Appendix E: Wetland Delineation Specialist Assessment - Phola/3... · PHOLA-KUSILE CONVEYOR September 2011 i TABLE OF CONTENTS 1. BACKGROUND INFORMATION 1 2. TERMS OF REFERENCE 1

Appendix E:Wetland Delineation Specialist

Assessment

Structuring of the Specialist Studies in terms of GNR 543 Section 32 Requirements

Legal and Regulatory Requirement Cross Reference to Report Section

GNR 543 Section 32

Specialist reports and reports on specialized processes

1. An applicant or the EAP managing an application may appoint a person to

carry out a specialist study or specialized process. Appendices to the EIA main report

2. The person referred to in sub-regulation (1) must comply with the

requirements of regulation 17 [declaration of independence]

Declaration of independence signed by

specialists provided at back of each specialist

report

3. A specialist report or a report on a specialized process prepared in terms of

these Regulations must contain-

(a) Details of-

(i) the person who prepared the report; and

(ii) the expertise of that person to carry out the

specialist study or specialized process;

Second page after cover page - Document

Summary Data

(b) A declaration that the person is independent in a form as may be

specified by the competent authority;

Declaration of independence signed by

specialists provided at back of each specialist

report

(c) An indication of the scope of, and the purpose for which, the report

was prepared;

Chapter 1 - Background Information

Chapter 2 – Terms of Reference

(d) A description of the methodology adopted in preparing the report or

carrying out the specialized process;

Chapter 10, Section 10.1 - Methodology

(e) A description of any assumptions made and any uncertainties or gaps

in knowledge;

Chapter 3 - Limitations

(f) A description of the findings and potential implications of such findings

on the impact of the proposed activity, including identified alternatives,

on the environment;

Chapter 6 - Findings

(g) Recommendations in respect of any mitigation measures that should

be considered by the applicant and the competent authority;

Chapter 10, Section 10.2 – Project

Description

Chapter 11 – Recommendations

(h) A description of any consultation process that was undertaken during

the course of carrying out the study;

Consultation Process discussed in EIA main

report

(i) A summary and copies of any comments that were received during

any consultation process; and

All issues received to date included in

Section 6 of the EIA main report

(j) Any other information requested by the competent authority. Not applicable

WETLAND DELINEATION AND ASSESSMENT FOR THE PHOLA-KUSILE CONVEYOR

For: Mari Wolmarans Synergistics Environmental Services PO Box 1822 Rivonia 2128 Johannesburg

Wetland Consulting Services (Pty.) Ltd. PO Box 72295 Lynnwood Ridge Pretoria 0040 Tel: 012 349 2699 Fax: 012 349 2993 Email: [email protected]

Reference: 785/2011 (EIA REFERENCE NO: S0403-PK-WET-01-WETLAND-DELINEATION-REPORT)


September 2011 APPROVAL

COMPILED BY: CHECKED BY: APPROVED BY:

NAME: A Batchelor

NAME:

NAME:

DATE: September 2011

DATE:

DATE:

DISTRIBUTION LIST

AGENCY, ORGANISATION OR PERSON NO. OF COPIES

Synergistics Environmental Services 1

REVISION

DATE No. DESCRIPTION OF REVISION OR AMENDMENT INITIAL


September 2011 DOCUMENT SUMMARY DATA

PROJECT: Wetland Delineation and Impact Assessment: Phola-Kusile

Conveyor

CLIENT: Synergistics Environmental Services

CONTACT DETAILS: Mari Wolmarans PO Box 1822 Rivonia 2128 Johannesburg Tel: +27 11 807 8225

Fax: +27 11 807 8226

CONSULTANT: Wetland Consulting Services, (Pty) Ltd.

CONTACT DETAILS: Allan Batchelor

PO Box 72295

Lynnwood Ridge

0040

Telephone number: (012) 349 2699

Fax number: (012) 349 2993

E-mail: [email protected]


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TABLE OF CONTENTS

1. BACKGROUND INFORMATION 1

2. TERMS OF REFERENCE 1

3. LIMITATIONS 1

4. STUDY AREA 2

4.1 CATCHMENTS 2 4.2 Geology and Soils 3 4.3 Vegetation 4

5. APPROACH 6

5.1 Wetland Delineation and Classification 6 5.2 Present Ecological State 6 5.3 Ecological Importance & Sensitivity 8 5.4 Functional Assessment 9

6. FINDINGS 9

6.1 General Wetland Description & Classification 10 6.1.1 Channelled valley bottom wetlands 13 6.1.2 Hillslope seepage wetlands 13

6.2 Functional Assessment 14

7. PRESENT ECOLOGICAL STATUS (PES) ASSESSMENT 15

8. ECOLOGICAL IMPORTANCE AND SENSITIVITY 17

9. CONCLUSIONS 17

10. IMPACT ASSESSMENT 17

10.1 Methogology 18 10.2 Project Description 19

10.2.1 Loss of vegetation 21 10.2.2 Interference with the free movement of water dependant fauna. 22 10.2.3 Interruption of hydrology 22 10.2.4 Water quality deterioration as a consequence of construction related activities 24


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11. RECOMMENDATIONS 28

12. REFERENCES 28

TABLE OF FIGURES Figure 1. A map showing the regional setting of the conveyor. ..............................................2

Figure 2. A map showing the relationship between the conveyor routes and the quaternary catchments .............................................................................................................................3

Figure 3. Map indicating the dominant geology of the site. (source 1:250 000 2528, 2628 geology maps) ........................................................................................................................4

Figure 4 Map showing the proposed alignments of the conveyor in relation to the vegetation types ......................................................................................................................................5

Figure 5. Schematic illustrating types of wetlands and their positions in the landscape ........10

Figure 6. Map showing the wetlands, expressed as hydrogeomorphic units (HGM) crossed by the conveyor alignments. .................................................................................................11

Figure 7. A channelled valley bottom wetland on looking upstream from the proposed conveyor crossing (HGM-5) .................................................................................................13

Figure 8. A photograph of a hillslope seepage wetland (HGM-1) .........................................14

Figure 9. Alternative alignment that could be considered to avoid the impacts on the wetlands associated with one of the tributaries of the Klipfontein Spruit. ..............................21

Figure 10. Schematic illustrating a proposed method to ensure that groundwater flows (blue arrows) are not interrupted by the conveyor crossing. .............................................................

