Touwsriver Solar_Final EIR_20 April 2011.pdf Touwsriver Solar_Final EIR_20 April 2011.pdf
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 Touwsrivier Solar Energy Facility, Western Cape

2009 - 2010


The environmental impacts have been assessed by the respective specialists and the findings are summarised below:


The proposed development may have two negative impacts, a threat to botanical biodiversity and loss of rare and threatened species; and increased soil loss, through new access routes. This holds true for all the development phases of the project (Construction, Operation and Decommissioning phases). However, if the proposed mitigation measures are followed the development may have positive impacts on the environment, as current ongoing operations continue to result in the degradation of the area.


The use of areas of untransformed natural vegetation for the proposed development will result in the loss of habitat of certain sensitive faunal species. This is considered of high significance without mitigation, but becomes low with mitigation. This impact is mitigated by restricting the establishment of all infrastructure to the transformed parts of the site, i.e. old lands, roads, railway line, and so forth. Option 1a is preferred for the transmission power line route in terms of habitat loss. 

The construction of the solar tracking infrastructure may further destabilize or transform the sensitive drainages on the site, which represent sensitive fauna habitat and should thus be avoided. Any vehicular access across any of the drainages should be constructed with minimum bank and natural vegetation disturbance. A 15 m undisturbed natural buffer strip should be maintained on both sides of the middle of each drainage line during all phases of the project. This impact is assessed to be of high significance without mitigation and low with mitigation.

Habitat and population fragmentation will occur due to the security fence around the outer perimeter of the area for populations of smaller and medium sized vertebrates. This may result in the fragmentation of important areas of habitat for species such as hares, mongooses, porcupines, tortoises and certain ground birds. In mitigation of this negative impact, a small gap of ±150 mm should be provided at ground level, all along the security boundary fence around the affected area.

There is some potential for larger birds colliding with infrastructure when in flight. The affected area is not a known “flight” path for larger birds, although bustards and blue cranes to occur in the area. The problem generally relates to relatively “invisible” infrastructure like cables and power cables. The security fence should be adequately marked and the entire length of the 132 kV transmission line should be marked with bird “flappers” or diverters to make it visible.

The establishment of the proposed development may displace certain faunal species, temporarily or permanently, as a result of the noise and physical disturbance that will be associated with the construction phase of the development. Permanent displacement of any particular species should not have any lasting negative impact on the survival of the population of that species, because of the extensive availability of identical habitat immediately adjacent to the affected area.

There is a possibility that nocturnal insect‐eating bats may be attracted to the solar power infrastructure at night by their prey insects that are attracted by security lights. The use of yellow light rather than white light would mitigate this impact from medium to low since yellow light does not attract flying insects.

The development may impact on Red Data listed vertebrates such as the Fynbos golden mole, the Cape golden mole, white‐tailed rat and the striped weasel. This can be mitigated by restricting the development to the already transformed areas and that no part of the untransformed Renosterveld or Succulent Karoo should be disturbed in the interests of maintaining habitat and refuge for both Red listed and other species. The drainage that lies across the study area must also be retained undisturbed as part of the “natural” habitat and corridor area. None of the listed Red Data mammal species are likely to be negatively impacted by the preferred transmission line Option 1a.

Of the 71 bird species predicted to occur on the study area, only 2 are listed as Red Data species (Barnes, 2000). These are the blue crane (classed as vulnerable) and the black harrier (classed as near threatened). There are also numerous other productive cultivated lands in the district which can be used by these two Red Data species, so they are unlikely to be negatively impacted by the use of the transformed part of the study area for the proposed development. The preferred power transmission line Option 1a is unlikely to have any permanent negative impact on the avifauna, other than the possibility of collisions. In addition to the Red Data bird species, the endemic or near endemic bird species of the study area should also be considered important because these species are endemic to the Subregion, which is thus entirely responsible for their global survival. The long term protection of these natural parts of the study area will thus assist with the local conservation of these endemics and near endemics.


Given the topography and nature of the landscape at the Touwsrivier site, the remoteness of the area and the existing infrastructure on the site, it is anticipated that the solar energy facility would have a medium to high visual impact before mitigation. It would be difficult to mitigate the proposed solar facility, given its large footprint and its wide viewing angle as seen from the N1 National Road. The visual impacts can, however, be partly reduced by applying the visual mitigation measures, and it is anticipated that the visual impact would be medium after mitigation.

