPA SURFACE WATER MD4703-RHD-ZZ-XX-RP-Z-0001 iii Project related Figure 8 - Riparian Areas in the Study Area – Koornplaas Area 34 Figure 9 - Riparian Areas in the Study Area – Vanwyksberg Area 35 Figure 10 - Riparian Areas in the Study Area – Merweville Area 36 Figure 11 - Riparian Areas in the Study Area – Leeu Gamka Area 37 Figure 12 - Riparian Areas in the Study Area – Leeurivier Area 38 Figure 13 - Riparian Areas in the Study Area – Beaufort West Area 39 Figure 14 - Riparian Areas in the Study Area – Rhernosterkop Area 40 Figure 15 - Riparian Areas in the Study Area – Three Sisters Area 41 Figure 16 - Riparian Areas in the Study Area – Gamma Substation Area 42 Figure 17 – Flow along the Sout River within Corridor 1 in June 2013 44 Figure 18 - Example of emergence of surface flow over bedrock outcropping from gravelly substrate and subsequent ‘disappearance’ in a tributary watercourse of the Buffels River in the Spitskop area (Corridors 1&1A)’ 45 Figure 19 - Pools along the Waaikraal River at Kranskraal (Corridor 1) 46 Figure 20 - Flood wrack trapped behind a Vachellia karroo shrub 47 Figure 21 - Extensive salt precipitate along the Brak River (Corridor 1) 48 Figure 22 - Hypothetical cross-section of landscape showing the fractured sandstone aquifer of the Table Mountain Group overlying the fractured shales and groundwater discharges controlled by faults and by geological contacts (le Maitre et al, 2009) 49 Figure 23 - Wide sandy channel bed of the Waaikraal River in Corridor 2 51 Figure 24 - Alluvial deposits adjacent to the primary channel along the upper reaches of the Buffels River in Corridor 1 with a secondary lateral flow channel in the right of the picture 52 Figure 25 – The Knoffelskloof River near the Spitskop Farm in Corridors 1&1A, displaying little or no riparian corridor due to the presence of rocky strata on the edge of the channel 53 Figure 26 - Channel on the outer edge of the Leeu River riparian corridor near Volmoed (Corridor 1). Although located far away from the primary channel, this is arguably part of the lower zone 54 Figure 27 – Elevated view of the Leeu River riparian zone in Corridor 1 showing Salsola- dominated alluvial flats with Vachellia karroo woodland closer to the channel 56 Figure 28 - Stipagrostis namaquensis along a secondary channel 58 Figure 29 - Dense Vachellia karroo thickets and luxuriant understorey within the Platdorings River riparian corridor in Corridor 2 59 Figure 30 - Atriplex nummularia and Prosopis within the Gamka River riparian zone near Steynskraal 60 Figure 31 - Sensitive Surface Water Sites in the South-western Part of the Study Area 63 Figure 32 - Sensitive Surface Water Sites in the Central Part of the Study Area 64 Figure 33 – Sensitive Surface Water Sites in the North-eastern Part of the Study Area 65 Figure 34 - Existing power line servitude within the riparian corridor of the Sout River in Corridor 1 cleared of all herbaceous vegetation 69 9/23/2020 GAMMA-KAPPA SURFACE WATER MD4703-RHD-ZZ-XX-RP-Z-0001 iv Project related Figure 35 - Power line servitude within the riparian corridor of the Sout River in Corridor 1 cleared of most vegetation with extensive bare areas 70 Figure 36 – Parts of the Corridors to be avoided – Map 1 73 Figure 37 - Parts of the Corridors to be avoided – Map 2 74 Figure 38 - Parts of the Corridors to be avoided – Map 3 75 Figure 39 - Parts of the Corridors to be avoided – Map 4 76 Figure 40 - Parts of the Corridors to be avoided – Map 5 77 Figure 41 - Parts of the Corridors to be avoided – Map 6 78 Figure 42 - Parts of the Corridors to be avoided – Map 7 79 Figure 43 - Parts of the Corridors to be avoided – Map 8 80 Figure 44 - Parts of the Corridors to be avoided – Map 9 81 Figure 45 Parts of the Corridors to be avoided – Map 10 82 Figure 46 - Parts of the Corridors to be avoided – Map 11 83 Appendices Appendix 1 - Impact Rating Methodology Appendix 2 - CV of Author 9/23/2020 GAMMA-KAPPA SURFACE WATER MD4703-RHD-ZZ-XX-RP-Z-0001 v Project related Executive Summary MDT Environmental Consultants have appointed Royal HaskoningDHV on behalf of Eskom Holdings Ltd. to update a surface water assessment study for the proposed development of 765kV transmission power lines in the Karoo districts of the Western and Northern Cape between Touws Rivier and Three Sisters.(the Gamma-Kappa Project).Eskom has previously undertaken Environmental Impact Assessment (EIA) studies for the proposed development of the Gamma-Kappa Power line Project, but these EIA processes were terminated. Royal HaskoningDHV completed the first draft of the EIA surface water report in 2013, and a subsequent updated draft of the report in 2017 Eskom are currently undertaking an environmental screening study to determine the feasibility of developing a power line along the route and have amended the original corridors of the power line.

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