Figure 11. Schematic showing plan and cross section through a transfer station to illustrate the concepts briefly discussed in text ...................................................................................26

TABLE OF TABLES

Table 1. Table showing the mean annual precipitation, run-off and potential evaporation per quaternary catchment (Middleton, B.J., Midgley, D.C and Pitman, W.V., 1990). .....................3

Table 2 Interpretation of impact scores and health category associated with Present Ecological Status (PES) (Macfarlane et.al. 2008) ...................................................................8

Table 3. Scoring system used for the EIS assessment. ..........................................................9

Table 4. A list of the types of wetlands that will be crossed by the conveyor given its current alignment. .............................................................................................................................12

Table 5. Impact scores for the HGM units affected by the proposed conveyor, with the PES derived from the lowest impact score ...................................................................................16


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Table 6. The determined ecological management classes of the wetland units that will be affected by the current proposed conveyor alignment. ..........................................................17

Table 7. Ranking Scales for impact assessment .................................................................19

Table 8. Summary of assessed impacts of the conveyor route on the wetlands ...................27


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INDEMNITY AND CONDITIONS RELATING TO THIS REPORT The findings, results, observations, conclusions and recommendations given in this report are based on the author’s best scientific and professional knowledge as well as available information. The report is based on survey and assessment techniques which are limited by time and budgetary constraints relevant to the type and level of investigation undertaken and Wetland Consulting Services (Pty.) Ltd. and its staff reserve the right to modify aspects of the report including the recommendations if and when new information may become available from ongoing research or further work in this field, or pertaining to this investigation. Although Wetland Consulting Services (Pty.) Ltd. exercises due care and diligence in rendering services and preparing documents, Wetland Consulting Services (Pty.) Ltd. accepts no liability, and the client, by receiving this document, indemnifies Wetland Consulting Services (Pty.) Ltd. and its directors, managers, agents and employees against all actions, claims, demands, losses, liabilities, costs, damages and expenses arising from or in connection with services rendered, directly or indirectly by Wetland Consulting Services (Pty.) Ltd. and by the use of the information contained in this document. This report must not be altered or added to without the prior written consent of the author. This also refers to electronic copies of this report which are supplied for the purposes of inclusion as part of other reports, including main reports. Similarly, any recommendations, statements or conclusions drawn from or based on this report must make reference to this report. If these form part of a main report relating to this investigation or report, this report must be included in its entirety as an appendix or separate section to the main report.


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EXECUTIVE SUMMARY

A conveyor to transport coal from Phola to Kusile is planned. Four alternative alignments have been considered. The proposed alignments cross between 10 and 12 wetlands/streams. An alternative alignment that reduces the number of crossings by at least 3 has been proposed. None of the wetlands crossed were pristine, having been subjected to a range of impacts associated with current land use practices, predominantly related to agricultural practices. However they continue to reflect the movement of, for the most part, clean water out of their catchments. As such they support flora and its associated fauna and avifauna dependant on this habitat. Impacts on the remaining wetlands and streams cannot be avoided. The identified impacts include:

Loss of vegetation Alteration of hydrology Water quality impairment Soil loss.

An additional impact that was considered was the interruption of the movement of aquatic fauna, but this was considered unlikely given the proposed method statements. It could however be significant if the conveyor servitude is fenced. It is understood that fencing is not considered for stream crossings, but may well be applied in particularly hillslope seepage wetlands. Of the other impacts that were considered all, with the exception of the loss of vegetation, can be effectively mitigated by adopting appropriate methods, and by possibly considering realignment of the conveyor and/or the service road where its current position indicates travelling within a stream and in particular HGM units 5.


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Copyright © 2010 Wetland Consulting Services (Pty.) Ltd. 1

1. BACKGROUND INFORMATION Wetland Consulting Services (Pty) Ltd was appointed by Synergistics Environmental Services to undertake a wetland delineation and assessment of a preferred route for a coal conveyor to transport coal from the existing Phola Coal Processing Plant to the Kusile coal stockyard. The purpose of this report is to provide the extent and a description of the wetlands that will be impacted by the conveyor in order to comply with the requirements of:

NEMA (ACT 107 OF 1998): GN 386 NATIONAL WATER ACT (ACT 36 OF 1998): SECTION 40

Following on from this Phase 1 report the Phase 2 report will be compiled, which will address the impact assessment and recommended mitigation measures for the proposed conveyor.

2. TERMS OF REFERENCE The following tasks were identified in order to comply with the terms of reference for this study: Initial desktop delineation of suspected wetland areas in the additional areas; Groundtruthing of the additional areas to verify extent of delineated wetland areas; Assessment of the current condition (PES) of the wetlands; Functional assessment of the wetlands; Compilation of a wetland assessment report incorporating the findings Assess the impacts of the conveyor on the wetlands Identify mitigation measures Compile a report with the findings.

3. LIMITATIONS Every attempt was made to collect the types of information necessary to assist in the assessment of the status of the wetlands on site. The baseline information on the wetlands was collected using a rapid assessment technique and the wetland boundaries were field delineated to an accuracy of approximately 30m. An assessment of key determinants of wetland maintenance and functioning was made using soil augering, anecdotal evidence and indicators of hydric conditions. Most of the vegetation at the time of the visit had been burnt which precluded the compilation of other than a short list of those plants that could be identified. This baseline study was based on a once-off assessment of the wetland habitats and thus does not depict the seasonal variations in plant species composition and richness that may occur.


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4. STUDY AREA The study area was confined to the immediate alignment of the proposed conveyor, illustrated in the Figure below. Only those areas suspected of being wetlands, based on an initial desktop delineation, were visited. An independent soil survey was used for guidance purposes.

Figure 1. A map showing the regional setting of the conveyor.

4.1 CATCHMENTS The study area is located within the Oliphant’s River Catchment (Primary Catchment B), and more specifically within quaternary catchment B20F and B20G. The catchment drains into the Wilge River. Information regarding catchment size, mean annual rainfall and runoff for the quaternary catchment is provided in the table below (Middleton, B.J., Midgley, D.C and Pitman, W.V., 1990). Figure 2 indicates the position of the study area in relation to the affected quaternary catchment.


