UPGRADE OF ROAD D4407 BETWEEN HLUVUKANI AND TIMBAVATI (7.82 KM), ROAD D4409 AT WELVERDIEND (6.88 KM) AND ROAD D4416/2 BETWEEN WELVERDIEND AND ROAD P194/1 (1.19 KM) IN THE BOHLABELA REGION OF THE MPUMALANGA PROVINCE
FRESHWATER ASSESSMENT REPORT
PREPARED FOR: COMPILED BY:
DATED: March 2020
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DOCUMENT CONTROL
TITLE: Upgrade of Road D4407 between Hluvukani and Timbavati (7.82 Km), Road D4409 At Welverdiend (6.88 Km) and Road D4416/2 between Welverdiend And Road P194/1 (1.19 Km) in the Bohlabela Region of the Mpumalanga Province
LOCATION: Bohlabela Region of the Mpumalanga Province CLIENT: Lidwala Consulting Engineers CONSULTANT: NCC Environmental Services (Pty) Ltd DOCUMENT NUMBER: TBC REVISION: 00 DATE: 18/03/2020
CLIENT REPRESENTATIVE: AUTHOR: Etiene Roux Craig Burne Project Engineer Freshwater Ecologist T · 082 852 5323 T · 078 467 3685 E · [email protected] E · [email protected]
REVIEWED BY: APPROVED BY: Jonathan Szoke Operations Manager: SHERQ Consulting T · 083 232 6356 in E · [email protected]
REVIEWED BY:
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DOCUMENT GUIDE
The table below provides the 2014 NEMA requirements (as amended) for specialist reports and the relevant sections in the report where these requirements are addressed:
EIA Regulations Description Page/Section 2014, GN982 in the report (as amended in 2017) Appendix 6 (a) A specialist report prepared in terms of these Regulations must contain details of— Page 3 i. the specialist who prepared the report; and Also see BAR ii. the expertise of that specialist to compile a specialist report including a curriculum vitae Appendix 6 (b) A declaration that the specialist is independent in a form as may be specified by the Page 3 competent authority Appendix 6 (c) An indication of the scope of, and the purpose for which, the report was prepared Sections 2, 4 & 5 Appendix 6 (cA) An indication of the quality and age of base data used for the specialist report Sections 8, 9 & referenced throughout Appendix 6 (cB) A description of existing impacts on the site, cumulative impacts of the proposed Sections 8 & 9 development and levels of acceptable change Appendix 6 (d) The duration, date and season of the site investigation and the relevance of the season Section 8 to the outcome of the assessment Appendix 6 (e) A description of the methodology adopted in preparing the report or carrying out the Section 8 specialised process inclusive of equipment and modelling used Appendix 6 (f) Details of an assessment of the specific identified sensitivity of the site related to the Maps in proposed activity or activities and its associated structures and infrastructure, inclusive Sections 3, 9 of a site plan identifying site alternatives & Annexures I & M Also see BAR Appendix 6 (g) An identification of any areas to be avoided, including buffers Sections 9, 10 & Annexure N Appendix 6 (h) A map superimposing the activity including the associated structures and Section 9 infrastructure on the environmental sensitivities of the site including areas to be avoided, including buffers; Appendix 6 (i) A description of any assumptions made and any uncertainties or gaps in knowledge; Sections 6, 7 & Annexure K Appendix 6 (j) A description of the findings and potential implications of such findings on the impact Section 9 & of the proposed activity or activities Annexure N Appendix 6 (k) Any mitigation measures for inclusion in the EMPr; Section 10 & Annexure N Appendix 6 (l) Any conditions for inclusion in the environmental authorisation; Section 10 & Annexure N Appendix 6 (m) Any monitoring requirements for inclusion in the EMPr or environmental Section 10 & authorisation; Annexure N Appendix 6 (n) A reasoned opinion— Sections 11 & i. whether the proposed activity, activities or portions thereof should be authorised; 12 (iA) regarding the acceptability of the proposed activity or activities; and ii. if the opinion is that the proposed activity, activities or portions thereof should be authorised, any avoidance, management and mitigation measures that should be included in the EMPr, and where applicable, the closure plan; Appendix 6 (o) A description of any consultation process that was undertaken during the course of See BAR preparing the specialist report; Appendix 6 (p) A summary and copies of any comments received during any consultation process and See BAR where applicable all responses thereto Appendix 6 (q) Any other information requested by the competent authority. None
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DECLARATION OF INDEPENDENCE
I, Craig Burne, as duly authorised representative of NCC Environmental Services (Pty) Ltd (NCC), hereby confirm my independence as a specialist and declare that neither I nor NCC have any interest; be it business, financial, personal or other, in any proposed activity, application or appeal in respect of NCC being appointed as environmental assessment practitioner in terms of the National Environmental Management Act, 1998 (Act No. 107 of 1998), other than fair remuneration for the work performed. This is specifically in connection with the appointment of NCC, by Lidwala Consulting Engineers, to undertake a NEMA Section 24G Rectification Process via Basic Assessment for the Upgrade of road D4407 between HluvukanI and Timbavati, Road D4409 at Welverdiend and road D4416/2 between Welverdiend and road P194/1 in the Bohlabela region of the Mpumalanga Province. In terms of the prerequisites of the Natural Scientific Professions, 2003 (Act No. 27 of 2003) and as a registered member of the South African Council for Natural Scientific Professions, I will undertake my profession in accordance with the Code of Conduct of the Council. I declare this study to be my own work prepared independently of any influence or prejudice with respect to any other party where the findings and conclusions have been made, to the best of my ability, with objective and truthful intention.
Signed:
Craig Burne Pr.Sci.Nat. MSc (Freshwater Ecology) 18 March 2020 NCC Environmental Services (Pty) Ltd
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EXECUTIVE SUMMARY
Lidwala Consulting Engineers SA (Pty) Ltd (Lidwala) were appointed by the Mpumalanga Province, Department of Public Works, Roads and Transport (DPWRT) for the planning, design, tender documentation, and construction supervision for the “Upgrading of road D4407 between Hluvukani and Timbavati (7.82 km), road D4409 at Welverdiend (6.88 km) and road D4416/2 between Welverdiend and road P194/1 (1.19 km) in the Bohlabela region of the Mpumalanga Province”. NCC Environmental Services (Pty) Ltd (NCC) were appointed by Lidwala to conduct a NEMA Section 24G application after it was confirmed that the road upgrade project triggered NEMA listed activity no. 19 of Listing Notice 1 and listed activity no. 14 of Listing Notice 3. Construction activity subsequently commenced without acquiring the mandatory environmental authorisation required for the project. In terms of the NEMA Section 24G rectification process, a freshwater assessment relating to freshwater resources (watercourses/drainage lines, riparian zones and wetlands) associated with the project is one of the specialist studies required as part of the basic environmental assessment process and application for environmental authorisation. NCC was duly appointed by Lidwala to conduct the freshwater assessment.
An initial desktop study and literature review was conducted followed by field visit and ground-truth verification for purposes of more accurate delineation and mapping of freshwater resources in the broader study area. As part of the scope of the delineation, the 32m watercourse regulated area in terms of the NEMA EIA Regulations and the respective 100m and 500m watercourse and wetland regulated areas in terms of section 21 (c) & (i) of the National Water Act (NWA) were used for the delineation and for proposing buffers to afford protection to freshwater resources within the regulated area of the project footprint. Wetlands within the regulated area were classified and assessed in terms of their present ecological state and (PES) ecological importance and sensitivity (EIS) using the widely utilised tools namely Wet-Health (after Macfarlane et al., 2008), Wet-Ecoservices (after Kotze et al. 2009) and DWS EIS assessment criteria (after Kleynhans, 1999).
Given the non-perennial nature of the watercourses in the study area and no flow underway at the time of the assessment, the components of freshwater aquatic systems typically included in an aquatic impact assessment were not possible to assess. No in-situ water quality assessment and no field-based assessments of macroinvertebrates, fish or vegetation were carried out. A riparian and instream habitat assessment using the Index of Habitat Integrity (IHI) (after Kleynhans, 1996) with background literature and studies and aerial imagery combined with the field observations informing the watercourse PES and EIS assessments. A risk assessment relating to potential impacts of the development on watercourses and freshwater biodiversity in
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terms of section 21 (c) and (i) of the NWA was carried out using the DWS-regulated risk matrix approach promulgated in GN509 dated 26th August 2016 and DEAT guidelines on impact assessment.
Freshwater resource maps have been developed for the study area indicating the location of freshwater features. Six wetlands, two seep systems and four artificial benches (dams) were identified within 500m of the road and borrow pit footprints. Two drainage culvert road crossings and one bridge crossing are directly within non-perennial watercourses traversed by the existing gravel road. B PES categories were assigned to three of the wetlands (W01, W02 and W03) with a C PES for W04, W05 and W06. With the exception of W05 with a Low/Moderate EIS, the EIS for the other five wetland sub-systems was estimate to be Low. A recommended ecological category (REC) for the duration of the project is for wetlands to remain in the same condition as their PES ratings. Localised construction impacts associated with the road upgrade are contributing factors in the scoring approach which were considered in conjunction with other predominant land-use activities of human settlement and agriculture, both livestock and croplands. Preferential flow paths still do exist and continue to function, albeit with some modification owing to existing impacts.
At an ecosystem / landscape level, the wetlands in the study area are not afforded any international protection status (i.e. are not Ramsar sites) however they have a degree of formal protection being considered wetland Freshwater Ecosystem Priority Areas (FEPAs). In terms of the 2015 Mpumalanga Biodiversity Sector Plan (MBSP) Freshwater Assessment, there are no wetland or wetland cluster Ecological Support Areas (ESAs) or wetland Critical Biodiversity Areas (CBAs) in the study area. Much of the road footprint traverses through other natural areas or areas which are heavily transformed around the towns of Hluvukani and Welverdiend.
In terms of the riparian and instream assessment, the bridge site over a non-perennial tributary of the Nwaswitstonsto River (a watercourse road crossing at culvert 22) was assessed and assigned a C Ecological Category (EC). In all cases and where available, historical aerial imagery was used to further substantiate the assessment scores. A detailed field-based PES and EIS assessment using reference fish and invertebrate data was not considered feasible. Based on existing literature, the presence of an endangered red data species, Serranochromis meridianus (Lowveld largemouth), has historically been found in relatively low numbers in the Sabie Sand tributaries of the Inkomati River System. Peer-reviewed literature does indicate that individuals of this species were translocated to various dams on tributaries of the Sand River in the Kruger National Parks several decades ago. With respect to sensitivity of aquatic biodiversity in relation to the project footprint and the broader study area, desktop screening indicates a low combined sensitivity.
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Further desktop assessments indicate that for conservation purposes, Fish Support Areas, a type of Ecological Support Area (ESA), have been delineated downstream of the project footprint in catchment W32H with a River Critical Biodiversity Area (CBA), delineated in catchment X32H on a non-perennial tributary of the Phungwe River. The lower half of the road footprint traverses between quaternary catchments X32H and X32G adjacent to the River CBA where a significant portion of X32H has been delineated as an important sub-catchment ESA in terms of the 2015 MBSP. According to the most recent (2019) DWS reserve determination study of water resources in the Inkomati catchment i.e. the Inkomati- Usuthu Water Management Area (WMA), catchment X40C (Nwaswitsontso) and X32H (Phungwe) were assigned a C PES and Low EIS respectively. EIS in the adjacent catchment X32G (Khokovela) was also Low with a D PES. Freshwater resources within the study area were estimated to as C PES and Low EIS respectively with a C EC.
In terms of risks to watercourses during construction, threat ratings based on expert workshops indicate that threats posed by the transportation sector (paved road infrastructure) and the low-impact/risk mining sector (e.g. borrow pits) are mostly low to very low. Sedimentation and turbidity are the main potential risks/threats rated as high to very high. The outcomes of the watercourse risk assessment on impacts to watercourses posed by the road upgrade and borrow pit activities found that if detailed control and mitigation measures are implemented, a low residual risk rating is achievable for all activities. Based on the disturbance levels and land-use activity underway i.e. upgrading of an existing gravel road to a paved surface facilitated by low-intensity borrow pits (quarrying) operations, a 32m buffer for watercourses and a 40m buffer for the wetlands (dams and seeps) is recommended. It is also recommended that the report maps be considered during all phases of the development to aid in the protection and conservation of any freshwater features and habitats within the broader study area.
Given that one wetland seep (W03) occurs a reasonable distance away from the road for a relatively large area within the 500m road buffer but outside the 100m road buffer, it does extend almost to the road edge in the vicinity of where culvert 34 is positioned for surface drainage purposes. Unless the existing road alignment of the most northern section was to be re-directed to the east away and out of the proposed 40m wetland buffer for W03, maintaining a 40m buffer distance from the edge of the road footprint would not be possible. The physical road footprint and culverts 14, 22 and 25 also intersect directly with and are situated within non-perennial drainage lines; hence adhering to the recommended 32m buffer is not practically possible in these cases.
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Many of the potentially negative impacts are likely to be relatively short-lived, localised and largely limited to the construction phase. Erosion, sedimentation and turbidity impacts are predicted to be the most likely risks which can extend beyond the construction timeframe if all controls and mitigation measures are not strictly implemented. On the basis of strict control and mitigation being adhered to, ‘raw risk’ (no mitigation) can be reduced to an acceptable level of ‘residual risk’ (with mitigation). Furthermore, if appropriate resources, planning and monitoring systems are put in place to control and minimise the risks to W03 and the other watercourses within the recommended buffers, it is likely that the road upgrade activity will have limited freshwater biodiversity impacts and low risks to watercourses downstream of the project footprint.
With respect to the current gravel road condition and its continual degradation, this is also a highly likely contributory factor to downstream sedimentation and turbidity. The long-term benefit of upgrading and surfacing the road is favourable from the perspective that watercourses in the study area may be somewhat restored to an improved state given the erosion that has progressed over several decades of expansion of human settlement in the region of Welverdiend.
If effective monitoring and maintenance is continued during the operational phase, the road will pose only minor risks to water resource quality in the downstream receiving environment and should not compromise the requirements of the ecological reserve and other downstream water users. The author is of the opinion that section 21(c) and (i) water uses associated with road upgrade activity and borrow pit 2 falls within the ambit of a General Authorisation (GA) where the authority (IUCMA) can consider an application for such water use through a GA application process and grant one in terms of the NWA. The author’s opinion is however subject to an internal review by the authority and their interpretation on the risks associated with a GA application.
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TERMINOLOGY BAR Basic Assessment Report BSP Biodiversity Sector Plan CD: NGI Chief Directorate: National Geospatial Information CSIR Council for Scientific and Industrial Research DARDLEA Department of Agriculture, Rural Development and Environmental Affairs DPWRT Department of Public Works, Roads and Transport DEA Department of Environmental Affairs DWAF Department of Water Affairs and Forestry DWS Department of Water and Sanitation EA Environmental Authorisation EC Ecological Category EDM Ehlanzeni District Municipality EIA Environmental Impact Assessment EIS Ecological Importance and Sensitivity EMPr Environmental Management Programme FEOW Freshwater Ecoregions of the World FRAI Fish Response Assessment Index GA General Authorisation GN Government Notice GPS Global Positioning System HGM Hydrogeomorphic Unit IAP Invasive Alien Plant ICLEI International Council for Local Environmental Initiatives IHAS Invertebrate Habitat Assessment System IHI Index of Habitat Integrity IUA Integrated Unit of Analysis IUCMA Inkomati-Usuthu Catchment Agency IUCN International Union for the Conservation of Nature KNP Kruger National Park MIRAI Macroinvertebrate Response Assessment Index MPTA Mpumalanga Tourism and Parks Agency NBA National Biodiversity Assessment NEMA National Environmental Management Act NEMBA National Environmental Management: Biodiversity Act NEMPAA National Environmental Protected Areas Act NFEPA National Freshwater Ecosystem Priority Area NWA National Water Act NWM National Wetland Map PES Present Ecological State RAM Risk Assessment Matrix REC Recommended Ecological Category RR Road Reserve SASS South African Scoring System SAIAB South African Institute of Aquatic Biodiversity SANBI South African National Biodiversity Institute SDF Spatial Development Framework ToR Terms of Reference WMA Water Management Area WRC Water Research Commission WULA Water Use License Application
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CONTENTS DECLARATION OF INDEPENDENCE ...... 4 EXECUTIVE SUMMARY ...... 5 TERMINOLOGY ...... 9 1 INTRODUCTION ...... 12 1.1 Broad overview ...... 12 1.2 Project background ...... 13 2 TERMS OF REFERENCE ...... 14 3 STUDY AREA BACKGROUND ...... 14 3.1 Location ...... 14 3.2 Freshwater resources ...... 15 3.3 Climate ...... 18 3.4 Geology & Soil erodibility ...... 19 3.5 Vegetation ...... 19 3.6 Summary of the study area jurisdictional and biophysical environment ...... 19 4 LEGAL CONTEXT ...... 21 4.1 National Environmental Management Act (Act 107 of 1998) (NEMA) ...... 21 4.2 The National Water Act (Act 36 of 1998) (NWA)...... 21 4.2.1 Risk Matrix ...... 22 4.2.2 Exclusions ...... 24 4.3 Other relevant legislation relating to freshwater ecosystems ...... 24 5 AIMS OF THIS STUDY ...... 24 6 LIMITATIONS AND ASSUMPTIONS OF THE STUDY ...... 25 7 BACKGROUND RATIONALE TO METHODS USED ...... 25 8 METHODS ...... 26 8.1 Desktop study ...... 26 8.2 Fieldwork site visit ...... 26 8.3 Freshwater Ecosystem classification ...... 27 8.4 Wetland habitat assessment ...... 27 8.4.1 Present Ecological State (PES) ...... 27 8.4.2 Wetland Eco-services ...... 28 8.4.3 Wetland Ecological Importance and Sensitivity (EIS) ...... 29 8.4.4 Recommended Ecological Category (REC) ...... 30 8.5 Riparian and Instream habitat assessment ...... 31 8.5.1 Index of Habitat Integrity ...... 31 8.5.2 Instream and riparian PES and EIS ...... 33 8.5.3 REC ...... 33 8.6 Risk/Impact assessment on watercourses ...... 34 8.7 Freshwater biodiversity assessment ...... 34 8.7.1 Cumulative impacts...... 36 9 RESULTS ...... 36 9.1 Freshwater resource delineation ...... 36 9.2 Freshwater ecosystem classification ...... 44
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9.3 Wetland habitat assessment ...... 45 9.3.1 Wetland PES ...... 46 9.3.2 Wet-Ecoservices ...... 46 9.3.3 Wetland EIS ...... 49 9.3.4 Wetland REC ...... 50 9.4 Riparian and Instream habitat assessment ...... 51 9.4.1 Index of Habitat Integrity ...... 51 9.4.2 PES and EIS ...... 51 9.4.3 REC ...... 53 9.5 Watercourse impact assessment ...... 54 9.6 Freshwater biodiversity assessment ...... 54 9.6.1 Cumulative impacts...... 54 10 RECOMMENDED MITIGATION MEASURES ...... 57 10.1 Threats/risks to watercourses ...... 57 10.2 Impact and risk mitigation ...... 57 10.3 Recommended buffers based on activities ...... 57 10.4 Monitoring and management recommendations ...... 61 11 DISCUSSION ...... 66 12 CONLCUSION ...... 67 13 REFERENCES...... 69 ANNEXURE A: SELECTED BORROW PIT, WATERCOURSE AND WETLAND (BENCH AND SEEP) PHOTOGRAPHS* ...... 72 ANNEXURE B: SELECTED HISTORICAL AERIAL IMAGERY ...... 78 ANNEXURE C: HISTORICAL TOPOGRAPHICAL MAPS ...... 86 ANNEXURE D: GEOLOGY AND SOIL ERODABILITY ...... 87 ANNEXURE E: TERRAIN UNIT INDICATORS FOR WETLANDS/DAMS (ELEVATION/LONGITUNDIAL PROFILES) ...... 88 ANNEXURE F: GUIDANCE ON INLAND WETLAND/AQUATIC ECOSYSTEM CLASSIFICATION ...... 91 ANNEXURE G: GUIDANCE ON WETLAND SOIL AND VEGETATION IDENTIFICATION ...... 93 ANNEXURE H: SOIL AUGER SAMPLES TAKEN ADJACENT TO CULVERT 2 ...... 94 ANNEXURE I: PROJECT IN CONTEXT OF THE 2015 MBSP FRESHWATER ASSESSEMENT ...... 95 ANNEXURE J: PROJECT FOOTPRINT LOCALITY IN CONTEXT OF FRESHWATER ECOREGIONS OF THE WORLD ...... 96 ANNEXURE K: RATIONALE FOR NOT ASSESSING CERTAIN AQUATIC COMPONENTS ...... 97 ANNEXURE L: CLOSEST DATA *SITES IN RELATION TO STUDY AREA ...... 98 ANNEXURE M: OVERVIEW OF AQUATIC BIODIVERSITY IN THE STUDY AREA ...... 100 ANNEXURE N: WATERCOURSE (FRESHWATER RESOURCE) RISK ASSESSMENT ...... 101 ANNEXURE O: RISK (IMPACT) ASSESSMENT METHODOLOGY ...... 103 ANNEXURE P: GENERIC MEASURES FOR WETLAND & DRAINAGE LINE REHABILITATION* ...... 105
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1 INTRODUCTION
1.1 Broad overview The inland aquatic and wetland biodiversity of Southern Africa is highly diverse and of great regional importance to local livelihoods and economies. Functional, un-polluted rivers serve as sources of freshwater for various domestic, industrial, agricultural and ecological requirements. Healthy river systems provide various goods and services (i.e. water supply, breakdown of pollutants, natural habitat, flood attenuation, natural resource-use supply and recreation) and in so doing, they significantly support and contribute towards human welfare, socio-economic growth and biodiversity conservation. Wetlands are one of the most valuable and diverse ecosystems on the planet and are essential for human existence. Wetlands filter the water we drink as well as provide nutritious food in the form of plants and fish, provide organic materials which can be used for medicinal purposes, help protect settlements from flooding and storm surges, store water which is released in times of drought, provide key habitat for a significant array of critically endangered flora and fauna and play a key role in the mitigation of climate change which is predicted to have a major impact on human livelihoods.
