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BOHLWEKI-SSI ENVIRONMENTAL

Construction of a 132KV Distribution Line from the Kudu Substation to the Dorstfontein Substation in Mpumalanga Wetlands Assessment Report Issue Date: 3 December 2010 Project Number: 10710

Date: 26 November 2010

Document Title: Construction of a 132KV Distribution Line from the Kudu Substation

to Dorstfontein Substation in Mpumalanga

Author: Shaun Taylor

Revision Number: #1

Checked by: Paul da Cruz

Approved: Paul da Cruz

Signature:

For: SiVEST Environmental Division


ESKOM DISTRIBUTION LINE PROJECT

WETLANDS REPORT

Contents Page

1 INTRODUCTION 1

1.1 Wetlands and Hydromorphic Soils 1

1.2 Aims of the Study 2

1.3 Project Description 2

1.4 Legislative Context 4

1.5 Assumptions and Limitations 6

2 STUDY AREA DESCRIPTION 7

2.1 Drainage Context 7

3 METHODOLOGY 9

3.1 Desktop Delineation of Wetlands 9

3.2 Field-based Wetland Delineation and Assessment Techniques 9

4 FINDINGS OF ASSESSMENT 11

4.1 Wetland Occurrence 11

4.2 Desktop Delineated Wetlands 12

4.3 Field-assessed Wetlands 20

4.4 Comment on State and Functionality of Wetlands Assessed 28

5 POTENTIAL IMPACT OF PROPOSED POWERLINES ON WETLANDS 29

5.1 Potential Impacts of the construction and operation of Transmission Lines on Surface Water Resources 29

5.2 Nature of the Potential Impacts associated with the Proposed Powerlines along the alternative routes 31

5.3 Impact Rating Tables 34

6 COMPARATIVE ASSESSMENT OF ALTERNATIVE ROUTES 35 7 CONCLUSIONS AND RECOMMENDATIONS 36

7.1 Recommendations for CEMP Walk downs 37

8 REFERENCES 38 List of Tables Table 1– Functional State of the wetlands able to be assessed in the field. ................................ 28 Table 2 – Site specific impacts for those wetlands assessed in the field. ..................................... 33 Table 3 – Comparative Assessment of Routes in terms of wetland Crossings ............................ 35 List of Figures Figure 1- Study Area Map. .............................................................................................................. 3 Figure 2 – Example of 132kVSteel Monopole Tower ...................................................................... 4 Figure 3 – Catchment and surface water features of the Study Area. ............................................ 8 Figure 4 - General Wetland Occurrence across the proposed alignments ................................... 13 Figure 5 - Problem powerline spanning area for wetland area 5. Yellow dashed lines indicate likely wetland area and red line indicates alternative route 1. ....................................................... 14 Figure 6 - Satellite identified wetland areas 6 & 7 over route alternatives 1 and 3. Both alternatives essentially follow the same route and are indicated in green. ................................... 15

BOHLWEKI-SSI ENVIRONMENTAL prepared by: SiVEST ESKOM DISTRIBUTION LINE PROJECT Revision No. 0.1 26 November 2010 Page 1 P:\10000\10710 Kudu Dorstfontein\Technical\Wetland Assessment\Reports\Kudu-Dorstfontein Wetland Report (Finalised Version) 03.12.2010.docx


ESKOM DISTRIBUTION LINE PROJECT

WETLANDS REPORT

1 INTRODUCTION

SiVEST have been appointed by Bohlweki-SSI Environmental on behalf of Eskom Distribution to undertake a wetland impact assessment for the proposed development of power distribution lines and associated electricity infrastructure (hereafter referred to as the proposed development). The proposed development is intended to serve as a link between the Kudu Substation and the Dorstfontein Substation in western Mpumalanga. This project has been proposed in order to improve the electricity supply of the greater network. As part of the broader environmental basic assessment (BA) study that is currently being undertaken, the need to undertake a wetlands study has been identified. Accordingly, this study has been conducted to identify all potential wetlands and wetland related impacts and issues in the context of the proposed development. The study aims to identify potential issues and impacts on wetlands associated with the construction and operation phases of the proposed powerlines. Detected wetlands potentially crossed by the powerlines components were earmarked as areas of potential sensitivity that may be subject to impacts. Recommendations are made in terms of preferred alignment alternatives with the alternative associated with the least anticipated impacts on wetlands being recommended.

1.1 Wetlands and Hydromorphic Soils

Surface water features (including wetlands) are a very important component of the natural environment, as they are typically characterised by high levels of biodiversity and are critical for the sustaining of human livelihoods through the provision of water for drinking and other human uses. Surface water resources are sensitive features of the natural environment, and pollution or degradation of surface water can result in a loss of biodiversity, as well as an adverse impact on the human users which depend on the resource to sustain their livelihoods. As such surface water resources and wetlands are specifically protected under the National Water Act, 1998 (Act No. 36 of 1998) and generally under the National Environmental Management Act, 1998 (Act No. 107 of 1998).


Hydric soils are soils found within wetlands are defined by the U.S. Department of Agriculture Natural Resources Conservation Service (NRCS) as being "soils that formed under conditions of saturation, flooding or ponding long enough during the growing season to develop anaerobic conditions in the upper part". These anaerobic conditions would typically support the growth of hydromorphic vegetation (vegetation adapted to grow in soils that are saturated and starved of oxygen) and are typified by the presence of redoximorphic features (see section 3 for definition). The presence of hydric (wetland) soils on the site of a proposed development is significant, as the alteration or destruction of these areas, or development within a certain radius of these areas would require authorisation in terms of the National Water Act (36 of 1998) and in terms of the Environmental Impact Assessment Regulations promulgated under the National Environmental Management Act, 1998 (Act No. 107 of 1998).

1.2 Aims of the Study

The primary aims of this study are to:

identify all wetlands potentially affected by the proposed powerlines and associated infrastructure;

undertake a wetland prioritisation exercise, to identify highly sensitive wetlands within the study area;

delineate the boundaries of ‘priority’ wetlands along the power line alignments, where appropriate;

assess the potential impacts of the proposed power lines on wetlands along the alignment;

to recommend remediation and mitigation measures, that need to be taken, where relevant;

recommend preferred alignment alternatives, where relevant.