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Table 1. Table showing the mean annual precipitation, run-off and potential evaporation per quaternary catchment (Middleton, B.J., Midgley, D.C and Pitman, W.V., 1990).

Quaternary Catchment

Catchment Surface Area

km2

Mean Annual Rainfall (MAP)

in mm

Mean Annual Run-off (MAR)

in mm

MAR as a % of MAP

B20F 504 667 33 5 B20G 522 669 44 6.7

Figure 2. A map showing the relationship between the conveyor routes and the quaternary catchments

4.2 Geology and Soils According to the 1:250 000 Geological Map Series of South Africa 2528 and 2628, the study area is underlain by predominantly sandstones and shales associated with the Vryheid formation of the Karoo Supergroup (Pe, Pv) , Figure 3.


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Figure 3. Map indicating the dominant geology of the site. (source 1:250 000 2528, 2628 geology maps) The soils associated with this site range from moderately deep sandy soils , cultivated in the past to shallow soils, in some instances underlain by a well-developed ferricrete horizon, to rocky in places. The soils within the wetlands vary, with the valley bottom systems being typically Rensburg or Katspruit soil forms, while the seepage wetlands are generally sandy underlain by a hard or soft plinthic horizon. 4.3 Vegetation According to the Vegetation of South Africa, Lesotho and Swaziland (Mucina & Rutherford, 2006) the study area is located within the Grassland Biome and the Mesic Highveld Grassland Bioregion. Three specific vegetation types occur on site, the Rand Highveld Grassland, Eastern Highveld Grasslands and Eastern Temperate Freshwater Wetlands. The vegetation type, Eastern Highveld Grasslands is the dominant vegetation type along the conveyor route. The Rand Highveld Grassland is a mesic grassland type which occurs in regions on the Highveld with a strongly seasonal summer-rainfall of between 570 and 730 mm MAP and with warm temperate conditions and very dry winters. It has been mapped in areas of Gauteng, North-West, Free State and Mpumalanga Provinces primarily in areas between rocky ridges. The vegetation is species-rich wiry, sour grassland and occurs over a highly variable landscape with extensive sloping plains and slightly elevated ridges. Common grasses on the plains include species of Themeda, Eragrostis, Heteropogon and Elionurus. Due to extensive transformation by cultivation,


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plantations, urbanisation and dam-building and poor conservation (only 1%), Rand Highveld Grassland is considered Endangered. Eastern Highveld Grassland is mostly confined to Mpumalanga and western Swaziland, occurring marginally as well into Gauteng. The conservation status of this vegetation type is Endangered (Mucina & Rutherford, 2006), and whilst the conservation target is 24%, only a small fraction (<1%) is currently protected and 44% is considered to be transformed, mostly by cultivation, forestry, mines, dams and urbanisation. Typical Eastern Highveld Grassland is dominated by a variety of grass species, including Aristida aequiglumis, Aristida congesta, Aristida junciformis, Brachiaria serrata, Cynodon dactylon, Digitaria monodactyla, Digitaria tricholaenoides, Elionurus muticus, Eragrostis chloromelas, Eragrostis curvula, Eragrostis plana, Eragrostis racemosa, Eragrostis sclerantha, Heteropogon contortus, Loudetia simplex, Michrochloa caffra, Monocymbium ceresiiforme, Setaria sphacelata, Sporobolus africanus, Sporobolus pectinatus, Themeda triandra, Trachypogon spicatus, Tristachya leucothrix and T. rehmannii. A number of herbaceous plants may also be found, including Berkheya setifera, Haplocarpha scaposa, Justicia anagalloides and Pelargonium luridum. (Mucina & Rutherford, 2006). Eastern Highveld Grassland and Rand Highveld Grassland are listed as Vulnerable in the Draft National List of Threatened Ecosystems (GN1477 as published in GG32689, 2009)

Figure 4 Map showing the proposed alignments of the conveyor in relation to the vegetation types


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5. APPROACH 5.1 Wetland Delineation and Classification The National Water Act, Act 36 of 1998, defines wetlands as follows:

“Land which is transitional between terrestrial and aquatic systems where the water table is usually at or near the surface, or the land is periodically covered with shallow water, and which land in normal circumstances supports or would support vegetation typically adapted to life in saturated soil.”

During the current survey, wetlands were delineated according to the delineation procedure given in “A Practical Field Procedure for the Identification and Delineation of Wetlands and Riparian Areas” (DWAF 2005). Indirect indicators of prolonged saturation, namely wetland plants (hydrophytes) and wetland soils (hydromorphic soils) were used to identify wetland areas. Hydromorphic soils must display signs of wetness (mottling and gleying) within 50cm of the soil surface for an area to be classified as a wetland. The study area was sub-divided into transects and the soil profile was examined for signs of wetness within 50 cm of the surface using a hand augur along transects. The wetland boundaries were then determined by the positions of augured holes that showed signs of wetness as well as by the presence or absence of hydrophilic vegetation. The wetlands were subsequently classified according to their hydro-geomorphic determinants based on the system proposed in the National Wetland Classification System (SANBI, 2010) (in the case of the delineation undertaken in 2002, the classification of the wetlands was updated to align with the recently developed National Wetland Classification System – systems classified as “drainage lines” in the 2002 Report were reclassified as either channelled or unchannelled valley bottom wetlands). 5.2 Present Ecological State Two tools have recently been developed to facilitate the derivation of scores to reflect the present ecological sate, namely the Index of Habitat Integrity (IHI) DWA,2007, and Wet-Health, developed by Macfarlane et al., 2008. Both these tools have limitations in that they were developed primarily to assess conditions of floodplain and valley bottom wetlands and hillslope seepage wetlands linked to drainage lines. The former tool was developed to provide a rapid assessment of the Present Ecological Status (PES) specifically for application in reserve studies, while the latter tool was developed to support the Working for Wetlands program. The objective of the latter tool was to provide a semi quantitative assessment of the state of wetland prior to rehabilitation, and one post rehabilitation to demonstrate “improvement”. The intention in defining the health category (PES) of a wetland is to provide an indication of the current “condition” of a wetland in order to inform a management class. The latter provides the guidelines against that inform water quality and quantity required to maintain or improve the quality of the water resource.


