DRAFT SOIL AND AGRICULTURAL POTENTIAL REPORT - Ingula/2... · 2010. 5. 12. · • Mispah (Orthic A horizon over hard rock); • Glencoe (Orthic A horizon over yellow-brown apedal

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April 2010

SOIL AND AGRICULTURAL

POTENTIAL

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ZITHOLELE CONSULTING

EEXXEECCUUTTIIVVEE SSUUMMMMAARRYY

Eskom is in the process of constructing the Ingula Pumped Storage Scheme (IPSS), which requires the relocation of approximately twenty (20) traditional graves, which are situated within the vicinity of the upper Bedford Dam. The need for the graves to be relocated is in order to establish and fill the upper reservoir with water. Eskom proposes the relocation of these graves to one of several properties (Farm Hamilberg, Wilge River or Bronsbury) that Eskom acquired to the north of the proposed Dam. Therefore this project proposes the establishment of the Ingula Burial Grounds. Six site alternatives were identified and evaluated as part of the assessment.

The assessment identified four main soil groups within the study area including deep, rocky, plinthic and clay soils. In terms of the suitability for agricultural use, the deep soils are the most suitable, the plinthic and clay soils moderately suitable and the rocky soils the least suitable. The same can be said for the suitability of the soils for use as a burial ground with the deep soils being the most suitable and the rocky soils the least suitable. Therefore Alternatives 1, 2 and 7 are the most suitable from a soil and agricultural potential perspective.

The impact assessment of the soils and agricultural potential at the proposed Ingula burial ground has found that the proposed development has the potential to have a low impact on the soils and their agricultural potential. These impacts can be mitigated by the successful implementation of the mitigation measures proposed in this report. Although the mitigation measures will not eliminate the impact, it will ensure that the impact is limited to the footprint of the burial grounds. It is therefore recommended that the development be approved conditional to the implementation of the mitigation measures described in this report.

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TABLE OF CONTENTS

SECTION PAGE

1 INTRODUCTION ........................................................................................ 1

1.1 PROJECT BACKGROUND .................................................................... 1 1.2 STUDY SCOPE ...................................................................................... 3 1.3 STUDY APPROACH .............................................................................. 3 1.4 PROJECT PERSONNEL ........................................................................ 3 1.5 ASSUMPTIONS AND LIMITATIONS ....... Error! Bookmark not defined.

2 SOILS ........................................................................................................ 4

2.1 DATA COLLECTION .............................................................................. 4 2.2 REGIONAL DESCRIPTION .................................................................... 4 2.3 SITE DESCRIPTION .............................................................................. 4

2.3.1 Rocky Soils ............................................................................... 5 2.3.2 Deep Soils ................................................................................ 6 2.3.3 Plinthic Soils ............................................................................. 7 2.3.4 Clay Soils .................................................................................. 8

3 AGRICULTURAL POTENTIAL (LAND CAPABILITY) ............................. 13

3.1 DATA COLLECTION ............................................................................ 13 3.2 REGIONAL DESCRIPTION .................................................................. 13 3.3 SITE DESCRIPTION ............................................................................ 13

4 IMPACT ASSESSMENT METHODOLOGY ............................................. 17

4.1 SIGNIFICANCE ASSESSMENT ........................................................... 17 4.2 SPATIAL SCALE .................................................................................. 19 4.3 DURATION SCALE .............................................................................. 19 4.4 DEGREE OF PROBABILITY ................................................................ 19 4.5 DEGREE OF CERTAINTY ................................................................... 20 4.6 QUANTITATIVE DESCRIPTION OF IMPACTS .................................... 20 4.7 CUMULATIVE IMPACTS ...................................................................... 21 4.8 NOTATION OF IMPACTS .................................................................... 22

5 IMPACT ASSESSMENT .......................................................................... 23

5.1 INITIAL IMPACT ................................................................................... 23 5.2 ADDITIONAL IMPACT.......................................................................... 24 5.3 CUMULATIVE IMPACT ........................................................................ 24 5.4 MITIGATION MEASURES .................................................................... 25 5.5 RESIDUAL IMPACT ............................................................................. 25

6 CONCLUSION ......................................................................................... 26

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LIST OF FIGURES

Figure 1-1: Proposed Study Area. ...................................................................................... 2

Figure 2-1: Mispah Soil Form (Soil Classification, 1991) .................................................... 5

Figure 2-2: Dresden and Glencoe Soil Forms (Soil Classification, 1991) ........................... 6

Figure 2-3: Hutton and Clovelly soil forms (Soil Classification, 1991) ................................. 7

Figure 2-4: Avalon and Westleigh Soil Form (Soil Classification, 1991) ............................. 8