1.3 Project Description

The proposed project entails the construction of a 132kV overhead powerline linking the Kudu and new Dorstfontein Substations (Error! Reference source not found.). The power generated by Eskom can only be utilised from those points of supply which transform the power into a usable voltage. In this light, the proposed transmission lines are required to supply the greater area. Three alignment alternatives are being considered by Eskom and will be evaluated during the environmental assessment process to determine the best environmentally practicable alignment. Sub-transmission line conductors are strung on in-line (suspension) towers and bend (strain) towers. The proposed structures to be used for the proposed132 kV Sub-transmission


line for this project are the 132 kV steel monopole structures (Figure 2). The size of the footprint ranges from 0,6 m x 0,6 m to 1,5 m x 1,5 m, with the larger footprint associated with the guyed suspension and angle strain pole used as bend/strain structures. The self-supporting structure (suspension pole) is typically used along the straight sections of the powerline, while the guyed intermediate or guyed suspension and angle strain structures are used where there is a bend in the powerline alignment. The average span between two towers is 200 m, but can vary between 250 m and 375 m depending on the ground profile (topography) and the terrain to be spanned. The servitude width for a 132 kV Sub-transmission line is 36 m (15.5 m on either side of the centre line of the powerline). A minimum 8 m (4 m either side of the centre line of the powerline) wide strip is also to be cleared of all trees for stringing purposes. The minimum working area required around a structure position is 20 m × 20 m.

Figure 1- Study Area Map.


Figure 2 – Example of 132kVSteel Monopole Tower

1.4 Legislative Context

The National Water Act, 1998 (Act No. 36 of 1998) hereafter referred to as the Act was created in order to ensure the protection and sustainable use of water resources in South Africa. The Act recognises that the ultimate aim of water resource management is to achieve the sustainable use of water for the benefit of all users. Bearing these principles in mind, there are a number of stipulations within the Act that are relevant to the potential impacts on wetlands that may be associated with the proposed development. These stipulations are explored below and are discussed in the context of the proposed development. Firstly, it is important to discuss the type of surface water resource protected under the Act. Under the Act, a ‘water resource’ includes a watercourse, surface water, estuary, or aquifer. Specifically, a watercourse is defined as (inter alia):

a river or spring; a natural channel in which water flows regularly or intermittently; a wetland, lake or dam into which, or from which, water flows;

In this context it is important to note that reference to a watercourse includes, where relevant, its bed and banks.


It is important to note that water resources, including wetlands, are protected under the National Water Act. ‘Protection’ of a water resource, as defined in the Act entails the:

Maintenance of the quality and the quality of the water resource to the extent that the water use may be used in a sustainable way;

Prevention of degradation of the water resource; Rehabilitation of the water resource

In the context of the proposed development and the identification of potential impacts on surface water resources in the construction, operation and decommissioning phase of the proposed development, the definition of pollution and pollution prevention contained within the Act is relevant. ‘Pollution’, as described by the Act is the direct or indirect alteration of the physical, chemical or biological properties of a water resource, so as to make it (inter alia):

less fit for any beneficial purpose for which it may reasonably be expected to be used; or harmful or potentially harmful to the welfare or human beings, to any aquatic or non-

aquatic organisms, or to the resource quality. The inclusion of physical properties of a water resource within the definition of pollution entails that any physical alterations to a water body, for example the excavation of a wetland or changes to the morphology of a water body can be considered to be pollution. Activities which cause alteration of the biological properties of a watercourse, i.e. the fauna and flora contained within that watercourse are also considered pollution. In terms of section 19 of the Act, owners / managers / people occupying land on which any activity or process undertaken which causes, or is likely to cause pollution of a water resource must take all reasonable measures to prevent any such pollution from occurring, continuing or recurring. These measures may include measures to (inter alia):

cease, modify, or control any act or process causing the pollution comply with any prescribed waste standard or management practice contain or prevent the movement of pollutants remedy the effects of the pollution; and remedy the effects of any disturbance to the bed and banks of a watercourse

Lastly, under section 21 of the Act, ‘water use’ is defined inter alia, as: (a) taking water from a water resource; (c) impeding or diverting the flow of water in a watercourse; (i) altering the bed, banks, course or characteristics of a watercourse;


If the above activities occur as part of the construction, operation and decommissioning of the proposed development they will need to be licensed in accordance with the Act. The above stipulations of the Act have implications for the proposed development in the context of wetlands. Accordingly the potential impacts of the proposed development on wetlands have been scoped and identified in this report.

1.5 Assumptions and Limitations

This study has focused on the delineation of wetlands and wetland boundaries along the Eskom routings provided to SiVEST. A full delineation and mapping of all wetlands in the wider area has therefore not been undertaken. Moreover, identified wetlands were only accurately delineated where continuous areas of wetlands extended further than the spanning capability of the proposed powerlines (approximately 200m) and would therefore be impacted upon. Similarly, the delineation of the actual wetland boundary only covered a width of 100m or less along the proposed alignment for practical reasons. These provisions were implemented due to budgetary constraints and time restrictions. Hence, the entire delineation exercise has been streamlined for the purpose of the proposed development. A limited landowner database was only available to SiVEST in order to contact landowners in order to arrange access. As a result, permission to access properties along the proposed alignments had to be sought in the field. Because of this, the field survey was largely hindered by the lack of access to private property. Where contact details of landowners were obtained, access was also not always possible due to the landowner not being contactable or simply not granting access. Certain landowners refused access, denying any knowledge of the project, and as such the delineation of the wetlands in these locations were not possible. Furthermore, due to accessibility constraints, several identified wetlands along the proposed alignment (that were initially identified as potentially affected wetlands in terms of the proposed development) were delineated at a desktop level. Importantly, these particular wetlands were originally earmarked for delineation. However, as already stipulated, the delineation of these wetlands was not possible. In this light, it is very important to recognise that the desktop delineated wetlands shapefile along the various route alternatives, where specified, have not been validated in-situ, unlike the wetlands that were field assessed. It is critical that the boundaries of the wetlands along the finalised alignment be validated during the CEMP phase by an in-field wetland delineation to confirm precisely which wetlands are unable to be singly spanned.


No corridor was provided for assessment, only exact proposed alignments along the various route alternatives. A wider corridor (as is often provided for assessment in Eskom Transmission lines EIAs) was thus not assessed.