South Africa’s status as a water-stressed country facing a potential freshwater deficit by 2025 (DWAF 2004a, Oberholster and Ashton 2008) is of concern, yet the country remains highly dependent on natural resources for economic health and prosperity (Hill et al., 2011). Predictions associated with future global climate change and some of the climatic effects currently being observed rank the region amongst some of the most vulnerable in the world (IPCC 2013). South Africa’s freshwater biodiversity is therefore under significant pressure from human activities (Darwall et al. 2009). Freshwater species and habitats are, on average around the world, more imperilled than their terrestrial counterparts. Yet, large-scale conservation planning efforts have rarely targeted freshwater biodiversity. Impacts include aquatic ecosystem destruction/loss, habitat transformation, loss of biodiversity, climate change and invasion of alien species.
River health is deteriorating more rapidly than it can be measured with existing data suggesting that human impacts are detrimentally compromising biodiversity and healthy functioning of freshwater ecosystems (Darwall et al. 2009). The 2011 National Biodiversity Assessment (NBA) found that 55% of South Africa’s river ecosystems are threatened by pollution and over-abstraction and that only 21% of these systems are moderately or well protected (Nel and Driver 2012). The more recent 2018 NBA found that 64% of South Africa’s river ecosystem types and 79% of wetland ecosystem types are threatened, a significant deterioration in six years (van Niekerk et al. 2019).
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Other research indicates that on a global scale, freshwater ecosystems are the most endangered in the world which presents a major threat to the ~126 000 described species that depend upon freshwater habitats for any critical part of their life cycle (Dudgeon et al., 2006). If people continue to utilise aquatic systems in a non-sustainable and over-consumptive manner, the impacts may be permanently detrimental with the loss of their functional ability to adequately support our needs. The fundamental need to protect and maintain these ecosystems in a state of good ecological health to ensure a future and sustainable supply of their various benefits to both nature and society is unequivocal. The importance of implementing conservation and management strategies that protect all elements of freshwater biodiversity and guarantees future freshwater availability in the future is paramount. The National River Health Programme (RHP) was first launched in 1994 in response to the need for more detailed information on the state of South Africa’s aquatic ecosystems. The programme assesses river health by measuring selected ecological indicator groups (e.g. fish, invertebrates or riparian vegetation) that represent the condition of the larger ecosystem. The data are simplified and represented as various indices.
The initiation of the National Freshwater Ecosystem Priority Areas (NFEPA) programme was another response to the declining integrity of freshwater ecosystems in South Africa as documented during the 2004 NSBA (Driver et al., 2004). This programme intends to respond to high levels of threats prevalent in river, wetland and estuary ecosystems of South Africa (Driver et al. 2005) by providing strategic spatial priorities for conserving the country’s freshwater ecosystems and supporting sustainable use of water resources. The main NFEPA stakeholders include all government departments, SANBI, SAIAB, provincial conservation agencies, municipalities, non-governmental organisations and large state-owned enterprises such as Eskom, SANRAL and Transnet, including others.
1.2 Project background The project comprises the upgrading (gravel to asphalt surfacing) of a 15.89km section of three adjoining gravel roads; the D4407, D4409 and D4416, between the towns of Hluvukani and Welverdiend in the Bohlabela region, Bushbuckridge Municipality, Mpumalanga. The D4407 traverses a total length of 7.82km between the towns of Hluvukani and Timbavati where it intersects with the D4409. At the intersection, the D4409 traverses through Welverdiend for 6.88km where it then intersects with the D4416. From that intersection the D4416 then runs for 1.19km ending at the R531. The establishment and utilisation of two borrow pits for sourcing road-building material are associated with the road upgrade development and are therefore included as an activity associated with the project footprint.
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2 TERMS OF REFERENCE Lidwala Consulting Engineers SA (Pty) Ltd (Lidwala) were appointed by the Mpumalanga Province, Department of Public Works, Roads and Transport (DPWRT) for the planning, design, tender documentation, and construction supervision for the “Upgrading of road D4407 between Hluvukani and Timbavati (7.82 km), road D4409 at Welverdiend (6.88 km) and road D4416/2 between Welverdiend and road P194/1 (1.19 km) in the Bohlabela region of the Mpumalanga Province” (hereafter referred to as “the project”)1. NCC environmental Services (Pty) Ltd (NCC) were appointed by Lidwala (the Client) to conduct a NEMA Section 24G application after it was confirmed that the road upgrade project triggered NEMA listed activity no. 19 of Listing Notice 1 and listed activity no. 14 of Listing Notice 3. Construction activity subsequently commenced without acquiring the mandatory environmental authorisation required for the project.
In terms of the NEMA Section 24G rectification process, a freshwater assessment relating to freshwater resources / watercourses (which includes wetlands) associated with the project is one of the specialist studies required as part of the basic environmental assessment process and application for environmental authorisation. NCC was duly appointed by Lidwala to conduct the freshwater assessment. The field work component of the freshwater assessment was carried out on 18th February 2020 with the final report dated and submitted on 16th March 2020.
3 STUDY AREA BACKGROUND 3.1 Location The project is located in the Ehlanzeni District (formerly the Bohlabela District) within the province of Mpumalanga, approximately 70km north of Hazyview (as the crow flies) and 30km east of Acornhoek in the Bushbuckridge Local Municipality (BLM) (Figure 1). The GPS coordinates of the road footprint, including the two borrow pits, are indicated below: Road Upgrade Latitude Longitude Project start S27o47’13.33” E30o09’46.60” Project end S27o47’14.38” E30o09’46.60” Borrow Pit 1 Borrow Pit 2 Corners Latitude Longitude Corners Latitude Longitude 1 S 24°33'19.29" E31°19'54.12"E 1 S24°35'37.12" E31°20'47.90" 2 24°33'17.67" E31°19'52.38"E 2 S24°35'38.04" E31°20'46.78" 3 24°33'15.14" E31°19'54.57"E 3 S24°35'41.06" E31°20'46.49" 4 24°33'16.79" E31°19'56.37"E 4 S24°35'42.52" E31°20'50.28" 5 S 24°35'39.32" E31°20'50.31"
1As stated throughout this report wherever the words ‘the project’ are used, they are synonymous with and refer to the “Upgrading of road D4407 between Hluvukani and Timbavati (7.82 km), road D4409 at Welverdiend (6.88 km) and road D4416/2 between Welverdiend and road P194/1 (1.19 km) in the Bohlabela region of the Mpumalanga Province”.
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Figure 1: Ehlanzeni district map indicating the general locality of road upgrade site in the Bushbuckridge local municipality, denoted by the red arrow (Map source: Robin, 2017).
3.2 Freshwater resources
The occurrence of wetlands in the BLM are illustrated in Figure 2 while the distribution freshwater resources (watercourses and wetlands) are shown in Figure 3. The development footprint (road upgrade and borrow pits) are included in Figure 3. At the catchment and water management level, Figure 4 indicates that the road upgrade footprint traverses three quaternary catchments (X32G, X32H & X40C) in the Inkomati-Usuthu Water Management Area (WMA). The northern section of the road is located in quaternary catchment B73E in the Olifants WMA.
Figure 2: Bushbuckridge local municipality map indicating the distrubution of wetlands (Map source: Robin, 2017).
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Figure 3: Freshwater resources (rivers and wetlands) in the study area. The development footprint (road and borrow pits) are denoted respectively by the red line and orange shading on the map (Source: W. Cape Government, 2020).
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Figure 4: Location of the road upgrade footprint traverses three quaternary catchments, X32G, X32H & X40C in the Inkomati-Usuthu WMA. The northern section of the road is located in quaternary catchment B73E in the Olifants WMA. Brown and orange 500m buffer lines around the road and borrow pits are shown respectively.
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3.3 Climate
The project is situated in the lowveld region of Mpumulanga which has a subtropical climate strongly influenced by close proximity to the Indian Ocean. It is in a summer rainfall region with rains season normally lasting from October to March. The average mean annual precipitation for the Ehlanzeni district varies between 750 and 860 mm (DWAF 2000) with winter rainfall considered rare (Robin, 2017). In terms of temperature, historically there has been a strong seasonality between the winter and summer months. The cooler winter season ranges between May and August with the warmer summer months occurring between December and February. As depicted in Figure 5, the coolest and hottest months have historically been June and February respectively with records showing a very moderate temperature variation between winter and summer months (Robin, 2017). For comparative purposes, rainfall recorded in the project area (Weverdiend) during 2019 is illustrated in Figure 6.
Figure 5: Climatic conditions characteristic of the Ehlanzeni District Municipality (Source: CSAG, 2020).
Monthly rainfall total (mm)
140 129 120 100 80 60 53 39 40 33 20 0 Apr-19 May-19 Jun-19 Jul-19 Aug-19 Sep-19 Oct-19 Nov-19 Dec-19 Figure 6: Rainfall records for the project area (Welverdiend) recorded between April and December 2019. (Source: Lidwala, 2020). www.ncc-group.co.za D4407 Road Upgrade Freshwater Assessment Report – Mar 2020 Page 18 of 105
3.4 Geology & Soil erodibility
Refer to Annexure D for spatial information relating to the geology and soil erodibility in the study area. Soils in the study area have an erodibility K-factor of 0.39 which is lower than surrounding areas to the west with a K-factor of 0.6. Soils in the study area are estimated to be medium textured, such as silty loam, which tend to have moderate K values (between 0.25 and 0.40) and are moderately susceptible to detachment producing moderate runoff (See photos in Annexure A). In contrast, soils having high silt content (K value >0.40) are general most erodible of all soils, more easily detached by running water, tend to crust and produce high rates of runoff (Renard et al. 1997).
3.5 Vegetation
The vegetation in the study area falls broadly within the Savanna biome and is more specifically classified as Granite Lowveld (Mucina & Rutherford 2006) (Figure 7). The terrestrial biodiversity study and report for the project, carried out by NCC (2020), can be referred to for further information on vegetation.
Figure 7: Project footprint located within Granite Lowveld (SVl 3) of the Savanna Biome (NCC, 2020).
3.6 Summary of the study area jurisdictional and biophysical environment
Table 1 summarises the background of the study area from jurisdictional, water resource, geo-climatic and ecological perspectives.
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Table 1: Summary of jurisdictional, water resource, geo-climatic & ecological information for the study area.
Province Mpumalanga District Ehlanzeni Local Municipality Bushbuckridge Ward 34 1: 50 000 grid reference 2431CB WMA Inkomati-Usuthu (WMA 3) and Olifants (WMA 2) CMA IUCMA (Inkomati-Usuthu Catchment Management Agency) Primary catchments X (Inkomati) and B (Olifants) Secondary catchments X3 and B7 Quaternary catchments X32G, X32H, X40C and B73E Main rivers / drainage Khokhovela and Phungwe (tributaries of Sand River), Nwaswitsontso (tributary of Komati River) and Sesete (tributary of Timbavati which is tributary of Olifants River) Ecoregion Level I (Kleynhans et al. 2005) 3 Bushveld Ecoregion Level II (Kleynhans et al. 2005) 3.07 Freshwater Ecoregion of the World (FEOW) Zambezian Lowveld Biome (Mucina & Rutherford, 2006) Savanna (Svl3) Bioregion (Mucina & Rutherford, 2006) Lowveld Bioregion Geomorphic Province (Partridge et al., 2010) Lowveld Terrain Morphology: Broad division Plains; Low Relief; Plains; Moderate Relief; Lowlands, Hills and (dominant types in bold) (Primary) Mountains; Moderate and High Relief (limited); Open Hills, Lowlands; Mountains; Moderate to High Relief; (limited) Closed Hills; Mountains; Moderate and High Relief (Limited) Vegetation types (dominant types in bold) Mopane Bushveld; Mopane Shrubveld; Mixed Lowveld Bushveld; Sour (Primary) Lowveld Bushveld; Sweet Lowveld Bushveld; Natal Lowveld Bushveld; Lebombo Arid Mountain Bushveld; Mixed Bushveld, North Eastern Mountain Grassland Altitude (m a.m.s.l) 0-700; 700-1300 limited Geology Era: Swazian Sources: (Council for Geoscience, 2003; Acid and intermediate extrusives: Makhutswi Gneiss and Timbavati WR2012) Gabbro (Lithology) Light grey migmatitic tonalite, granodiorite, gabbro, olivine gabbro, and quartz gabbro (Lithostratigraphy) Soils (Source: Schulze, 2007). Dominant soil type (LmSs-SaLm (Sand loam) 3 Gs15 50 Hu35 20 Ms10 10 Mean annual temp (°C) 16 to >22 Mean daily max. temp. (°C): February 24 to 32 Mean daily max. temp. (°C): July 18 to >24 Mean daily min. temp. (°C): February 14 to >20 Mean daily min temp. (°C): July 4 to >10 Mean annual precipitation MAP (mm) 600-720mm (Source: WR2012 data) Coefficient of Variation <20 to 35 (% of annual precipitation) Rainfall concentration index 30 to >65 Rainfall seasonality Early to late summer Median annual simulated runoff (mm) for 10 to >250 quaternary catchment EIS Category (EI and ES) (DWS, 2014b). EI=High ES=Low (Nwaswitsontso); EI=High ES=V. Low (Phungwe); EI=Moderate ES=Moderate (Khokovela) 2014 EC (DWS, 2014b). B (X40C outside KNP) and A (X40C & D) - Nwaswitsonto 2011 Desktop PES Category (DWS, 2014b). B (Nwaswitsonto); A (Phungwe); C (Khokovela) 2019 Reserve Determination (PES, EIS, REC). C, Low, C (Nwaswitsonto); D, Low, D (Khokovela); C, Low, C (Phungwe)
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4 LEGAL CONTEXT
The legal requirements for activities affecting watercourses/freshwater ecosystems and for using water are summarised below:
4.1 National Environmental Management Act (Act 107 of 1998) (NEMA)
In terms of the NEMA EIA Regulations (as amended), activity number 12 and number 19 in GNR983 (Listing Notice 1) dated 4 December 2014 require that prior to any development taking place within 32m of a watercourse or if more than 10m3 is to be dredged from any watercourse, an application for environmental authorisation (EA) process needs to be followed via a Basic Assessment (BA) process in term of GNR982 should any of these activities be triggered. Activity number 14* in GNR985 (Listing Notice 3) dated 4 December 2014 also applies in Mpumalanga outside urban areas to developments of infrastructure or structures with a physical footprint of 10m2 or more where such occurs within a watercourse within 10 kilometres from national parks or world heritage sites or 5 kilometres from any other protected area identified in terms of the National Environmental Management: Protected Areas Act (57 of 2003) or from the core area of a biosphere reserve, where such areas comprise indigenous vegetation. As the listed activities have already commenced, the requirement for a Section 24G NEMA rectification application via a BA process has been confirmed by the relevant provincial authority (Mpumalanga DARDLEA).
*Activity 14 (ii)(a)(f)(i) (hh).
4.2 The National Water Act (Act 36 of 1998) (NWA)
The NWA recognises that the entire aquatic ecosystem and not just the water itself in any given water resource constitutes the resource and as such, needs to be conserved and sustainably utilised. As such, the NWA provides the overarching legal framework for the effective and sustainable management of the country’s water resources. Other than a Schedule 1 water use, no other water use activity, including where any development footprint area(s) are situated within the “regulated area” for watercourses (which include wetlands and riparian zones) may take place unless authorised by the relevant authority within the Department of Water and Sanitation (DWS).
Amongst the various types of water uses as contemplated in section 21 of the Act, Government Notice (GN) 509 in Government Gazette No. 40229 promulgated on 26 August 2016 provides further effect for the implementation of section 39 of the NWA. Section 39 outlines procedures for applying for a General Authorisation (GA) to use water in terms of sections 21(c) and (i). To further clarify, a section 21(c) water use is one which can impede or divert the flow of water in a watercourse while a section 21(i) water use can lead to the altering of the bed, banks, course or characteristics of a watercourse.
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The primary objective of GN509 is to allow water users or potential water users to apply for a GA as opposed to a full Water Use Licence Application (WULA).This is contingent on the level of risk that the water uses will have on resource quality and includes the risks to affected water resources/watercourses. Depending on the context, section 21(c) and (i) water uses i.e. those within the regulated area of a watercourse as defined within GN509, can occur within either one or across several Phases which include Construction, Operations, Maintenance and/or Emergency work, River and Stormwater management and Wetland or River Rehabilitation.
4.2.1 Risk Matrix In order for an existing or potential water use to qualify for a GA under GN509, the water uses/ water use activities must be subject to assessment using the approach in the Department of Water and Sanitation’s (DWS) Risk Assessment Matrix (RAM). A suitably qualified natural scientist professionally registered with the South Africa Council for Natural Scientific Professions (SACNASP) should carry out the risk assessment. Any licensing or authorisation of regulated water uses is then subject to application to the relevant DWS authority, in this case, a formally established Catchment Management Agency (CMA) called the Inkomati- Usuthu CMA (IUCMA) established in terms of section 78(1) of the Act under GN397 of 26 March 2004 in Government Gazette No. 26185.
The Risk Assessment Matrix (RAM) is used to determine the risk of the proposed water uses/activities to the receiving aquatic ecosystem in terms of Section 2(c) and (i) of the Act. In its design, the RAM factors in the inclusion of risk mitigation measures. Assuming the recommended risk mitigation and controls are carried out, the rationale is that rating (scoring) of risks can be reduced to acceptable levels. The three risk rating classes are Low, Moderate or High. If the water uses are determined to be a Low risk to the watercourse, then they may fall within the ambit of a GA subject to confirmation with the relevant authority. If the risks are calculated to fall within a Moderate or High class, then the water uses/activities would be subject to an application for authorisation via a full WULA process. The difference between the two processes (GA vs WULA) is the timeline of assessment and subsequent outcome decision. The full WULA process can take between 153 - 300 days whilst a GA process has the potential to be concluded within 30 - 60 days. Figure 8 illustrates an overview of the generic steps/stages to follow during a GA process (DWS, 2014a) with Figure 9 highlighting the main steps and timeframe for a full WULA (DWS, 2017).
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Figure 8: Generic water use authorisation process for a GA (Source: DWS, 2014a).
Figure 9: Main steps and timeframes which form part of a full WULA process (Source: DWS, 2017).
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4.2.2 Exclusions It should be noted that what is contemplated in GN509 does not apply to the following water use activities: i) Water use for the rehabilitation of a wetland as contemplated in GN1198 in Government Gazette No. 32805 promulgated on 18 December 2009; ii) Use of water within the “regulated area” of a watercourse where the Risk Class is Moderate or High. iii) Where any other water use as defined in section 21 of the Act must be applied for; iv) Where storage of water results from section 21 (c) and/or (i) water uses; v) Any water use associated with the construction, installation or maintenance of any sewerage pipeline, pipelines carrying hazardous materials and to raw water and wastewater treatment works.
4.3 Other relevant legislation relating to freshwater ecosystems
National Environmental Management: Biodiversity Act, No. 10 of 2004 National Environmental Management: Protected Areas Act, 57 of 2003 National Environmental Management: Waste Act, No 59 of 2008 Conservation of Agricultural Resources Act, No.43 of 1983 Mpumalanga Nature Conservation Act, No. 10 of 1998
5 AIMS OF THIS STUDY • Identification and assessment of freshwater resources (wetlands and watercourses) associated with the road upgrade development and within a 500m radius from the project footprint; • Assess risks to watercourses associated with the project; • Provide mitigation and management measures for the impacts that the road infrastructure footprint i.e. the road, culverts and bridges and other physically affected areas i.e. borrow pits, construction camps and laydown areas will have on freshwater resources in the study area; • Provide monitoring recommendations for the management and mitigation of negative impacts on affected freshwater resources and the broader aquatic ecosystem during construction; • Provide input into stormwater management and surface water drainage planned for the project and recommend measures to minimise impacts on receiving water resources; • Provide recommendations for the rehabilitation of disturbed watercourses and wetlands post- construction; • Provide recommendations for the application for a water use authorisation (WUA) for the project.
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6 LIMITATIONS AND ASSUMPTIONS OF THE STUDY Construction on the project had already commenced prior to this study. As a result, there is a likelihood that several freshwater resources may have already been impacted upon and were therefore not assessed in their condition prior to construction. It was assumed during this assessment that information and available ecological data on freshwater/aquatic ecosystems from previous reserve determination studies were reliable sources to utilise. Wherever data from existing sources and previous reports or literature are presented or discussed in this report, the relevant sources have been duly acknowledged in the text and are provided in the reference list. Lack of surface flow in the study area confined the aquatic biota assessments to a desktop survey as no field-based methods were feasible to carry out. Maps produced were aided by the available data at the time of this study and ground-truthing of the entire study area was not possible given time and physical access constraints.
7 BACKGROUND RATIONALE TO METHODS USED
‘EcoClassification’ (the term used for the ecological classification process) refers to the determination and categorisation of the ‘Present Ecological State’ (PES; or health / integrity) of various biophysical attributes of watercourses, which includes wetlands, relative the natural or close to the natural reference condition (Kleynhans & Louw, 2007). The purpose of the EcoClassification process is to gain insight and understanding into the causes and sources of the deviation of the PES of biophysical attributes from the reference condition. This provides the information needed to derive desirable and attainable future ecological objectives for the watercourse.