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The present ecological state or health of wetlands has only been applied to the “natural” wetlands, i.e. those that have developed naturally as a consequence of the presence of water. Wetlands are rated on a scale of A to F, with A being a natural or unimpacted wetland and F being a completely modified and disturbed wetland (Table 1). The Wet-Health assesses the following four factors that influence the “health” or condition of wetlands and in this particular application pans or depressions:

hydrology, geomorphology vegetation, and ideally water quality.

Hydrology is defined in this context as the distribution and movement of water through a wetland and its soils. This module focuses on changes in water inputs as a result of changes in catchment activities and characteristics that affect water supply and its timing (extrinsic), as well as on modifications within the wetland that alter the water distribution and retention patterns within the wetland, intrinsic factors. Geomorphology is defined in this context as the distribution and retention patterns of sediment within the wetland. This module focuses on evaluating current geomorphic health through the presence of indicators of excessive sediment inputs and/or losses for clastic (minerogenic) and organic sediment (peat). Vegetation is defined in this context as the vegetation structural and compositional state. This module evaluates changes in vegetation composition and structure as a consequence of current and historic onsite?. Water Quality largely self-explanatory and reflecting the changes in quality as a consequence of changes in land use or as a direct result of activities within the wetland itself that could lead to changes in the quality of the water flowing through and within the wetland The explanation of scores assigned to the various PES categories are summarized in Table 2.


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Table 2 Interpretation of impact scores and health category associated with Present Ecological Status (PES) (Macfarlane et.al. 2008)

. 5.3 Ecological Importance & Sensitivity Ecological Importance and Sensitivity is a concept introduced in the reserve methodology to evaluate a wetland in terms of: - Ecological Importance; - Hydrological Functions; and - Direct Human Benefits The scoring assessments with these three aspects of wetland importance and sensitivity have been based on the requirements of the NWA, the original Ecological Importance and Sensitivity assessments developed for riverine assessments (DWAF, 1999), and the work conducted by Kotze et al (2008) on the assessment of wetland ecological goods and services (the WET-EcoServices tool).

Description Combined impact score

PES Category

Unmodified, natural. 0 – 0.9 A Largely natural with few modifications. A slight change in ecosystem processes is discernible and a small loss of natural habitats and biota may have taken place.

1 – 1.9 B

Moderately modified. A moderate change in ecosystem processes and loss of natural habitats has taken place but the natural habitat remains predominantly intact

2 – 3.9 C

Largely modified. A large change in ecosystem processes and loss of natural habitat and biota and has occurred.

4 – 5.9 D

The change in ecosystem processes and loss of natural habitat and biota is great but some remaining natural habitat features are still recognizable.

6 – 7.9 E

Modifications have reached a critical level and the ecosystem processes have been modified completely with an almost complete loss of natural habitat and biota.

8 – 10 F


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Table 3. Scoring system used for the EIS assessment.

Ecological Importance and Sensitivity categories Range of Median

Ecological Management Class

Very high >3 and <=4 A Wetlands that are considered ecologically important and sensitive on a national or even international level. The biodiversity of these wetlands is usually very sensitive to flow and habitat modifications. They play a major role in moderating the quantity and quality of water of major rivers.

High >2 and <=3 B Wetlands that are considered to be ecologically important and sensitive. The biodiversity of these wetlands may be sensitive to flow and habitat modifications. They play a role in moderating the quantity and quality of water of major rivers. Moderate >1 and <=2 C Wetlands that are considered to be ecologically important and sensitive on a provincial or local scale. The biodiversity of these wetlands is not usually sensitive to flow and habitat modifications. They play a small role in moderating the quantity and quality of water of major rivers.

Low/marginal >0 and <=1 D Wetlands that is not ecologically important and sensitive at any scale. The biodiversity of these wetlands is ubiquitous and not sensitive to flow and habitat modifications. They play an insignificant role in moderating the quantity and quality of water of major rivers. 5.4 Functional Assessment

A functional assessment of the wetlands on site was undertaken using the level 2 assessment as described in “Wet-EcoServices” (Kotze, Marneweck, Batchelor, Lindley & Collins 2008). This method provides a scoring system for establishing wetland ecosystem services. It enables one to make relative comparisons of systems based on a logical framework that measures the likelihood that a wetland is able to perform certain functions

6. FINDINGS The presence of wetlands in the landscape can be linked to the presence of both surface water and perched groundwater. Wetland types are differentiated based on their hydro-geomorphic (HGM) characteristics; i.e. on the position of the wetland in the landscape, as well as the way in which water moves into, through and out of the wetland systems. A schematic diagram of how these wetland systems are positioned in the landscape is given in Figure 3 below.


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Figure 5. Schematic illustrating types of wetlands and their positions in the landscape 6.1 General Wetland Description & Classification Thirteen wetlands are affected by the conveyor, labelled HGM-1 to 13, Figure 6. In some instances the HGM unit comprises one or more types of wetlands. For example HGM-5 comprises a channelled valley bottom wetland flanked on both sides by hillslope seepage wetlands. The position and boundaries of each of these main wetland types found on site are given in Figure 6, while the start and end coordinates, and a description of the affected wetlands by the conveyor route are summarised in Table 4.


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Figure 6. Map showing the wetlands, expressed as hydrogeomorphic units (HGM) crossed by the conveyor alignments.


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Table 4. A list of the types of wetlands that will be crossed by the conveyor given its current alignment.

HGM UNIT DESCRIPTION OF WETLAND TYPES

CO-ORDINATES Start

CO-ORDINATES end

HGM 1 Conveyor Option 3

Hillslope seepage wetland -26.030845 29.003437

-26.028834 29.001083

HGM 2 Conveyor option 1


-26.021424 29.010465



-26.019523 28.980958



-26.020549 28.983689



-26.019523 28.980958

HGM 4 Hillslope seepage wetland -26.016483 28.959373

-26.016364 28.956077

HGM 5a HGM 5ab

Channelled valley bottom wetland -26.015940 28.949061 -26.012475 28.937144

-26.014708 28.942901 -26.011647 28.935191


-26.012661 28.937422

HGM 7 Channelled valley bottom wetland flanked by hillslope seepage wetlands

-26.010748 28.925765

-26.010161 28.925504


-26.001949 28.923146

-26.001127 28.922459


-25.997277 28.919823

HGM 10 Hillslope seepage wetland -25.978559, 28.915048

-25.977181 28.916024


-25.974605 28.918174

-25.971142 28.920779


-25.968372 28.923010

HGM 13 Channelled valley bottom wetland -25.949037 28.933021 -25.948533 28.935894