2 STUDY AREA DESCRIPTION

The study area is located in the western Mpumalanga Highveld region. Most of the alignment falls within rural areas largely characterised by intensive commercial agricultural and pastoral landuses, as well as coal mining activities. Emalahleni is situated approximately 35km to the northwest whilst Middelburg (north) is similarly distanced for the study area. Several main roads allow general access to study area and include the R544, R542, R547 and the R35. Otherwise farm entrances and dirt roads can be used where permissible. The Grassland biome covers much of the Mpumalanga province. However, the study area fits specifically into the Mesic Highveld Grassland bioregion. Moreover, the particular vegetation unit for this area is described as containing short dense grassland dominated by the usual Highveld grass composition with small scattered rocky outcrops with wiry sour grasses and some woody species (Mucina & Rutherford, 2006). The proposed route alternatives can be found at an altitude of between1550-1650m above seal level. The climate generally exhibits strongly seasonal summer rainfall, with very dry winters (Mucina & Rutherford, 2006).

2.1 Drainage Context

Each alternative of the proposed development, to a greater or lesser extent, courses through the Quarternary Catchment B11B (Figure 3). However, a part of alternative route 1 crosses into Quarternary Catchments B11E and B11D. These sub-catchments are embedded within the greater Olifants Primary Catchment (or Water Management Area) which ultimately drains to the east of South Africa. The topography is characterised by slightly to moderately undulating plains along with low hills and pan depressions (Mucina & Rutherford, 2006). Two main rivers flow across the proposed development route. The Olifants cuts across all route alternatives whilst the Koningspruit crosses alternative routes 1 and 3. The soil of the immediate area expresses red to yellow sandy soils found on shales and sandstone of the Madzaringwe Formation (Mucina & Rutherford, 2006).


Figure 3 – Catchment and surface water features of the Study Area.


3 METHODOLOGY

3.1 Desktop Delineation of Wetlands

The first step of the scoping phase for the wetlands assessment methodology was to conduct a preliminary desktop analysis of the study area using available information. Primarily, this was undertaken using Geographic Information Software (GIS). The software ArcView (version 9.3) developed by ESRI was used. The basis of information included the Biobase Mpumulanga, RSA wetlands and SANBI national wetlands databases. The use of Google Earth™ and aerial photography supplemented these data sources. Hence, prevailing surface water features according to the databases were easily mapped and highlighted. This also gave an indication of which main wetlands should be delineated along the proposed alignments. Additionally, the use of aerial photography and satellite imagery allowed other potentially overlooked wetland areas not contained within the above mentioned databases to be identified and verified in the field work phase. On colour satellite imagery wetland vegetation appears as a different hue (being darker or different in colour) than the grassy vegetation in the surrounding non-wetland grasslands, thus allowing wetland vegetation to be demarcated. The occurrence of wetland vegetation as apparent on the images was used to mark the boundaries of the wetlands. On colour (Google Earth™) satellite imagery, soil colour is able to be used as a further means of delineating wetland boundaries through remote sensing, especially where agricultural activities have transformed the natural vegetation within the wetlands and within the surrounding wetland catchment. Wetland soil colours are often ‘greyer’ in hue, reflecting the gleyed soils that typically occur within wetlands. These can be differentiated from the orange / brown / yellow more oxidised non-wetland soils that exist outside of the wetland. A GIS shapefile was created to represent the boundaries of the delineated wetlands.

3.2 Field-based Wetland Delineation and Assessment Techniques

Wetlands were delineated primarily on soil wetness indicators. For an area to be considered a wetland, redoximorphic features must be present within the upper 50cm of the soil profile (Collins, 2005). Redoximorphic features are the result of the reduction, translocation and oxidation (precipitation) of Fe (iron) and Mn (manganese) oxides that occur when soils alternate between aerobic (oxygenated) and anaerobic (oxygenless) conditions. Only once soils within 50cm of the surface display these redoximorphic features can the soils be considered to be hydric soils. Redoximorphic features typically occur in three types (Collins, 2005):


A reduced matrix – i.e. an in situ low chroma (soil colour), resulting from the absence of Fe3+ ions which are characterised by “grey” colours of the soil matrix.

Redox depletions - the “grey” (low chroma) bodies within the soil where Fe-Mn oxides have been stripped out, or where both Fe-Mn oxides and clay have been stripped. Iron depletions and clay depletions can occur.

Redox concentrations - Accumulation of iron and manganese oxides (also called mottles). These can occur as:

i) Concretions - harder, regular shaped bodies ii) Mottles - soft bodies of varying size, mostly within the matrix, with variable shape

appearing as blotches or spots of high chroma colours iii) Pore linings - zones of accumulation that may be either coatings on a pore surface,

or impregnations of the matrix adjacent to the pore. They are recognized as high chroma colours that follow the route of plant roots, and are also referred to as oxidised rhizospheres.

According to the DWAF guidelines for the delineation of wetlands (DWAF, 2005), soil wetness indicators (i.e. identification of redoximorphic features) are the most important indicator of wetland occurrence. This is mainly due to the fact that soil wetness indicators remain in wetland soils, even if they are degraded or desiccated. It is important to note that the presence or absence of redoximorphic features within the upper 50cm of the soil profile alone is sufficient to identify the soil as being hydric or non-hydric (non-wetland soil) (Collins, 2005). The potential occurrence / non-occurrence of wetlands and wetland (hydric) soils along the proposed routings have been assessed according to the method contained within the DWAF guideline, “A practical field procedure for the identification and delineation of wetlands and riparian areas” (DWAF, 2005). Three other indicators (vegetation, soil form and terrain unit) were used in combination with soil wetness indicators to supplement findings. Where soil wetness and/or soil form could not be identified, information and personal professional judgment was exercised using the other indicators to determine what area would represent the outer edge of the wetland. In the actual delineation process, soil samples were drawn using a soil augur at depths between 0.50-1.5 metres in the soil profile to determine where the outer edge of the temporary zone lies as well as the appropriate soil form. The outer edge of the temporary zone (where present) will also usually constitute the full extent of the wetland, encompassing inner lying saturated zones. Points are then recorded at these locations along the length of the wetland for each identified wetland zone. A conventional handheld Global Positioning System (GPS) is used to record the points taken in the field. The GPS points are then imported into a GIS system to map the identified zones. The GPS is expected to be accurate up to 5 metres.