The substation and operational buildings would have a medium visual impact before mitigation, and medium to low impact after mitigation. The transmission lines in both options would have a medium visual impact both before and after mitigation, as there is little opportunity for visual screening or mitigation. The cumulative visual impacts are not considered to be significant, as there are no other known planned energy facilities within the viewshed or adjacent to the area, nor proposals for expansion of the solar energy facility.


During construction, the key social issues associated with Project include:

  • Creation of employment and business opportunities, and the opportunity for skills development and on‐site training;
  • Influx of construction workers employed on the project;
  • Influx of job seekers;
  • Increased risk of stock theft, poaching and damage to farm infrastructure associated with construction workers; and
  • Loss of agricultural land associated with construction related activities.
During operation, the key social issues associated with the Project include:
  • Creation of employment and business opportunities. The operational phase would also create opportunities for skills development and training;
  • The establishment of infrastructure to generate renewable energy;
  • Potential impact on tourism;
  • Impact on farming activities; and
  • The visual impacts and associated impact on sense of place and landscapes.

The findings of the SIA indicate that none of the potential negative impacts associated with the construction or operational phase would have a bearing on the decision. In addition all of the potential negative impacts can be effectively mitigated if the recommended mitigation measures are implemented. As a result the significance of all of the negative impacts with mitigation for decisionmaking was rated as low. However, the potential impacts associated with large solar energy facilities on an areas sense of place and landscape cannot be ignored. There exist opportunities to enhance the positive impacts, namely local employment and business opportunities. The proposed development also represents an investment in clean, renewable energy infrastructure, which, given the challenges created by climate change, represents a positive social benefit for society as a whole.


There are three types of potential impacts:

  • Impact to cultural landscape (based on rural / wilderness qualities of the area);
  • Impact to pre‐colonial archaeology; and
  • Impact to historical industrial archaeology and built environment.

These negative impacts would all be of low significance if mitigation is applied and there is the potential for a positive impact to the cultural landscape should the Project be decommissioned. Mitigation relating to the cultural landscape would be based on those measure proposed in the VIA for screening, whilst a policy of minimal intervention is required for the surviving rail heritage. A final walk down of the proposed 132 kV route is required to assist with the siting of towers to avoid sensitive areas.


The impact of the proposed development on fossil heritage is likely to be local in extent, since fairly rich fossil localities within the same geological units are already known elsewhere in the region. Loss of recorded or unrecorded fossil heritage during the construction phase of the proposed development is permanent, whereas the operational and decommissioning phases of the wind energy facility would not involve further significant adverse or other impacts on palaeontological heritage. The intensity of the impact on fossil is considered to be low in view of the relatively sparse distribution of fossils within the study area as inferred from the field assessment study. Furthermore, large‐volume excavations of potentially fossiliferous bedrock are not envisaged for this development project. Since the Voorstehoek Formation that underlies the greater part of the proposed development footprint is known to be generally fossiliferous, it is considered probable that construction of the solar energy facility would have an impact on fossil heritage. In view of the above, the overall impact significance of the proposed development on fossil heritage is considered to be low. The expected impacts of the different grid connections proposed are more or less identical, and the No‐Go option would not have a significant impact on local fossil heritage.


Agricultural Potential

The former cultivated lands of the study area are no longer economically productive and their productive potential was probably originally overestimated. Both the extremes of the climate and the nature of the substrate make the further agricultural cultivation of the area unwise and difficult to justify financially. Even rehabilitation under the expert guidance of the Department of Agriculture was not successful. Water extraction for cultivation would have a negative impact on the general area, and would result in the further aridification of the land.

It is therefore recommended that the former cultivated lands of the study area should not be used for agricultural production and that the disturbed areas can be made available for some other type of land use such as the Touwsrivier Solar Energy Facility.

Geology and Hydrology

In summary, based on the geotechnical information gathered, the site is considered to be suitable for the proposed development. The geotechnical specialist has set out a number of development considerations based on the existing geology within the study area. These would assist with the design of the facility and the layout in particular. Although it has not formed part of the impact assessment, opportunities have been identified to improve the overall quality of the environment within the study area. These are summarised as follows:

  • Implement measures to stabilise the drainage system including channels, dams and buffers;
  • Detailed water sampling and testing is required to confirm suitability of borehole water for use during construction and pperation;
  • Potential to source construction materials on or near the site; and
  • Design of the facility should take into account the geological conditions and recommendations in order to save time and money.