Figure 2-5: Wasbank and Longlands Soil Form (Soil Classification, 1991) ......................... 8

Figure 2-6: Katspruit and Willowbrook Soil forms (Soil Classification, 1991) ...................... 9

Figure 2-7: Rensburg and Arcadia soil forms (Soil Classification, 1991) .......................... 10

Figure 2-8: Inhoek soil form (Soil Classification, 1991) ..................................................... 11

Figure 2-9: Soil Type Map ................................................................................................ 12

Figure 3-1: Agricultural Potential Map .............................................................................. 16

Figure 5-1: Example of what the burial ground could look like .......................................... 23

Figure 5-2: Erosion scars found on site next to roads (left) and because of cattle paths (right) ..................................................................................................................... 24

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LIST OF TABLES

Table 2-1: Main soil groups identified on site ..................................................................... 5

Table 3-1: Agricultural Potential criteria ........................................................................... 13

Table 2-3: Agricultural Land Capability of the soils on site for agricultural use ................. 14

Table 4-1: Quantitative rating and equivalent descriptors for the impact assessment criteria .............................................................................................................................. 17

Table 4-2 : Description of the significance rating scale..................................................... 18

Table 4-3 : Description of the spatial rating scale ............................................................. 19

Table 4-4: Description of the temporal rating scale .......................................................... 19

Table 4-5 : Description of the degree of probability of an impact occurring ...................... 20

Table 4-6 : Description of the degree of certainty rating scale .......................................... 20

Table 4-7 : Example of Rating Scale ................................................................................ 21

Table 4-8 : Impact Risk Classes ...................................................................................... 21

Table 4-9: Impact Rating Example ................................................................................... 21

Table 5-1: Impact Rating Matrix for soils and agricultural potential................................... 25

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1 INTRODUCTION

1.1 PROJECT BACKGROUND

1.2 PROJECT BACKGROUND

Eskom obtained an Environmental Authorisation to construct the new Ingula Pumped Storage Scheme near the town of Van Reenen on the Free State – KwaZulu Natal Provincial border. The construction of the Ingula Pumped Storage Scheme commenced in 2002.

The new Ingula Pumped Storage Scheme requires the relocation of twenty (20) family graves and provision will be made to accommodate eight (8) living family descendants. The need to relocate the graves is in order to establish and flood the upper Bedford Dam with water. Eskom proposes the relocation of these graves to one of several properties that Eskom acquired to the north of the proposed Dam. Therefore this project proposes the establishment of the Ingula Burial Grounds. At present six alternatives are being investigated, namely (Figure 1-1):

Alternative 1 and 2: Farm Bronsbury (S 28o10.043’ E29o35.651’ and S 28o09.894’ E29o36.427’)

The Farm Bronsbury 1888 borders on the Farm Hamilberg with the Wilge River forming a boundary between the two farms. The provincial dirt road also traverses over this farm allowing relatively good access.

Alternative 3: Farm Hamilberg (S 28o08.493’ E29o35.623’)

The Farm Hamilberg 51 Portion 1 is located to the north of an existing provincial dirt road. The farm therefore has a good access road in place and a small school is located adjacent to the site. Furthermore the farm is bisected by the Sikulubha River. Alternative 3 has a good access road available from the provincial road.

Alternative 4, 5 and 6: Farm Wilge River (S 28o12.469’ E29o32.955’, S 28o10.832’ E29o35.187’ and S 28o11.774’ E29o33.356’)

The Farm Wilge River 319 is located to the south of the other two farms and as the name suggests the farm is dominated by the Wilge River. There are two points where the Provincial dirt road provides access to the farm.

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Figure 1-1: Proposed Study Area.

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1.3 STUDY SCOPE

Eskom’s Generation Division has appointed Zitholele Consulting (Pty) Ltd, an independent company, to conduct a Basic Assessment (BA) process to evaluate the potential environmental and social impacts of the proposed project. As part of the Environmental Impact Assessment for the aforementioned project Zitholele conducted the soil assessment detailed in this report.

1.4 STUDY APPROACH

Zitholele Consulting undertook the soil impact assessment during a site visit conducted from the 3rd – 4th March 2010. Each of the 6 sites was visited and the observations were noted.

1.5 PROJECT PERSONNEL

Mr. Konrad Kruger graduated from the University of Pretoria with a BSc Honours in Geography in 2003. He has been involved in a variety of environmental projects in the last six years and has become specialised in undertaking specialist studies, mapping and environmental consulting. He has undertaken GIS mapping for mining, residential as well as industrial developments. He is also an experienced land ecologist and will provide expertise for this project in terms of soil surveys, land capability assessments and mapping.