Depending on the type of land use or development proposed, an appropriate buffer zone to protect the wetland should also be delineated (DWAF, 2005). Buffer zones are typically required to ensure that the ecotones between aquatic and terrestrial are protected. Ecotones are ecologically significant especially for species that utilise these opposing habitats for different stages of their lifecycle. However, buffer zones are necessary where developments transform a landuse from the natural state. At present there are no official requirements for buffer zones in the Mpumalanga province. Nevertheless, in the case of power transmission lines, no physical continuous boundary will be established and will therefore, not impact greatly on the habitat and movement of species in and out of wetlands. The anticipated impacts for the proposed development relate primarily to the construction phase. Hence, in this instance, the establishment of a wetland buffer is not deemed necessary.

4 FINDINGS OF ASSESSMENT

The findings of the assessment are presented below for the identified wetlands that could not be spanned singly based on the average spanning distance (200m) for the proposed towers and were therefore, likely to be impacted. The section is split into three sub-sections. The first section reports on the general occurrence of wetlands. The second section focuses on those wetlands that were restricted to distanced observation and drive-by surveys that consequently had to be delineated by means of remote sensing at the desktop level. The last section reports specifically on those prioritised wetlands that were accessible and assessed in the field. This section provides a more site-specific assessment of the wetlands.

4.1 Wetland Occurrence

Figure 4 indicates all surface water features as represented by the Biobase, SANBI and RSA Wetlands Databases, as well as those wetlands identified at the desktop level and those identified and verified in the field, thereby illustrating the general wetland occurrence along all the proposed alternative alignments and across the greater Study Area. All assessed wetlands are numbered accordingly. As mentioned earlier, the wetland areas delineated as part of the project have only been demarcated in the vicinity of the proposed lines. As such, wider wetland occurrence is represented by the various databases on the map. As can be seen in the illustration below, a total of seventeen wetland areas are either jointly or separately traversed by each of the proposed development alignments. Nine of these were delineated by means of desktop assessment and the remainder were assessed in the field. Seven desktop delineated wetlands and six field assessed wetlands are located along alternative route 1 making up a total of thirteen wetlands along this route whereas, two desktop delineated


wetlands and one field assessed wetlands along can be found alternative route 2 totalling three wetlands along this route. Finally, seven desktop delineated wetlands and three field assessed wetlands are found along alternative route number 3 making up a total of 10 wetlands along this particular route.

4.2 Desktop Delineated Wetlands

4.2.1 Wetland Area 1

Wetland area 1 can be found over both alternative routes 1 and 3. For the most part, this wetland area is surrounded and largely impacted by agricultural activities (Photo 1). However, a more detailed assessment could not be attained due to accessibility problems. Despite this, the area could be observed from a distance and wetland indicators (vegetation and terrain associated with wetlands) were visibly present. The results in this instance are therefore, tentative. Should this option be selected for the proposed development a thorough assessment should be conducted.

Photo 1. Agricultural fields around wetland area 1.


Figure 4 - General Wetland Occurrence across the proposed alignments



Wetland area 5 was inaccessible. However, satellite imagery revealed a potential wetland area along alternative route 1 where the proposed power line will change direction from north east to east specifically (Figure 5). This area indicates a wetland area extensive enough to be impacted by the proposed development (towers) which will need to be placed in the concerned area and therefore, warrants further investigation should this alignment be chosen.

Figure 5 - Problem powerline spanning area for wetland area 5. Yellow dashed lines indicate likely wetland area and red line indicates alternative route 1.

4.2.3 Wetland Areas 6 & 7

Wetland areas 6 and 7 are situated in amongst agricultural activities which extend up a railway line to the north (Figure 6). Accessibility to the identified potential wetland areas was not possible. These two areas do, however, show that wetlands covering a sufficient enough area will be impacted by the proposed development, if chosen. Furthermore, it is apparent that the drainage from these areas feed into the stream system to the north and is significant as such. A more detailed assessment is needed here to define the actual boundaries of these wetlands.

Approx. 430 metres


Figure 6 - Satellite identified wetland areas 6 & 7 over route alternatives 1 and 3. Both alternatives essentially follow the same route and are indicated in green.


It was possible to conduct a drive-by survey for wetland area 9. However, no access was granted and therefore a thorough assessment could not be conducted without the appropriate authorisation. Nevertheless, this area forms a seepage point which has been impounded further south of this point. The immediate area is covered by grasslands although bounded by agriculture (Photo 2). The approximate distance estimated to be covered by this wetland area is in the region of 400 metres along the proposed alignment of alternative 1. Hence, the exact boundaries of this wetland will need to be determined.

Wetland Area 6

Wetland Area 7


Photo 2. Hillslope seepage wetland (encircled in red) identified at wetland area 9.

4.2.5 Wetland Area 10 & 11

The owner of the properties where potential wetland area 10 and 11 was identified did not allow access to this area. These two areas are significant in that each drains into the Blinkpan wetland (Photo 3). The identification of the boundaries will need to be conducted once permission is obtained.

Photo 3. Representation of Blinkpan wetland (encircled in red) seen in the distance.



Two evaporation ponds along proposed alternative route 1 (Photo 4) are situated within the Koornfontein Mines. These areas are not wetlands per se, although spanning problems will be experienced at this juncture. In light of this, if the powerline pylons cannot be placed between the ponds it is envisaged that the structures will need to be placed further south in an area which is natural wetland. In this case, the lower lying wetland has been delineated and is assessed in the following section (refer to Section 4.3.4).

Photo 4. Evaporation Ponds of the Koornfontein coal mines obstructing the proposed route for alternative 1.


Wetland area 15 suffers the same accessibility problems and impacts (photo 5) of adjacent wetland area 1 in relative close proximity. However, wetland area is located exclusively along the proposed alternative route 3. Observation revealed that the wetland areas identified as experiencing spanning problems here are located within a drainage area between agricultural fields. The presence of typical wetland vegetation (Imperata cylindrica) was also apparent. This area should similarly be subjected to a thorough assessment.


Photo 5. Wetland area 2 showing drainage lines of the immediate catchment as well as Imperata cylindrica fields (both features encircled in red).