-25.947420 28.933502 -25.947796 28.936062


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6.1.1 Channelled valley bottom wetlands Typical of all these types of systems on site, a tall emergent plant community zone dominates the lower elevations (areas that remain inundated or wet for longest). Dominant plants in the tall emergent zone include obligate hydrophytic plants such as the sedge Cyperus fastigiatus. The bulrush Typha capensis is noticeably absent from many of these systems (with the exception of areas associated directly with dams), probably due to the highly seasonal nature of these systems. Shorter mixed grass/sedge meadows occur immediately adjacent to the tall emergent zone and the dominant plant species here include the grass Leersia hexandra and the sedges Juncus oxycarpus and Fimbristylis complanata. There is generally a rapid transition from the mixed grass/sedge zone of these more seasonally wet habitats to the more temporarily wet habitat associated with the adjacent marginally wet grasslands. These areas comprise a mixture of grasses, the dominant species being the upland grass Themeda triandra. Facultative wetland and facultative indicator category species such as Eragrostis plana and Setaria sphacelata respectively are co-dominant in many places providing evidence of temporary wetting.

Figure 7. A channelled valley bottom wetland on looking upstream from the proposed conveyor crossing (HGM-5)

6.1.2 Hillslope seepage wetlands Hillslope seepage wetlands, as their name indicates, occur on sloping terrain, and are either connected to a channel or isolated within the surrounding terrestrial landscape. They are characteristically supported primarily by diffuse, sub-surface flows maintained at or near the soil surface by some form of impermeable layer within the soil profile which prevents or limits the vertical infiltration of water into the deeper soil horizons. This layer may be present as a hard or soft plinthic horizon or as shallow bedrock. The source of flows is expected to be mainly


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groundwater driven, with both precipitation and surface runoff contributing to the maintenance of the wetland hydrology to a lesser degree under natural conditions. Flow outputs may either feed the surface water resource directly if the wetland is linked to a channel and/or may contribute to groundwater recharge. Water expressed in hillslope seepage wetlands may also move in the weathered profile at the contact between the derived soils and the weathered parent material, or in fracture planes in for example shales. Hillslope seepage wetlands appear where these features pinch out on the side slopes.

Figure 8. A photograph of a hillslope seepage wetland (HGM-1)

6.2 Functional Assessment Despite the widely held notions about wetland functionality, extensive literature searches reveal that very few practitioners have actually quantified these benefits (Batchelor, 2002). Moreover, it appears that these functions are highly variable depending on the characteristics of the wetlands and the landscape. In the present study, it was not possible to perform the types of investigations necessary for determining functionality such as nutrient balance studies or flood attenuation quantifications. This was due both to the complexity of the task and the costs and time that would have been involved. It is therefore difficult to speculate on the functional values of the wetlands on site. Nevertheless, some general discussion is possible based on experience and other projects undertaken in the region. These are discussed for each of the main wetland types found within the study area.


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Valley bottom wetlands Valley bottom wetlands within the study area are predominantly channelled with impoundments at sites along their path. They thus serve as conduits for water draining from the landscape. They together with impoundments are capable of slowing the velocity of water moving out of the catchments, in the process trapping sediments. Phoshpates typically bound to the sediments may be removed as a consequence of sedimentation. In most cases these sediments are colonised by plants that assist phosphate retention and uptake by maintaining aerobic conditions within the sediments. In the absence of plants anaerobic conditions may prevail that are conducive for phosphate release into the water column. In so doing they may be performing a purification service. The wetlands are not expected to be playing an important role in replenishing or recharging groundwater supplies, mainly because of their impervious clay bases. They may however be helping to retain water for longer in sections of the drainage lines and thus in the catchment and they probably contribute towards the biodiversity of the catchment by creating wet patches in a landscape that is dominated by dry grassland and temporarily wet wetlands. Certainly the valley bottom wetlands and their associated dams are used by livestock as a source of both water and fodder, while the water in the systems is used for irrigation. It should be noted that the wetlands do not produce water but reflect its presence. Hillslope seepage wetlands As is the case of the other wetland types, hillslope seepage wetlands support plants in particular, and associated insects, birds and small mammals adapted to the seasonal moisture regime. At the time of the survey most of the hillslope seepage wetlands were either burnt or in some instances ploughed over or cultivated. Under the circumstances no plant surveys were undertaken. However hillslope seepage wetlands on the New Largo mining areas characteristically comprise mixed grass-sedge meadows. Patches dominated by the grass Imperata cylindrica are common along the edges of most of the seepage wetlands. The majority of the plant species occurring in the hillslope seepage wetlands are tolerant of seasonal root zone saturation. In addition hill slope seeps support conditions that facilitate both sulphate and nitrate reduction as interflow emerges through the organically rich wetland soil profile, and they can thus play an important role in maintaining water quality. They typically represent low energy environments, and where soil moisture conditions remain high throughout the year, can accumulate carbon. As hillslope seepage wetlands, for the most part, are dependent on the presence of an aquiclude, either a hard or soft plinthic horizon they are not generally regarded as significant sites for groundwater recharge (Parsons, 2004).

7. PRESENT ECOLOGICAL STATUS (PES) ASSESSMENT


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No pristine wetlands were found to occur within the study area, with all of the wetlands on site having undergone a degree of degradation due to changes in landuse and other anthropogenic activities. All of the wetlands on site have been exposed to impacts associated with agricultural activities. Cultivation has had some direct impact on some of the hill slope seeps where cultivation has intruded into the wetlands. Further impacts from cultivation include an increase in sediment transported into the adjacent wetlands. All of the wetlands on site have however been affected by livestock grazing, with overgrazing resulting in decreased diversity as well as decreased cover, increasing the risk of erosion, while cattle paths and trampling by cattle further create erosion nick points. Incorrect burning regimes and too frequent burning exacerbate the problems caused by cattle. Building of farm dams has also had a significant impact on the wetlands through changing the hydrological regime of the wetlands and leading to flow concentration, resulting in erosion. All of the above impacts have resulted in the current condition of the wetlands on site departing significantly from the reference or unimpacted condition of the wetland. This is reflected in the results of the PES assessment which indicates that most of the wetlands are in a moderately modified condition (PES C) due to the various impacts discussed above.