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2 SOILS

2.1 DATA COLLECTION

During the site visit in March 2010 soils were augered at 200m intervals along transects on site using a 150 mm bucket auger, up to refusal or 1.2 m. Soils were identified according to Soil Classification; a taxonomic system for South Africa (Memoirs on the Natural Resources of South Africa, no. 15, 1991). The following soil characteristics were documented:

• Soil horizons;

• Soil colour;

• Soil depth;

• Soil texture (Field determination);

• Wetness;

• Occurrence of concretions or rocks; and

• Underlying material (if possible).

2.2 REGIONAL DESCRIPTION

The soils in the region are mostly derived from the geology of the region namely, mudstone and sandstone which feature prominently in the area. Clay soils accumulate in the lower lying areas and are often associated with wet conditions. The soils are generally shallow with a light brown colour.

2.3 SITE DESCRIPTION

During the site visit several soil types were identified and these can be grouped into the main types as indicated in Table 2-1 below, while Figure 2-9 provides an illustration of the location of these soil types. The land capability (agricultural potential) of the soil types identified in Section 2 is described in more detail in Section 3. The soil characteristics given below were described according to the definitions provided in the Soil Classification; a taxonomic system for South Africa (Memoirs on the Natural Resources of South Africa, no. 15, 1991).

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Table 2-1: Main soil groups identified on site. Soil Unit Soil Types Defining Characteristic

Rocky soils Mispah

Shallow A horizon over hard resistant layer Glencoe Dresden

Deep, apedal soils Clovelly Apedal B horizon Hutton

Plinthic soils

Westleigh

Soft or Hard Plinthic B or C horizon some with Elluvial B horizon Avalon

Longlands Wasbank

Clay soils Katspruit Diagnostic G horizon with clay accumulation Willowbrook

2.3.1 Rocky Soils

The rocky soil management unit is made up of soils that are generally shallow and that overlie an

impeding layer such as hard rock or plinthite. These soils are not suitable for cultivation and in

most cases are only usable for light grazing. The unit comprises of the following soil forms:

• Mispah (Orthic A horizon over hard rock);

• Glencoe (Orthic A horizon over yellow-brown apedal B over hard rock);

• Dresden (Orthic over hard plinthic);

Mispah Soil Form

The Mispah soil form is made up of an Orthic A - horizon over rock as indicated in Figure 2-1 below. This soil form is present on most of the rocky ridges found on site.

Figure 2-1: Mispah Soil Form (Soil Classification, 1991).

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Dresden and Glencoe Soil Forms

Dresden and Glencoe soil forms are characterized by a hard plinthic layer as indicated in Figure 2-2. The Hard plinthic horizon is formed when a soft plinthic horizon has hardened irreversibly into ferricrete (Hard Plinthic Horizon). Over time the clays in the soil were washed down the slope and accumulated in the valley to form soft plinthic horizons. In time these clay horizons dried out and hardened irreversibly.

Figure 2-2: Dresden and Glencoe Soil Forms (Soil Classification, 1991).

2.3.2 Deep Soils

The deep soils are the preferred soil type as these soils have all the required characteristics for the burial grounds. As the name implies these soils are deep and therefore can accommodate the relocated graves. Two main soil types have been identified, with the main distinction being the soil colour.

Hutton / Clovelly Soil Forms

Hutton Soil Forms are identified based on the presence of an apedal (structureless) “red” B-horizon and Clovelly Soil Forms with an apedal “yellow” B-horizon as indicated in Figure 2-3 below. These soils are the main agricultural soil in South Africa due to their deep, well-drained nature. The soils are restricted to footslopes of the study area and were present at Alternatives 1, 2, the majority of 7 and parts of 6.

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Figure 2-3: Hutton and Clovelly soil forms (Soil Classification, 1991).

2.3.3 Plinthic Soils

Plinthic soils show signs of water movement through the horizon, whether it be historical (hard plinthic) or current (soft plinthic). These soils are not ideal for use as a burial ground due to the water movement.

Avalon, and Westleigh Soil Forms

The Avalon and Westleigh soil forms are characterised by the occurrence of a soft plinthic B – horizon (See Figure 2-4). This horizon has the following characteristics:

• Has undergone localised accumulation of iron and manganese oxides under conditions of a fluctuating water table with clear redbrown, yellowbrown or black strains in more than 10% of the horizon;

• Has grey colours of gleying in or directly underneath the horizon; and

• Does not qualify as a diagnostic soft carbonate horizon.

These soils are found on the north-eastern boundary of the site directly adjacent to the hard plinthic layers on site. This area is a zone of clay accumulation where the clays have not hardened like in the hard plinthic horizons (See Glencoe / Dresden soil forms).