The Olifants River courses directly through alternative route 2. Once again, access could not be obtained from the relevant property owners and alternative routes leading to the concerned area were simply fenced off. Fortunately, access via adjacent properties could be attained and a drive-by survey could be undertaken. As can be seen, existing powerlines already traverse the river system in question. From this, it is apparent that the powerlines of proposed alternative route 2 may similarly span the area. However, further north of the river was not visible. Satellite imagery reveals that this area does not show signs of any potential wetland. Importantly though, due to the close proximity of the Olifants River this area deserves a more detailed assessment should this route be chosen.


Photo 6. Wetland area 17 over the Olifants River system. Note the existing powerlines over rocky outcrops on terrestrial land.


Much like wetland area 12, wetland area 18 likewise encompasses artificial water features (slimes/tailings dams) belonging to the Komati Power Station (Photo 7). Hence, this area is not natural wetland area but will experience powerline spanning problems. Should the powerlines be routed around these features, it is not envisaged that any wetland will be impacted provided the lines follow the border of these artificial dams.

Photo 7. Slimes/Tailings dams of Komati Power Station.


4.3 Field-assessed Wetlands

In accordance with the DWAF (2005) methodology, detailed wetland delineations were conducted where necessary and if possible. Taking into account all indicators, each wetland area delineated in-field is described.


This landscape is used primarily for pastoral activities. Hence, grazing and burning impacts affect this site. The prevailing vegetation reflects these impacts and actual species identification was not possible as no flowering parts were present at the time the study was undertaken. Regardless, few smaller sedge species (Cyperaceae sp.) were observed within the grassland. Further north, agricultural activities are conducted. This agricultural land engulfs a hillslope seepage zone (Photo 8) which leads into a low lying, palustrine valley bottom wetland system below.

Photo 8. Seepage zone surrounded by agriculture. The soils in the low-lying wetland area contain moderately light grey, sandy clay particles. The substrate may be described as predominantly mineral soils. The soil profile indicates an Orthic A topsoil horizon (Photo 9) overlying an unspecified E horizon (Photo 10) suggesting the Fernwood Soil Form. Equally, mineral soils may be found in the outer lying temporary zone. Here, the soils have a light brown colour and a sandy, friable texture presumably reflecting the parent material (sandstone) of the region. Faint low chroma dark orange mottles are evident in the sub-soil along in this reduced layer.


Photos 9. Depiction of the top-soil profile of the Permanent Zone. Some mottling present near the surface of the topsoil.

Photo 10. Persistent grey matrix of the lower-lying E horizon of the permanent zone.

Photo 11. Sandy topsoils of the temporary zone.

Photo 12. Close-up of faint low chroma dark orange mottles of the temporary zone.

4.3.2 Wetland Areas 3 & 4

Wetland areas 3 and 4 essentially show the same vegetation characteristics. Both are covered predominantly by Imperata cylindrica (photo 13) fields and small sedges (photo 14) but are relatively disturbed with prevailing invasive vegetation fringing encroaching on these areas and lining adjacent dirt roads (such as Verbena bonarensis). Equally, each area is also situated amongst agricultural fields. Wetland area 3 specifically is situated in a depression high up in the landscape whilst wetland area 4 is situated similarly in a depression between undulating plains eventually sloping into a lower lying valley bottom. These wetlands were found to seasonal wetlands. Wetland Area 3 can be descried as a crest depression whereas wetland area 4 can be described as a mid-slope depression.


Photo 13. Imperata fields in the depression wetland area of wetland area 3)

Photo 14. Small sedge species found within the vegetation cover of wetland areas 3 and 4.

The substrate of wetland area 3 contains mineral sandy soils showing orange chroma mottles within 50 cm of the surface (Photo 15). Below the soils become slightly more leached and reductions are evident in the soil matrix (Photo 16). This region of the temporary zone can be attributed the Longlands Soil Form. Wetland area 4 is characterised by the same soil form as wetland area 3 but with a higher sandy component.

Photo 15. Top 30cm profile of wetland area 3 showing sings of wetness.

Photo 16. Leached soils in the lower horizons of wetland area 3.


Photo 17. Diffuse mottling in the top 50 cm of the soil profile at wetland area 4.

Photo 18. Lower leached horizons in soil of wetland area 4.


Wetland area 8 is situated in a valley bottom and is bound by a railway line to the south and a main road to the north. The wetland is can be described as a palustrine valley bottom channelled wetland (Photo 19 & 20). Grasses in this area were dominated by Helictotrichon turgidulum whilst Helichrysum sp. and Ledeboria ovatifolia was also present. Disturbance near the fringes of the grassland were apparent close to adjacent dirt roads. Signs of wetness were found within the sub-soil of the wetland area showing orange and grey mottles in the Soft Plinthic B horizon (Photo 21) indicating the Westliegh Soil Form.

Photo 19. Picture showing the topography of the wetland area (Valley Bottom).

Photo 20. River system flowing through the wetland.


Photo 21. Typical iron sesquioxide mottles associated within the soft plinthic B horizon.


Already mentioned, wetland area 12 may need to be impacted should alternative routes 1 and 3 be chosen for the proposed development in light of the fact that artificial features already present may force the alignments into this sensitive area. The wetland is located at a valley bottom and is un-channelled and palustrine in nature (Photo 22). The vegetation cover is dominated by H. turgidulum and is disturbed. The substrate is characterised by an Orthic A horizon and an underlying soft plinthic B horizon (Photo 23). This soil is attributed with the Westleigh Soil Form.

Photo 22. Picture of the valley bottom wetland area 12.

Photo 23. Good example of red/orange mottling in the soft plinthic B horizon of wetland area 12.



This wetland area is found in a valley bottom. There is however, a dry channel coursing through the wetland which presumably flows seasonally or intermittently at least (Photo 24). The wetland is palustrine in character and covered by short grasslands. Hydrophytic vegetation could be found including but not limited to Typha capensis, Schoenoplectus corymbosus and a few other sedges and rushes. Some tree species (Rhus pyroides) were also present. To the south of the wetland area, the topography is modified (Photo 25) along the foot slope making an absolute distinction of the temporary zone difficult near the Komati Power Station which borders the wetland. Nonetheless, boundaries could be established. The upper topsoil horizon of this area revealed an Orthic A horizon with signs of wetness (Photo 26) overlying a bleached horizon (Photo 27) suggesting the Katspruit Soil Form.

Photo 24. Dry channel coursing through the wetland.

Photo 25. Impoundment and other raised topography south of the wetland border.

