SCOPING REPORT On contract research for ILISO CONSULTING Proposed Construction of a 65 MW Photovoltaic Power Plant, Duvha Power Station, Mpumalanga Province Soils and Agricultural Potential Scoping Study By D.G. Paterson (Pr. Sci. Nat. 400463/04) Report Number GW/A/2014/xx January 2015 ARC-Institute for Soil, Climate and Water, Private Bag X79, Pretoria 0001, South Africa Tel (012) 310 2500 Fax (012) 323 1157 1
DECLARATION I hereby declare that I am qualified to compile this report as a registered Natural Scientist and that I am independent of any of the parties involved and that I have compiled an impartial report, based solely on all the information available. D G Paterson January 2015 2
CONTENTS Page 1. TERMS OF REFERENCE 4 2. SITE CHARACTERISTICS 5 3. METHODOLOGY 6 4. SOILS 7 5. AGRICULTURAL POTENTIAL 9 6. IMPACTS 9 7. CONCLUSION 10 REFERENCES 10 APPENDIX A: MAP OF LAND TYPES 3
1. TERMS OF REFERENCE The ARC-Institute for Soil, Climate and Water (ARC-ISCW) was contracted by Iliso Consulting to undertake a soil investigation near Witbank (emalahleni), in Mpumalanga Province. The purpose of the investigation is to contribute to the scoping phase of the Environmental Impact assessment (EIA) process for a proposed Photovoltaic (PV) power generation facility at Eskom s Duvha Power Station. Scoping Report The scoping report must include:» a description of the environment that may be affected by the activity and the manner in which the environment may be affected by the proposed project» a description and evaluation of environmental issues and potential impacts (including direct, indirect and cumulative impacts) that have been identified» Direct, indirect and cumulative impacts of the identified issues must be evaluated within the Scoping Report in terms of the following criteria: what will be affected and how it will be affected; (limited to the immediate area or site of development), regional, national or international» a statement regarding the potential significance of the identified issues based on the evaluation of the issues/impacts» identification of potentially significant impacts to be assessed within the EIA phase and details of the methodology to be adopted in assessing these impacts. The objectives of the study are; To obtain all existing soil information and to produce a soil map of the specified area as well as To assess broad agricultural potential. 4
2. SITE CHARACTERISTICS 2.1 Location The area that was investigated, on portions of the farms Speekfontein 336JS and Rhenosterfontein 318JS, lies approximately 15 km south-east of Witbank, adjacent to the Duvha Power Station. The position of the site is shown by the green areas on the map in Figure 1. The area lies between 25 o 55 and 25 o 58 S and between 29 o 19 and 29 o 22 E. Figure 1 Locality map Of the various areas that were identified, four areas are adjacent to the Power Station, while two areas lie further north, north of the ash disposal facility at Duvha (see map in Appendix A). 2.2 Terrain The site has gentle slopes toward the west and north-west, with slopes of less than 5%, and lies at a height of approximately 1 500 to 1 600 metres above sea level. 5
The area is situated close to two watercourses (especially in the north), so potentially wet areas may well be present. 2.3 Climate The climate of the study area (Koch, 1987) can be regarded as warm to mild, with rain in summer and dry winters. The long-term average annual rainfall in this region is 680 mm, of which 578.8 mm, or 85%, falls from November to April. The total annual evaporation is approximately 1 925 mm per year, peaking at approximately 7.0 mm per day in December. Temperatures vary from an average monthly maximum and minimum of 27.0ºC and 13.8ºC for January to 17.5ºC and -0.8 o C for July respectively. The extreme high temperature that has been recorded is 38.9 o C and the extreme low 13.3ºC. Frost occurs most years on around 57 days on average between mid-may and mid September. 2.4 Parent Material The geology of the area comprises sandstone of the Vryheid Formation, Ecca Group (Geological Survey, 1978). 3. METHODOLOGY Existing soil information was obtained from the map sheet 2528 Pretoria (Schoeman et al., 1978) from the national Land Type Survey, published at a scale of 1:250 000. A land type is defined as an area with a uniform terrain type, macroclimate and broad soil pattern. The soils are classified according to MacVicar et al (1977). The areas under investigation (as shown in white on the map in Appendix A) are covered by two one land type, namely: Ba4 (Mainly red, highly weathered, structureless plinthic soils) Fa8 (Mainly shallow soils with no lime, and some rock) The land type boundary is shown by the yellow line in Appendix A. 6
