Palaeontological Impact Assessment May Be Significantly Enhanced Through Field Assessment by a Professional Palaeontologist
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PALAEONTOLOGICAL SPECIALIST STUDY: DESKTOP ASSESSMENT Proposed Lunsklip Wind Farm on farms Melkoutefontein 480 (Portion 135), Holvlei 630 (Remainders 2 and 3), Luinsklip 472 (Remainder portions 7, 2, 25) and Luinsklip 626, Still Bay, Western Cape John E. Almond PhD (Cantab.) Natura Viva cc, PO Box 12410 Mill Street, Cape Town 8010, RSA [email protected] August 2012 1. SUMMARY The study area of the proposed 20MW Lunsklip Wind Farm north of Still Bay, Western Cape, is almost entirely underlain by ancient aeolianites (wind-blown sands) of the Wankoe Formation (Bredasdorp Group) of Plio-Pleistocene age. These sediments have an extensive outcrop area along the southern Cape coast and are generally sparsely fossiliferous – the commonest fossils are various terrestrial snails – although rare concentrations of fossil mammalian bones and teeth associated with carnivore (e.g. brown hyaena) dens may also occur here. Potentially fossiliferous marine sediments of the Lower Bokkeveld Group (Ceres Subgroup, Early Devonian) and De Hoop Vlei Formation (Bredasdorp Group, Miocene – Pliocene) crop out on the southwestern edge of the study area along the Kafferkuil River valley but these formations are unlikely to be directly impacted by the wind farm development. The proposed wind energy facility is inferred to be of LOW overall impact significance in terms of palaeontological heritage resource conservation. Impacts are only likely during the construction phase of the development and are equally low for all three turbine layout options under consideration. Cumulative palaeontological impacts due to this and other proposed wind farm developments in the Still Bay – Mossel Bay region are rated as low. Future changes in infrastructure layout for the wind or solar energy projects will not materially affect the conclusions and recommendations made in this palaeontological report, provided that direct impacts on the outcrop areas of the Bokkeveld Group and De Hoop Vlei Formation are not involved. In view of the overall low significance of the proposed developments on palaeontological heritage resources, it is concluded that no further palaeontological heritage studies or specialist mitigation are required for this alternative energy project, pending the discovery or exposure of any substantial fossil remains (e.g. concentrations of vertebrate bones and teeth) during the construction phase. The ECO responsible for this development should be alerted to the possibility of important fossil remains being found either on the surface or exposed by fresh excavations during construction. Should fossil remains be discovered during construction, these should be safeguarded (preferably in situ) and the ECO should alert Heritage Western Cape so that appropriate mitigation (e.g. recording, sampling or collection) can be taken by a professional palaeontologist. The specialist involved would require a collection permit from SAHRA. Fossil material must be curated in an approved repository (e.g. museum or university collection) and all fieldwork and reports should meet the minimum standards for palaeontological impact studies developed by SAHRA. These recommendations should be incorporated into the EMP for the Lunsklip Wind Farm project. John E. Almond (2012) 1 Natura Viva cc 2. INTRODUCTION & BRIEF The company Bergwind Energy are proposing to develop a small wind energy facility, known as the Lunsklip Windfarm, of 20 MW maximum generation capacity on several land parcels situated to the north of the small town of Still Bay on the southern Cape coast, Western Cape (Fig. 1). The following land parcels are involved: Farm Melkoutefontein 480 (Portion 135), Farm Holvlei 630 (Remainders 2 and 3), Farm Luinsklip 472 (Remainder portions 7, 2, 25) and Farm Luinsklip 626. As shown in Fig. 2, these parcels form two separate areas situated on the eastern side of the Kafferkuil River. The main infrastructural components of the Lunsklip Windfarm of relevance to the present palaeontological desktop assessment include: Wind turbines (probably 11 or 12); A hard standing area (approx. 