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Figure 2-4: Avalon and Westleigh Soil Form (Soil Classification, 1991).

Wasbank, Kroonstad and Longlands Soil Forms

The Wasbank, Kroonstad and Longlands soil forms are all typified by an eluvial horizon. These are also recognized as wetland soils. The E-horizon is a horizon that has been washed clean by excessive water movement through the horizon. These soils occur in the main drainage channel of the site and for the outside boundary of the wetlands on site. Refer to Figure 2-5 for an illustration of the soil types.

Figure 2-5: Wasbank and Longlands Soil Form (Soil Classification, 1991).

2.3.4 Clay Soils

The clay soil management unit is found in areas where clays have accumulated to such an extent

that the majority of the soil matrix is clays. These soils are usually indicative of seasonal or

permanent wetland conditions and are therefore not suitable for utilisation as a burial ground. Soil

forms in this unit include:

• Rensburg;

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• Arcadia;

• Inhoek;

• Katspruit; and

• Willowbrook

Katspruit and Willowbrook Soil Forms

The Katspruit and Willowbrook soil forms are found in areas of semi-permanent wetness. These

soils are typified by an Orthic A horizon (Katspruit) or a Melanic A horizon (Willowbrook) over a

diagnostic G horizon, as indicated in Figure 2-6. The G horizon has several unique diagnostic

criteria as a horizon, including:

• Saturated with water for long periods unless drained;

• Dominated by grey, low chroma matrix colours, often with blue or green tints, with or without mottling;

• Undergoing marked removal of colloid matter, usually accumulation of colloid matter has taken place in the horizon;

• Consistency at least one grade firmer than that of the overlying horizon;

• Lacking saprolitic character; and

• Lacking plinthic character.

Figure 2-6: Katspruit and Willowbrook Soil forms (Soil Classification, 1991)

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Rensburg and Arcadia soil forms

Arcadia and Rensburg soils are characterised by a vertic A-horizon. In the Rensburg the Vertic A

is underlain by a G-horizon as described above, while the Arcadia is a pure vertic horizon. The

Vertic horizon has several unique diagnostic criteria as a horizon, namely:

• A strong developed structure;

• At least one of the following:

§ Clearly visible, regularly occurring slicken sides in some part of the horizon or in

the transition to an underlying layer

§ A plasticity index greater than 32 (using the SA Standard Casagrande cup to

determine liquid limit), or greater than 36 (using the British Standard cone to

determine liquid limit).

Figure 2-7: Rensburg and Arcadia soil forms (Soil Classification, 1991).

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Inhoek Soil Forms

The Inhoek soil form is typified by a Melanic A horizon. The Melanic horizon is characterised by

the following (refer to Figure 2-8):

• Dark colours in the dry sate with a value and chroma of 3 or less with the exception of 10YR 3/3 and colours redder than 5YR;

• No slickensides present as in the vertic clays;

Inhoek Soil Forms

The Inhoek soil form is typified by a Melanic A horizon. The Melanic horizon is characterised by

the following (refer to Figure 2-8):

• Dark colours in the dry sate with a value and chroma of 3 or less with the exception of 10YR 3/3 and colours redder than 5YR;

• No slickensides present as in the vertic clays;

Figure 2-8: Inhoek soil form (Soil Classification, 1991).

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Figure 2-9: Soil Type Map.

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3 AGRICULTURAL POTENTIAL (LAND CAPABILITY)

3.1 DATA COLLECTION

A literature review was conducted in order to obtain any relevant information concerning the area, including information from the Environmental Potential Atlas (ENPAT), Weather Bureau and Department of Agriculture. Results from the soil study were taken into consideration when determining the agricultural potential also known as the land capability of the site. The land capability assessment methodology as outlined by the National Department of Agriculture, 2002 was used to assess the soil’s capability to support agriculture on site.

3.2 REGIONAL DESCRIPTION

The regional land capability is mostly class IV soils with limitations. This is evident in the large number of grazing land as opposed to cultivated lands found in the region. This is due to the fact that the effective soil depth is too shallow or too wet to cultivate, and livestock is grazed instead.

3.3 SITE DESCRIPTION

According to the land capability methodology, the potential for a soil to be utilised for agriculture is based on a wide number of factors. These are listed in the table below along with a short description of each factor.

Table 3-1: Agricultural Potential criteria

Criteria Description

Rock Complex If a soil type has prevalent rocks in the upper sections of the soil it is a limiting factor to the soil’s agricultural potential

Flooding Risk The risk of flooding is determined by the closeness of the soil to water sources.

Erosion Risk The erosion risk of a soil is determined by combining the wind and water erosion potentials.

Slope The slope of the site could potentially limit the agricultural use thereof.