The procedure of EcoClassification describes the health of a water resource, and derives and formulates management targets / objectives / specifications for the resource. ‘’Ecological Importance" of a water resource is an expression of its importance to the maintenance of ecological diversity and functioning on local and wider scales. "Ecological Sensitivity" refers to the system’s ability to resist disturbance and its capability to recover from disturbance once it has occurred. The ‘Ecological Importance and Sensitivity’ (EIS) provides a guideline for determination of the ‘Recommended Ecological Category’ (REC).
At a broad scale where more resources and skills are available (i.e. at a regional or catchment level), it is a competency of the National Department of Water and Sanitation (DWS) to determine the ecological reserve for all watercourses and in so doing, the process of EcoClassification is often followed and applied. This mostly occurs during reserve determination studies which typically involve collaborative efforts by the authority (DWS), input and studies by specialists and participation by various public sector bodies and water
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users. There are many types of water users in any given catchment or water management area whose activities and livelihoods depend on a regular water supply as well as the ecosystem goods and services provided by watercourses.
Recent studies over several years were initiated for the Inkomati-Usuthu and Olifants Water Management Areas (WMAs) and are available in various volumes of reports1 published and made available by the Resources Directed Measures (RDM) Directorate, a competency within DWS. Hence there was various baseline data and information which informed and was consulted during this site-specific wetland habitat assessment.
8 METHODS 8.1 Desktop study A desktop study and literature review relating to the project and the receiving natural environment was first carried out to gather existing information to inform a more detailed fieldwork assessment. Tasks/activities which formed part of the overall assessment included: • Desktop review of available / existing information, spatial data, literature and studies; • Desktop screening and mapping of watercourses and wetlands within the broader study area to inform which watercourses are likely to be directly or indirectly impacted upon by the project footprint and associated construction activities.
8.2 Fieldwork site visit
This site visit was undertaken on 18th February 2020 and included:
• A rapid survey of wetland and riparian vegetation habitats; • Identification and more refined ground-truthing/verification of watercourses and associated freshwater resource units/ecosystems located within the study area and within 32m, 100m and 500m (“regulated area”) from the edges of the project development footprint. The approach, methods and techniques in the ‘Updated Manual for the Identification and Delineation of Wetlands and Riparian Areas’ (DWAF, 2008) were consulted during the study when assessing the outer boundary of any wetlands, riparian areas or watercourses within the regulated area. Soil auger samples were taken adjacent to the culvert 2; • Delineation of appropriate buffers around the project footprint(s) in relation to freshwater resource units for purposes of protection against negative impacts on any freshwater biodiversity and the downstream ecological reserve; 1 http://www.dwa.gov.za/rdm/Projects_SurfaceWater.aspx
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• Identify water resources in the “regulated area” of the project footprint where Section 21 (c) and/or (i) water uses will require authorisation.
8.3 Freshwater Ecosystem classification
Wetlands, rivers, streams and riparian areas in the study area were classified using the approach in the ‘National Wetland Classification System for Wetlands and other Aquatic Ecosystems in South Africa’ (after Ollis et al., 2013).
8.4 Wetland habitat assessment
This component of the study included a Present Ecological State (PES) and Ecological Importance and Sensitivity (EIS) functional assessment of wetlands likely to be impacted upon in term of their biodiversity value and ecosystem functioning.
8.4.1 Present Ecological State (PES) A Wet-Health level 1 rapid assessment was conducted (after Macfarlane et al., 2008) to establish the PES of wetlands within 500m of the project footprint. WET-Health is a tool designed to assess the health (present state) or integrity of a wetland. Wetland health is defined as a measure of the deviation of wetland structure and function from the wetland’s natural reference condition (Macfarlane et al. 2008). The tool assesses the health of the hydrological, geomorphological and vegetation components in three separate modules. An aggregation of scores for the 3 components of hydrology, geomorphology and vegetation are calculated according to the following formula:
{(Hydrology score) x 3 + (Geomorphology score) x 2 + (Vegetation score) x 2)} ÷7
This produces a final score ranging from 0 (pristine) to 10 (critically impacted in all respects). Table 2 illustrates how the resultant impact scores fall into one of six health categories (A - F) on a gradient from “unmodified/natural” (Category A) to “severe/complete deviation from natural” (Category F).To provide further context and aid with the assessment, a series of photographs (current) (See Annexure A) and historical aerial imagery (See Annexure B) visualising the conditions of the wetland units was compiled to review in conjunction with the PES ratings assigned post the field visit.
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Table 2: Health categories used by WET-Health for describing the integrity of wetlands (Source: Macfarlane et al. 2008). Health (PES) Description Impact Impact category score range category A Unmodified, natural. 0-0.9 None Largely natural with few modifications. A slight change in ecosystem 1-1.9 Small B processes is discernible and a small loss of natural habitats and biota may have taken place. Moderately modified. A moderate change in ecosystem processes and loss 2-3.9 Moderate C of natural habitats has taken place but the natural habitat remains predominantly intact. Largely modified. A large change in ecosystem processes and loss of natural 4-5.9 Large D habitat and biota and has occurred. The change in ecosystem processes and the loss of natural habitat and biota 6-7.9 Serious E is great but some remaining natural habitat features are still recognisable. Modifications have reached a critical level and the ecosystem processes 8-10 Critical F have been modified completely with an almost complete loss of natural habitat and biota.
8.4.2 Wetland Eco-services
To facilitate with wetland EIS determination, the ecosystem goods and services that wetlands within the road upgrade and borrow pit 500m buffers provide was assessed using the rapid scoring method, Wet- EcoServices (after Kotze et al. 2009). The tool qualitatively and rapidly assesses and scores the various ecosystem goods and services which are supplied by wetland ecosystems. The various benefits and aspects assessed in terms of their importance/sensitivity are indicated in Table 3. As per the datasheets a rating of zero (low importance) to four (very high) is allocated to each factor/service assessed. The tool is designed to assign either an estimated percentage range or a qualitative description (e.g. low or high) in conjunction with the score. This depends on the type of services which are provided by the wetland under assessment; an example extract is illustrated from the datasheet (Table 4).
Table 3: Ecosystem services supplied by wetlands and assessed by WET-EcoServices (after Kotze et al. 2009). The spreading out and slowing down of floodwaters in the Flood attenuation wetland, thereby reducing the severity of floods downstream. The trapping of carbon by the wetland, principally as soil organic Carbon storage matter. INDIRECT Streamflow regulation Sustaining streamflow during low flow periods. BENEFITS Sediment trapping The trapping and retention in the wetland of sediment carried by (Regulating runoff waters. and Phosphate assimilation Removal by the wetland of phosphates carried by runoff waters. supporting) Water quality Nitrate assimilation Removal by the wetland of nitrates carried by runoff waters. enhancement Toxicant assimilation Removal by the wetland of toxicants (e.g. metals, biocides and salts) carried by runoff waters. Erosion control Controlling of erosion at the wetland site, principally through the protection provided by vegetation. Through the provision of habitat and maintenance of natural Biodiversity maintenance process by the wetland, a contribution is made to maintaining DIRECT biodiversity. BENEFITS Cultural heritage Places of special cultural significance in the wetland, e.g. for Cultural baptisms or gathering of culturally significant plants. Tourism and recreation Sites of value for tourism and recreation in the wetland, often
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associated with scenic beauty and abundant birdlife. Education and research Sites of value in the wetland for education or research. Provision of water for The provision of water extracted directly from the wetland for human use domestic, agriculture or other purposes. Provision of harvestable The provision of natural resources from the wetland, including Provisioning resources livestock grazing, craft plants, fish etc. Provision of cultivated The provision of areas in the wetland favourable for the foods cultivation of foods.
Table 4: *Scoring approach for the various ecosystem services assessed by the WET-EcoServices datasheet.
SCORE 0 1 2 3 4 % RANGE <3% 3-5% 6-8% 9-11% >11% (e.g. for the average slope of the wetland) RATING DESCRIPTION Low/ Moderately Intermediate Moderately High/ (e.g. extent of toxicant sources in the wetland’s decrease low high increase catchment) *Only an extract example from the datasheet.
8.4.3 Wetland Ecological Importance and Sensitivity (EIS) Ecological sensitivity refers to a system’s ability to tolerate disturbance and its capacity to recover from disturbance once it has occurred (DWAF, 1999; Kleynhans & Louw, 2007). Ecological Importance (EI) is an expression of the importance of an aquatic resource in terms of the maintenance of biological diversity and ecological functioning on local and wider scales (Kleynhans & Louw, 2007). Previous case studies of rapid reserve assessments undertaken have indicated however that whilst WET-EcoServices is valuable, the outputs do not align well with EIS assessments undertaken for other water resource types. To align the WET- EcoServices outputs more closely with the DWS EIS approaches, a tool for assessing importance and sensitivity was developed using criteria from the WET-Ecoservices (Kotze et al. 2005) tool and the earlier DWS EIS assessment tools (e.g. Kleynhans, 1999). The tool was developed to provide an integrated scoring approach where three aspects of wetland importance and sensitivity, based essentially on the requirements of the NWA (Act 36 of 1998), and the work conducted by Kotze et al. (2009) on the assessment of wetland ecosystem goods and services. The Importance and Sensitivity tool for wetlands currently proposes three suites of importance criteria, namely:
i) Ecological Importance and Sensitivity - incorporating the traditionally examined criteria used in EIS assessments of other water resources by DWS (formerly DWAF and DWA) and thus enabling consistent assessment approaches across water resource types; ii) Hydro-functional importance - which considers water quality, flood attenuation and sediment trapping ecosystem services that the wetland may provide; iii) Importance in terms of basic human benefits - this suite of criteria considers the subsistence uses and cultural benefits of the wetland system.
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It is a recommendation that the highest of these three suites of scores be used to determine the overall Importance and Sensitivity class/category of the wetland system/s. For the purposes of this assessment, the scores attained for biodiversity maintenance as well as the combined and averaged scores for hydro- functional importance were used to calculate EIS (Table 5). These EIS categories in Table 5 can arguably be used for wetlands, rivers and riparian habitats.
Table 5: EIS categories and the interpretation of median scores for biota and habitat determinants (adapted after DWA, 2013 and Kleynhans, 1999). EIS rationale/general description Score EIS range Categories Wetlands/quaternary catchments that are not unique or ecologically important and sensitive at >0 and ≤1 Low / any scale. The biodiversity of these systems (in terms of biota and habitat) is ubiquitous and not Marginal (D) sensitive to flow and habitat modifications and they play an insignificant role in moderating the quantity and quality of water of major rivers and have a substantial capacity for use. Wetlands/quaternary catchments that are considered to be ecologically important and sensitive on >1 and ≤2 Moderate a provincial or local scale due to habitat diversity, species diversity, unique species and (C) rare/endangered species. The biodiversity of these systems (in terms of biota and habitat) are not usually sensitive to flow and habitat modifications and they play a small role in moderating the quantity and quality of water of major rivers and often have a substantial capacity for use. Wetlands/quaternary catchments that are considered to be unique, ecologically important and >2 and ≤3 High sensitive on a national scale due to habitat diversity, species diversity, unique species and (B) rare/endangered species. The biodiversity of these systems (in terms of biota and habitat) may be sensitive to flow and habitat modifications and they play a role in moderating the quantity and quality of water of major rivers. May still have substantial capacity for use. Wetlands/quaternary catchments that are considered ecologically important and sensitive on a >3.0 and ≤ Very high national or even international level based on unique biodiversity due to habitat diversity, species 4 (A) diversity, unique species and rare/endangered species and the biodiversity of these systems (in terms of biota and habitat) are usually very sensitive to flow and habitat modifications. They play a major role in moderating the quantity and quality of water of major rivers with no or only a small capacity for use.
8.4.4 Recommended Ecological Category (REC) The Recommended Ecological Category (REC) is a recommendation from an ecological viewpoint which is considered within the decision-making process in the National Water Resource Classification System (NWRCS). This recommendation (i.e. set of management objectives) is based on either maintenance or improvement of the PES. The REC is based on ecological criteria only and considers the EIS, the restoration potential and attainability thereof. According to DWAF (2007b), the PES and EIS of water resources must drive management objectives when there is no water resource classification (i.e. EcoClassification) available yet for a water management area/catchment. For water resources that do not yet have a REC allocated for the system, information illustrated in Table 6 may be utilised. The intersection of the PES and EIS categories provide the basis for the derivation of the REC.
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Table 6: PES and EIS as management objectives for watercourses/wetland resources for derivation of the REC. EIS PES Very High High Moderate Low A Maintain Maintain Maintain Maintain B Improve Improve Maintain Maintain C Improve Improve Maintain Maintain D Improve Improve Maintain Maintain E/F Improve Improve Maintain Maintain
8.5 Riparian and Instream habitat assessment 8.5.1 Index of Habitat Integrity The 1996 Index of Habitat Integrity (IHI), version 2 (Kleynhans, 1996) was used to obtain a habitat integrity class for the instream habitat and riparian zone. The IHI tool was applied to the in-stream/riparian areas in order to inform the rating of the condition, or PES, drainage lines within the 100m road buffer, in line with the NWA legislative requirements. The tool compares the current state of the in-stream and riparian habitats, with any existing impacts, relative to the estimated reference state (in the absence of human impacts). This involved the assessment and rating of a range of criteria for instream and riparian habitats (see Table 7) scored individually (from 0-25) guided by the rating categories in Table 8. The assessment was first informed by the field visit and further refined based on a desktop literature review of reach and catchment- scale impacts based on existing catchment studies, historical satellite and aerial imagery and land cover information. The instream and riparian components were analysed separately to yield two separate ecological conditions (i.e. Instream and Riparian components). However, it should be noted that the data for the riparian area is primarily interpreted in terms of the potential impact upon the instream component. Owing to the qualitative nature and subjectivity of the IHI scoring system the most recent version of the IHI application (after Kleynhans et al., 2008) and the Model Photo Guides (after Graham and Louw, 2008) were consulted to assist in moderating the scoring approach.
Table 7: Summary rating table used to determine the Index of Habitat Integrity (after Kleynhans, 1996). IMPACT CLASS DESCRIPTION RATING No discernible impact or the modification is located in such a way that it has no impact None 0 on habitat quality, diversity, size and variability. The modification is limited to very few localities and the impact on habitat quality, Small 1-5 diversity, size and variability are also very small. The modifications are present at a small number of localities and the impact on habitat Moderate 6-10 quality, diversity, size and variability are also limited. The modification is generally present with a clearly detrimental impact on habitat Large 11-15 quality, diversity, size and variability. Large areas are, however, not influenced. The modification is frequently present and the habitat quality, diversity, size and Serious variability in almost the whole of the defined area are affected. Only small areas are 16-20 not influenced. The modification is present overall with a high intensity. The habitat quality, diversity, Critical size and variability in almost the whole of the defined section are influenced 21-25 detrimentally.
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Table 8: Description of criteria to assess river habitat integrity (after Kleynhans, 1996). CRITERIA RELEVANCE/ DESCRIPTION INSTREAM Water Direct impact on habitat type, abundance and size. Also implicated in flow, bed, channel and water abstraction quality characteristics. Riparian vegetation may be influenced by a decrease in the supply of water. Flow Consequence of abstraction or regulation by impoundments. Changes in temporal and spatial modification characteristics of flow can have an impact on habitat attributes such as an increase in duration of low flow season, resulting in low availability of certain habitat types or water at the start of the breeding, flowering or growing season. Bed Regarded as the result of increased input of sediment from the catchment or a decrease in the ability of modification the river to transport sediment (Gordon et al., 1993). Indirect indications of sedimentation are stream Channel bankMay beand the catchment result of aerosion. change Purposeful in flow which alteration may alter of thechannel stream characteristics bed, e.g. the causing removal a ofchange rapids in for modification navigationmarginal instream (Hilden and& Rapport, riparian 1993) habitat. is also Purposeful included. channel modification to improve drainage is also included. Water quality Originates from point and diffuse point sources. Measured directly or agricultural activities, human modification settlements and industrial activities may indicate the likelihood of modification. Aggravated by a decrease in the volume of water during low or no flow conditions. Inundation Destruction of riffle, rapid and riparian zone habitat. Obstruction to the movement of aquatic fauna and influences water quality and the movement of sediments (Gordon et al., 1992). Exotic Alteration of habitat by obstruction of flow and may influence water quality. Dependent upon the species macrophytes involved and scale of infestation. Alien aquatic The disturbance of the stream bottom during feeding may influence the water quality and increase fauna turbidity. Dependent upon the species involved and their abundance. Solid waste A direct anthropogenic impact which may alter habitat structurally. Also a general indication of the disposal misuse and mismanagement of the river. RIPARIAN ZONE Vegetation Impairment of the buffer the vegetation forms to the movement of sediment and other catchment runoff removal products into the river (Gordon et al., 1992). Refers to physical removal for farming, firewood and overgrazing. Includes both exotic and indigenous vegetation. Exotic Excludes natural vegetation due to vigorous growth, causing bank instability and decreasing the buffering vegetation function of the riparian zone. Allochthonous organic matter input will also be changed. Riparian zone encroachment habitat diversity is also reduced. Environmental consequences of invasion by exotic woody species: Exotics often have a higher water consumption than indigenous plants. They restrict access to banks for animals (and people) They disrupt indigenous plants and Wet and Dry Bank Zone vegetation. They can increase fire hazard by increasing fuel loads and burning more fiercely than indigenous riparian plants and increase indigenous plant fire deaths. They often cause increased sedimentation. The effects of floods becomes more severe and devastating floods become more common-place. (Dr C Boucher, Botany Department, University of Stellenbosch, Dec 2001). Bank erosion Decrease in bank stability will cause sedimentation and possible collapse of the river bank resulting in a loss or modification of both instream and riparian habitats. Increased erosion can be the result of natural vegetation removal, overgrazing or exotic vegetation encroachment. Channel May be the result of a change in flow which may alter channel characteristics causing a change in modification marginal instream and riparian habitat. Purposeful channel modification to improve drainage is also included. Any densification of woody exotic species would lead to channel shape change through increased sediment deposits. This has serious implications for more extensive bank over-topping during flood events with increased scouring along outer edges of the Dry Bank. It is the extremes, i.e. drought or very wet events, which are particularly crucial sensitive periods to be considered. (Dr C Boucher, Botany Department, University of Stellenbosch Dec 2001). Water Direct impact on habitat type, abundance and size. Also implicated in flow, bed, channel and water abstraction quality characteristics. Riparian vegetation may be influenced by a decrease in the supply of water. Inundation Destruction of riffle, rapid and riparian zone habitat. Obstruction to the movement of aquatic fauna and influences water quality and the movement of sediments (Gordon et al., 1992). Flow Consequence of abstraction or regulation by impoundments. Changes in temporal and spatial modification characteristics of flow can have an impact on habitat attributes such as an increase in duration of low flow season, resulting in low availability of certain habitat types or water at the start of the breeding, flowering or growing season.
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8.5.2 Instream and riparian PES and EIS
8.5.2.1 Present Ecological State (PES) In this context, the PES of a freshwater ecosystem (at the time of an assessment or survey) describes the extent to which a river or wetland has been altered by humans from its original, natural condition. The PES is described in six ecological categories ranging from A (natural) to F (critically/extremely modified) and is derived using expert assessment of criteria known to influence the condition of freshwater ecosystems (See Table 2). The ecological categories represent a simplified measure of the extent of ecological alteration as assessed by regional experts.
8.5.2.2 Ecological Importance and Sensitivity (EIS) Ecological Importance (EI) of a river is an expression of its importance to the maintenance of ecological diversity and functioning on local and wider spatial scales. EI relates to biophysical aspects such as diversity, uniqueness and scarcity in a sub-quaternary reach that relate to the capacity to function sustainably. Ecological sensitivity (or fragility) refers to the system’s ability to tolerate disturbance and its capacity to recover from disturbance once it has occurred (resilience). ES considers the attributes of the sub-quaternary reach that relates to the severity of response to stressors i.e. the sensitivity of biophysical components to general environmental changes such as flow, physico-chemical and geomorphic modifications DWAF, 1999b). Essentially, the EI and the ES of sub-quaternary reaches are assessed to obtain an indication of its vulnerability to environmental modification within the context of the PES. This would relate to the ability of the sub-quaternary reach to endure, resist and be resilient enough to recover from various forms of human use (DWA, 2013). The EIS rationale in Table 5 adapted from DWAF (1999b) can also be used as surrogate for the estimation of the EIS of a river reach or sub-catchment.
Ecological aspects considered in the EIS assessment should include, as far as possible, the presence of any rare and/or endangered species, unique species (i.e. endemic or isolated populations) and communities, intolerant species, species diversity, habitat diversity (e.g. pools, riffles, runs, rapids, waterfalls, riparian forests, etc), the importance of a river or river reach in providing connectivity between different sections of the river, e.g. presence of migration routes/corridors for species movements, presence of conservation or relatively natural areas along the river, the sensitivity of the system and its resilience (i.e. the ability to recover following disturbance) of the system to environmental changes should also be considered.
8.5.3 REC The Ecological Category (EC) is a simplified measure of the extent that a freshwater ecosystem has been altered from natural condition due to human impact. As with PES, there are six ecological categories ranging from A (natural) to F (critically/extremely modified) derived using expert assessment of specific criteria. The
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Recommended Ecological Category (REC) for the study area was based on a desktop study of available literature for the catchment in which the site is located combined with the observations during the field- based assessment.