22m x 45m) adjacent to each turbine position for turbine assembly, maintenance and decommissioning; Temporary laydown areas for the placement of the turbine equipment during construction and decommissioning; A 66kV overhead transmission powerline to the existing substation on the western side of Stillbay; An access road & permanent internal road network to the wind turbines. The final concept and layout details, and the associated structures and infrastructure (roads, overhead power lines, sub-stations, grid connections etc.), will be informed by and adjusted according to the incoming wind data, as well as by inputs and feedback gathered from the project team and the public through the environmental impact process. Three layout alternatives are under consideration at this stage: Alternative One – Lunsklip “visual line” which is made up of 6 x 3MW turbines; Alternative Two – Lunsklip “visual line” 2MW which is made up of 10 x 2MW turbines; Alternative Three – Lunsklip “minimum CO2” which is made up of 6 x 3MW turbines with minimum carbon emission standards. Proposed wind turbine positions for all these optional layouts are shown on the satellite image of the study area in Fig. 3. The present fossil heritage desktop study forms part of the Basic Assessment for the Lunsklip Wind Farm that is being co-ordinated by Cape EAPrac, George (Contact details: Ms Melissa Mackay, Cape EAPrac, 5 Progress Street, Eagles View Building, First Floor / P.O. Box 2070, George, 6530; Tel: 044 874 0365; Fax: 044 874 0432; Cell: 084 584 7419; email: mel@cape- eaprac.co.za). The Heritage Impact Assessment component of the EIA process is being co- ordinated by Mr Stefan de Kock of PERCEPTION Heritage Planning (PO Box 9995, GEORGE, 6530; Fax: +27(0)86 510 8357; Mobile: +27(0)82 568 4719). In accordance with the National Heritage Resources Act, 1999, a palaeontological heritage assessment is required as part of a Heritage Impact Assessment for this alternative energy project since that study area overlies potentially fossiliferous Palaeozoic and Caenozoic sediments of the Bokkeveld and Bredadorp Groups. The various categories of heritage resources recognised as part of the National Estate in Section 3 of the Heritage Resources Act include, among others: geological sites of scientific or cultural importance; palaeontological sites; palaeontological objects and material, meteorites and rare geological specimens. John E. Almond (2012) 2 Natura Viva cc The Terms of Reference for the present palaeontological heritage report, as specified by Bergwind Energy (Pty) Ltd, are briefly to undertake a Paleontological Impact Assessment in relation to the proposed Lunsklip Wind Farm near Still Bay in the Western Cape. A desk top study should be conducted initially to determine the likelihood and need for detailed paleontological assessment. 2.1. Approach used for this specialist palaeontological study This palaeontological report provides an assessment of the recorded or inferred palaeontological heritage within the Lunsklip wind energy facility study area, with recommendations for specialist palaeontological mitigation where this is considered necessary. The report is based on (1) a review of the relevant scientific literature, including palaeontological assessments for wind farm projects near Mossel Bay (Almond 2010) and Vleesbaai (Almond, in progress); (2) published geological maps and accompanying sheet explanations; project data supplied by Cape EAPrac. In preparing a palaeontological desktop study the potentially fossiliferous rock units (groups, formations etc) represented within the study area are determined from geological maps. The known fossil heritage within each rock unit is inventoried from the published scientific literature, previous palaeontological impact studies in the same region, and the author’s field experience (Consultation with professional colleagues as well as examination of institutional fossil collections may play a role here, or later following scoping during the compilation of the final report). This data is then used to assess the palaeontological sensitivity of each rock unit to development (Provisional tabulations of palaeontological sensitivity of all formations in the Western, Eastern and Northern Cape have already been compiled by J. Almond and colleagues; e.g. Almond & Pether 2008). The likely impact of the proposed development on local fossil heritage is then determined on the basis of (1) the palaeontological sensitivity of the rock units concerned and (2) the nature and scale of the development itself, most notably the extent of fresh bedrock excavation envisaged. When rock units of moderate to high palaeontological sensitivity are present within the development footprint, a field-based assessment by a professional palaeontologist is usually warranted. On the basis of the desktop and any recommended follow-up field assessment studies, the likely impact of the proposed development on local fossil heritage and any need for specialist mitigation are then determined. Adverse palaeontological impacts normally occur during the construction rather than the operational or decommissioning phase. Mitigation by a professional palaeontologist – normally involving the recording and sampling of fossil material and associated geological information (e.g. sedimentological data) – is usually most effective during the construction phase when fresh fossiliferous bedrock has been exposed by excavations,