Texture The texture of the soil can limits its use by being too sandy or too clayey.

Depth The effective depth of a soil is critical for the rooting zone for agricultural crops.

Drainage The capability of a soil to drain water is important as most grain crops do not tolerate submergence in water.

Mechanical Limitations Mechanical limitations are any factors that could prevent the soil from being tilled or ploughed.

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Criteria Description

pH The pH of the soil is important when considering soil nutrients and hence fertility.

Soil Capability This section highlights the soil type’s capability to sustain agriculture.

Climate Class The climate class highlights the prevalent climatic conditions that could influence the agricultural use of a site.

Land Capability / Agricultural Potential

The land capability or agricultural potential rating for a site combines the soil capability and the climate class to arrive at the sites potential to support agriculture.

The soils identified in Section 2 above were classified according to the methodology proposed by the Agricultural Research Council – Institute for Soil, Climate and Water (2002). The criteria mentioned above were evaluated in the table below. Figure 3-1 illustrates the various land capability units on site.

Table 3-2: Agricultural Land Capability of the soils on site for agricultural use

Management unit

Deep Plinthic Rocky Clay

Alternative Sites 1, 2 and 7.

Isolated parts of 6 Site 3 Site 5 and 6 No alternative

Rock Complex No Yes – Occasional

hard plinthic Yes – hard rock No

Flooding Risk F1 – None F2 – Rare F1 - None F4 - Common

Erosion Risk E2 – Low to Moderate E5 – Moderate to

High

E5 – Moderate to

High E1 - Low

Slope % 2 – 10 % 2 – 10 % 3 – 15 % 0 – 5 %

Texture T1 – 15 – 45% Clay T1 – 15 – 45% Clay T1 – 15 – 45% Clay T3 - >55% Clay

Depth D1 - > 120 cm D2 – 60 – 80 cm D4 – 10 – 30 cm D3 – 40 – 60 cm

Drainage W2 – Well drained W4 – Somewhat

poorly drained W2 – Well drained W5 – Poorly drained

Mechanical Limitations

MB0 - None MB3 – Occasional

hard plinthite

MB3 – Shallow soils

on rock MB0 - None

pH pH > 5 pH > 5 pH > 5 pH > 5

Soil Capability II VI VII V

Climate Class C2 C2 C2 C2

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Management unit

Deep Plinthic Rocky Clay

Land Capability II – Arable Land VI – Light Grazing VII – Very Light

Grazing V - Grazing

Due to the relatively large distances between the various sites there is a distinct variation in the soil types and the agricultural potential of these soil types. A variety of soils are found in the study area and hence the assessment is best suited to compare alternatives. The results of the agricultural potential analysis are:

• High Agricultural Potential – Sites 1, 2, parts of 5 and 6;

• Moderate Potential – Rivers and Streams;

• Low Potential – Sites 3, 4 and parts of 5

The soils on site are utilised mainly for grazing of livestock, although the land has recently been acquired by Eskom and the grazing pressure has since been lessened. In a way the above classification also indicates the suitability of the sites for use as a burial ground with the high potential agricultural soils being the most suitable and the low potential soils the least suitable for use as a burial ground. This is mainly due to the depth and workability of the soil, the same features that give soils a high agricultural potential, also give them suitable properties for the establishment of a burial ground.

No limitation

Low to Moderate

Moderate High Very Limiting

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Figure 3-1: Agricultural Potential for the Study Area.

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4 IMPACT ASSESSMENT METHODOLOGY

The impacts will be ranked according to the methodology described below. Where possible, mitigation measures will be provided to manage impacts. In order to ensure uniformity, a standard impact assessment methodology was utilised so that a wide range of impacts can be compared with each other. The impact assessment methodology makes provision for the assessment of impacts against the following criteria:

• Significance;

• Spatial scale;

• Temporal scale;

• Probability; and

• Degree of certainty.

A combined quantitative and qualitative methodology was used to describe impacts for each of the aforementioned assessment criteria. A summary of each of the qualitative descriptors along with the equivalent quantitative rating scale for each of the aforementioned criteria is given in Table 4-1.

Table 4-1: Quantitative rating and equivalent descriptors for the impact assessment criteria.

Rating Significance Extent Scale Temporal Scale 1 VERY LOW Isolated sites / proposed

site Incidental

2 LOW Study area Short-term 3 MODERATE Local Medium-term 4 HIGH Regional / Provincial Long-term 5 VERY HIGH Global / National Permanent

A more detailed description of each of the assessment criteria is given in the following sections.