The proposed development site does not pose a threat to the environment, both in terms of botanical biodiversity pattern (rare or threatened plant species) or important ecological processes. If mitigation measures are followed the proposed development holds no potential negative cumulative impacts on the local environment or Critical Biodiversity Areas in the region. The most important mitigation actions required are to retain the proposed solar farm site to the non‐sensitive areas, and to exclude the sensitive Succulent Karoo and drainage lines. For the transmission line routes Option 1a is by far the least sensitive option as an access road is already available along the full length of the proposed route. The crossings of the water drainage areas, including those of transmission line Option 1a), should be upgraded to prevent soil loss.


Most of the sensitive species are largely restricted to the natural Renosterveld, Succulent Karoo and drainage line habitats. It thus follows that by excluding these natural habitats from the area to be developed, these Red listed fauna species will remain unaffected by the development. This is the primary mitigation of this study. Vlok (2011) agrees that the Succulent Karoo areas should be excluded in terms of botanical sensitivity but does not recommend the particular protection of the Renosterveld areas. These, however, should also be excluded from development area in the interests of sensitive fauna conservation. In terms of the less sensitive (commoner) fauna, it is also necessary to consider their needs. For example, the larger grey rhebok (Pelea capreolus) and steenbok (Raphicerus campestris) that were observed on the old lands must eventually be excluded from the developed area, in a manner that is safe for them i.e. fence design. Other fauna utilizing the transformed area will simply move away to undisturbed patches or continue to use the area in between the solar generation units. 


improvement should occur in the interests of this resident fauna (e.g. rodents, lizards, geckos, tortoises, birds). It can thus be concluded that no sensitive fauna, or fauna population, will be universally or locally threatened by the proposed development, provided that the natural Renosterveld, Succulent Karoo and drainage line habitats are excluded from the area to be developed and that the mitigatory measures are effectively implemented. These include a soil control programme to stabilise and protect the drainage areas, vegetation establishment where the drainages have been disturbed, rehabilitation of the former cultivated lands area by sowing in a variety of karroid shrubs and grasses, reduce wind erosion and improve small fauna habitat and restore natural soil health; providing a small gap (±150 mm), at ground level, all along the security fence; ensuring that the security fence and all power lines are adequately marked and maintain a protected and rehabilitated buffer zone along the drainages for 15 m on both sides. It is recommended that the site and transmission line route should be monitored during construction and at intervals (agreed by the relevant parties) during the operational phase of the project to determine avian and other faunal mortalities.


The visual assessment indicates that the potential visual impacts for the proposed solar energy facility would be medium to high before mitigation, and medium after mitigation. Visual impacts for associated infrastructure would be medium before mitigation, and medium to low after mitigation, while the transmission lines would remain medium as there is little opportunity for visual mitigation. 

Given the location and scale of the proposed solar energy facility, only minor mitigations can be put forward, which could partly reduce the visual impact significance. It is doubtful if the potential visual impacts alone would constitute a fatal flaw. However, the solar energy facility should be subject to the visual mitigation measures in order to reduce the potential visual impacts at the Touwsrivier site. Such measures include a Visual Setback Line, and site layout and design considerations such as building design, screening, signage and lighting. The use of the existing spoil heaps on the site for construction materials would be a visual benefit resulting from the project.

Cumulative visual impacts are not considered to be significant as no other energy facilities are proposed within the surroundings, and no future expansion of the proposed Project is planned. However, two options for a 132 kV transmission line are proposed, Option 1a being 5 km long in a south‐east direction, and Option 1b 7 km long in an east direction following the existing 66 kV line and rail line. In both cases the alignment is progressively distant from the N1, and located in a relatively remote area.


The findings of the SIA undertaken for the proposed Project indicate that the development would create employment and business opportunities for locals during both the construction and operational phase of the project. The proposed development also represents an investment in clean, renewable energy infrastructure, which, given the challenges created by climate change, represents a positive social benefit for society as a whole. The potential visual impacts associated with the facility would impact on the areas rural sense of place and landscape character. This impact would be for the entire operational lifespan (approximately 25‐30 years) of the facility. However, these impacts are not considered to represent a fatal flaw. It is therefore recommended that the facility as proposed be supported, subject to the implementation of the recommended mitigation measures and management actions contained in the report.