8.6 Risk/Impact assessment on watercourses
Impact (risks) of the development on watercourses in terms of Section 21 (c) and/or (i) of the NWA were assessed using the DWS-regulated risk matrix approach promulgated in terms of GN509 of 26th August 2016. Refer to Annexure M for the risk assessment methodology.
8.7 Freshwater biodiversity assessment
The Guideline Documentation on EIA Regulations (DEAT, 1998) provided guidance on methods for the assessment of potential impacts on aquatic biodiversity. The criteria forming part of the impact assessment and the terminology descriptions are summarised below:
Nature of the Impact - This is an appraisal of the type of effect the project would have on the environment. This description includes what would be affected and how and whether the impact is expected to be positive (+ve) or negative (-ve). Extent of the Impact - A description of whether the freshwater biodiversity impact will be local, limited to the study area and its immediate surroundings, regional, or on a national scale. Duration of the Impact - This provides an indication of the lifespan of the impact (the time period over which freshwater biodiversity is affected). Severity (Magnitude) of the Impact - This indicates the degree to which the impact would affect freshwater biodiversity. Probability of Occurrence - This describes the probability of the impact on freshwater biodiversity actually occurring. This is rated as improbable (low likelihood), probable (distinct possibility), highly probable (most likely) or definite (impact will occur regardless of any prevention measures). Degree of Confidence - This describes the degree of confidence for the predicted impact on freshwater biodiversity based on the available information and level of knowledge and expertise. It has been divided into low, medium or high.
Table 9 presents an overview of an impact characterisation and criteria matrix with the various impact criteria described and rated on a numerical scale using numerical values.
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Table 9: Characterisation and criteria matrix for impacts on freshwater biodiversity.
Numerical Numerical Description Description value value Temporary - period of less Unlikely - probably will not 1 1 than 1 year happen Short term - period of less Improbable - some possibility, but
2 2 than 5 years low likelihood Medium term - period of 3 Likely - distinct possibility 3 less than 15 years
Occurrence Long term - period of less
Duration 4 Highly likely - most likely 4 than 20 years Likelihood Permanent - a period that Definite - impact will occur exceeds the life of the 5 regardless of any prevention 5 development measures On-site - impacts that are No effect - will have no effect on limited to the site/project 1 0 the environment footprint Local - impacts that are Minor - minor and will not result limited to the project site 2 2 in an impact on processes and adjacent properties Regional - impacts that are experienced at a regional Low -low and will cause a slight
3 4
scale e.g. impact on processes municipal/provincial
National - impacts that are Moderate - moderate and will
Extent Severity Severity experienced at a national 4 result in processes continuing but 6 scale in a modified way High - processes are altered to the extent that they temporarily 8 Trans-boundary / cease International - impacts 5 Very high - results in complete that are experienced destruction of patterns and outside of South Africa 10 permanent cessation of processes
The environmental significance of each potential impact is then calculated using the following formula:
Significance Points (SP) = (Severity + Duration + Extent) x Likelihood
The maximum value is 100 significance points (SP) with potential impact significance ranked as HIGH, MODERATE or LOW based on the criteria in Table 10.
Table 10: Significance criteria ranking. ≤ 30 significance points LOW environmental significance 31 - 60 significance points MODERATE environmental significance ≥ 61 significance points HIGH environmental significance
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8.7.1 Cumulative impacts The approach to assessing cumulative freshwater biodiversity impacts is to screen potential interactions with other land-uses on the basis of past, present impacts and future impacts and surrounding land uses and development pressures. This cumulative impact assessment took into consideration the 2010 Ehlanzeni SDF 2015 Mpumalanga BSP (Lötter, 2015) in the context of the associated sensitivity delineations for freshwater resources within the study area and project footprints. Key considerations for the assessment are the current land uses and local anthropogenic activities.
9 RESULTS
9.1 Freshwater resource delineation Figure 10 illustrates the entire project footprint (road and borrow pits) and the position of drainage culverts in relation to drainage lines and 20m contours in the respective quaternary catchments. Surface freshwater resources within the study area, delineated using a combined desktop and fieldwork verification assessment, are shown in Figures 11 – 14 (where letters A & B represent a map & an aerial satellite image respectively). Figures 15 and 16 show the borrow pit footprints at a finer level of detail. The use of aerial satellite imagery (See Annexure A) and historical topographical maps (See Annexure C) aided in the delineation. In terms of primary drainage and direction of surface water flow, Annexure D shows four main rivers, all non-perennial, within the broader study area being. These are: (i) The Khokhovela (receives southward and westward flowing drainage from culverts 1 to 17); (ii) The Nwaswitsontso (receives southward and eastward flowing drainage from culverts 12 to 35); (iii) The Phungwe (receives southward and eastward flowing drainage from culverts 1 to 11) and; (iv) The Sesete (a Timbavati River tributary) which may receive northward and westward flowing drainage from culvert 35.
32m, 100m and 500m buffers are indicated around both the road upgrade footprint and borrow pits to show proximtiy to freshwater resources. All wetlands (artificial and natural) which exist within the road and borrow pit 500m buffers are associated with the Nwaswitsontso River, a non-perennial watercourse. A desktop review of satellite imagery does reveal more robust (i.e. darker green) vegetation growth within some of the drainage lines. The boundary of the watercourse exists where a perceived change/transition in the vegetation’s physical structure, i.e. where a more vigorous and robust growth form (darker green) was identified to be different to that of the adjacent (i.e. terrestrial) area. For some of the desktop-mapped spatial watercourses however, vegetation was not a good indicator as a determining factor between riparian and adjacent terrestrial vegetation. Figure G2 (Annexure G) shows a typical cross section of a river channel
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with a distinct riparian zone. Terrestrial vegetation, mostly woody species and grasses, were pre-dominant within the 100m road buffer and beyond with very little diagnostic signs of a distinct riparian zone.
Only water resources associated with borrow pit 2 and with culverts 14, 22 and 25 warranted further risk assessment in this study. All other culverts within the road footprint are greater than 100m from a watercourse with the exception of culverts 19, 20 and 26 where the adjacent watercourses (as mapped in existing CDNGI data) do extend into the 32m and 100m road buffers. There appears to be an incongruity between the physical observations in the field coupled with careful inspection of historical imagery and topographical maps where the beginning/start of the respective tributaries, in the vicinity of culverts 19, 20 and 26 are, in the opinion of the author, greater than 100m from the outer edge of the project footprint.
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Figure 10: Road upgrade footprint and position of drainage culverts in relation to drainage lines and contours in the respective quaternary catchments. The main (named) river systems are also shown on the map as darker blue lines. www.ncc-group.co.za D4407 Road Upgrade Freshwater Assessment Report – Mar 2020 Page 38 of 105
11A
11B
Figure 11A & 11B: Most northern section of road project showing road drainage culverts 24 – 30 and borrow pit 1 in proximity to freshwater resources.
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12A
12B
Figure 12A & 12B: Road drainage culverts 13 - 23 and borrow pit 2 showing proximity to freshwater resources.
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13A
13B
Figure 13A & 13B: Road drainage culverts 4 - 12 showing proximity to freshwater resources. No wetlands in 500m buffer.
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14A
14B
Figure 14A & 14B: Road drainage culverts 1 - 3 showing proximity to freshwater resources. No wetlands in 500m buffer.
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Figure 15: BP1 (red shading) showing proximity to freshwater resources. Non-perrenial drainage lines shaded as light blue lines, NFEPA wetlands shaded black and NWM5 seep wetland shaded purple. 32m (pink line), 100m (green line) and 500m (orange line) buffers indicated.
Figure 16: BP2 (red shading) showing proximity to freshwater resources. 32m (pink line), 100m (green line) and 500m (orange line) buffers indicated. Farm dam (NFEPA bench wetland with seeps) left unshaded to show features. (Refer also to Figures B17 & B18; Annexure B for higher resolution aerial images).
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9.2 Freshwater ecosystem classification
Classification of freshwater resources in the study area is summarised in Table 11. The geomorphological zonation of the watercourses in the study area is indicated in Figure 17.
Table 11: Level 1 to 6 of the classification system to wetlands in the 500m road and borrow pit buffers. All wetlands (artificial and natural) within the 500m road buffer are associated with the upper foothills of the Nwaswitsontso River, a non-perennial watercourse. Freshwater Level 1 Level 2 Level 3 Level 4: HGM unit Level 5 Level 6 resource System DWS NFEPA Landscape 4A 4B 4C Hydrological Descriptor (study unit Ecoregion WetVeg Unit regime name) Group/s (of drainage, not wetland) W01 and W02 were likely part of the seep W01 Lowveld (with Permanent Inland Bushveld Bench n/a Artificial Group 3 channelled dammed water outflow) before the dams were built. The dams are artificial wetlands, originally all a
W02 Lowveld natural seep, Permanent Inland Bushveld Bench n/a Artificial
Group 3 associated with dammed water thill
a non-perennial o river drainage system.
W03 Lowveld fo Upper Inland Bushveld Seep Hillslope seep n/a Seasonal Natural Group 3 W04 Lowveld Permanent Inland Bushveld Bench Artificial dams n/a Artificial Group 3 on a non- dammed water perennial river W05 Lowveld Permanent Inland Bushveld Bench drainage n/a Artificial Group 3 system. dammed water
W06 Lowveld Inland Bushveld Seep Hillslope seeps n/a Seasonal Natural Group 3 Lowveld Natural (also Nwaswitsontso Inland Bushveld Stream/River n/a n/a Non-perennial Group 3 See Table 1)
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Figure 17: Streams in the study area are upper foothills in term of geomorphological zonation, after Rowntree et al (2000) (Source: FBIS; https://freshwaterbiodiversity.org/).
9.3 Wetland habitat assessment
As determined in the desktop study and field visit, four of the freshwater wetland units are artificial in nature (i.e. farm dams) and exist as benches at the landscape level. W01 and W02 are artificial, modified impoundments associated with a natural slope seep (W03) on which they were built. They may have permanent water all year round however this depends on the summer season and local climatic factors. W04 is also a dam which was created on one of the Nwaswitsontso’s non-perennial tributaries. Historical aerial photography and maps indicate that W04 existed as far back as the 1970s but not in ~1944 (Annexure B). It is likely that at the time of creation, the main drainage streams in the region were dammed for purposes of water supply for livestock and household consumption.
To date, increasing human settlement in the area is evident, particularly around Welverdiend and present- day Hluvukani, formerly Tsakane (See Annexure C). In terms of primary preferential flow paths and directions, these have remained largely unchanged, apart from the natural process of streams altering their courses over time. As the assessment was carried out in summer after recent heavy rainfall, all dams contained surface water (See Annexure A). Based on visual inspection, there was little evidence that the dam levels during the study were lower than normal during the summer (rainfall) season. Given that stream flow is minimal in the main drainage channels, sub-surface flow and possibly groundwater recharge is a likely contributory water input to these farm dams.
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Riparian vegetation and wetland hydrophytes were not dominantly abundant or distinct at W01, W02, W03 and W04, apart from the margins of W01 and W02. Dichrostachys cinerea (sicklebush) pre-dominated the margins of W01 and W02 with hygrophilous grasses present within only a few metres from the water’s edge of W01. Impacts from livestock watering and trampling were visible with some headward slope erosion developing at W01 owing to livestock. The W04 dam wall is a concrete structure as opposed to the earthen dam wall at W02.
There are several natural seep slope HGM units (W06) on the periphery of W05 which would have been historically associated with a centrally depressed drainage line, which is now inundated with surface water and exists presently as an artificial dam. The remnant natural seeps connected with W05 are defined as specific HGM unit types and are included in the Wet-Health assessment approach. It remains a challenge to estimate the original wetland extent (if it was in fact larger than present day) that may have existed pre- human settlement and damming of the respective non-perennial watercourse. Comparing available historical aerial photographs with the recent / current scenario, there is presently less riparian vegetation in the watercourse within which W01 and W02 are situated (Figure B8 & B9, Annexure B).
9.3.1 Wetland PES The results of the Wet-Health PES assessment on freshwater resources in the study area is summarised in Table 12.
9.3.2 Wet-Ecoservices The results of the Wet-Ecoservices assessment on freshwater resources in the study area is summarised in Tables 13 and 14.
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Table 12: February 2020 PES and associated scores for study area freshwater units, assessed using Wet-Health.
Feb 2020 Study Unit GPS co-ords individual scores Combined Comments unit area (centre of PES Hyd Geo Veg Scores name (ha) unit)
Primary and secondary impacts include the dam itself (a derivation from the original aquatic 24°33’37.00”S ecosystem reference condition), an existing farm/rural gravel road running +/- 40 to 60m to W01 0.29 2.50 1.50 1.50 13.5 B 31°20’9.09”E the south of W01, W02 and W03 respectively as well as the D4407 gravel road with upgrading (asphalt surfacing) underway, trampling by livestock for watering purposes at the dam causing pockets of erosion and bush encroachment of Dichrostachys cinerea (sicklebush) in the 24°33’40.37”S W02 0.92 2.50 1.50 1.50 13.5 B 31°20’17.21”E immediately surrounding terrestrial area (See Photos 5-13, Annexure A). In terms of historical and recent imagery (See Fig B8 and B9, Annexure B), there is evidence of surrounding pasture 19.2 (agricultural land-use) existence at both time periods, and this was confirmed by the study 24°33'43.72"S W03 (within 2.50 1.50 1.50 13.5 B field visit. However there appears little change to the vegetation density within the 500m 31°20'21.56"E buffer) watercourse and surrounding the seep and dams (now artificial wetlands). In terms of historical and recent imagery (See Fig B10 and B11, Annexure B), this dam did not exist in 1944. The development of rural settlement and rural farm roads in the area, the dam is seen to have been built/exist by 1974 (Fig B12). During the time of this study it was observed that surrounding human settlement and road infrastructure is within 100m from the edge of the dam. As is the case with W01 and W02, this artificial bench wetland exists as a farm dam built on a non-perennial drainage tributary of the Nwaswitsontso. Primary and secondary 24°35'5.93"S W04 0.43 2.50 1.50 2.50 15.5 C impacts include the dam itself (a derivation from the original aquatic ecosystem reference 31°19'46.76"E condition), existing farm gravel roads within 100m from the dam edge, trampling by livestock for watering purposes at the dam causing pockets of soil disturbance and erosion with potential sedimentation / siltation impacts further downstream in the watercourse. However as dams also capture sediment run-off due to erosion in areas surrounding the dam, this may counterbalance any downstream sedimentation /siltation impacts which may result from livestock trampling. Primary and secondary impacts include the dam itself (a derivation from the original aquatic ecosystem reference condition), an existing gravel farm road, trampling by livestock for W05 1.23 2.60 1.70 1.90 15 C (artificial) watering at the dam causing erosion and sedimentation and a recent nearby borrow pit where 24°35'33.68"S gravel materials are being sourced. Run-off from exposed & disturbed soil surfaces (road, 31°20'50.77"E borrow pit and erosion dongas) remain a risk for further erosion/siltation of the dam. The W06 seeps on the periphery of the dam remain relatively un-changed in terms of hydrological and 0.36 2.60 1.70 1.90 15 C (natural) geomorphological impacts. Vegetation removal and alien plant encroachment have resulted in some changes (negative impacts) to the natural seeps from their original condition. www.ncc-group.co.za D4407 Road Upgrade Freshwater Assessment Report – Mar 2020 Page 47 of 105
Table 13: Wetland ecosystem service importance scores for the six wetland units evaluated using Wet-EcoServices in February 2020.
Ecosystem good & Overall average scores for the wetland units combined (out of 4 as a maximum score) services W01 W02 W03 W04 W05 & W06 (bench, artificial) (bench, artificial) (seep, natural) (bench, artificial) (artificial wetland and natural slope seeps along dammed watercourse) Flood attenuation 1.7 1.7 1.7 1.7 1.7 Streamflow regulation 2.0 2.0 2.0 2.0 2.0 Sediment trapping 2.3 2.3 2.3 2.3 2.3 Phosphate trapping 2.2 2.2 2.2 2.2 2.2 Nitrate removal 2.4 2.4 2.4 2.4 2.4 Toxicant removal 1.9 1.9 1.9 1.9 1.9 Erosion control 2.4 2.4 2.4 2.4 2.4 Carbon storage 1.8 1.8 1.8 1.8 1.8 Maintenance of biodiversity 1.0 1.0 1.0 1.0 1.5 Water supply for human use 2.0 2.0 2.0 2.5 2.5 Natural resource 0.0 0.0 0.0 0.0 0.0 Cultivated foods 0.0 0.0 0.0 0.0 0.0 Cultural significance 0.0 0.0 0.0 0.0 0.0 Tourism and recreation 0.6 0.6 0.6 0.6 0.6 Education and research 0.5 0.5 0.5 0.5 0.5 Overall score 20.8 20.8 20.8 21.3 21.8 Average score 1.39 1.39 1.39 1.42 1.45 4
Radar diagrams
Average size (ha) 0.29 0.92 12.9 (within 500m buffer) 0.43 1.23 (artificial) 0.4 (natural)
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Table 14: Summarised results for ecological services provided by the wetland based on direct and indirect benefits.
WETLAND IMPORTANCE W01 W02 W03 W04 W05 W06 Indirect Benefits 2.1 2.1 2.1 2.1 2.1 2.1 Biodiversity Maintenance 1.0 1.0 1.0 1.0 1.0 1.5 Direct Benefits 0.2 0.2 0.2 0.2 0.2 0.2
9.3.3 Wetland EIS The EIS assessment was applied to the delineated freshwater units described in the previous section to estimate the levels of sensitivity and ecological importance of the wetlands. Information which was considered for the EIS assessment is presented in Table 5. EIS scores below (Table 15) reflect the observations during the field visit couple with the desktop literature review and assessment of historical maps and imagery. From a terrestrial biodiversity perspective, in terms of the occurrence of any red data floral species occurring or predicted to occur within the study area, the terrestrial biodiversity assessment (NCC, 2020) can be consulted. No species-specific data was gathered during the study in terms of populations of unique or potentially obligate animal species (such as invertebrates, amphibians, birds or mammals) which may rely on wetlands for habitats, migration, breeding, or feeding sites within wetlands. Draft NEMA EIA guidelines on species specific environmental assessments for terrestrial biodiversity (animals and plants) have been released for public comment in GN9 dated 10 January 2020 however these do not relate to aquatic (or wetland) biodiversity. Freshwater aquatic species include fish, diatoms, aquatic macroinvertebrates and aquatic plants.
Table 15: EIS estimation for wetlands within the 500m “regulated area” of the project footprint. W01 W02 W03 W04 W05 W06 EIS 0.95 0.95 0.95 0.95 1.5 0.95 EIS Category Low Low Low Low Moderate Low Hydrological / Functional Importance 2.1 2.1 2.1 2.1 2.1 2.1 Direct Human Benefits 0.52 0.52 0.52 0.52 0.60 0.60
At an ecosystem / landscape level, the wetlands in the study area are not afforded any international protection status (i.e. are not Ramsar sites) however they have a degree of formal protection being considered wetland FEPAs which are a priority for management to ensure continued provision of essential ecosystem services. Although not a FEPA, W03 is a seep based on the most recent National Wetland Map (NWM), version 5. In terms of the 2015 Mpumalanga Biodiversity Sector Plan (MBSP) freshwater www.ncc-group.co.za D4407 Road Upgrade Freshwater Assessment Report – Mar 2020 Page 49 of 105
assessment, there are no wetland or wetland cluster Ecological Support Areas (ESAs) or wetland Critical Biodiversity Areas (CBAs) in the study area. Much of the road footprint traversers through Other Natural Areas (ONAs), much of which are heavily transformed or modified in the towns of Hluvukani and Welverdiend (See Annexure I).
In terms of size and rarity of the wetland type/s present (artificial dams and seeps), these are relatively smaller and more common features in the landscape in comparison to other more rare wetland types, such as endorheic pans, or larger wetland types, such as floodplain wetlands. In terms of habitat diversity, there is still intact vegetation on the dam peripheries as well as the inundated area where wetland/aquatic fauna such as amphibians, fish and water birds may utilise. Seeps are typically not sensitive to changes in floods or changes in water quality whereas are more sensitive to changes in the dry season where recharge through sub-surface flows become more important e.g. see Figure B17 and B18 (Annexure B).
Based on the reserve determination of water resources for the Inkomati catchment (GN998 of 19 July 2019), wetland sites in the Bushveld and Granite Lowveld regions are moderate to small or cryptic with low density and low diversity. Refer also to Figure 2 showing the general low distribution and density of wetlands in the jurisdiction of the Bushbuckridge Municipality. Entire catchments are impacted by urbanisation of former homeland areas and the study area (between Welverdiend and Hluvukani) is no exception (See Annexure C). Apart from lower quaternary catchments within Kruger National Park and private conservation areas, the EIS scores are generally low.
9.3.4 Wetland REC Wetland Resource Quality Objectives (RQOs) and recommended ecological categories for surrounding secondary catchments and tertiary catchments in the Inkomati (X) have been set in terms of integrated units of analysis (IUAs), but none for catchment X4. There are possibly more priority wetlands in the other catchments which warranted attention in the most recent studies (See DWS, 2014). Given this, the recommended ecological category (REC) for the wetland units, all in catchment X40C, is for no further decline in the PES and EIS scores. X40C is the only catchment where freshwater resources in this study were delineated within the NWA “regulated area” of a watercourse. If the PESEIS categories remain as is for each unit (i.e. B/C and Moderate/Low) and rehabilitation is carried out effectively after the road upgrade development, maintenance of the ecological category (EC) for catchment X40C, rather than ay decline, may be attainable. Given the historical and existing land-use impacts in the immediate study area, a C REC should in the author’s opinion be acceptable for the bench wetlands (farm dams) and seeps within the study area.