4.1 SIGNIFICANCE ASSESSMENT

Significance rating (importance) of the associated impacts embraces the notion of extent and magnitude, but does not always clearly define these since their importance in the rating scale is very relative. For example, the magnitude (i.e. the size) of area affected by atmospheric pollution may be extremely large (1 000 km2) but the significance of this effect is dependent on the concentration or level of pollution. If the concentration is great, the significance of the impact would be HIGH or VERY HIGH, but if it is diluted it would be VERY LOW or LOW. Similarly, if 60 ha of a grassland type are destroyed the impact would be VERY HIGH if only 100 ha of that grassland type were known. The impact would be VERY LOW if the grassland type was common. A more detailed description of the impact significance rating scale is given in Table 4-2 below.

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Table 4-2 : Description of the significance rating scale

Rating Description 5 Very high Of the highest order possible within the bounds of impacts which

could occur. In the case of adverse impacts: there is no possible mitigation and/or remedial activity which could offset the impact. In the case of beneficial impacts, there is no real alternative to achieving this benefit.

4 High Impact is of substantial order within the bounds of impacts, which could occur. In the case of adverse impacts: mitigation and/or remedial activity is feasible but difficult, expensive, time-consuming or some combination of these. In the case of beneficial impacts, other means of achieving this benefit are feasible but they are more difficult, expensive, time-consuming or some combination of these.

3 Moderate Impact is real but not substantial in relation to other impacts, which might take effect within the bounds of those which could occur. In the case of adverse impacts: mitigation and/or remedial activity are both feasible and fairly easily possible. In the case of beneficial impacts: other means of achieving this benefit are about equal in time, cost, effort, etc.

2 Low Impact is of a low order and therefore likely to have little real effect. In the case of adverse impacts: mitigation and/or remedial activity is either easily achieved or little will be required, or both. In the case of beneficial impacts, alternative means for achieving this benefit are likely to be easier, cheaper, more effective, less time consuming, or some combination of these.

1 Very low Impact is negligible within the bounds of impacts which could occur. In the case of adverse impacts, almost no mitigation and/or remedial activity are needed, and any minor steps which might be needed are easy, cheap, and simple. In the case of beneficial impacts, alternative means are almost all likely to be better, in one or a number of ways, than this means of achieving the benefit. Three additional categories must also be used where relevant. They are in addition to the category represented on the scale, and if used, will replace the scale.

0 No impact There is no impact at all - not even a very low impact on a party or system.

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4.2 SPATIAL SCALE

The spatial scale refers to the extent of the impact i.e. will the impact be felt at the local, regional, or global scale. The spatial assessment scale is described in more detail in Table 4-3.

Table 4-3 : Description of the spatial rating scale

Rating Description 5 Global/National The maximum extent of any impact. 4 Regional/Provincial The spatial scale is moderate within the bounds of impacts

possible, and will be felt at a regional scale (District Municipality to Provincial Level).

3 Local The impact will affect an area up to 5 km from the proposed study area.

2 Study Area The impact will affect an area not exceeding the study area.

1 Isolated Sites / proposed site

The impact will affect an area no bigger than proposed burial ground footprint.

4.3 DURATION SCALE

In order to accurately describe the impact it is necessary to understand the duration and persistence of an impact in the environment. The temporal scale is rated according to criteria set out in Table 4-4.

Table 4-4: Description of the temporal rating scale

Rating Description 1 Incidental The impact will be limited to isolated incidences that are

expected to occur very sporadically. 2 Short-term The environmental impact identified will operate for the duration

of the construction phase or a period of less than 5 years, whichever is the greater.

3 Medium term The environmental impact identified will operate for the duration of life of the burial ground.

4 Long term The environmental impact identified will operate beyond the life of operation.

5 Permanent The environmental impact will be permanent.

4.4 DEGREE OF PROBABILITY

The probability or likelihood of an impact occurring will be described as shown in Table 4-5 below.

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Table 4-5 : Description of the degree of probability of an impact occurring

Rating Description 1 Practically impossible 2 Unlikely 3 Could happen 4 Very Likely 5 It’s going to happen / has occurred

4.5 DEGREE OF CERTAINTY

As with all studies it is not possible to be 100% certain of all facts, and for this reason a standard “degree of certainty” scale is used as discussed in Table 4-6. The level of detail for specialist studies is determined according to the degree of certainty required for decision-making. The impacts are discussed in terms of affected parties or environmental components.

Table 4-6 : Description of the degree of certainty rating scale Rating Description

Definite More than 90% sure of a particular fact. Probable Between 70 and 90% sure of a particular fact, or of the likelihood

of that impact occurring. Possible Between 40 and 70% sure of a particular fact, or of the likelihood

of an impact occurring. Unsure Less than 40% sure of a particular fact or the likelihood of an

impact occurring. Can’t know The consultant believes an assessment is not possible even with

additional research. Don’t know The consultant cannot, or is unwilling, to make an assessment

given available information.