Given that the study area has a long history of industrial use, in‐part being the site of the junction of railway lines, and the various attempts to construct the Hexton Tunnel complex, reuse of the site for industrial purposes is considered acceptable in terms of historic continuity but clashes with the current wilderness/rural character of the site. The proposed activity would not impact negatively on surviving historical railway infrastructure. With respect to mitigation, a policy of minimal intervention is recommended with respect to the surviving historical railway infrastructure. In terms of archaeology, the site is considered to be insensitive however a walk‐over would be required for the transmission lines once a route has been approved.


The overall significance of the proposed development on palaeontological heritage is low and specialist palaeontological mitigation of this project ‐ such as monitoring during the construction phase when palaeontological impacts are generally most likely ‐ is not necessary. However, should substantial fossil remains be exposed during construction, notably dense concentrations of wellpreserved shelly fossils such as “starfish beds”, these should be carefully recorded (e.g. photographed, with GPS location) and safeguarded by the responsible Environmental Control Officer (ECO), preferably in situ. Heritage Western Cape and / or a qualified palaeontologist should be alerted as soon as possible so that any appropriate mitigation measures can be considered. 

Impact Statement for the Touwsrivier Solar Energy Facility

The avoidance of negative environmental impacts, wherever possible, has been adopted as the approach for this environmental assessment process, with mitigation measures as a secondary reaction to those impacts which cannot be prevented. It has been assessed that the proposed development does not pose a threat to the natural environment, both in terms of botanical biodiversity (rare or threatened plant species) or important ecological processes. Residual negative impacts which remain after mitigation are mostly of low significance apart from the visual impacts assessed as medium or medium to low during all project phases.

The key benefit will be the employment, training and business opportunities generated in the context of the Touwsrivier local economy, assessed as medium or high to medium significance. The physical environment would also be enhanced, namely through the mitigation of existing soil erosion along the drainage channels assessed as having a high positive impact. In terms of palaeontology, the potentially low negative impact may well change to positive as findings may contribute to and improved understanding of local fossil heritage. The Project is further supported by the current policy context and contributes to climate change mitigation through the investment in clean, renewable energy generation and this is assessed has being of medium significance.

There are potential cumulative impacts which would arise from the development, although they are assessed as not significant or low negative significance. The No Go Option results in no change to the status quo which may not necessarily be preferable for all disciplines such as the botanical, faunal and hydrological disciplines which would benefit from the opportunity for rehabilitation and stabilisation of the drainage line. Social benefits such as the employment, training and business opportunities would not be realised. At a broader level, the No‐Go option would represent a lost opportunity for South Africa to supplement its current energy needs with clean, renewable energy. These negative socio‐economic impacts in the form of opportunity losses have been assessed as having a medium significance.

Three grid connection alternatives were assessed: Option 1a involving a new 5 km transmission line along the farm boundary Hartebeeskraal 1/36 connecting to Eskom’s 132 kV line to the south‐east; Option 1b, a 7 km transmission line traversing two other farms (740 and RE/34) connecting to Eskom’s 132 kV line to the east; and Option 2, a direct on‐site connection to the Eskom 66 kV line with a reduced capacity. The environmental assessment has found Option 1a as the preferred alternative as the route follows an area of poor species richness which already has an access road along most of its length as well as a farm boundary fence. Option 1b is longer and affects more properties. Unlike Option 2, Option 1a would allow the full potential of the 50 MW facility to be reached.

On the basis of the information above, the EEU finds no reason or fatal flaw which should prevent the Touwsrivier Solar Energy Facility from being granted environmental authorisation. With respect to grid connection, Option 1a is motivated as the preferred alternative on environmental and project feasibility grounds and has been assessed as having an overall environmental impact of low significance. However, approval of Option 2 which would have a neutral environmental impact is requested in addition to the preferred transmission line option in the event that access to the 132 kV line is not technically feasible, as advised by Eskom. The grid connection and related capacity of the project that would be developed as the Touwsrivier Solar Energy Facility will therefore ultimately be decided by Eskom and the Department of Energy. The approval of two grid connections options has been discussed and agreed to in principle by Department of Environmental Affairs.