Photo 26. Typical iron oxidisation associated with the root channels of vegetation in the temporary zone of wetland area 13.

Photo 27. Soil sample of the bleached horizon showing sandy soils with associated mottling.



To the north of the Komati Power Station, this wetland area is located in between undulating low hills in the valley bottom (Photo 28). Some channelling and pooling can be observed towards the permanent zone (which primarily could be a result of the bridge crossing that traverses the wetland) although it should not be regarded as a channelled wetland per se. The wetland has been impacted by channel diversions to the south of this wetland. In terms of vegetation, this wetland is also covered by grasslands made up of species similar to that of wetland area 13 although Phragmites australis, I. cylindrica and Polypogon monspeliensis can also be found in certain areas. The soil form of the temporary zone of the wetland reflects an Orthic A horizon and an underlying G horizon mimicking the Katspruit Soil Form of wetland area 14.

Photo 28. Picture of the wetland area in the low lying valley. Note the bridge crossing the wetland.

Photo 29. Artificial channel diversions within the wetland area.

Photo 30. Top 30 cm profile of the temporary zone of the wetland.

Photo 31. Mixture of gleying and mottling in the soil profile for the temporary zone of the wetland.



This extensive wetland area is characterised by hillslope seepages (Photo 32) in the surrounding catchment which drains internally into a valley bottom which has a series of both small and larger impoundments along its course (Photo 33 & 34). The wetland is channelled and palustrine in nature. The surrounding terrain here comprises low undulating hills which have to a large extent been transformed into agricultural fields. Essentially, the wetland areas have been left largely (not entirely) intact in so far as the boundaries of the agricultural fields for the most part line the edge of the wetland area. However, many dirt roads crossed wetland areas impeding the hydrological connectivity between systems somewhat. The temporary zones of the wetland area were difficult to delineate as vertic soils were common. As such, this particular delineation was based mainly on vegetation and terrain unity indicators in conjunction to aerial photography and satellite imagery.

Photo 32. Hillslope seepage point originating from the mid-slope.

Photo 33. Large impoundment along the wetland.

Photo 34. Small impoundments. Photo 35. Example of vertic soils.


4.4 Comment on State and Functionality of Wetlands Assessed

An important land use impact of the wetlands is the encroachment of agriculture. Soil conditions within well-established wetlands very often do not support agriculture as it is impractical within areas of permanent water-logging and soils with high clay content. Agriculture has therefore largely remained within the outer limits or the temporary zones of most of the wetlands. Where the wetlands are less well established, agricultural activity very often has transformed the entire habitat unit. Mining activities however, will impact greatly on wetlands where excavating and the processing of soils are concerned. Table 1– Functional State of the wetlands that were able to be assessed in the field.

Route Wetland Area #

Condition Primary Functions

Alternative Route 1 2 Good - Current impacts restricted to burning and grazing.

Terrestrial habitat, biogeochemical cycling, flood attenuation.

Alternative Route 1 3

Good – Vegetation slightly disturbed. Terrestrial habitat, biogeochemical cycling, flood attenuation.

Alternative Route 1

4 Good – Vegetation slightly disturbed. Terrestrial habitat, biogeochemical

cycling, flood attenuation.

Alternative Route 1 & 3

8

Moderate – Channel incision and erosion evident indicating lowered water table. Slightly disturbed vegetation.

Flow regulation, improvement of water quality, aquatic and terrestrial habitat, flood attenuation, nutrient spiralling and biogeochemical cycling.


12 Good – Current impacts restricted to burning and grazing.

Terrestrial habitat, biogeochemical cycling, flood attenuation.


13

Good – However, stream bed dry perhaps indicating impacted hydrology upstream. Slightly disturbed vegetation.



14

Moderate – Anthropogenic impacts (water diversions and altered topography), Vegetation moderately disturbed.


Alternative Route 2

16

Good Flow regulation, improvement of water quality, aquatic and terrestrial habitat, flood attenuation, sediment trapping, nutrient spiralling and biogeochemical cycling.


5 POTENTIAL IMPACT OF PROPOSED POWERLINES ON WETLANDS

5.1 Potential Impacts of the construction and operation of Transmission Lines on Surface Water Resources

The anticipated types of impacts will be similar between the wetlands identified at the desktop level those assessed in the field, and therefore equally applies. Distribution powerlines are not typically associated with impacts on surface water resources, as the powerlines do not have a physical footprint over the length of the powerline other than the footprint of each tower position. As the lines are strung above the ground and as the towers are spread approximately over 200m apart, most wetlands and rivers are able to be ‘spanned’ by the powerlines and thus avoid being physically affected. Powerlines can however be associated with impacts on surface water resources if the towers are placed within a river or wetland. The process of constructing the powerline can also cause impacts on surface water resources, especially if certain mitigation measures and procedures are not followed (i.e. transgression of vehicle in the wetland). These potential impacts are explored in greater detail below.

5.1.1 Placing of Towers in Wetlands

Towers / electricity pylons are large structures and require foundations in order for the structures to remain standing. The process of excavating the foundations would disturb the substrate and entail the removal of soil and vegetation from parts of the footprint, as well as the potential damage to vegetation due to the movement of construction machinery in the vicinity. Moreover, sedimentation as a result of disrupted soils and consequent erosion and deposition via surface run-off into streams can affect the functioning of a wetland. If towers are constructed within a wetland, this activity could potentially adversely affect the wetland soil and vegetation through the compaction of wetland soils, the trampling / smothering of wetland vegetation and the resultant exposure of wetland soils that could result in their desiccation and subsequent erosion. The presence of concrete, as well as machinery in or near a wetland may result in leakages (fuel, oils and cement) into the wetland resulting in the introduction of pollutants into the wetland. Furthermore, the movement of heavy construction machinery into the wetland could result in the alteration of the sub-surface hydrology of the wetland by creating alternative routes or conduits for the movement of water in the wetland as a result of the tracks left by vehicles. The placing and construction of a tower in a wetland would also require a licence from the Department of Water Affairs and Forestry as this activity would fall under one of the specified water uses under Section 21 of the National Water Act: (i) altering the bed, banks, course or characteristics of a watercourse.