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9.4 Riparian and Instream habitat assessment
9.4.1 Index of Habitat Integrity The results of the IHI assessment, based on criteria in Table 8, are summarised in Table 16 with comments on major impacts provided.
Table 16: Index for Habitat Integrity (IHI) values obtained during February 2020 for the upper Nwaswitsontso (X40C) in the context of surrounding land-use and construction activity.
Site Component IHI (%) EC Major Impacts
The Nwaswitsontso River originates outside the Kruger National Park (KNP) with only the first 5km of 97km falling outside the Park and adjacent Reserve areas. The occurrence of dams, overgrazing, erosion and agriculture renders the overall SQ (X40C-00513) an EC of a B in terms of a DWS RQO study dated Instream 67 C April 2015. Further dowsntream, in the KNP, the EC is considered unmodified Habitat (an A EC). However at the site of the project road upgrade in the far upper catchment (X40C) reaches near the town of Welverdiend, the river's beds and channels have been historically modified, more so after the 1960's/1970's as seen in historical aerial photography. Small scale sand mining activities, erosion scars, increasing human settlements around Welverdiend and small scale agriculture (crops and livestock) has increased somewhat in the upper Culvert 22 crossing the D4407 over reaches of the Nwaswitsontso over the last +/- 40years. At the catchment the Nwaswitsontso River scale, the watercourse drainage lines start in catchment X40C in the vicinity of Welverdiend through which the road traverses. Due to the historical disturbances combined with the road diversion and bridge building activities, an EC of a C has been assigned during this study. If the correct measures are Riparian 62 C taken to control erosion and run-off and improve the road infrstructure, Habitat improvements to the riparian and in-stream habitats will be likely. The non- perennial nature of the river in this part of the catchment (upper foothill) has very intermittent and seasonal flow and if correct mitigation measures are taken during construction to minimise sedimentation and turbidity, these impacts will be short-term and reversible if good engineering and environmental practise is followed.
9.4.2 PES and EIS Given the non-perennial nature of the streams and no biological assessments of aquatic fauna being feasible or carried out in this study, a detailed field-based PESEIS assessment using fish and invertebrate data was also not considered feasible. There was no surface flow at the time of the field visit and a distinct riparian vegetation zone (i.e. with obligate wetland and/or riparian species) was poorly defined and/or did not exist along many of the drainage lines (See Annexure A). Existing aerial imagery and recent DWS RDM/RQO studies were consulted in this component of the assessment.
In terms of presence of IUCN red data species, and endangered (EN) fish species, Serranochromis meridianus (Lowveld Largemouth), was found in relatively low numbers in the Sabie Sand tributaries of the Inkomati River System, albeit in previous surveys and studies in the 1980s and before that time (Kleynhans 1984, Skelton 1987). The habitat preference for S. meridianus is large sandy pools with well vegetated banks
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(Phragmites sp.) as well as overhanging vegetation (Roux et al. 2017). These pools range from 5m to 15m wide, more than 1m deep with a sandy substratum (Kleynhans 1984). It is a predatory species preying on small fish, insects and other invertebrates whose natural population has experienced continuous decline as a result of habitat degradation via over-abstraction, reduced water quality, increased sedimentation and siltation (Skelton 2001). This species was translocated to various dams on tributaries of the Sand River in the Kruger National Park (Skelton 1987). Based on the February 2020 field visit, these preferred habitat types were not observed in close proximity anywhere within the project footprint and surrounding drainage lines.
In terms of the 2015 Mpumalanga Biodiversity Sector Plan (MBSP) freshwater assessment, ESAs (Fish Support Areas) have been delineated for this species (and possibly others) downstream of the project footprint in W32H with a River CBA (the Phungwe River) delineated in X32H (See Annexure I). The lower half of the road traverses along the catchment boundary between X32H and X32G adjacent to the River CBA and ESA where a significant portion of X32H is also delineated as an ‘Important sub-catchment ESA’ in terms of the 2015 MBSP (Lötter, 2015).
In terms of a 2014 DWS desktop study (DWS, 2014b) desktop EIS and Ecological Category (EC) for downstream watercourses which have connectivity to the study area, the Khokovela was assigned a ‘Moderate’ mean EI and ES class with a C EC whilst the Phungwe was assigned a ‘High’ EI and ‘Very Low’ ES classes with a B EC. With respect to the main receiving stream in relation to the study area, the Nwaswitsontso was assigned a ‘High’ EI in a different quaternary catchment to the study area (X40D-00660). In terms of EC, a B was assigned in the first 5km in X40D and an A for the rest of the river (DWS, 2015). The occurrence of dams, overgrazing, erosion and agriculture in X40C (SQ reach X40C-00513) resulted in a B EC being assigned. The rest of the Nwaswitsontso River instream and riparian habitats in downstream tributaries (X40C and X40D) were found to be mostly unmodified and fall within an A EC (DWS, 2014b).
According to a 2015 DWS study on Resource Quality Objectives (RQOs) in the Inkomati WMA, the Khokovela (SQ reach X32G-00549), was assigned a C PES where non-flow impacts include rural agriculture (fields), bed and channel disturbances, overgrazing/trampling, sedimentation, grazing (land-use) and vegetation removal while water quality impacts include runoff/effluent and associated algal growth. In terms of the Phungwe (SQ reach X32H-00560), an A PES was assigned where natural areas/nature reserves are the main land-use. A B PES was assigned for the first 5km of the Nwaswitsontso (SQ reach X40C-00513) due to occurrence of dams, overgrazing, erosion and agriculture with a A PES assigned for the rest of the river down catchment in the Kruger National Park (DWS, 2015). The most recent reserve determination study of water resources in the Inkomati catchment i.e. the Inkomati-Usuthu WMA, catchment X40C (Nwaswitsontso) and X32H
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(Phungwe) were assigned a C PES and Low EIS respectively. EIS in the adjacent catchment X32G (Khokovela) was also Low faring slightly worse with a D PES (DWS, 2019).
Notwithstanding existing desktop literature and studies conducted at a broader scale where extrapolations are often based on only one or a few reference sites, Table 17 below provides the author’s estimation of the EIS categories for the sections of watercourses over which the project footprint traverses directly, aided by the site visit observations and desktop review of available literature and historical imagery. The assessment and scoring approach (See Table 5) followed that for determining wetland EIS.
Table 17: Summary of February 2020 PES and EIS scores for non-perennial watercourses within the 100m “regulated area” of the project footprint.
Freshwater resource Nwaswitsontso - X40C Nwaswitsontso - X40C X32H (Phungwe) (study unit reference) (at road culvert 22) (at road culverts 14 & 25) PES C C C EI Low Low High ES Low Low V. Low EIS Category Low Low Low
9.4.3 REC According to a 2015 DWS study on Resource Quality Objectives (RQOs) in the Inkomati WMA, the occurrence of dams, overgrazing, erosion and agriculture within the catchment (drained by the Nwaswitsontso in the case of the affected freshwater resources in this study) found certain reaches in the catchment to be largely natural with few modifications. A slight change in ecosystem processes was discernible and a small loss of natural habitats and biota may have taken place (DWS, 2015). In terms of more recent reserve determination study of water resources in the Inkomati catchment (i.e. the Inkomati-Usuthu WMA), legally promulgated in terms of GN998 published in Government Gazette 42584 dated 19th July 2019, catchment X40C (Nwaswitsontso) and X32H (Phungwe) were assigned a C REC. Adjacent catchment X32G (Khokovela) was rated to have been ecologically more transformed and was assigned a D REC (DWS, 2019).
Based on the findings of the desktop literature and historical imagery survey and the in-field observations and results, freshwater ecosystems adjacent to the project footprint and within the broader study area were found to be in a reasonably fair ecological condition (i.e. moderately modified), despite visible evidence of localised areas of physical degradation. However similar impacts, mainly human-induced through settlement and agriculture, were also obvious throughout the broader study area. Based on existing land-use impacts (settlement, agriculture, construction activity) occurring adjacent to the watercourse reaches in the study area i.e. at a site-specific level at the scale of the site footprint, the DWS-assigned REC for these
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watercourses should be used as a proxy for the Construction phase. For alignment to and conformance with the ecological categories assigned to the SQ reaches in the DWS studies, a C REC during construction is attainable. For the operational phase and with correct control and mitigation measures in place at the culvert crossings, site-specific impacts on watercourses should be significantly less than during construction and again, a C REC (and D for X32G) should be reasonably attainable and able to be maintained.
9.5 Watercourse impact assessment
Refer to Annexure N for the full risk assessment matrix (RAM).
9.6 Freshwater biodiversity assessment
As seen in Figure 18 and in terms of freshwater biodiversity resources in Mpumalanga as per the 2015 Biodiversity Sector Plan, the aquatic biodiversity value for the study area is in Category 5 – Ecosystem Maintenance with the sub-catchments being identified as important ESAs (Ecological Support Areas) where a rating of 2 for fish migration and fish refugia was assigned (Nel et al. 2011b). ESAs are not essential for meeting freshwater biodiversity targets but play an important role in supporting the ecological functioning of freshwater CBAs. It is however the main perennial rivers in the sub-catchments, such as the Sand River and lower Nwaswitsontso where freshwater fish biodiversity habitats are more critically important in terms of certain reaches being identified as freshwater Critical Biodiversity Areas (CBAs). There are no wetland or aquatic species CBAs within the study area however a river CBA (Phungwe in catchment X32H) has been delineated (Also See Annexure I). Refer back to wetland and watercourse PES, EIS and REC under report sections 9.3 and 9.4.
A summary of impacts on watercourses within the NEMA and NWA “regulated areas”, illustrated using buffers around the road and borrow pit footprint, are summarised in Tables 18 and 19. Impacts on freshwater biodiversity are included in the summary tables.
9.6.1 Cumulative impacts Freshwater resources within the study area which will be impacted by the development have been modified to an extent as a result of the existing road and structures as well as surrounding land use activities. Considering that the construction activity is to existing road infrastructure, it can be argued that the cumulative impact of upgrading (paving) the road will be of low significance on the immediately adjacent aquatic ecosystem and freshwater biodiversity. With implementation of mitigation and controls, there is potential to improve the present situation into a future operational scenario of improved drainage. However it can also be argued that this assumption is made strictly in the context of the road upgrade project in isolation. When considering that land-use types 12 (linear engineering structures such as hardened roads)
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and 15 (surface mining and dumping) in the 2020 Ehlanzeni SDF provide the highest levels of environmental impact and are essentially associated with this project, the long terms cumulative impact of road developments are cumulatively destructive, more so on terrestrial biodiversity but likewise on aquatic biodiversity. Residual biodiversity that does persist is often artificially maintained and may generally be modified into assemblages of plant and animal species with more resilient evolved biological traits, mechanisms and strategies to tolerating cumulative anthropogenic disturbance and natural habitat loss.
Figure 18: Mpumalanga Biodiversity Sector Plan freshwater assessment map showing location of the study area (project footprint) (Source: Lötter, 2015).
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Table 18: Summary of environmental significance of freshwater impacts on bench wetlands (W01, W02, W04 & W05) and seeps (W03 & W06) within the NWA and NEMA “regulated areas” i.e. those falling within the 32m, 100m and 500m road and borrow pit buffers. Impacts Significance points Without mitigation With mitigation 1) Loss / disturbance of wetland and aquatic habitats
Construction Phase 32 (moderate) 16 (low) Operations and Maintenance Phase 33 (moderate) 22 (low) 2) Loss / disturbance of wetland and aquatic biodiversity
Construction Phase 32 (moderate) 16 (low) Operations and Maintenance Phase 33 (moderate) 22 (low) 3) Modified hydrological functioning (flow modification)
Construction Phase 40 (moderate) 24 (low) Operations and Maintenance Phase 52 (moderate) 26 (low) 4) Modified water quality / chemistry (includes sedimentation and turbidity) Construction Phase 40 (moderate) 20 (low) Operations and Maintenance Phase 52 (moderate) 26 (low)
Table 19: Summary of environmental significance of freshwater impacts at culverts 14, 25 and 22 (bridge construction site) in non-perennial watercourse tributaries of the Nwaswitsontso within the NWA and NEMA “regulated area” i.e. directly in a watercourse. Impacts Significance points Without mitigation With mitigation 1) Loss / disturbance of wetland and aquatic habitats
Construction Phase 32 (moderate) 16 (low) Operations and Maintenance Phase 33 (moderate) 22 (low) 2) Loss / disturbance of wetland and aquatic biodiversity
Construction Phase 32 (moderate) 16 (low) Operations and Maintenance Phase 33 (moderate) 22 (low) 3) Modified hydrological functioning (flow modification)
Construction Phase 40 (moderate) 24 (low) Operations and Maintenance Phase 52 (moderate) 26 (low) 4) Modified water quality / chemistry (includes sedimentation and turbidity) Construction Phase 40 (moderate) 20 (low) Operations and Maintenance Phase 52 (moderate) 26 (low)
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10 RECOMMENDED MITIGATION MEASURES
10.1 Threats/risks to watercourses
In terms of risks to watercourses during construction, threat ratings based on expert workshops are highlighted in Table 20. These ratings indicate the threats which are mostly low (L) to very low (VL) for the transportation sector (paved road infrastructure) and the low-impact/risk mining sector (borrow pits). In this scenario, sedimentation and turbidity are the only threats which are rated as very high (VH).
10.2 Recommended buffers based on activities
Freshwater resource maps have been developed for the study area indicating the location of freshwater features. It is recommended that the report maps be considered during all phases of the development to aid in the protection and conservation of any freshwater features and habitats within the study area. Rather than buffer the freshwater features with the various regulated area distances to wetlands and watercourses, road and borrow pit buffer zones have been developed to show the project the area of the footprint and what areas should be avoided and those which should be adhered to. With no deviations beyond these buffers, the impacts to any Resource Quality Objectives (RQOs) or downstream water users will arguably be minor.
Based on the disturbance levels and land-use activity underway i.e. upgrading an existing gravel road to an paved (asphalt) surface facilitated by low-intensity borrow pits (quarrying) operations, a 32m buffer for watercourses and a 40m buffer for the wetlands (dams and seeps) is recommended (See Table 21). In this instance however, an established road already exists and it may therefore be appropriate to permit the upgrade activity within the recommended buffers as long as the activity does not result in any further deterioration of the buffer or watercourses (See Granger et al., 2005). Given that W03 (seep) occurs a reasonable distance away from the road for a relatively large area within the 500m but outside the 100m buffer, it extends almost to the road edge where culvert 34 is positioned for drainage purposes. Unless the road alignment between the most northern point was to be re-directed to the east away and out of the proposed 40m wetland buffer, maintaining a 40m buffer distance from the edge of the road footprint would not be possible. The physical road footprint and culverts 14, 22 and 25 also directly cross and are within non- perennial drainage lines, hence adhering to the 32m buffer is not practically possible in these cases.
10.3 Threat and risk mitigation
In terms of mitigation measures for threats/risks to watercourses during Construction and Operations, these have been summarised in Tables 22 and 23.
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Table 20: Desktop threat *ratings for construction activities based on expert workshops (Source: Macfarlane et.al, 2009).
DESKTOP THREAT RATINGS FOR CONSTRUCTION PHASE ACTIVITIES
Water Water Water Water Water Water Water quality - Quality - quality – Quantity Quantity Quality - quality - Water Land use / Sedimentation increased increased changes Water SECTOR - - increased concentratio quality - activity and turbidity organic metal in temperature volumes patterns inputs of n of salts pathogens contaminant contaminant acidity of flow of flow nutrients (salinisation) s s (pH)
Transportation Paved VL L VH N/A VL M M N/A N/A N/A infrastructure roads Low-risk Mining quarrying VL L VH VL L VL VL VL VL VL operations *VH - Very High; H - High, M - Moderate; L - Low; VL – Low; N/A - Not Applicable
Table 21: Minimum buffer widths for different wetland and rivers in the presence of service infrastructure development, in this case paving an unpaved gravel road surface and low-risk quarrying (borrow pit) operations (adapted from Graham and de Winnaar, 2009).
Land Use Activity Buffer width (m) for freshwater ecosystems Disturbance Primary Category Secondary Category Watercourses Seeps & bench (artificial) wetlands
Moderate Services/ Infrastructure Roads 32 40
Moderate to High Mining Low-intensity quarrying operations 100 100
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Table 22: Proposed threat/risk mitigation measures during the Construction Phase for the road upgrade and borrow pits (project footprint) adjacent to wetlands and drainage lines within the watercourse regulated area. Additional Refined Threat Threat Basic description of proposed mitigation measures mitigation Threat Specialist justification for refined threat ratings type Class (See also Annexure N) measures? Class Water Quantity - VL N VL volumes of flow M Y Adequate road design, Stormwater management plan and method L Although the natural drainage system surrounding the project footprints is statements during construction phase including on-site attenuation, non-perennial with little to no flow most of the year, a residual risk of appropriate design of culverts and storm water drainage system (inlets & increased runoff remains during construction activities. Efforts to slow Water Quantity - outlets) to minimise concentrated flows and erosion. Earth berms to be down flow velocity and dissipate energy of flows before entering patterns of flow constructed to limit concentrated flow paths forming. Remain out of freshwater resources and to implement an effective storm-water proposed watercourse buffers. Implementation of rehabilitation in terms management system will aid to reduce these risks. of a Rehabilitation Plan at end of construction prior to the Operational phase. H Y Adequate road design and Stormwater management plan and method L Although the natural drainage system surrounding the project footprints is statements with practical on-site management measures to control non-perennial with little to no flow most of the year, a residual risk of erosion at culverts. For example, use of silt fences, sandbags, stone- increased sedimentation and turbidity remains during construction Sedimentation and pitching, storing and reuse of topsoil for rehabilitation of disturbed areas activities. Efforts to slow down flow velocity and dissipate energy of flows turbidity after construction, ceasing construction activity in wet conditions. Where before entering freshwater resources and to implement an effective possible, fully construct the individual drainage culverts in workable storm-water management system will aid to reduce these risks. The sections before the road surface. Remain out of proposed watercourse natural drainage system surrounding the project footprints is also non- buffers. perennial with little to no flow most of the year. Water Quality - VL Y Generic pollution control measures aimed at reducing risk of spills, VL Increased inputs of managing potential soil and water contamination on site which may nutrients persist and have potential negative ecological effects. Water quality - VL Y Generic pollution control measures aimed at reducing risk of spills, VL Increased managing potential soil and water contamination on site which may toxic organic persist and have potential negative ecological effects. contaminants Water Quality - L Y Generic pollution control measures aimed at reducing risk of spills, L Increased managing potential soil and water contamination on site which may metal persist and have potential negative ecological effects. contaminants Water quality - VL N VL Changes in acidity (pH) Water quality - VL N VL concentration of salts (salinisation) Water temperature VL N VL Water quality - VL Y Generic recommendations for management of wastes / sanitation. VL pathogens (See risk matrix Annexure N).
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Table 23: Proposed threat/risk mitigation measures for the *Operational Phase of the road infrastructure adjacent to wetlands and drainage lines within the watercourse regulated area. Additional Refined Threat Threat Description of proposed mitigation measures mitigation Threat Specialist justification for refined threat ratings type Class (See also Annexure N) measures? Class Water Quantity – VL N VL volumes of flow M Y Adequate Design, Rehabilitation Plan implemented after construction, L Although the natural drainage system surrounding the project footprints is Operational Monitoring and Management Plan including aspects of also non-perennial with little to no flow most of the year, a residual risk of Water Quantity – monitoring and maintenance of stormwater infrastructure (culverts and increased surface runoff remains after construction during operational patterns of flow bridges). phase, owing to a paved (hard) road surface. Monitoring and maintenance of the storm-water management system will aid to reduce the risk.
H Y Adequately designed road, Rehabilitation Plan implemented after L A risk of increased runoff from a paved (hard) road surface will remain construction, Operational Monitoring and Management Plan including during operational phase. aspects of monitoring and maintenance of stormwater infrastructure Sedimentation and (culverts and bridges). In terms of permanent (long-term) measures, Efforts to direct flows away from sensitive water resources and to turbidity adopt an integrated approach of both ‘soft’ (bioengineering) and ‘hard’ implement a storm-water management system will help to reduce these engineering i.e. vegetated (grass-lined) swales and gabions, stone-filled risks. infiltration ditches, rock reno-matresses and concrete V-drains. Water Quality – VL Y Generic pollution control measures aimed at managing VL Increased inputs of potential soil and water contamination on site which may persist and nutrients have negative ecological effects, reducing risk of spills, etc. Water quality - VL Y Generic pollution control measures aimed at managing VL Increased potential soil and water contamination on site which may persist and toxic organic have negative ecological effects, reducing risk of spills, etc. contaminants Water Quality - L Y Generic pollution control measures aimed at managing L Increased potential soil and water contamination on site which may persist and metal have negative ecological effects, reducing risk of spills, etc. contaminants Water quality - VL N VL Changes in acidity (pH) Water quality - VL N VL concentration of salts (salinisation) Water temperature VL N VL Water quality - VL N VL pathogens *The assumption is that the borrow pits will be appropriately rehabilitated post-construction with vegetation to closely resemble the surrounding topography.
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10.4 Monitoring and management recommendations
In addition to the recommendations provided above, best practice for the mitigation of negative impacts specific to the project footprint and the associated sensitive environments i.e. freshwater resources should be detailed in a project-specific Environmental Management Programme (EMPr). Additionally, amongst the detailed environmental method statements which should be developed by the project’s appointed contractor(s), a specific method statement for working within and close to watercourses (i.e. at the road culverts and borrow pit 2) should be prepared and submitted for approval.
