• Abstract and Figures
• Public Full-text

THE PROPOSED CONSTRUCTION OF AN 88kV DISTRIBUTION POWERLINE FROM THE EXISTING STRAATSDRIFT SUBSTATION TO THE PROPOSED SILWERKRAANS SUBSTATION WITHIN THE RAMOTSHERE MOILOA, MOSES KOTANE AND KGETLENGRIVIER LOCAL MUNICIPALITIES, NORTH WEST PROVINCE Ecological & Avifauna Component June 2017 Compiled by: Prepared for: Pachnoda Consulting CC Baagi Environmental Consultancy Lukas Niemand Pr.Sci.Nat PostNet Suite 412 PO Box 72847 Private Bag x4 Lynwood Ridge MENLO PARK Pretoria 0102 0040 Pachnoda Consulting cc Straatsdrift - Silwerkraans 88kV powerline EXECUTIVE SUMMARY Pachnoda Consulting CC was contracted by Baagi Environmental Consultancy CC to provide a terrestrial ecological report (general ecology and avifauna) for the proposed construction of an 88 kV distribution powerline from the existing Straatsdrift substation to the proposed Silwerkraans substation within the Ramotshere Moiloa, Moses Kotane and Kgetlengrivier Local Municipalities, North West Province. The project consists of two proposed corridors: Preferred Corridor (47.2 km) on the eastern section of the study area; and Alternative Corridor (45.8 km) on the western section of the study area. The terms of reference for this assessment are to: provide a general description of the affected environment concerning the avifaunal and terrestrial habitat types; conduct an assessment of all available information in order to present the following results: o typify the regional and local vegetation that will be affected by the proposed corridors; o provide an indication on the occurrence of threatened, “near- threatened”, endemic and conservation important plant, bird or animal species likely to be affected by the proposed corridors; o provide an indication of sensitive bird, fauna habitat and vegetation corresponding to the proposed corridors; o highlight areas of concern or hotspot areas; o identify potential impacts on the terrestrial ecological environment that are considered pertinent to the proposed development; o identify negative impacts and feasible mitigation options. A site visit was conducted during 19 - 23 June 2017 whereby the physical environment of the proposed corridors was inspected by road and on foot of selected points ("sampling points") following an evaluation of GIS based information on the biotic and biophysical attributes of the area. In summary, the alternative corridor transects a larger surface area of untransformed Zeerust Bushveld which is also less intensively grazed (and which has a higher basal cover of graminoid plant species) when compared to the preferred alternative. The preferred corridor traverses more surface area that is intensively grazed and human- induced or human-associated activities (e.g. pastoralism) have a higher potential to displace large-bodied mammal and bird species from the area. In addition, the southern section of the alternative corridor coincided with game and rotational cattle farms which are more conducive towards the preservation of mammal, avifaunal and floristic richness, whereby grazing capacities are maintained within functional limits. Ecological & Avifauna Report i June 2017 In addition, the alternative corridor traverses a higher number of perennial and seasonal drainage lines and is also located more or less in close proximity to a higher number of small-surfaced waterbodies. Considering the larger number of drainage lines and dams along the alternative corridor, it is of the opinion that concentrations of waterfowl and wading birds associated with these wetland features are exposed to a higher risk of potential bird collisions when compared to the preferred corridor. On the other hand, the preferred corridor traverses fewer drainage lines and perennial rivers features when compared to the alternative option, thereby rendering this corridor "more feasible". Also, a large section of the preferred corridor is located alongside an existing, and recently constructed distribution line, which emphasises the "feasibility" of the preferred corridor in increasing the visibility of the lines to approaching bird species. More intensive mitigation (and costs incurred) will be required to minimise potential bird collisions along the alternative corridor when compared to the preferred section (e.g. during the installation of bird flight diverters). Although the preferred corridor is "more feasible" from an ecological perspective, a re-alignment along its northern section is highly recommended to avoid potential damage to the floodplains of the Marico River and to minimise the potential risk of bird collisions since this particular area is perceived as a potential bird flyway. Two re-alignment options were proposed to the south of the recently constructed power line. It was strongly advised that a second survey be conducted during the austral summer season in the form of a pre-construction "walkdown" of the preferred corridor. Ecological & Avifauna Report ii June 2017 TABLE OF CONTENTS EXECUTIVE SUMMARY ............................................................................................ I TABLE OF CONTENTS ........................................................................................... III LIST OF FIGURES ................................................................................................... IV LIST OF TABLES ...................................................................................................... V LIST OF APPENDICES ............................................................................................. V DECLARATION OF INDEPENDENCE ............................................................................. VI 1. INTRODUCTION ................................................................................................ 1 1.1 BACKGROUND .............................................................................................. 1 1.2 TERMS OF REFERENCE ................................................................................. 2 2. METHODS & APPROACH ................................................................................. 4 2.1 DESKTOP ANALYSIS: BIOPHYSICAL ENVIRONMENT .......................................... 4 2.2 AVIFAUNAL EVALUATION ................................................................................ 5 2.3 VERTEBRATE FAUNA ..................................................................................... 5 2.4 VASCULAR PLANTS & VEGETATION ................................................................ 6 2.5 SENSITIVITY ANALYSIS .................................................................................. 7 2.6 LIMITATIONS ................................................................................................. 8 3. RESULTS AND DESCRIPTION OF THE AFFECTED ENVIRONMENT ........... 9 3.1 REGIONAL VEGETATION DESCRIPTION ......................................................... 10 3.2 GEOLOGY & SOILS ...................................................................................... 11 3.3 LAND COVER .............................................................................................. 12 3.4 CONSERVATION & PROTECTED AREAS ......................................................... 16 3.5 WETLAND AND DRAINAGE LINE CROSSINGS ................................................... 16 3.6 BROAD-SCALE HABITAT DESCRIPTION AND BIOTOPES ................................... 17 3.7 OCCURRENCE OF PLANT 'SPECIES OF CONSERVATION CONCERN' ................... 22 3.7.1 Threatened, near threatened and declining plant taxa ........................ 22 3.7.2 Protected plant species ...................................................................... 23 3.8 DECLARED ALIEN AND INVADER PLANT SPECIES ............................................ 26 3.9 RED LISTED, ENDEMIC AND CONSERVATION IMPORTANT FAUNA TAXA ........... 30 3.9.1 Faunal and vegetation impacts ........................................................... 31 3.10 AVIFAUNA: BIRD POPULATIONS LIKELY TO BE AFFECTED ................................ 35 3.10.1 Bird impacts associated with power lines ........................................... 35 3.10.2 Bird species likely to be impacted ...................................................... 41 3.11 ECOLOGICAL SENSITIVITY ............................................................................ 49 3.12 ANALYSIS OF PROPOSED ALTERNATIVES & AN OPINION REGARDING THE FEASIBILITY OF THE PROJECT (AS PER APPENDIX 6) ...................................... 52 3.13 RECOMMENDATIONS & MITIGATION MEASURES ............................................. 53 3.13.1 Avifauna ............................................................................................. 53 3.11.2 General ecological considerations ...................................................... 56 4. REFERENCES ................................................................................................. 58 5. APPENDICES .................................................................................................. 61 Ecological & Avifauna Report iii June 2017 LIST OF FIGURES Figure 1: A locality map illustrating the geographic position of the proposed 88 kV power line between the Straatsdrift substation and the proposed Silwerkrans substation. .......................................................................................................... 3 Figure 2: A satellite image illustrating the sampling points that were investigated to obtain a sem-quantified indication of the habitat types and vegetation associations on the study area. Also illustrated is the general

Load more

  91

Copy Link