4.6 QUANTITATIVE DESCRIPTION OF IMPACTS

To allow for impacts to be described in a quantitative manner in addition to the qualitative description given above, a rating scale of between 1 and 5 was used for each of the assessment criteria. Thus the total value of the impact is described as the function of significance, spatial and temporal scale as described below:

Impact Risk = (SIGNIFICANCE + Spatial + Temporal) X Probability

3 5

An example of how this rating scale is applied is shown below:

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Table 4-7 : Example of Rating Scale

Impact Significance Spatial Scale

Temporal Scale

Probability Rating

LOW Local Medium-term Could Happen Impact to air 2 3 3 3 1.6

Note: The significance, spatial and temporal scales are added to give a total of 8, that is divided by 3 to give a criteria rating of 2,67.

The probability (3) is divided by 5 to give a probability rating of 0,6. The criteria rating of 2,67 is then multiplied by the probability rating

(0,6) to give the final rating of 1,6.

The impact risk is classified according to five classes as described in the table below.

Table 4-8 : Impact Risk Classes

Rating Impact Class Description 0.1 – 1.0 1 Very Low 1.1 – 2.0 2 Low 2.1 – 3.0 3 Moderate 3.1 – 4.0 4 High 4.1 – 5.0 5 Very High

Therefore with reference to the example used for air quality above, an impact rating of 1.6 will fall in the Impact Class 2, which will be considered to be a low impact.

4.7 CUMULATIVE IMPACTS

It is a requirement that the impact assessments take cognisance of cumulative impacts. In fulfilment of this requirement the impact assessment will take cognisance of any existing impact sustained by the operations, any mitigation measures already in place, any additional impact to the environment through continued and proposed future activities, and the residual impact after mitigation measures.

Using the criteria as described above an example of how the cumulative impact assessment will be done is shown below:

Table 4-9: Impact Rating Example

Impact Significance Spatial Scale

Temporal Scale

Probability Rating

Initial / Existing Impact (I-IA)

2 2 2 1 0.4

Additional Impact (A-IA) 1 2 1 1 0.3 Cumulative Impact (C-IA) 3 4 2 1 0.6 Residual Impact after mitigation (R-IA)

2 1 2 1 0.3

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As indicated in the example above the Additional Impact Assessment (A-IA) is the amount that the impact assessment for each criterion will increase. Thus if the initial impact will not increase, as shown for temporal scale in the example above the A-IA will be 0, however, where the impact will increase by two orders of magnitude from 2 to 4 as in the spatial scale the A-IA is 2. The Cumulative Impact Assessment (C-IA) is thus the sum of the Initial Impact Assessment (I-IA) and the A-IA for each of the assessment criteria.

In both cases the I-IA and A-IA are assessed without taking into account any form of mitigation measures. As such the C-IA is also a worst case scenario assessment where no mitigation measures have been implemented. Thus a Residual Impact Assessment (R-IA) is also made which takes into account the C-IA with mitigation measures. The latter is the most probable case scenario, and for the purpose of this report is considered to be the final state Impact Assessment.

4.8 NOTATION OF IMPACTS

In order to make the report easier to read the following notation format is used to highlight the various components of the assessment:

• Significance or magnitude- IN CAPITALS

• Temporal Scale – in underline

• Probability – in italics and underlined.

• Spatial Extent Scale – in italics

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5 IMPACT ASSESSMENT

The impact assessment was undertaken for the construction, and operational phases of the project. The burial grounds will comprise a 30 m x 30 m area that will be designated for the relocation of approximately 20 traditional graves that will be flooded by the new Bedford Dam if not relocated. The 900 m2 area also includes some space for eight (8) living decendants to be buried with their ancestors. An example of similar burial grounds are given in Figure 5-1. The remains will be exhumed by a professional registered with the South African Heritage Resources Agency and re-buried using traditional methods at the new proposed location.

Figure 5-1: Example of what the burial ground could look like.

5.1 INITIAL IMPACT

The site alternatives have until very recently been used for the commercial production of cattle. Eskom acquired 8000ha of land on part of which the potential site alternatives are located, and these have since been allowed to recover naturally i.e. no grazing is taking place. The initial impact to soils in the study area is mainly in the form of erosion. There were a number of erosion scars in the landscape as a result of poor drainage conditions next to the provincial roads in the area as well as the erosion of cattle paths as shown in Figure 5-2 below.

In view of the discussion above the initial (baseline) impact to soils and agricultural potential is rated as a LOW negative impact that occurs on the isolated sites and will remain for the medium term. The impact has already occurred and is therefore rated as a Low impact.