The following mitigation measures are recommended as standard best practice measures applicable to a development of this nature and should be implemented during all phases of the development, during construction and where applicable, the operational phase. These are made in support of ensuring the protection of watercourse and wetland systems within the total project footprint and by extension, beyond (downstream) of the footprint:
Construction Phase A suitably qualified and independent Environmental Control Officer (ECO) should be appointed to monitor and report on environmental compliance relating to construction activity on the project and should remain until appropriate rehabilitation has been undertaken. All contractors and employees should undergo induction which includes a component of environmental awareness. Inductions and tool-box talks should include aspects such as sensitive ‘no-go’ areas, the need to avoid littering, use of ablutions, smoking rules, fire awareness, health and safety, wildlife interactions, reporting and cleaning of spills and leaks and general good housekeeping. The watercourse and wetland areas identified and mapped must be treated as areas of higher ecological sensitivity, more particularly the stream crossing and bridge construction site (culvert 22) and the bench wetland close to borrow pit 2. Although four bench wetlands (one associated with peripheral seeps) fall within the ‘regulated area’, any construction activity or access in or within these systems does not form part of the project scope. They should therefore be avoided at all times and be considered as ‘No-go’ areas for construction vehicles and personnel. Adequate ‘no-go’ signage should be placed at a suitable, visible location adjacent to these systems. In general all freshwater resources outside the physical road and borrow pit footprint are off-limits and should be considered ‘No-go’ areas to construction vehicles and personnel. Ensure that the road (including the culverts and any ancillary drainage infrastructure) and borrow pit footprints do not
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encroach any further into the adjacent freshwater features i.e. beyond the designed footprint boundaries. If this measure cannot be adhered to, stricter mitigation measures will be required to minimise the impact on the receiving watercourses in order to minimise any significant impacts and environmental damage. Allow only essential construction personnel and machinery within the “regulated area” for freshwater resources and only if and when absolutely necessary. Only trained and competent personnel, machinery and resources (concrete, steel, pipes, etc) required for culvert and bridge construction should be permitted to access the respective culvert and bridge footprints. As far as possible, all construction activities at road culverts should occur in the low flow season during the drier winter months. All watercourses are non-perennial which should allow construction to continue in the summer (wet) season however construction activity within or adjacent to the culverts, bridge site and borrow pit 2 should cease during and several days after significant rainfall events (i.e. > 10mm) to allow sufficient time for soils to dry out. Daily rainfall measurements by the appointed Contractor will therefore be necessary. For the road crossings through/over watercourses, culverts should cross at right angles as far as practically possible to minimise impacts in the receiving environment, and any areas where any erosion / bank failure is observed. Any erosion / bank failure due to the effects of such crossings should be immediately repaired by reducing the gradient of the banks to a 1:3 slope and where necessary, installing additional support structures. This may only be necessary if other existing access roads are not utilised. The time period (duration of possible impacts on freshwater resources) during which excavated areas and disturbed soil surfaces at the culvert crossings remain exposed to the elements should be minimised as far as possible. Immediate efforts should be put in to action to revegetate such areas as soon as possible, ideally as soon as construction activity at each culvert is complete. ‘Temporary footprints’ i.e. construction camps/offices, equipment storage/laydown areas, parking for plant and vehicles, waste storage areas, hazardous substances storage and ablution facilities serving the construction phase should be located a reasonable distance away from any freshwater resources. Any chemicals and hazardous substances to be used for construction must be stored in impermeable, water proof receptacles and/or bunded areas and on drip trays when in-use on site. ‘Temporary footprints’ need to be fenced/cordoned off and maintained throughout the project timeframe. A suitable and practical buffer distance for these ‘temporary footprints’ is >100m from freshwater resources. Any accidental spills of fuels, construction materials, chemicals, effluents or other hazardous substances are reported and acted upon immediately. Effective clean up procedures should be implemented with
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contractors required to have the necessary spill kits available to ensure that any fuel or oil spills are rapidly cleaned up and disposed of lawfully. All machinery and equipment should be inspected regularly for faults and possible leaks and should be serviced off-site at a dedicate workshop area. Re-fuelling must take place over impermeable surface areas/drip trays to prevent contamination of soils and water resources with hydrocarbons. No storage or dumping of any excavated soils (i.e. stockpiles) and no storage or dumping of any equipment or materials (including rubble) must be allowed within and in close proximity to freshwater resources. All stockpiles must be protected from erosion, stored on flat areas where run-off will be minimised and be surrounded by erosion berms. Any topsoil (primarily from the borrow pits) should be stockpiled between 2-3 meters in height, conserved and re-used for any rehabilitation purposes. Construction activities associated with the road upgrade and the associated soil and vegetation disturbances will provide opportunity (i.e. increase the risk) for invasion / spread of invasive alien plants (IAPs). An alien vegetation management and monitoring programme must be implemented during construction to control and remove any alien plants that may encroach into the road and borrow pit footprints as well as adjacent freshwater resources.
Stormwater and erosion control Appropriate measures must be put in place to minimise erosion and the amount of sediment entering the watercourses and downstream wetlands, regardless of whether the watercourses are non-perennial with little to no flow. Rainfall events, however infrequent, will still act as natural drivers of change and will transport any loose/unconsolidated sediments and/or soils from exposed surfaces. The risk of erosion is therefore greater during the summer rainfall season and effective stormwater management is therefore important to prepare for such events. An appropriate stormwater management plan must be designed and implemented during the construction phase to control significant changes in hydrology (preferential flow paths and surface water flow) to downstream (receiving) freshwater systems. Whilst the culverts will function to facilitate drainage and surface water flow during the operational phase when the road is complete (i.e. after the construction phase), monitoring of the culverts and immediate surrounding areas should continue during the operational phase. To give structure to road monitoring and maintenance, an operational manual or plan should be developed by the end-user, if one does not already exist. Monitor all areas for erosion and incision with particular focus on the bridge, culvert crossings and borrow pits. Any areas where erosion is taking place excessively should be rehabilitated, even if temporarily at first, prior to permanent, final rehabilitation at the end of the construction phase.
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To prevent the erosion of soils, management measures may include berms, soil traps, hessian curtains and stormwater diversion away from areas particularly susceptible to erosion. All vegetated areas surrounding the freshwater systems are important to maintain and avoid wherever possible, as they function to buffer and prevent against run-off and erosion. These areas function to slow down surface flow velocity, absorb surface storm water runoff and allow sediments to settle out prior to reaching downstream aquatic and wetland systems. Vegetation can also provide an additional filtering function for certain pollutants. During construction and before the final surfacing of the road is complete, consider installing erosion- control berms on sloped sections of gravel road surfaces. Berms every 50m should be installed where any disturbed soils have a slope of less than 2%, every 25m where the track slopes between 2% and 10%, every 20m where the track slopes between 10% and 15% and every 10m where the track slope is greater than 15%. Sheet runoff from access road surfaces should be slowed down by the strategic placement of berms and sandbags.
Waste and General Appropriate ablution facilities must be provided for the life of the construction and all waste removed to an appropriate waste facility. Implement effective waste management to prevent construction related waste from entering the freshwater features. Provide adequate rubbish bins to prevent litter and ensure the proper disposal of waste and spills Speed limits should be set and obeyed to limit dust and damage to the road surface under construction as excessive speeds and braking of vehicles and plant may contribute to soil erosion and associated sedimentation and turbidity impacts. No informal fires should be permitted in or near the construction areas.
Rehabilitation (including for borrow pits) It is recommended that a detailed rehabilitation plan be developed by a suitably experienced and qualified rehabilitation specialist during the construction phase (already underway) in order to address any specific rehabilitation requirements for the culvert crossings and borrow pits. All soils compacted as a result of construction activities falling outside of the project footprint areas should be ripped and profiled. Special attention should be paid to alien and invasive control within these areas. Alien and invasive vegetation control should take place throughout all construction and rehabilitation phases to prevent loss of floral habitat.
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As much vegetation growth as possible should be promoted within the disturbed areas of the project footprint in order to protect soils. Any alien vegetation, including at culvert crossings, should be removed from rehabilitated areas with consideration for re-seeding with indigenous grasses. Consultation with a suitably experienced and qualified ecologist in this regard is recommended. Vegetation cover (a mosaic of grasses, forbs, woody species) should be monitored to ensure that sufficient indigenous, natively occurring vegetation is returned to stabilise the culvert embankments and wing-wall slopes to prevent any erosion and incision; During the operational and maintenance phase of the road, the control of vegetation within the road reserve, including alien vegetation, remains a responsibility of the end-user (Mpumalanga DPWRT) and should continue. To this end, a vegetation management plan should be developed and implemented for this specific road upgrade development if one does not yet exist for the Department.
Important to note, any specific rehabilitation of the wetland systems in the 500m buffers do not form part of the project’s scope. Should total avoidance of the seeps and bench wetlands (farm dams) become unfeasible for whatever reason, the necessary wetland functionality assessments and wetland rehabilitation planning will need to be undertaken by a qualified wetland ecologist to assess the risks and opportunities for working within and/or performing rehabilitation work on these systems. GN1198 published in Government Gazette 32805 dated 18th December 2009 provides the legal framework for rehabilitation of wetlands and should be read in conjunction with GN509 published in Government Gazette 40229 dated 26th August 2016. Only if a qualified wetland ecologist assesses the risks of any rehabilitation to wetlands in the 500m buffers to be Low will the end-user (MDPWRT) be permitted to exercise such a water use activity (i.e. wetland rehabilitation) in terms of sections 21 (c) or (i) of the NWA. Further explanation in this regard can be found under section 6(1)(c)(v) of GN509.
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11 DISCUSSION
The findings of the study are a reflection of the results available at the time of field assessment (mid- February 2020) and report writing. Any results from a winter (dry season) assessment do not form part of the terms of reference for this study. Notwithstanding the findings being based on a desktop study and once-off field visit, most of the annual rainfall for the study area had fallen during and prior to the field visit (See Figure 6). Significant rainfall had also fallen the week prior to the field visit with no flow being observed in watercourses intersecting with/traversing the project footprint. In the South African context, specialist studies including those focussing on freshwater ecosystems (wetlands, rivers and riparian zones) should ideally be carried out in the summer rainfall season for a more accurate synopsis of both biotic and abiotic factors within both terrestrial and aquatic ecosystems. This study was carried out during an ideal seasonal period where any surface flows would have been more likely, despite there being none.
A central aim of the study was to determine the proximity and current state of freshwater ecosystems and aquatic biodiversity within the study area of the project footprint and assess the impacts of the activity on these ecosystems. The assessments carried out were done in accordance with the relevant legislation and standard practise guidelines with regards to managing the environment. A combined qualitative and quantitative assessment of potential and observed impacts resulting from the road upgrade was undertaken and recommendations for mitigation measures and minimising negative impacts have been provided.
Based on the findings of the desktop literature and historical imagery survey and the in-field observations and results, freshwater ecosystems within the project footprint were found to be in a reasonable ecological condition (i.e. moderately modified), despite visible evidence of localised areas of physical degradation. However similar impacts, mainly human-induced through settlement and agriculture, were also obvious throughout the broader study area. According to a 2015 DWS RQO study in the Inkomati WMA the occurrence of dams, overgrazing, erosion and agriculture within the catchment (drained by the Nwaswitsontso in the case of the potentially affected freshwater resources in this study) found certain reaches in the catchment to be largely natural with few modifications. A slight change in ecosystem processes was discernible and a small loss of natural habitats and biota may have taken place (DWS, 2015).
In terms of more recent reserve determination study of water resources in the Inkomati catchment (i.e. the Inkomati-Usuthu WMA), legally promulgated in terms of GN998 published in Government Gazette 42584 dated 19th July 2019, catchment X40C (Nwaswitsontso) and X32H (Phungwe) were assigned a C REC. The PES and EIS for both catchments is a C and Low respectively. Adjacent catchment X32G (Khokovela) fared slightly worse with a D REC, a D PES and a Low EIS.
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Possibly the main risk to the downstream resource quality is the higher sediment loads that are received as a result of vegetation removal for expanding human settlement and agricultural activity (livestock trampling and erosion as well as vegetation removal for crops). With respect to the current gravel road condition and its continual degradation, this is a likely contributory factor to downstream sedimentation and turbidity. The long-term benefit of upgrading and surfacing the road is favourable from the perspective that watercourses in the study area may be somewhat restored to an improved state of ecological integrity given the erosion that has progressively worsened over several decades of expansion of human settlement in the area of Welverdiend. For reference, erosion scars along the banks of the watercourse downstream from the bridge construction site (Culvert 22) can be seen in dated aerial photographs (Figures B3 - B6, Annexure B).
Although overall aquatic biodiversity is considered low within the broader study area (Annexure M), the ecological status and overall biodiversity (both aquatic and terrestrial) for protected areas declared for conservation and eco-tourism purposes downstream of the road should not be overlooked. The Nwaswitsontso drains first into Manyeleti Game Reserve approximately 2.5km from the road footprint and then into the Kruger National Park (KNP) a further ~18km away. The Phungwe also flows into the Manyeleti Game Reserve and Sabi Sands Private Nature Reserve before its confluence with the Sand River which enters the KNP further down catchment. The Khokovela is a tributary of the Sand River which ultimately flows into the KNP. The intact and remaining natural habitats associated with the study area freshwater resources, particularly the dams which are semi to permanently aquatic; still have ecological importance in providing refugia, food resources and breeding habitats for various invertebrates, fish, birds, amphibians and small mammals.
12 CONLCUSION
If the recommendations and mitigation measures highlighted above are implemented (Section 10) and if appropriate planning and monitoring systems are put in place to control and minimise risks to watercourses, it is likely that the road upgrade activity will have limited freshwater biodiversity impacts and low risks to watercourses downstream of the project footprint. Negative impacts are likely to be relatively short-lived and restricted to the construction phase. If all recommended mitigation measures and temporary rehabilitation measures are rigorously and effectively implemented and enforced during construction activities and if rehabilitation is carried out as soon as construction is complete, the residual risks to watercourses have been assessed to be Low, contingent on implementation of all required mitigation. If effective monitoring and maintenance is continued during the operational phase, the road will pose only
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minor risks to water resource quality in the downstream receiving environment and should not compromise the requirements of the ecological reserve and other downstream water users.
The author is of the opinion that section 21(c) and (i) water uses associated with road upgrade activity and borrow pit 2 falls within the ambit of a General Authorisation (GA) where the authority (IUCMA) can consider an application for such water use through a GA application process and grant one in terms of the NWA. The author’s opinion is however subject to an internal review by the authority (See Figure 1) and their interpretation on the risks associated with a GA application.
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DWAF (Department Of Water Affairs and Forestry). 1999a. Resource Directed Measures for Protection of Water Resources. Volume 3: River Ecosystems Version 1. Report No. N/29/99, Pretoria.
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DWS (Department Of Water Affairs and Sanitation). 2014a. Section 21(c) and (i) Risk-based assessment and authorisation. Edition 03, FINAL. March 2018.
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DWS. 2015. The determination of water resource classes and associated resource quality objectives in the Inkomati Water Management Area. Main summary report. Compiled by D Louw and S Koekemoer for Rivers for Africa. DWS Report, RDM/WMA05/00/CON/CLA/0215.
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DWS. 2017. Regulations regarding the procedural requirements for water use licence applications and appeals. GN267 in Government Gazette No. 40229 dated 24th March 2017.
DWS. 2019. Reserve determination study of water resources in the Inkomati catchment. GN998 published in Government Gazette 42584 dated 19th July 2019.
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Graham, M. and Louw, M.D. 2008. River Ecocassification: Manual for Ecostatus Determination (Version 2). Module G: Index of Habitat Integrity. Section 2: Model Photo Guide. WRC Report No. TT 378/08. Water Research Commission, Pretoria, South Africa.
Granger, T., T. Hruby, A. McMillan, D. Peters, J. Rubey, D. Sheldon, S. Stanley, E. Stockdale. 2005. Wetlands in Washington State - Volume 2: Guidance for Protecting and Managing Wetlands. Washington State Department of Ecology. Publication #05-06-008. Olympia, WA.
Kleynhans, C.J. 1984. Die verspreiding en status van sekere seldsame vissoorte van die Transvaal en die ekologie van sommige spesies. University of Pretoria.
Kleynhans, C.J. 1996. A qualitative procedure for the assessment of the habitat integrity status of the Luvuvhu River (Limpopo System, South Africa). 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.
Kleynhans, C.J., Thirion, C.A., Moolman, J. & Gaulana, L. 2005. A Level II River Ecoregion classification System for South Africa, Lesotho and Swaziland. Report No. N/0000/00/REQ0104. Department of Water Affairs and Forestry - Resource Quality Services, Pretoria, South Africa.
Kleynhans, C.J. and Louw, M.D. 2007. Module A: EcoClassification and EcoStatus determination in River EcoClassification: Manual for EcoStatus Determination (Version 2). Joint Water Research Commission and Department of Water Affairs and Forestry report. WRC Report No. TT 329/08.
Kotze, D.C., Marneweck, G.C., Batchelor, A.L, Lindley, D.S. and Collins, N.B. 2005. A rapid assessment procedure for describing wetland benefits. Mondi Wetland Project.
Kotze, D.C., Marneweck G.C., Batchelor, A.L., Lindley, D.S. and Collins, N.B. 2007. Wet-EcoServices. A technique for rapidly assessing ecosystem services supplied by wetlands. WRC Report No. TT 339/09. Water Research Commission, Pretoria.
Macfarlane D.M., Dickens. J. and Von Hase F. 2009. Development of a methodology to determine the appropriate buffer zone width and type for developments associated with wetlands, watercourses and estuaries Deliverable 1: Literature Review. INR Report No: 400/09.
Macfarlane, D.M., Kotze, D.C., Ellery, W.N., Walters D., Koopman V., Goodman, P. and Goge, M. 2009. WET- Health: a technique for rapidly assessing wetland health. WRC Report No. TT 340/09. Water Research Commission, Pretoria.
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Mucina, L. & Rutherford, M.C. 2006. The Vegetation of South Africa, Lesotho and Swaziland. Strelitzia 19. South Africa National Biodiversity Institute, Pretoria.
Nel, J.L. & Driver, A. 2012. National Biodiversity Assessment 2011: Technical Report. Volume 2: Freshwater Component. CSIR Report Number CSIR/NRE/ECO/IR/2012/0022/A. Council for Scientific and Industrial Research, Pretoria.
Nel, J.L., Murray, K.M., Maherry, A.M., Petersen C.P., Roux, D.J., Driver, A., Hill, L., Van Deventer, H., Funke, N., Swartz, E.R., Smith-Adao, L.B., Mbona, N., Downsborough, L. and Nienaber, S. 2011a. Technical Report: National Freshwater Ecosystem Priority Areas project. WRC Report No. 1801/2/11. WRC, Pretoria.
Nel, J.L., Driver, A., Strydon, W.F., Maherry, A., Petersen, C., Hill, L., Roux, D.J., Nienaber, S., Van Deventer, H., Swartz, S. & Smith-Adao, L.B. 2011b. Atlas of Freshwater Ecosystem Priority Areas in South Africa. WRC Report No.TT 500/11. Water Research Commission, Pretoria.
Renard, K.G., Foster, G.R., Weesies G.A., McCool, D.K and Yoder, D.C. 1997. Predicting Soil Erosion by Water: A guide to conservation planning with the Revised Universal Soil Loss Equation (RUSLE). USDA Agricultural Handbook No. 703, 404 pp. Available online http://www.ars.usda.gov/SP2UserFiles/Place/64080530/RUSLE/AH_703.pdf [accessed 10 March 2020].
Robin, K. 2017. Local Action for Biodiversity: Wetland Management in a Changing Climate. Ehlanzeni District Municipality Wetland Report. ICLEI – Local Governments for Sustainability. March 2017.
Roux, F., Hoffman, A. and Diedericks, G.J. 2017. Serranochromis meridianus. The IUCN Red List of Threatened Species 2017: e.T20160A99462846. https://www.iucnredlist.org/species/20160/99462846
Rowntree, K.M., Wadeson R.A. and O'Keefe, J. 2000. The development of a geomorphological classification system for the longitudinal zonation of South African rivers. S. Afr. Geogr. J. 82 (3) 163-172.
Russel, W.B. 2009. WET-RehabMethods: National guidelines and methods for wetland rehabilitation. WRC Report No. 341/09. Water Research Commission, Pretoria.
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Skelton, P.H. 1987. South African Red Data Book - Fishes. South African National Scientific Programmes Report 137. Council for Scientific and Industrial Research, Pretoria.
Skelton, P.H. 2001. A Complete Guide to the Freshwater Fishes of Southern Africa. Struik Publishers, Cape Town, South Africa.
South African Biodiversity Institute (SANBI). 2011. National Biodiversity Assessment 2011: Synthesis Report. South African National Biodiversity Institute. Pretoria.
Van Ginkel, C.E., Glen, R.P., Gordon-Gray, K.D., Cilliers, C.J., Muasya, M. and van Deventer, P.P. 2011. Easy identification of some South African Wetland Plants (Grasses, Restios, Sedges, Rushes, Bulrushes, Eriocaulons and Yellow-eyed grasses). WRC Report No. TT479/10. Water Research Commission, Pretoria.
Van Niekerk, L., Adams, J.B., Lamberth, S.J., MacKay, C.F., Taljaard, S., Turpie, J.K., Weerts S.P. & Raimondo, D.C., 2019 (eds). South African National Biodiversity Assessment 2018: Technical Report. Volume 3: Estuarine Realm. CSIR report number CSIR/SPLA/EM/EXP/2019/0062/A. South African National Biodiversity Institute, Pretoria. Report Number: SANBI/NAT/NBA2018/2019/Vol3/A. http://hdl.handle.net/20.500.12143/6373.