Table 5. Impact scores for the HGM units affected by the proposed conveyor, with the PES derived from the lowest impact score

HGM UNIT

DESCRIPTION OF WETLAND TYPES

Hydrology Geomorphology Vegetation Overall PES

HGM 1 Hillslope seepage wetland 3.8 4.1 2.9 C/D HGM 2 Hillslope seepage wetland 1.3 5.2 2.0 C/D HGM 3 Hillslope seepage wetland 1.1 1.0 1.85 B HGM 4 Hillslope seepage wetland 2.3 1.9 7.8 E HGM 5 Channelled valley bottom

wetland 4.1 4.3 4.2 D

HGM 6 Hillslope seepage wetland 2.1 2.1 7.4 D/E HGM 7 Channelled valley bottom

wetland flanked by hillslope seepage wetlands

5.3 4.1 4.1 D


3.5 2 2 C

HGM 9 Hillslope seepage wetland 2 2 7 E HGM 10 Hillslope seepage wetland 2 3.2 7 E HGM 11 Channelled valley bottom

wetland flanked by hillslope seepage wetlands

2 2.1 2.7 C

HGM 12 Hillslope seepage wetland 2.1 2.0 4 D HGM 13 Channelled valley bottom

wetland 4.2 4 3.7 D


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8. ECOLOGICAL IMPORTANCE AND SENSITIVITY The results of the EIS assessment are presented in the Table 6 , below. Most of the wetlands on site are considered to be of moderate importance and sensitivity, with only those wetlands that have undergone extensive degradation being considered of low importance. It is however important to point out that all wetlands, irrespective of their state of degradation, are considered as sensitive landscapes and reflect the movement of water through the landscape.

Table 6. The determined ecological management classes of the wetland units that will be affected by the current proposed conveyor alignment.

HGM UNIT DESCRIPTION OF WETLAND TYPES EIS HGM 1 Hillslope seepage wetland C HGM 2 Hillslope seepage wetland C HGM 3 Hillslope seepage wetland B HGM 4 Hillslope seepage wetland D HGM 5 Channelled valley bottom wetland C HGM 6 Hillsllope seepage wetland C HGM 7 Channelled valley bottom wetland flanked by hillslope

seepage wetlands D


C

HGM 9 Hillslope seepage wetland C HGM 10 Hillslope seepage wetland D HGM 11 Channelled valley bottom wetland flanked by hillslope

seepage wetlands B

HGM 12 Hillslope seepage wetland C HGM 13 Channelled valley bottom wetland C

9. CONCLUSIONS Nonetheless, it is important to point out that all water resources, irrespective of their state of degradation are considered sensitive landscapes and that any activity which is contemplated and which will impact on the wetlands within the study area is subject to authorisation under Section 21 of the National Water Act (Act 36, 1998). As such, all proposed wetland crossings will require a Water Use License.

10. IMPACT ASSESSMENT


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10.1 Methodology

The impact assessment methodology used in this report is based on the requirements of DWA’s ‘Operational Guideline (Department of Water Affairs, 2010).

The assessment process requires that all the relevant data to the water uses and to the impact of the water uses on the water resources be sourced and used in the assessment. The process included:

Monitoring data collected and stored;

Published data;

Data available from the DWA or other stakeholders in the area.

The above-mentioned data was used for risk identification of the water uses on the water resource. The impact assessment will be based on the following key elements:

Probability of occurrence: this describes the likelihood of the impact actually occurring and is indicated as:

Improbable, where the likelihood of the impact is very low;

Probable, where there is a distinct possibility of the impact to occur;

Highly probable, where it very likely that the impact will occur;

Definite, where the impact will occur regardless any management measure.

Consequence of occurrence in terms of:

Nature of the impact;

Extent of the impact, either local, regional, national or across international borders;

Duration of the impact, either short term (0-5 years), medium term (6-15 years) or long-term (the impact will cease after the operational life of the activity) or permanent, where mitigation measures by natural processes or human intervention will not occur;

Intensity of the impact, either being low, medium or high effect on the natural, cultural and social functions and processes.

Significance level of the risk posed by the water use, this is determined through a synthesis of the probability of occurrence and consequence of occurrence.

The ranking of the risks was based on the quantitative assessment as described above and categorized into high, medium, or low risks. Management measures were then identified to mitigate, prevent and / or reduce the risk. These measures primarily focused on the risks identified as high in the ranking matrix, but will also include measures for medium and low risks. The management measures will be taken forward in the IWULA, as part of the water use authorisation process.

In order to assess each of the factors for each impact, the ranking scales as contained in Table 7 were used.


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Table 7. Ranking Scales for impact assessment

PROBABILITY = P 5 – Definite / don’t know 4 – High probable 3 – Medium probability 2 – Low probability 1 – Improbable 0 – None

DURATION = D 5 – Permanent 4 – Long-term (ceases after operational life) 3 – Medium-term (5 – 15 years) 2 – Short-term (0-5 years) 1 - Immediate

EXTENT = E 5 – International 4 – National 3 – Regional 2 – Local 1 – Site 0 – None

MAGNITUDE = M 10 – Very high / Don’t know 8 – High 6 – Moderate 4 – Low 2 – Minor

*Note: the magnitude is rated from 1 to 5, but this is done twice. Once for the environmental impact and once for the impact on society, thereby having a total weight of 10 points.

Once the factors had been ranked for each impact, the environmental significance of each impact could be assessed by applying the SP formula. The SP formula can be described as:

SP = (magnitude (environmental + society) + duration + extent) x probability

The maximum value of significance points (SP) is 100. Environmental effects could therefore be rated as either high (H), moderate (M), or low (L) significance on the following basis:

More than 60 points indicates high (H) environmental significance

Between 30 – 60 points indicate moderate (M) environmental significance

Less than 30 points indicates low (L) environmental significance

These impacts are rated prior to mitigation and again post mitigation so a comparison can be drawn. 10.2 Project Description The project involves the construction and operation of a conveyor to transport coal from the Phola Coal Processing Plant to the coal stockyard at the Kusile Power Station. Activities to be undertaken potentially impacting on wetlands include the following: - Construction of

The coal conveyor The transfer stations, consisting of a bunded area where dirty runoff will be channelled to a

silt trap, followed by a small evaporation dam, where these are located in a wetland.