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Figure 5-2: Erosion scars found on site adjacent to roads (left) and because of cattle paths

(right)

5.2 ADDITIONAL IMPACT

The additional impacts to soils and agricultural potential during construction of the burial grounds will be caused by the erection and installation of a perimeter fence and the physical relocation of the graves (digging up of the soil). Other than the physical digging in the soil to re-bury the human remains and to erect the fences, the impact to soils will be limited to the impacts from the vehicles transporting the graves and the workers. There is a potential for hydrocarbon spillage as well as compaction of the soil by the vehicles. This is however a negligible impact as the period on site is estimated to be less than a week during the reburial of the exhumed graves. The establishment of the graves will only temporarily disturb the soil profiles, but after time the soil types will re-form.

Therefore the additional impact to soils and agricultural potential during the construction phase is rated as a VERY LOW negative impact occurring in the isolated sites and acting in the short term. This impact will occur and as such is rated as a Low impact.

During the operational phase the relocated graves will remain. The potential activities on site will be visitations from the relatives as well as the potential for additional graves to be established as more relatives pass away. These impacts will however be identical to those rated above.

Due to the type of development, no closure or rehabilitation phase is envisaged. A rating summary is provided in Table 5-1.

5.3 CUMULATIVE IMPACT

The cumulative impact during the construction phase remains as assessed above for the additional impact and the initial impact does not occur in the same area and hence does not combine to form a larger impact. Therefore the impact remains a Low impact. The same is applicable for the operational phase.

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5.4 MITIGATION MEASURES

• Ensure that the burial grounds are established on a relatively flat slope to prevent erosion;

• Ensure that all machinery on site is in a good working order;

• Avoid unnecessary removal of vegetation;

• If soils are excavated, ensure that the soil is utilised elsewhere for cover material in the burial ground and

• Fence the area to prevent damage to graves and injury to livestock.

5.5 RESIDUAL IMPACT

The residual impact with the successful implementation of the mitigation measures mentioned above will remain as assessed for the initial impact. The mitigation measures will ensure that the impacts from the burial ground are adequately managed but it will not change the initial impacts to soils. Therefore the residual impact rating remains a Low impact.

Table 5-1: Impact Rating Matrix for soils and agricultural potential. Construction phase Impact Type Significance Spatial Temporal Probability Rating Initial Low Isolated

sites Medium Term Is Occurring 2 - Low

Additional Very Low Isolated sites

Short Term Will occur 1.3 - Low

Cumulative Low Isolated sites

Medium Term Is Occurring 2 - Low

Residual Low Isolated sites


Operational Phase Impact Type Significance Spatial Temporal Probability Rating Additional Very Low Isolated

sites Medium Term

Will occur 1.6 - Low

Cumulative Low Isolated sites


Residual Low Isolated sites


Closure and Rehabilitation Phase Impact Type Significance Spatial Temporal Probability Rating No such phase

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6 CONCLUSION

In conclusion, the Ingula Pumped Storage Scheme requires the relocation of approximately twenty (20) traditional graves in order to establish and flood the upper Bedford Dam with water. Ingula Pumped Storage Scheme project proposes the relocation of these graves to one of several properties that Eskom acquired to the north of the proposed upper Dam. Therefore this project proposes the establishment of the Ingula Burial Grounds. Six site alternatives were identified and included as part of the assessment.

The assessment identified four main soil groups within the study area including deep soils, rocky soils, plinthic soils and clay soils. In terms of the suitability for agricultural use, the deep soils are the most suitable, the plinthic and clay soils moderately suitable and the rocky soils the least suitable. The same can be said for the suitability of the soils for use as a burial ground with the deep soils being the most suitable and the rocky soils the least suitable.

The impact assessment of the soils and agricultural potential at the proposed Ingula burial ground has found that the proposed development has the potential to have a Low impact on the soils and the agricultural potential. These impacts can be mitigated by the successful implementation of the mitigation measures proposed in this report. Although the mitigation measures will not eliminate the impact, it will ensure that the impact is limited to the footprint of the burial grounds. It is therefore recommended that the development be approved conditional to the implementation of the above mentioned mitigation measures.

ZITHOLELE CONSULTING (PTY) LTD

Konrad Kruger Jacqui Hex Z:\PROJECTS\ZPJ12613 – BA FOR INGULA BURIAL GROUNDS\REPORTS\SPECIALISTS\SOILS\12613 INGULA SOIL AND AGRICULTURE JH REVIEW.DOC

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DRAFT SOIL AND AGRICULTURAL POTENTIAL REPORT - Ingula/2... · 2010. 5. 12. · • Mispah (Orthic A horizon over hard rock); • Glencoe (Orthic A horizon over yellow-brown apedal