5.1.2 Other Construction-related impacts

Even if towers are not placed in wetlands, the process of constructing the powerline could potentially impact on surface water resources. A number of activities, especially those relating to the access of construction vehicles along the alignment of the powerline being constructed can result in damage to and impacts on surface water resources. Construction vehicles and machinery that move along the alignment of a powerline during construction would typically need to cross rivers and drainage lines. Accesses across these surface water resources may need to be constructed should existing accesses for vehicles not exist (this is often the case as powerlines can run in rural settings in which there is little human infrastructure). Accordingly, the following impacts on surface water resources can result from construction activities along the powerline servitude:

The uncontrolled interaction of construction workers with watercourses that could lead to the pollution of the water in these drainage systems. Examples of this may be the washing of equipment in water within the watercourse, dumping of construction material into the drainage system etc.

The lack of provision of adequate sanitary facilities and ablutions on the servitude may lead to the direct of indirect faecal pollution of surface water resources.

Leakage of hazardous materials, including chemicals and hydrocarbons such as fuel, and oil, which could potentially enter nearby surface water resources through stormwater flows. This may arise from their incorrect use or incorrect storage.

The incorrect mixing (batching) of cement could lead to siltation and contamination of watercourses.

Inadequate stormwater management and soil stabilisation measures in cleared areas could lead to erosion that may lead to siltation of nearby watercourses.

The placing and use of access roads for construction traffic across watercourses may lead to the erosion of banks and disturbance of riparian vegetation that may trigger the further development of gulley (donga) erosion.

Construction of access routes across watercourses may impede the natural flow of water (especially if access is required across running water). This would alter the hydrology of the watercourse and potentially act as a barrier to the movement of aquatic biota. Uncontrolled access of vehicles through wetlands, including moist grasslands can cause a significant adverse impact on the hydrology and soil structure of these areas through rutting (which can act as flow conduits) and through the compaction of soils.


5.1.3 Operational Impacts

Similarly, impacts on water resources may result during the operational phase of the project. These would relate mainly to residual impacts that arose during the construction phase, as well as to the incorrect rehabilitation of construction-related access. Certain operational activities such as the clearing of the servitude through the use of herbicides may also pollute nearby watercourses if not properly undertaken. Operational Access for vehicles to inspect the servitude and lines may impact watercourses and other wetlands if existing access roads / routes are not utilised, or if existing road access across watercourses are not properly maintained.

5.1.4 Mitigation

It is very important to note that Eskom have a set of procedures to mitigate the above impacts. Should these procedures be followed as is stipulated in all Eskom transmission construction projects, the majority of these impacts will be avoided or reduced to an acceptable level. In order to avoid towers impacting on wetlands by being placed within a wetland, it is very important that the detailed route alignment process take the presence of wetlands and other surface water features along the route of the powerline into account. The routing of the powerline should aim to avoid physically affecting water resources where possible. Where wetlands are very wide, and thus not able to be spanned, the routing should aim to deviate from these wetlands or cross them at a point where the wetland is narrower. Where this is not possible, a detailed set of mitigation measures to reduce impacts of the tower construction on the wetland should be identified. In this instance, towers should be placed within the ‘drier’ temporary zone of the wetland rather than in the more permanently inundated (and thus more sensitive) sections of the wetland.

5.2 Nature of the Potential Impacts associated with the Proposed Powerlines along the alternative routes

As explored above, a number of different types of impacts may be associated with the proposed powerlines. These impacts are rated in the impact rating tables below.


Wetlands in which towers will need to be placed occur along all alternative routings and will thus be a factor irrespective of which alternative route is selected as being the preferred alignment. This would thus entail the placing of towers in a certain part of the wetland. Importantly, this is stipulated as a water use under the National Water Act and a license for this activity would need to be sought from the Department of Water Affairs. This activity would also be considered as ‘pollution’ as defined by the National Water Act, as this would entail the physical disturbance of soils and vegetation in the footprint of the tower, and on any required access route into the wetland to the tower location. Many of these large systems have largely been identified to have a very high level of functionality and thus the disturbance of these systems by the placing of towers and access routes into the towers could have a significant localised impact on the current functionality and state of the identified wetlands. The placing of access routes into the wetland to construct towers moreover could be particularly damaging to the wetland state in terms of soils, vegetation and hydrology. Enabling access of heavy machinery to the tower location could necessitate the construction of a running track that may entail the import of fill material, which if not removed could have a concomitant impact on the hydrology and soils of this part of the wetland, with potential knock-on effects such as alien invasive vegetation encroachment. As stated above, the potential impact of poor construction activities and placing of access roads into other narrower wetlands would be largely nullified if Eskom’s standard construction mitigation procedures are followed in the construction and operation of the powerlines. However, each respective route could be associated with a number of negative site specific impacts including vegetation removal, soil disruption, erosion and compaction. This is due primarily to the width the wetland areas exceeding the distance needed to place the towers along the proposed route making single spanning impossible. The towers are highly likely then to be placed within the wetland. Furthermore, access routes may need to be constructed into the wetland leading to further degradation of wetland quality. The table below indicates the distance to be spanned for each alternative route.


Table 2 – Site specific impacts for those wetlands assessed in the field. Route Wetland Width to be

spanned (m) Alternative Route 1

& 3 1 Route 1 – approx.

419m Route 2 – approx.

1026m Alternative Route 1 2 Approx. 340m Alternative Route 1 3 Approx. 450m Alternative Route 1 4 Approx. 530m Alternative Route 1 5 Approx. 430m Alternative Route 1

& 3 6 Approx. 590m


7 Approx. 290m


8 Approx. 294m


9 Approx. 740m


10 Approx. 383m


11 Approx. 273m


12 Approx. 470m


13 Approx. 432m


14 Approx. 965m

Alternative Route 3 15 Approx. 235m Alternative Route 2 16 Approx. 1210m Alternative Route 2 17 Approx. 358m Alternative Route 2 18 Approx. 602m


5.3 Impact Rating Tables

Impact Extent Duration Status Probability Significance before Mitigation

Significance After

Mitigation Rating

(localised-external)

Value (1-10)

Rating (short-

medium-long)

Value (1-10)

Rating Slight-

moderate-severe)

Value (1-10)

Rating

(May-likely-will occur)

Value (1-10)

Rating (Low-

moderate-high)

Value (1-10)

Rating (Low-

moderate-high)