It should be clearly noted that, since the information contained in the land type survey is of a reconnaissance nature, only the general dominance of the soils in the landscape can be given, and not the actual areas of occurrence within a specific land type. Also, other soils that were not identified due to the scale of the land type survey may also occur. The site was not visited during the course of this study, and so the detailed composition of the specific land types has not been ground-truthed. A summary of the dominant soil characteristics of the land types is given in Table 1 below. The distribution of soils with high, medium and low agricultural potential within each land type is also given, with the dominant class shown in bold type. 4. SOILS A summary of the dominant soil characteristics is given in Table 1 below. 7
Land Type Ba4 Table 1 Depth (mm) 900-1200 600-1200 Land types occurring (with soils in order of dominance) Dominant soils Percent Characteristics of land type Hutton 14/15/16 36% Red, structureless, sandy loam to sandy clay loam soils on weathering rock Avalon/Glencoe 14/16 20% Brown to yellow-brown, structureless, sandy loam to sandy clay loam soils on mottled, soft or hard plinthite Agric. Potential (%) High: 55.6 Mod: 30.1 Low: 14.3 Fa8 300-1000 300-600 100-450 Longlands 21/ Cartref 21/31 Hutton/Clovelly 26 Mispah 10/11 16% 36% 31% Brown to grey-brown, structureless bleached sandy loam soils on mottled soft plinthite or weathering rock Red and yellow-brown, structureless, sandy loam to sandy clay loam soils on weathering rock Brown to grey-brown, structureless sandy loam to sandy clay loam topsoils on rock or hard plinthite High: 0.0 Mod: 9.5 Low: 90.5 - Rock 25% 8
5. AGRICULTURAL POTENTIAL The area comprises a mixture of soils, mainly non-structured, with some variable depth (as can be seen from the information contained in Table 1). The high rainfall in the area (Section 2.3) means that rain-fed cultivation can be successfully practiced on suitable soils. The landscape represented by land type Ba4 is dominated by soils with high (occasionally moderate) agricultural potential, with very few low potential soils, However, the area covered by land type Fa8 is predominantly low potential, generally due to shallow soil depth and occasional rockiness. For this reason, more detailed survey investigation would be required to delineate the areas of the various soil types. This would involve carrying out a systematic soil survey of the area or areas selected as viable alternatives, using a hand-held soil auger at a grid of investigation of 150 x 150 m. Samples of topsoil and subsoil from representative soils will be collected and analyzed, so that the soils occurring can be mapped and characterized for the grade of agricultural potential. A detailed soil map and report will be prepared, with all relevant soil-related information. 6. IMPACTS The major impact on the natural resources of the study area would be the loss of arable land due to the construction of the various types of infrastructure. With the possibility of moderate to high potential agricultural soils in the vicinity, this impact would in all probability have a degree of significance, although local in extent. At the end of the project life, it is anticipated that removal of the structures would enable the land to be returned to more or less a natural state following rehabilitation, with little impact. The impact can be summarized as follows: Table 3 Nature of impact Extent of impact Impact significance Loss of agricultural land Site only Land that is no longer able to be utilized due to construction of infrastructure Confined to areas within the site where infrastructure will be located 9
7. CONCLUSION The area investigated is comprised of a variety of soils, but with a significant percentage of shallow soils. The area can be considered as having mainly high potential for agricultural purposes, taking into consideration the annual rainfall. The soil information used in this report is based on a reconnaissance scale survey, revealing only broad soil patterns. If more detail on the soil patterns is required, then a soil survey (see Section 5) will be necessary to determine the detailed soil patterns that might not be obvious in this report. However, since the property is owned and operated by Eskom, the use of the land for agricultural production would not likely be an option for future development and therefore not accounted for as a loss. 10
REFERENCES Geological Survey, 1978. 1:250 000 scale geological map 2528 Pretoria. Department of Mineral and Energy Affairs, Pretoria. Koch, F.G.L., 1987. Climate data. In: Land types of the maps 2526 Rustenburg and 2528 Pretoria. Mem. Agric. nat. Res. S. Afr. No. 8. Department of Agriculture and Water Supply, Pretoria. MacVicar, C.N., de Villiers, J.M., Loxton, R.F, Verster, E., Lambrechts, J.J.N., Merryweather, F.R., le Roux, J., van Rooyen, T.H. & Harmse, H.J. von M., 1977. Soil classification. A binomial system for South Africa. ARC-Institute for Soil, Climate & Water, Pretoria. Schoeman, J.L., Meldal-Johnson, A., Fitzpatrick, R.W. & Verster, E., 1978. Land types of the map 2528 Pretoria. Field information. Mem. Nat. Agric. Res. S. Afr. No. 8. ARC-Institute for Soil, Climate and Water, Pretoria. 11
APPENDIX A MAP OF LAND TYPES 12
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