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ANNEXURE A: SELECTED BORROW PIT, WATERCOURSE AND WETLAND (BENCH AND SEEP) PHOTOGRAPHS* *Annotated with basic descriptions.
Photo 1: Borrow pit 1 (BP1), north facing view. Photo 2: BP1, north and west facing view. Photo 3: Borrow pit 2 (BP2), south and west facing view.
Photo 4: Borrow pit 2 (BP2), south and east facing view. Photo 5: W01 (NFEPA Unit ID_10589), north and east Photo 6: W01, east facing view. facing view. GPS location (centre): 24°33'37.64"S; 31°20'8.93"E www.ncc-group.co.za D4407 Road Upgrade Freshwater Assessment Report – Mar 2020 Page 72 of 105
Photo 7: W01, north and west facing view towards W03. Photo 9: W01, south facing view. Photo 8: W01, north facing view.
Photo 10: W02 (NFEPA Unit ID_10595), north and west Photo 11: W02, west facing view. Photo 12: W02 earth dam wall, north facing view. facing view. GPS location (centre): 24°33'40.33"S ; 31°20'17.14"E
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Photo 13: Agriculture activity +/-70m north of W02, north Photo 14: W04 (NFEPA Unit ID - 10740), west facing view. Photo 15: W04, south-west facing view. facing view. GPS location (centre): 24°35'5.99"S; 31°19'46.91"E
Photo 16: W04, south facing view. Photo 17: W04, north-west facing view. Photo 18: W05 (NFEPA Unit ID_10780), a tributary of the Nwaswitsontso. Downstream / east facing view. GPS location (centre): 24°35'32.84"S; 31°20'51.95"E
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Photo 19: W05, west facing view. Photo 20: Tributary of of the Nwaswitsontso above W05, Photo 21: W05, west facing view showing BP2 in far upstream / west facing view. background.
Photo 22: Acces road through W05, south facing view. Photo 23: Drainage line donga due east of Culvert 14 +/- Photo 24: Drainage line donga due east of Culvert 14, Borrow pit 2 can be seen on right hand side in far 5m from the D4407, north-west facing view. An un- downstream (east-facing) view. background. named, non-perennial watercourse originates at this point flowing into W05 +/-1.6km downstream from the D4407.
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Photo 25: Planned poistion of Culvert 25 before the western bend in the road direction towards Culvert 26. The start of the drainage line/active watercourse channel is +/- 80m to the east from the edge of the road.
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Photo 26: Culvert 22 bridge construction site on tributary Photo 27: West facing (upstream) view of the Photo 28: Temporary road diversion and drainage culvert of the Nwaswitsontso, south facing view. Nwaswitsontso non-perrenial tributary adjacent to the installed on road / watercourse crossing whilst bridge bridge crossing site (Culvert 22). construction is underway (far background).
Photo 29: East facing view of the Nwaswitsontso non- Photo 30: Bridge construction underway for the Photo 31: Bridge construction site in the Nwaswitsontso perrenial tributary immediately downstream of the permanent road, east (downstream) facing view. tributary at D4407 road crossing, north facing view. temporary (diverted) road crossing and drainage culvert.
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ANNEXURE B: SELECTED HISTORICAL AERIAL IMAGERY
B1 – 1944 B2 – 2018
Figure B1 & B2: Historical aerial imagery showing drainage and the landscape pre-existence of the D4407 (left image dated 1944) and the current road position north of the drainage lines (right image dated 2018). Installation of culverts 27-32 are planned for road drainage purposes along this section of the D4407. Scale not indicated. (Source: CDNGI).
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Figure B3: Historical aerial image, dated 24.06.1974, of an unnamed non-perrennial watercourse flowing eastward through the settlement of Welverdiend. The watercourse is a tributary of the Nwaswitsontso, also a non-perrennial stream in the upper reaches. Some historical erosion scars are visible at the road crossing as well as along the stream bank downstream from the road crossing. The D4407 crosses this watercourse where a new bridge is currently under construction at Culvert 22. Scale not indicated. (Source: CDNGI).
Figure B4: Historical aerial image (dated 24.05.1996) of the same unnamed watercourse showing the D4407 road/watercourse crossing. Historical erosion is visible at the road crossing as well as along the stream bank downstream from the road crossing. Scale not indicated. (Source: CDNGI).
Figure B5: Recent historical aerial image dated 09.05.2018. The positions of the bridge (Culvert 22) and several other drainage culvert positions along the D4407 are shown. Scale not indicated. (Source: Google Earth). www.ncc-group.co.za D4407 Road Upgrade Freshwater Assessment Report – Mar 2020 Page 79 of 105
Figure B6: Recent satellite image, dated 24.05.2019, of D4407 road / watercourse crossing at Culvert 22 (GPS: 24°34'47.44"S; 31°21'3.24"E) prior to bridge and road construction (Source: Google Earth).
Figure B7: Recent satellite image, dated 29.07.2019, of D4407 road showing construction works and diversions at culvert 22 for purposes of bridge construction (Source: Google Earth).
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Figure B8: Wetlands (farm dams) W01 and W02. Aerial image dated 21.06.1974. Scale not indicated. Reference: Job no, photo no. & strip no: 740_14_02121. (Source: CDNGI).
Figure B9: Wetlands (farm dams) W01 and W02. Aerial image dated 09.02.2018. Scale not indicated. Reference job no: 07_2018_1310 (Source: CDNGI).
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Figure B10: W04 (farm dam) present in 2018. Scale not indicated. Reference job no: 07_2018_1310 (Source: CDNGI).
Figure B11: W04 (farm dam) not present in 1944. Scale not indicated. Reference job no, photo no. & strip no: 56_27_02925 (Source: CDNGI).
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Figure B12: Wetland /farm dam W04 (10740). Aerial image dated 21.06.1974. Damming of the watercourse would have been done between 1944 and 1974. Scale not indicated. Reference: Job no, photo no. & strip no: 740_14_02121 (Source: CDNGI).
Figure B13: Wetland /farm dam W04 (10740). Aerial image dated 24.05.1996. Scale not indicated. Reference: Job no, photo no. & strip no: 740_14_02121 (Source: CDNGI).
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Figure B14: Farm dam / W05 (10780). Aerial image dated 21.06.1974. Scale not indicated. Reference: Job no, photo no. & strip no: 740_14_02121. (Source: CDNGI).
Figure B15: Farm dam / W05 (10780) (aerial image dated 24.05.1996). Scale not indicated. Reference: Job no, photo no. & strip no: 986_40_05416. (Source: CDNGI).
Figure B16: Farm dam / W05 (10780). Aerial image dated 09.02.2018. Scale not indicated. Reference job no: 07_2018_1310 (Source: CDNGI).
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Figure B17: Aerial image of W05 dated 29.07.2019 with Borrow pit 2 footprint highlighted in red (Source: Google Earth).
Figure B18: Aerial image of W05 dated 09.05.2018 with Borrow pit 2 footprint highlighted in red. Riparian and wetland vegetation growth more prominent and visible (Source: Google Earth).
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ANNEXURE C: HISTORICAL TOPOGRAPHICAL MAPS
Figure C1: Topographical map extract (2431CB Manyeleti) photographed in Figure C2: 2018 topographical map showing the D4407 road upgrade project
1965 drawn in 1970 showing the section of the D4407 between Welverdiend (red line on map) between Welverdiend and Hluvukani (Source: CDNGI). and Tsakane (what is today Hluvukani) (Source: CDNGI).
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ANNEXURE D: GEOLOGY AND SOIL ERODABILITY
Figure D1: Study area geology (lithology and lithostratigraphy). Figure D2: Study area soil erodability.
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ANNEXURE E: TERRAIN UNIT INDICATORS FOR WETLANDS/DAMS (ELEVATION/LONGITUNDIAL PROFILES)
Figure E1: Longitudinal profile on a non-perennial tributary of the Nwaswitsontso showing terrain unit indicator for W01, W02 and W03 (natural seep and benches / artificial dams on a non-perennial watercourse).
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Figure E2: Longitudinal profile on a non-perennial tributary of the Nwaswitsontso showing terrain unit indicator for W04 (bench as an artificial dams on a non-perennial watercourse).
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Figure E3: Longitudinal profile on a non-perennial tributary of the Nwaswitsontso showing terrain unit indicator for W05 (bench as an artificial dam with natural slope seeps, W06, on a non-perennial watercourse).
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ANNEXURE F: GUIDANCE ON INLAND WETLAND/AQUATIC ECOSYSTEM CLASSIFICATION
Figure F1: Conceptual illustration of the seven primary HGM Units and their typical landscape settings (Source: Ollis et al., 2013).
Figure F2: Conceptual illustration of a river showing the typical landscape setting and the dominant inputs, throughputs and outputs of water (Source: Ollis et al., 2013).
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Figure F3: Conceptual illustration of different bench type-wetland settings (Source: Ollis et al., 2013).
Figure F4: Conceptual illustration of a seep (a primary HGM type) showing the typical landscape setting and the dominant water inputs, throughputs and outputs (Source: Ollis et al., 2013).
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ANNEXURE G: GUIDANCE ON WETLAND SOIL AND VEGETATION IDENTIFICATION
The transition between terrestrial and wetland (hydrophytic) vegetation and redoxymorphic/hydromorphic and non-wetland (terrestrial) soils, which guided the site assessment, are illustrated in below.
Figure G1: Characteristic redoxymorphic soil features typically expected in the permanent, seasonal and temporary wetland zones (Source: DWAF, 2008).
Figure G2: Typical cross section of a river channel with a distinct riparian zone (Source: DWAF, 2005).
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ANNEXURE H: SOIL AUGER SAMPLES TAKEN ADJACENT TO CULVERT 2
Figure H1: Upper 25cm of soil core. Figure H2: Lower 25cm of soil core.
Figure H3: Soil diagnostic characteristics (colour, hue, Figure H4: Core taken at farm fence line +/-20m from the chroma, no mottling) indicative of a terrestrial soil. road edge.
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ANNEXURE I: PROJECT IN CONTEXT OF THE 2015 MBSP FRESHWATER ASSESSEMENT
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ANNEXURE J: PROJECT FOOTPRINT LOCALITY IN CONTEXT OF FRESHWATER ECOREGIONS OF THE WORLD
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ANNEXURE K: RATIONALE FOR NOT ASSESSING CERTAIN AQUATIC COMPONENTS
The Present Ecological Sate (PES) of a given river or river reach, which relates intrinsically to its habitat and aquatic biodiversity, is expressed in terms of various components. Components include drivers (physico- chemical, geomorphological and hydrological) and biological responses (fish, riparian vegetation and aquatic macroinvertebrates) (Kleynhans, 2008). Given the non-perennial nature of the streams in the study area and no flow underway at the time of the assessment, the components of freshwater aquatic systems which are typically included in an aquatic impact assessment were not possible to assess.
To summarise, the aquatic components not assessed as part of this study area were:
i) Water quality assessment (in-situ) *Including any historical water quality desktop assessment Given that aquatic biota are influenced by the environment in which they live, the assessment of water quality variables is important for the interpretation of any results obtained during biological investigations. However no flowing surface water was present at the time of the assessment and this phenomenon is the case for most of the time. The exception would be episodic, temporary flash floods when flow is intermittent but short-lived with water quality (physico-chemical variables) not feasible to repeatedly monitor.
ii) Aquatic macroinvertebrate assessment Aquatic macroinvertebrates are typically assessed using a combined approach using the Invertebrate Habitat Assessment System (IHAS) after by McMillan (1998) in conjunction with the South African Scoring System Version 5 (SASS5) (after Dickens and Graham, 2002) and the Macro-Invertebrate Response Assessment Index (MIRAI) (after Thirion, 2008) in order to determine the PES using reference data in combination with an assessment of the current situation i.e. a site-specific study. For the reasons provided above, no macroinvertebrate assessment was carried out.
iii) Fish (Icthyofauna) assessment As with macroinvertebrates, fish are useful bio-indicators in flowing streams and rivers, either at a site or in a given river reach/study area to assess impacts on habitat conditions (or integrity) or PES of the freshwater ecosystem. Whilst reference fish data does exist for perennial rivers in the broader catchment, there was none specific to the study area locality. For these reasons, the author considered it unfeasible for any field-based fish sampling or bio-assessment as part of this study.
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ANNEXURE L: CLOSEST DATA *SITES IN RELATION TO STUDY AREA
* FBIS sites, formerly Rivers database sites
FBIS site code Site description GPS location Geomorphological River Catchment zone X3SAND-ALLAN Allandale 24°43'54.39"S Lower foothill Sandrivier X32H Plantation 31°15'57.08"E X3SAND-OTHAW Othawa 24°46'1.34"S Lower foothill Sandrivier X32G 31°24'21.65"E
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Based on records in the Freshwater Biodiversity Information System (FBIS), Box 1 and 2 are summaries of available invertebrate data for the two closest sites in two of the four quaternary catchments relating to the study area. There are no fish or algal records at these sites.
(Source: 2015 Rivers Database accessed through FBIS - freshwaterbiodiversity.org)
Box 1 Box 2
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ANNEXURE M: OVERVIEW OF AQUATIC BIODIVERSITY IN THE STUDY AREA
Screening report map showing the sensitivity of aquatic biodiversity sensitivity (Low) in relation to the project footprint (site area) within the study area (Source: DEA Screening tool: https://screening.environment.gov.za).
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ANNEXURE N: WATERCOURSE (FRESHWATER RESOURCE) RISK ASSESSMENT
Borderline LOW / MODERATE Rating Classes (Residual Risk Rating if ALL
No Phase Activity Aspect(s) Impact(s) Control / mitigation measures Controls &
Biota
Severity
Duration Detection
Likelihood Mitigation
Legal Issues
Significance
Spatial Spatial Scale Flow Regime
Consequence measures are
Residual Rating Risk Frequency of Impact
Frequency of Activity implemented and EIS of Watercourses of EIS
followed) Watercourses of PES
Habitat Habitat (Geomorph & Vegetation)
Physico & Chemical (Water Quality) Confidence Level (Low, Med or High)
Potential surface water pollution and associated biotic impacts from spills/leaks of • Adhere to project-specific Environmental Management Programme (EMPr). hazardous substances such as oils, grease, hydrocarbons and volatile organic 1 2 1 1 1 1 1 3.3 2 2 5 3 12 39 L Med • Compile a Site Access & Layout Plan. L compounds (VOCs). • Detailed environmental method statements for working within and close to watercourses (i.e. at the road culverts and borrow pit 2) should be prepared and submitted for approval. • Temporary access roads, site camp laydown areas and storage areas for plant and vehicles should not encroach into any drainage lines / wetlands / waterbodies / freshwater habitats and the proposed 32m watercourse and 40m wetland buffers (No-go areas). Disturbance of riparian / wetland habitats (aquatic vegetation and fauna) and soils. 1 2 1 1 1 1 1 3.3 2 2 5 3 12 39 L Med L Operation of vehicles, plant, • Unless part of the construction footprint, adhere to the No-go areas. Site camp equipment and machinery; Site • Watercourse and wetland areas identified and mapped must be treated as areas of higher ecological sensitivity, more particularly the stream crossing and bridge construction site (culvert establishment clearing (vegetation stripping, Stripping of vegetation, alteration of soil profiles and exposure of bare soils to wind 22) and the bench wetland close to borrow pit 2. 1 1 2 1 1 1 1 1 3.3 2 2 5 3 12 39 L Med L (for soil disturbance and stockpiling) and rain effects will increase/accelerate the rate and risk of erosion. • Appoint ECO to monitor and report on environmental compliance until construction phase and appropriate rehabilitation has been undertaken. construction) material delivery, laydown • All contractors and employees to undergo environmental awareness induction training including inter alia aspects on sensitive ‘no-go’ areas (freshwater resources), the need to avoid storage, installations. Increased turbidity, suspended solids and sedimentation of nearby and downstream 1 2 1 1 1 1 1 3.3 2 2 5 3 12 39 L Med littering, use of ablutions, reporting and cleaning of spills and leaks. L water resources. • With the exception of W03 (seep wetland), all other delineated wetlands, although falling within the ‘regulated area’ (i.e. within the 500m buffers), do not form part of the project scope Stormwater (increased volumes and uncontrolled run-off). 1 2 1 1 1 1 1 3.3 2 2 5 3 12 39 L Med (footprint) and as such, no construction activity or access in or within these systems should be permitted. They should be avoided at all times and be demarcated as ‘No-go’ areas for L construction vehicles and personnel. Adequate ‘No-go’ signage should be placed at suitable, visible locations adjacent to these systems. Potential risk of alien plant invasion into watercourses due to ground surface 1 2 1 1 1 1 1 3.3 2 2 5 3 12 39 L Med • Ensure that the road (including the culverts and any ancillary drainage infrastructure) and borrow pit footprints do not encroach beyond the designed footprint boundaries any further L disturbance. towards adjacent freshwater resources. Changes to flow regime in the watercourse (potential alteration of natural flow • Allow only essential construction personnel and machinery to access and work adjacent to or in freshwater resources in the extent of the “regulated area”. This includes W03 and Culverts patterns, preferential flow paths, soil saturation rates, scouring and erosion due to 2 2 2 1 2 1 1 3.8 2 2 5 3 12 45 L Med 14, 22 and 25. L redirection of flows). • As far as practically possible, all construction activities at road culverts should occur in the low flow season during the drier winter months. All watercourses are non-perennial which should allow construction to continue in the summer (wet) season however construction activity within or adjacent to the culverts, bridge site and borrow pit 2 should cease during and several days Changes to the banks or course of the watercourse. 2 2 2 1 2 1 1 3.8 2 2 5 3 12 45 L Med L after significant rainfall events (i.e. > 10mm) to allow sufficient time for soils to dry out. Daily rainfall measurements by the appointed Contractor will therefore be necessary. • The time period (duration of possible impacts on freshwater resources) during which excavated areas and disturbed soil surfaces at the culvert crossings remain exposed to the elements Disturbance of riparian / wetland habitats (aquatic vegetation and fauna) and soils. 2 2 2 1 2 1 1 3.8 2 2 5 3 12 45 L Med should be minimised as far as possible. Immediate efforts should be put in to action to revegetate such areas as soon as possible, ideally as soon as construction activity at each culvert is L complete. • Culverts should cross at right angles as far as practically possible to minimise impacts in the receiving environment, and any areas where any erosion / bank failure is observed. Temporarily impede / divert the Loss of riparian habitat and structural ecological integrity. 2 2 2 1 2 1 1 3.8 2 2 5 3 12 45 L Med L Construction • Any erosion / bank failure due to the effects of such crossings should be immediately repaired by reducing the gradient of the banks to a 1: 3 slope and where needed necessary, installing natural flow of water during (upgrading) of additional support structures. construction (Excavations, 2 culverts within Stripping of vegetation, alteration of soil profiles and exposure of bare soils to the • ‘Temporary footprints’ i.e. construction camps/offices, equipment storage/laydown areas, parking for plant and vehicles, waste storage areas, hazardous substances storage and ablution cement/concrete, rebar, sand, 2 2 2 1 2 1 1 3.8 2 2 5 3 12 45 L Med L non-perennial elements increasong the potentiak erosion risk. facilities serving the construction phase should be located a reasonable distance away from any freshwater resources. Any chemicals and hazardous substances to be used for construction steel foundations, rock gabions, drainage lines must be stored in impermeable, water proof receptacles and/or bunded areas and on drip trays when in-use on site. pipes) Changes to water quality of the watercourse (increased risk of increased turbidity, • ‘Temporary footprints’ need to be fenced/cordoned off and maintained throughout the project timeframe. It should be possible, based on the position of freshwater resources in relation suspended solids, sedimentation/siltation and potential pollution, via hydrocarbon 2 2 2 1 2 1 1 3.8 2 2 5 3 12 45 L Med L to the project footprint, for these ‘temporary footprints’ to be positioned >100m from any such feature regardless of the proposed 32m and 40m buffers for the ‘Permanent (road) footprint’. spills, of downstream water resources). • Any accidental spills of fuels, cement, chemicals, effluents or other hazardous substances should be reported and acted upon immediately. Effective clean up procedures should be
Stormwater (increased volumes and uncontrolled run-off). 2 2 2 1 2 1 1 3.8 2 2 5 3 12 45 L Med implemented with contractors required to have the necessary spill kits available to ensure that any fuel or oil spills are rapidly cleaned up and disposed of lawfully. All machinery and L (W05) equipment should be inspected regularly for faults and possible leaks and should be serviced off-site at a dedicate workshop area. Re-fuelling must take place over impermeable surface Potential risk of alien plant invasion into watercourses due to ground surface 2 2 2 1 2 1 1 3.8 2 2 5 3 12 45 L Med areas/drip trays to prevent contamination/pollution of soils and water resources. L disturbance. • No storage or dumping of any excavated soils (i.e. stockpiles) and no storage or dumping of any equipment or materials (including rubble) must be allowed within and in close proximity to freshwater resources. All stockpiles must be protected from erosion, stored on flat areas where run-off will be minimised and be surrounded by erosion berms.