Impact of placing towers in wetlands

Localised 3 Medium term 2 Moderately Severe

6 May occur 3 Moderate 2 Low

Impact of Poor Construction Practices on Wetlands / Rivers

Localised 3 Short Term 1 Slight 5 May occur 3 Moderate 2 Low

Impact of Construction / Servitude Access into wetlands

Localised 3 Long Term 3 Moderately Severe

6 Likely to occur

6 Moderate 6 Low


6 COMPARATIVE ASSESSMENT OF ALTERNATIVE ROUTES

A linear structure such as a powerline will inevitably affect wetlands, surface water resources and other sensitive habitat units that occupy a relatively significant area. It is felt that the route that offers the best balance between socio-economic benefit and least ecological impacts should be implemented so that a greater proportion of the resources can be directed at appropriate mitigation measures that can abate negative impacts. In this instance, each proposed alternative route has been assessed in order to determine which is least likely to affect the above-mentioned wetlands along the concerned alignments. Particularly, the estimated numbers of wetlands to be affected were assessed in tandem with the approximate number of towers likely to be placed in identified and potentially affected wetlands. The comparative number of wetland crossings and associated factors can be used to assess the three route alternatives.

ALTERNATIVE ROUTE

NUMBER OF WETLAND

STRETCHES TOO WIDE TO BE SPANNED

TOTAL DISTANCE TO BE SPANNED BY

POWER LINES

APPROX. NUMBER OF TOWERS LIKELY

TO BE PLACED IN WETLANDS

1 14 4839 24 2 3 2170 10 3 11 5681 28

Table 3 – Comparative Assessment of Routes in terms of wetland Crossings Wetland stretches that are too wide to be singly spanned (and thus the number of towers in wetlands) are important in the context of wetland impacts. Narrower wetlands are able to be spanned with little or no impact on the wetland. In line with the assessment, In terms of the results above, the most important factor is the number of towers that need to be placed within the wetlands. As can be seen, the alternative route that is least likely to have the greatest impact on the number of wetlands is alternative route 2. This is not surprising since it is the most direct route and the shortest distance. Alternative routes 1 and 3 are fairly long and given the high occurrence of wetland features in the area, means that more wetland will be impacted. Concomitantly, the extensive width of many of the wetlands along these routes mean that a greater number of towers needing to be placed within wetlands. Moreover, alternative routes 1 and 3 share the same alignment for approximately three quarters of the distance and hence, share the same fate in terms of potential impacted wetland areas. However, alternative route 3 has fewer wetlands to be spanned but the wetlands along this particular route cover a greater area. Comparatively, between these two proposed routes, alternative route 1 would be


more favourable than alternative route 3 as fewer towers would need to be placed along the alignment. However, as already mentioned, alternative route 2 is the most favourable option. It should be noted that neither of the routes are seen as fatal flaws from a wetland crossing perspective, although it is strongly recommended that the route with the least number of problem towers to be placed in wetlands be selected for development.

7 CONCLUSIONS AND RECOMMENDATIONS

The proposed powerline routes would cross a number of wetland and riverine systems along the alignments. Some of these systems are able to be spanned without the wetland / riverine system being affected. However there are relatively many wetland systems along all of the proposed alternative routes. Inevitably, towers would be needed to be placed within wetlands. Consequently, the proposed development will be associated with impacts on the vegetation, soils and hydrology of the wetlands in question. These potential impacts have been taken into account in the comparative assessment of alignment alternatives along the respective routes, and alignment alternatives avoiding these wetlands have been recommended. As such Alternative Route 2 being the shorter alternative with the least amount of likely impacts to wetlands is proposed as the best option. It is important to note that water-use licences from the Department of Water Affairs will need to be sought for any wetlands / riparian zones in which towers are proposed to be placed. Impacts on all wetlands spanned by the proposed powerlines could result from poor construction or servitude management practices. However should Eskom’s standard environmental procedures for the undertaking of powerline construction and servitude management / operation be followed, the impacts of the proposed powerlines on the wetlands / rivers crossed by the route are likely to be minimised.


7.1 Recommendations for CEMP Walk downs

Due to the permission, access and fee constraints that did not allow most of the identified prioritised wetlands to be visited in the field, it is strongly recommended that a thorough walk-down (to feed into the Construction Environmental Management Plan - CEMP) of all pylon locations in wetlands be conducted should environmental authorisation for the proposed powerlines be granted. The walk-down should aim at accurately delineating the boundaries of all wetland stretches not able to be crossed by a single span. The results of the wetland delineation should then be used to place pylons along the alignment, and if possible re-align the route to avoid placing the pylons in the wetlands. If this is not possible, the results of the wetland delineation should be alternatively used to optimise the placement of the pylons within the wetland so as to minimise potential impacts. In this regard (if pylons have to be placed within the wetland) pylons should be placed as close to the boundaries of the wetland as possible (within the drier temporary zone of the wetland), and should not be placed within the wetter parts of the wetland to minimise hydrological and biogeochemical impacts. The process of locating the pylons should be conducted in consultation with the wetland specialist who undertook the delineations. Where pylons require placement within wetlands, site-specific mitigation measures for the accessing of the pylon location during construction must be included within the CEMP to ensure that as little environmental impact associated with the access of required machinery to the pylon location.


8 REFERENCES

Collins, N.B., 2005: Wetlands: The basics and some more. Free State Department of

Tourism, Environmental and Economic Affairs. Department of Water Affairs and Forestry., 2005: A practical field procedure for

identification and delineation of wetlands and riparian areas (edition 1). DWAF, Pretoria. SANBI., 2006: Vegetation map of South Africa, Lesotho and Swaziland. Mucina, L. and

Rutherford, M.C. (Editors). Strelitzia 19, South African National Biodiversity Institute, Kirstenbosch Research Centre, Claremont, South Africa.

Soil Classification Working Group., 1991: Soil classification – a taxonomic system for South Africa. Memoirs of the Agricultural Natural Resources of South Africa No. 15, The soil and Irrigation Research Institute, Department of Agricultural Development, Pretoria.

Van Oudtshoorn, F., 1999: Guide to grasses of southern Africa. Briza Publications, Pretoria.

SiVEST Environmental Division 51 Wessels Road, Rivonia. 2128. South Africa PO Box 2921, Rivonia. 2128. South Africa Tel + 27 11 798 0600 Fax +27 11 803 7272 Email [email protected] www.sivest.co.za Contact Person: Shaun Taylor Email: [email protected]

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