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The watercourse/wetland crossings where the conveyor belt will be held in position ensuring that it does not encroach on the 1:100 year floodline by gantries on either side fitted on concrete columns.

Construction of access/service road and drifts

The service road crossings at the streams have been designed as low water bridges. This ensures that crossing the streams are possible during normal flow, but without any restriction to flow during rain or flood events. The following design specifications has been proposed for the service road along the (from the upstream side to the downstream side): In the upstream zone Reno mattresses, up to 0.5m beneath the ground surface, will be

inserted for protection and stabilisation (total of 3.5m wide); These mattresses are followed by a 1m x 1.5m deep geotextile gabion and a gabion cut-off

(total of 1m wide); This is followed by the service road which will be lined with Armorflex, or a similar material

(total of 4m wide); The road is followed by another protection gabion at the downstream end (1m wide); No method statement was provided for crossing hillslope seepage wetlands, however it has been assumed that the same method proposed for the rivers will be used to cross the hillslope seepage wetlands. It is further assumed that no stock piling of material, the siting of construction camps or any unnecessary activity will take place in the wetlands or water courses, and that the all wetlands will be suitably marked with barrier tape in the immediate vicinity of the conveyor/wetland crossings to indicate sensitivity. Based on the current proposed alignments, the number of times the conveyor crosses wetlands ranges between 11 and 12 depending on the option selected. The difference between the alternatives is therefore not significant. However should the alignment be adjusted, particularly in the section that affects HGM units 5, 6 and 7, these crossings and their associated impacts can be avoided altogether. This option is illustrated in Figure 9.


September 2011


Figure 9. Alternative alignment that could be considered to avoid the impacts on the wetlands associated with one of the tributaries of the Klipfontein Spruit. If these recommendations are implemented, then the following impacts associated with the construction and operation of the conveyor can be expected. Most of the impacts will be initiated during the construction phase and will extend through the operational phase to decommissioning

10.2.1 Loss of vegetation This will occur in the wetlands as a consequence of the proposed method statements as a direct consequence of clearing and grubbing associated with constructing the servitude. The placement of dump rock to facilitate access to service the conveyor as well as to support the gantry will alter the substrate for the duration of the project, which will negatively impact the existing vegetation. It is also likely that the vegetation structure and height will be managed in a way to avoid interfering with the conveyor as well as reducing the fire risk. The impact on the vegetation in the wetlands will be associated with the conveyor is Mitigation. Mitigation for the loss of the vegetation within the conveyor servitude cannot be effectively mitigated if the assumed method of backfilling with dump rock followed by compaction is instituted.


September 2011


10.2.2 Interference with the free movement of water dependant fauna. The replacement of the natural substrate occurring within the wetland with dump rock could provide a local barrier to the movement of aquatic fauna. This is really only likely to materialise in the rivers. However it is expected that water will continue to flow over the placed material which should ensure that the movement of most aquatic fauna is not impeded. Fencing off of the conveyor to prevent theft and vandalism is likely to pose a greater threat to the movement of biota than the conveyor. It is however understood that fencing of the conveyor across streams (and wetlands?) is not being considered. Mitigation None required.

10.2.3 Interruption of hydrology This will occur as a consequence of the proposed method statement where the wetland soils will be replaced with compacted dump rock associated with the access road, the gabion structures, and reno-mattresses as well as the foundations required to support the conveyor. During construction, the areas where the pillars/plinths are constructed may have to be protected against flooding. This could have a partial and temporary impact on local stream flow. The relationship between the flow direction and its interception by the conveyor will differ if the crossing is perpendicular or horizontal/tangential to the flow. Mitigation The goal of the mitigation measures is to maintain hydrological connectivity across the conveyor servitude. The following method statement is offered for consideration to achieve this goal Conveyor crossing wetlands tangential to or parallel with the contours: It is recommended that an interceptor trench be excavated upstream of the proposed crossing as well as on the downstream side of the crossing, with the trench being 500mm deeper than the lower level of the compacted fill layer. The trench should be bidim lined and rock packed. 110mm pipes should be laid across the servitude 300mm below natural ground level to discharge into the trench on the downslope. This is to ensure that water can move unhindered across the servitude. See sketch below


September 2011


. Conveyor crossing perpendicular to contours

Bidim wrapped crushed rock 35-45mm no fines in trench

Conveyor

Connecting pipes

Back filled and compacted founding layer

Connecting pipesConveyor

Back filled and compacted founding layer

Figure 10. Schematic illustrating a proposed method to ensure that groundwater flows (blue arrows) are not interrupted by the conveyor crossing.


September 2011


Conveyor crossing wetlands at right angles to the contours: Owing to the relatively small cross sectional area of conveyor, it is unlikely that that the conveyor will have a significant impact on the behaviour of water where the conveyor crosses or approaches wetlands at right angles to contours, with the exception of perhaps concentrating rainfall intercepted on the conveyor roofing. This will form a drip line which could increases the erosion risk on the hillslope seeps because of the combination of slope and the fact that the soils are likely to saturate rapidly converting infiltration into runoff. Mitigation The project has been designed to mitigate the impact through reducing the flow path lengths by creating low level berms 300mm high with side slopes no greater than 1:5 to intercept and divert water off the conveyor servitude into the adjacent wetlands. The distance between the low berms should not be less than 20m, where slopes are in the order of 1%, but where slopes exceed this, the distance between the low ridges should be reduced to 7m between centres.