Loss / disturbance of wetland and aquatic biodiversity 2 2 2 1 2 1 1 3.8 2 2 5 3 12 45 L Med • Any topsoil (primarily from the borrow pits) should be stockpiled between 2-3 meters in height, conserved and re-used for any rehabilitation purposes. L Low/Moderate
• Construction activities associated with the road upgrade and the associated soil and vegetation disturbances will provide opportunity (i.e. increase the risk) for invasion / spread of invasive (W04, W05,W06)
Changes to the water quality (pollution) of watercourses impacting on frehwater C 3 2 2 1 2 1 1 4.0 2 2 5 3 12 48 L Med alien plants (IAPs). An alien vegetation management and monitoring programme must be implemented during construction to control and remove any alien plants that may encroach into L biota and downstream communities the road and borrow pit footprints as well as adjacent freshwater resources. Stormwater and erosion control Clearing, excavation or infilling of freshwater habitats - habitat loss 3 2 2 1 2 1 1 4.0 2 2 5 3 12 48 L Med L CONSTRUCTION • Appropriate measures must be put in place to minimise erosion and the amount of sediment entering the watercourses and downstream wetlands, regardless of whether the watercourses are non-perennial with little to no flow. Rainfall events, however infrequent, will still act as natural drivers of change and will transport any loose/unconsolidated sediments and/or soils Increased levels of sedimentation and siltation of watercourses / freshwater from exposed surfaces. The risk of erosion is therefore greater during the summer rainfall season and effective stormwater management is therefore important to prepare for such events. (W01, W02,W03)
3 2 2 1 2 1 1 4.0 2 2 5 3 12 48 L Med L B habitats - leading to habitat loss • An appropriate Stormwater management plan must be designed and implemented during the construction phase to control significant changes in hydrology (preferential flow paths and surface water flow) to downstream (receiving) freshwater systems. Whilst the culverts will function to facilitate drainage and surface water flow during the operational phase when the road
Modification of sub-surface water flow dynamics 3 2 3 1 2 1 1 4.3 2 2 5 3 12 51 L Med is complete (i.e. after the construction phase), monitoring of the culverts and immediate surrounding areas should continue during the operational phase. To give structure to road L (W01,Low W02,W03, W04, W06) Operation of large plant / monitoring and maintenance, an operational manual or plan should be developed by the end-user, if one does not already exist. Operation of vehicles, equipment and • Monitor all areas for erosion and incision with particular focus on the bridge, culvert crossings and borrow pits. Any areas where erosion is taking place excessively should be rehabilitated, borrow pit machinery; vegetation Uncontrolled runoff of stormwater 3 2 2 1 2 1 1 4.0 2 2 5 3 12 48 L Med L even if temporarily at first, prior to permanent, final rehabilitation at the end of the construction phase. 3 within clearing/grubbing/stripping, • To prevent the erosion of soils, management measures may include berms, soil traps, hessian curtains and stormwater diversion away from areas particularly susceptible to erosion. watercourse excavations, topsoil stripping Increased volumes of stormwater run-off 3 2 2 1 2 1 1 4.0 2 2 5 3 12 48 L Med • All vegetated areas surrounding the freshwater systems are important to maintain and avoid wherever possible, as they function to buffer and prevent against run-off and erosion. These L regulated area and stockpiling, removal of fill areas function to slow down surface flow velocity, absorb surface storm water runoff and allow sediments to settle out prior to reaching downstream aquatic and wetland systems. materials (gravel) for road. Changes to the banks or course of the watercourse 3 2 2 1 2 1 1 4.0 2 2 5 3 12 48 L Med Vegetation can also provide an additional filtering function for certain pollutants. L • During construction and before the final surfacing of the road is complete, consider installing erosion-control berms on sloped sections of gravel road surfaces. Berms every 50m should be installed where any disturbed soils have a slope of less than 2%, every 25m where the track slopes between 2% and 10%, every 20m where the track slopes between 10% and 15% and every 10m where the track slope is greater than 15%. Changes to the flow regime in the watercourse 3 2 2 1 2 1 1 4.0 2 2 5 3 12 48 L Med L • Sheet runoff from access road surfaces should be slowed down by the strategic placement of berms and sandbags.
Changes to the characteristics of the watercourse 3 2 2 1 2 1 1 4.0 2 2 5 3 12 48 L Med L
Compile an integrated waste management plan/method statement. Solid (general) Incorrect or poor waste All general waste bins should be covered with lids, secured and located as far as practicably possible from watercourses and should be serviced on a regular basis to prevent overflow / 4 waste management practises and Littering and pollution of surface water resources. 1 2 1 1 1 1 1 3.3 2 2 5 2 11 36 L Med L littering. management littering Compile a method statement for hazardous substances. A dedicated, centralised storage area for all hazardous substances (whether short or long-term) should be located >100m from the edge of any watercourse. Management (re-fuelling, Storage areas or receptacles for hazardous substances should be bunded on an impermeable surface to ensure that spills or leaks cause contamination of soil, groundwater or surface water Management of storage and use) of hazardous resources. hazardous substances (fuels, oils, grease, Potential soil and surface water contamination / pollution and associated negative 5 1 3 1 3 2 1 1 4.0 2 2 5 2 11 44 L Med Spill kits should be available at the storage and re-fuelling areas in the event of any accidental spillages or leaks. L substances/ pesticides, fertilisers, paints, biotic impacts (ecotoxicity impacts). All spills and contaminated soil/materials should be cleared up immediately and disposed of appropriately (i.e. as hazardous waste). chemicals volatile organic compounds, Any servicing, repairs or re-fuelling of plant, vehicles and machinery should not take place within 32m/40m from a watercourse / wetland. A dedicated re-fuelling area and workshop (if etc). applicable) should be located > 100m from any watercourse.
All hazardous waste bins should be located as far as practicably possible (>100m) from watercourses and should be serviced on a regular basis to prevent overflow and spillages. Hazardous waste Management (storage and Potential soil and surface water contamination / pollution and associated negative 6 1 3 1 3 2 1 1 4.0 2 2 5 2 11 44 L Med Receptacles for hazardous waste should be clearly, labelled, impermeable, sealed and situated on bunded platforms with adequate cover from rainwater ingress. L management disposal) of hazardous wastes. biotic impacts.
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• A detailed rehabilitation plan be developed by a suitably experienced and qualified rehabilitation specialist during the construction phase (already underway) in order to address any Uncontrolled runoff of stormwater 2 2 1 1 2 1 1 3.5 2 2 5 3 12 42 L Med specific rehabilitation requirements for the culvert crossings. L • All soils compacted as a result of construction activities falling outside of the project footprint areas should be ripped and profiled. Special attention should be paid to alien and invasive control within these areas. Alien and invasive vegetation control should continue from the construction phase into the rehabilitation phase to prevent loss of indigenous vegetation habitats Increased volumes of stormwater run-off 2 2 1 1 2 1 1 3.5 2 2 5 3 12 42 L Med for indigenous fauna. L • As much vegetation growth as possible should be promoted within the disturbed areas of the project footprint in order to protect soils. • Any alien vegetation, including at culvert crossings, should be removed from rehabilitated areas with consideration for re-seeding with indigenous grasses. Consultation with a suitably Rehabilitation of Operation of vehicles, plant and experienced and qualified ecologist in this regard is recommended. disturbed areas machinery; levelling , re- Increased levels of siltation 2 2 1 1 2 1 1 3.5 2 2 5 3 12 42 L Med L • Vegetation cover and re-growth (a mosaic of grasses, forbs, woody species to match the surrouding drainage lines) should be monitored to ensure that sufficient indigenous, natively around culvert shaping; returning topsoil; 7 occurring vegetation is returned. Vegetation will act to stabilise the culvert embankments and wing-wall slopes to minimise and slow down any future erosion and incision. Rehabilitation edges, bridge removal of alien vegetation; will include the disturbed drainage lines at the culverts and any erosion dongas/channels/rills. The need for shrubs or grasses to be replanted is dependant on amount removed during pillars and in indigenous vegetation Changes to the banks or course of the watercourse 2 2 1 1 2 1 1 3.5 2 2 5 3 12 42 L Med L Construction. Denuded and disturbed areas resulting from construction phase to be rehabilitated. watercourses reinstatement. • Any areas where active erosion is observed in the drainage line must be immediately rehabilitated in such a way as to ensure that the hydrology of the area is re-instated to conditions Changes to the flow regime in the watercourse 2 2 1 1 2 1 1 3.5 2 2 5 3 12 42 L Med which are as natural as possible. L • Cutting/ clearing of herbaceous layers within the watercourse buffer area should be avoided so as to retain soil stability provided by the grass root structure. Changes to the water quality of the watercourse 2 2 1 1 2 1 1 3.5 2 2 5 3 12 42 L Med • The culverts should be maintained by keeping debris clear and ensuring that watercourse does not undermine or scour foundations. Any cracks and / or damage should be repaired prior to L the summer rains. Future scouring can be prevented using a combination of methods: concrete repairs, stone pitching, rock mattresses, bioswales, hay, hessian geotextile fabrics e.g. geo- Changes to the characteristics of the watercourse 2 2 1 1 2 1 1 3.5 2 2 5 3 12 42 L Med jutte and re-vegetation. L
Changes to the water quality (pollution) of watercourses impacting on frehwater • A detailed rehabilitation plan be developed by a suitably experienced and qualified rehabilitation specialist during the construction phase (already underway) in order to address any 2 2 1 1 2 1 1 3.5 2 2 5 3 12 42 L Med L biota and downstream communities specific rehabilitation requirements for the borrow pits. • Erosion and siltation of adjacent watercourses (i.e. at Borrow pit 2) and permanent visual/aesthetic scaring should be prevented. Although the borrow pits are unlikely to be returned to
REHABILITATION Uncontrolled runoff of stormwater 2 2 1 1 2 1 1 3.5 2 2 5 3 12 42 L Med L their exact former state, every effort should be made to address the residual impacts during the closure/rehabilitation process. In this regard, the borrow pit footprints shall be rehabilitated and returned to a safe, stable and as closely as possible to their state before construction and borrowing of material.
Increased volumes of stormwater run-off 2 2 1 1 2 1 1 3.5 2 2 5 3 12 42 L Med L (W01, B W02,W03)(W04, C W05, W06) • Progressive rehabilitation in which depleted sections of the borrow pits are reclaimed and rehabilitated while extraction is still on-going in other sections of the same pit should be carried
Operation of vehicles, plant and out. Low (W01, W02, W03, W04, W06) (W05)Low/Moderate machinery; levelling , shaping Increased levels of siltation 2 2 1 1 2 1 1 3.5 2 2 5 3 12 42 L Med • All soils compacted as a result of construction activities falling should be ripped and profiled. L Rehabilitation of and contouring of surface; • As much vegetation growth as possible should be promoted within the disturbed areas of the project footprint in order to protect soils. 8 borrow pits returning topsoil; removal of Changes to the banks or course of the watercourse 2 2 1 1 2 1 1 3.5 2 2 5 3 12 42 L Med • An indigenous vegetation cover, as an estimated target percentage in relation to vegetation cover in the surrounding undisturbed areas, should be ensured within one full growing season L alien vegetation; indigenous during the contractual defects liability period. A 12-month timeframe from ceasing operation of the borrow pits to the target vegetation cover should be allowed for. vegetation reinstatement. Changes to the flow regime in the watercourse 2 2 1 1 2 1 1 3.5 2 2 5 3 12 42 L Med • Special attention should be paid to alien and invasive vegetation control. Alien and invasive vegetation clearing should take place throughout the construction and rehabilitation phases. L • The option of re-seeding with indigenous vegetation (active rehabilitation) in consultation with a suitably experienced and qualified ecologist is recommended. • Vegetation cover should be monitored to ensure that sufficient indigenous, natively occurring vegetation (ideally a mosaic of grasses, forbs, woody species) is re-established to stabilise Changes to the water quality of the watercourse 2 2 1 1 2 1 1 3.5 2 2 5 3 12 42 L Med the soil surface and prevent any erosion and land degradation, and in the case of Borrow pit 2, sedimentation of the adjacent watercourse. L • Rehabilitated borrow pits should be re-vegetated and free-draining upon closure. Changes to the characteristics of the watercourse 2 2 1 1 2 1 1 3.5 2 2 5 3 12 42 L Med L
Stormwater (increased volumes and uncontrolled run-off) 1 1 1 1 1 1 3 5.0 1 2 5 2 10 50 L Med • During the operational phase of the road, the control of vegetation within the road reserve, including alien vegetation, remains a responsibility of the end-user and should continue. L • To this end, a Routine maintenance / environmental monitoring and management plan should be developed and implemented for this specific road upgrade development if the end-user Impeding or diverting Uncontrolled runoff of stormwater 1 1 1 1 1 1 3 5.0 1 2 5 2 10 50 L Med does not have such a Plan.The Plan should include aspects of erosion control, weed control, general rehabilitation as and when required, correction of structures if siltation is excessive, etc. L the flow of water in a • The watercourse and wetland buffers should remain as 'No-go' areas during operations and routinely inspected (manually on foot) for any scour/erosion, litter, alien vegetation, siltation, watercourse. Installed correctly etc. Increased volumes of stormwater run-off 1 1 1 1 1 1 3 5.0 1 2 5 2 10 50 L Med L with rehabilitation carried out, • With proper construction methods followed, limited erosion should occur. Erosion should be monitored and corrective measures taken if observed. impacts to watercourses during • Any areas where active erosion is observed in the drainage line must be immediately rehabilitated in such a way as to ensure that the hydrology of the area is re-instated to conditions Use of paved the operational phase should Increased levels of siltation 1 1 1 1 1 1 3 5.0 1 2 5 2 10 50 L Med which are as natural as possible. L road with not increase beyond the pre- • Cutting/ clearing of herbaceous layers within the watercourse buffer area should be avoided so as to retain soil stability provided by the grass root structure. 9 upgraded construction road senario / • The culverts should be maintained by keeping debris clear and ensuring that watercourse does not undermine or scour foundations. Any cracks and / or damage should be repaired prior to drainage Changes to the banks or course of the watercourse 1 1 1 1 1 1 3 5.0 1 2 5 2 10 50 L Med L condition. Existing negative the winter rains. Future scouring can be prevented using a combination of methods: concrete repairs, stone pitching, rock mattresses, bioswales, hay, hessian geotextile fabrics e.g. geo-jutte culverts OPERATION impacts (erosion, siltation, and re-vegetation. sedilmentation) can be reversed Changes to the flow regime in the watercourse 1 1 1 1 1 1 3 5.0 1 2 5 2 10 50 L Med L gradually overt time if road
drainage infrastructure is (W01, B W02,W03)(W04, C W05, W06)
installed correctly. Changes to the water quality of the watercourse 1 1 1 1 1 1 3 5.0 1 2 5 2 10 50 L Med L Low (W01, W02, W03, W04, W06) (W05)Low/Moderate
Changes to the characteristics of the watercourse 1 1 1 1 1 1 3 5.0 1 2 5 2 10 50 L Med L
This phase must include routine site inspections. The maintenance phase forms part of routine Any small scale basic routine maitenance should be not have significant negative monitoring and maintenance of the road. impacts on watercourses. Positive impacts should result from routine monitoring, Maintenance should include clearing of invasive maintenance repairs and vegetation management in the road reserve. The same 10 In the event of large-scale maintenance or major repairs ro bridges or culverts, the Construction phase related-risks and mitigation measures above apply. vegetation, clearing of general litter & rubbish, construction related watercourse risks (as above) would apply if any large scale repair/rehabilitation of any developing erosion of maintenance and repairs to damages (e.g. re-surfacing of the entire road and/or watercourses and gullies along edges of the major bridge or culvert replacement/repairs) were to be planned in future years. MAINTENANCE culvert inlets and outlets.
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ANNEXURE O: RISK (IMPACT) ASSESSMENT METHODOLOGY
Impact rating tables and calculation of significance TABLE 1 - SEVERITY How severe does the aspects impact on the resource quality (flow regime, water quality, geomorphology, biota, habitat) ? Insignificant / non-harmful 1 Small / potentially harmful 2 Significant / slightly harmful 3 Great / harmful 4 Disastrous / extremely harmful and/or wetland(s) involved 5 Where "or wetland(s) are involved" it means that the activity is located within the delineated boundary of any wetland. The score of 5 is only compulsory for the significance rating.
TABLE 2 - SPATIAL SCALE How big is the area that the aspect is impacting on? Area specific (at impact site) 1 Whole site (entire surface right) 2 Regional / neighboring areas (downstream within quaternary catchment) 3 National (impacting beyond seconday catchment or provinces) 4 Global (impacting beyond SA boundary) 5
TABLE 3 - DURATION How long does the aspect impact on the resource quality? One day to one month, PES, EIS and/or REC not impacted 1 One month to one year, PES, EIS and/or REC impacted but no change in status 2
One year to 10 years, PES, EIS and/or REC impacted to a lower status but can be improved over this period through mitigation 3 Life of the activity, PES, EIS and/or REC permanently lowered 4 More than life of the organisation/facility, PES and EIS scores, a E or F 5 PES and EIS (sensitivity) must be considered.
TABLE 4 - FREQUENCY OF THE ACTIVITY How often do you do the specific activity? Annually or less 1 6 monthly 2 Monthly 3 Weekly 4 Daily 5
TABLE 5 - FREQUENCY OF THE INCIDENT/IMPACT How often does the activity impact on the resource quality? Almost never / almost impossible / >20% 1 Very seldom / highly unlikely / >40% 2 Infrequent / unlikely / seldom / >60% 3 Often / regularly / likely / possible / >80% 4 Daily / highly likely / definitely / >100% 5
TABLE 6 - LEGAL ISSUES How is the activity governed by legislation? No legislation 1 Fully covered by legislation (wetlands are legally governed) 5 Located within the regulated areas
TABLE 7 - DETECTION How quickly/easily can the impacts/risks of the activity be observed on the resource quality, people and property? Immediately 1 Without much effort 2 Need some effort 3 Remote and difficult to observe 4 Covered 5
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TABLE 8: RATING CLASSES RATING CLASS MANAGEMENT DESCRIPTION Acceptable as is or consider requirement for mitigation. 1 – 55 (L) Low Risk Impact to watercourses and resource quality small and easily mitigated. Risk and impact on watercourses are notably and require mitigation measures 56 – 169 M) Moderate Risk on a higher level, which costs more and require specialist input. Watercourse(s)Licence required. impacts by the activity are such that they 170 – 300 (H) High Risk impose a long-term threat on a large scale and lowering of the Reserve. Licence required. A low risk class must be obtained for all activities to be considered for a GA
TABLE 9: CALCULATIONS Consequence = Severity + Spatial Scale + Duration Likelihood = Frequency of Activity + Frequency of Incident + Legal Issues + Detection Significance\Risk = Consequence X Likelihood
Significance Rating Matrix
CONSEQUENCE (Severity + Spatial Scale + Duration) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 6 12 18 24 30 36 42 48 54 60 66 72 78 84 90
7 14 21 28 35 42 49 56 63 70 77 84 91 98 105 8 16 24 32 40 48 56 64 72 80 88 96 104 112 120
9 18 27 36 45 54 63 72 81 90 99 108 117 126 135 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 11 22 33 44 55 66 77 88 99 110 121 132 143 154 165
12 24 36 48 60 72 84 96 108 120 132 144 156 168 180 (Frequency of Activity + + Activity of (Frequency 13 26 39 52 65 78 91 104 117 130 143 156 169 182 195 14Detection) 28 42 56 70 84 98 112 126 140 154 168 182 196 210 15 30 45 60 75 90 105 120 135 150 165 180 195 210 225 16 32 48 64 80 96 112 128 144 160 176 192 208 224 240
17 34 51 68 85 102 119 136 153 170 187 204 221 238 255 LIKELIHOOD Frequency of Incident + Legal Issues + + Issues Legal + ofIncident Frequency 18 36 54 72 90 108 126 144 162 180 198 216 234 252 270 19 38 57 76 95 114 133 152 171 190 209 228 247 266 285 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300
Level of confidence Level of Contributing factors affecting confidence confidence Low A low confidence level is attributed to a low-moderate level of available project information and somewhat limited data and/or understanding of the receiving environment. Medium The confidence level is medium, being based on specialist understanding and previous experience of the likelihood of impacts in the context of the development project with a relatively large amount of available project information and data related to the receiving environment. High The confidence level is high, being based on a sound understanding of the state, functioning and sensitivity of the receiving environment, high availability of project-related data and good understanding of similar impact scenarios.
NCC Environmental Services (Pty) Ltd D4407 Road Upgrade Freshwater Assessment Report – Mar 2020 Page 104 of 105 Reg No: 2007/023691/07
ANNEXURE P: GENERIC MEASURES FOR WETLAND & DRAINAGE LINE REHABILITATION*
*Also see the WRC-published manuals by Day et al. (2016) and Russel (2009) for comprehensive descriptions of additional and further options, measures and recommendations.
- Insert gabion structures which assist in bank and soil stabilisation, reducing erosion and decreasing the speed of water flow. They also provide an area for vegetation to re-establish - Insertion of grass bales; these help bind the soil and slow the rate at which water travels. The slower the water flow, the lower the erosive power of water. Binding and stabilising soil prevents the soil from being washed downstream. The insertion of grass bales creates a backflow of water back into the wetland, pushing the water outwards to create a marshy area. - Drains and gullies can lower the water table and dry out wetlands. They produce excess sediment that affects the wetland downstream/below. It is important to stabilise gully sides and also to stop vertical erosion in the gully. This prevents further lowering of the water table. Materials that can be used are indigenous herbaceous or woody plants, hay bales, clay plugs, gabions filled with rock, geo-textile linings, soil material or loose rocks packed against head-cut faces - Block drainage channels that drain water from or divert polluted water to the wetland, with gabions or earthen plug - Place plugs in gullies to help with bank and soil stabilisation - Fence off sensitive areas to keep livestock grazers out and fence off areas that have been disturbed and which need time for vegetation to re-establish - Plant vegetation to stabilise the soil - Fill in and compact gullies with soil from other nearby area - Plug channels to restore or create wetlands. These can also be used to stabilise and raise the channel floors, thereby reducing flow velocity through the wetland
NCC Environmental Services (Pty) Ltd D4407 Road Upgrade Freshwater Assessment Report – Mar 2020 Page 105 of 105 Reg No: 2007/023691/07