10.2.4 Water quality deterioration as a consequence of construction related activities The fact that the conveyor crosses valley bottom wetlands, streams and hillslope seepage wetlands makes the water resource they represent, susceptible to pollution during both construction and during the operational phase. Dust generated by construction activities, eroded sediments, leaked hydrocarbons from construction vehicles, litter, and small amounts of construction materials can all find their way into the systems, negatively affecting water quality. In addition the conveyor route design includes the construction of support columns in at least one of the systems. This will require access to the construction site, excavation of in situ material and its subsequent replacement with suitable material, casting of concrete etc. This will undoubtedly result in an increase in turbidity. Diversion of the stream may be required to facilitate the construction. Post construction, during the operational phase coal fines and dust are likely to find their way into the wetlands and water courses. Mitigation From a consistency perspective the inclusion of a gantry should be considered in the crossings of all water resources including hillslope seepage wetlands. The inclusion of a gantry is indicated in order to prevent the probability of coal and coal fines from contaminating sites where there is a possibility of contaminating water. The project has been designed to mitigate the impact through the design of gantries having at least 1m freeboard between its underside and the 1:100 year flood line. There will then be another 1.2m space from the gantry floor to the conveyor belt line. This allows the gantry to catch any spills form the conveyor belt as well as allowing access for clean-up and maintenance crews. The belt will be isolated further with a “dog house” roof to prevent dust dispersion and rainfall contamination. The gantries will be anchored into the stream banks with plinths constructed with gabion protection blocks.


September 2011


Transfer stations Where transfer stations occur in wetlands the excavation of cut off trenches is contra-indicated. Instead a grout curtain, or similar barrier, should be inserted on the outside of the berm wall in order to divert interflow around the site. The construction of a cut off drain will simply create a cone of depression around the affected site that will lower the groundwater levels in the immediate vicinity of the site, and possibly cause reverse flow from within the bunded area to the groundwater. A schematic is presented below. A summary of the impacts, their significance pre and post the introduction of mitigation measures is presented in Table 8.


September 2011


Grout curtain/Bentofix or similar sheeting

Evaporation dam

Transfer Station Berm

Figure 11. Schematic showing plan and cross section through a transfer station to illustrate the concepts briefly discussed in text

Aquiclude/Aquitard

Grout curtain/Bentofix sheet to level of aquiclude

Berm enclosing the transfer station

Evaporation pond


September 2011


Table 8. Summary of assessed impacts of the conveyor route on the wetlands

Description of impact ScoreImpact Score Significance pre mitigation Mitigation measures Score

Impact Score Significance post mitigation

Probability 4 Probability 4Extent 1 Extent 1Duration 6 Duration 6Magnitude 4 Magnitude 4Probability 4 Probability 2Extent 1 Extent 1Duration 4 Duration 4Magnitude 6 Magnitude 4Probability 4 Probability 2Extent 1 Extent 1Duration 2 Duration 4Magnitude 4 Magnitude 2Probability 3 Probability 2Extent 2 Extent 1Duration 4 Duration 4Magnitude 4 Magnitude 2Probability 1 Probability 1Extent 1 Extent 1Duration 4 Duration 4Magnitude 1 Magnitude 1

None

Introduce systems to ensure hydrological connectivity

Construct low level water deflection berms

Separate dirty water from clean water construct gantries

None required

44

18

14

14

Soil loss (erosion)

Contamination of water from dust/spills

44

44

28

30

CONSTRUCTION & OPERATIONAL PHASE

Interruption of free movement of aquatic biota 6 Low Low

Moderate

Moderate

Low to moderate

Low to moderate

Moderate

Low

Low

Low

Loss of vegetation/biodiversity

Disruption of hydrology


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11. RECOMMENDATIONS The proposed alignment (Figure 9) that avoids the impacts on HGM units 5, 6 and 7 should be seriously considered. In addition the alternatives to creating a cut off trench and berm around transfer stations should be considered, with one option being the placement of an impermeable barrier between the upslope edge of the transfer station to divert perched water around the site without necessarily affecting the pre development water levels (figure 11).

12. REFERENCES Department of Water Affairs and Forestry. 1999a. Resource Directed Measures for Protection of

Water Resources. Volume 4. Wetland Ecosystems Version 1.0, Pretoria. Department of Water Affairs and Forestry. 1999b. Resource Directed Measures for Protection of

Water Resources. Volume 1. River Ecosystems Version 1.0, Pretoria. Department of Water Affairs and Forestry, 2005. A practical field procedure for identification and

delineation of wetland and riparian areas. DWAF, Pretoria. DWAF (2007). Manual for the assessment of a Wetland Index of Habitat Integrity for South African floodplain and channelled valley bottom wetland types by M. Rountree (ed); C.P. Todd, C. J. leynhans, A. L. Batchelor, M. D. Louw, D. Kotze, D. Walters, S. Schroeder, P. Illgner, M. Uys. and G.C. Marneweck. Report no. N/0000/00/WEI/0407. Resource Quality Services, Department of Water Affairs and Forestry, Pretoria, South Africa. Kleynhans, C.J. 1996. A qualitative procedure for the assessment of the habitat integrity status of

the Luvuvhu River. Journal of Aquatic Ecosystem Health 5: 41 - 54. Kleynhans, C.J. 1999. A procedure for the determination of the ecological reserve for the purposes

of the national water balance model for South African Rivers. Institute for Water Quality Studies. Department of Water Affairs and Forestry, Pretoria.

Kotze, D.C, Marneweck, G.C., Batchelor, A.L., Lindley, D. and Collins, N. 2004. Wetland Assess:

A rapid assessment procedure for describing wetland benefits. Mondi Wetland Project, Unpublished report.

Marneweck, G.C. and Batchelor, A. 2002. Wetland inventory and classification. In: Ecological and

economic evaluation of wetlands in the upper Olifants River catchment. (Palmer, R.W., Turpie, J., Marneweck, G.C and Batchelor (eds.). Water Research Commission Report No. 1162/1/02.

Macfarlane DM, Kotze DC, Ellery W N., Walters D., Koopman, V., Goodman P., Goge C., 2008. Wet-Health A rapid Technique for Assessing Wetland Health. WRC Report TT 340/08 Midgeley, DC, Pitman, W V 7 Middleton . Surface Water Resources of South Africa 1990. WRC Report 298/1.1/94


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Mucina, L. & Rutherford, M. C. (Eds) 2006. The vegetation of South Africa, Lesotho and

Swaziland. Strelitzia 19. South African National Biodiversity Institute, Pretoria. 807pp.

Wetland Inventory Consortium, 2000. A pilot project for the determination of methods for the National Wetland Inventory. Department of Environmental Affairs and Tourism, Pretoria.

Documents

Appendix E: Wetland Delineation Specialist Assessment - Phola/3... · PHOLA-KUSILE CONVEYOR September 2011 i TABLE OF CONTENTS 1. BACKGROUND INFORMATION 1 2. TERMS OF REFERENCE 1