Proposed construction of a 330 kv power line from the Zambezi substation to the Wanela/Sesheke border. Bird Impact Assessment Report

Transcription

1 Proposed construction of a 330 kv power line from the Zambezi substation to the Wanela/Sesheke border Bird Impact Assessment Report Prepared by: African Conservation Services cc Prepared for: Enviro Dynamics cc

2 Name of Project: Principal Client: Implementing Agent: Proposed construction of a 330 kv power line from the Zambezi substation to the Wanela/Sesheke border NamPower Enviro Dynamics cc info@envirod.com PO Box , Windhoek, Namibia Contact no: Fax no: Sub-Consultant: African Conservation Services cc ecoserve@iway.na PO Box 2604, Swakopmund, Namibia Contact no: / Names of Sub-consultant s representatives responsible for executing the sub-contracted services: Dr Ann Scott and Mike Scott Timeframe for Sub-Consultancy: 6 EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line ii

3 EXECUTIVE SUMMARY NamPower intends to construct a new 330 kv transmission line from the Zambezi substation near Katima Mulilo to the Wanela/Sesheke Border Post on the Namibia - Zambia border. Enviro Dynamics cc has been commissioned to carry out an Environmental Impact Assessment (EIA) for the project. This Bird Impact Assessment forms part of the EIA. The proposed power line is estimated to be approximately 3 km long. The servitude will be 80 m wide and, although only approximately 12 m width needs to be totally cleared of tall vegetation, a corridor of 300 m wide is being assessed. The tower structure will be either a guyed V or a self-supporting structure, or a combination. The new line will run in parallel to an existing 220 kv power line with self-supported structures. The study area has a relatively high conservation status, lying adjacent to three Namibian national parks to the west. It falls within the KAZA TFCA (Kavango-Zambezi Transfrontier Conservation Area), comprising the five countries of Angola, Botswana, Namibia, Zambia and Zimbabwe. The Eastern Caprivi Wetlands are classed as an Important Bird Area, involving the entire area east of the Kwando River. These highbiodiversity conservation areas are complemented by a number of communal conservancies and several community forests. East Caprivi as a whole, and its wetlands in particular, hold one of the richest diversities of bird species anywhere in Namibia. A total of 417 bird species has been recorded in the study area, representing 62% of the total number of species found in this country (676). This includes 28 species (7%) that are threatened in Namibia, and 17 (4%) that are Globally Threatened. The latter include one species not yet on the Namibian Red List. Thirty (7%) of the total number of species in the study area are endemic or near-endemic. One hundred and twenty-two species (29%) are migrant for at least some stage of their life and 131 (31%) are nomadic at some stage. It should be emphasised that both short and longer-distance bird movements are possible and highly likely between any of the wetland habitats throughout the area for most if not all of the species. Environmental conditions may change dramatically, especially under flooding, thereby increasing the risk of negative interactions with power lines. Of the total in the study area, 27 (5%) have been recorded as breeding species.(5%) Due to the relatively high number of species involved in the present study, risk assessment and mitigation efforts are directed towards those that have a high biological significance, i.e. primarily Red Data species. EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line iii

4 Thirty-four Red Data bird species are regarded as potentially at risk in these habitats, in particular the following 19 species. These include twelve raptor species, potentially at risk due to their nomadic and/or migrant habits at times, and to restricted binocular vision in some cases, namely Bateleur (E; GT: NT; breeding recorded); Tawny Eagle (E; breeding recorded); Martial Eagle (E; GT: NT); Booted Eagle (E); African Marsh-Harrier (E); African Fish-Eagle (V); Lappet-faced Vulture (V; GT: V); White-headed Vulture (V; GT: V); White-backed Vulture (NT; GT: NT; breeding recorded); Pallid Harrier (NT; GT: NT - in the adjoining area); Hooded Vulture (GT: E) and Secretarybird (GT: NT). Five Red Data aquatic/semi-aquatic bird species are also at risk largely due to their nomadic and/or migrant habits namely: Wattled Crane (CE; GT: V), Rufous-bellied Heron (E); Saddle-billed Stork (E); Lesser Flamingo (V; GT: NT); and Great White Pelican (V). Two Red-listed terrestrial species considered at risk from the proposed development are: Marabou Stork (E), a scavenger species attracted in large numbers to refuse disposal sites and Southern Ground Hornbill (E; GT: V), sensitive to collisions with stay wires, and disturbance/habitat destruction. Thirteen other Red-listed species also occur in the study area but are regarded as being at a lower risk, due to their relatively lower probability of occurrence within the study area. However, this does not imply that there is no risk. These species are: Pel's Fishing-Owl (CE), Blue Crane (CE; GT: V), Yellow-billed Oxpecker (E), Rock Pratincole (E), African Finfoot (E), Slaty Egret (E); Great Crested Grebe (E), African Skimmer (V; GT: NT), Peregrine Falcon (NT), Black-winged Pratincole (NT; GT: NT), Grey Crowned Crane (NT; GT: V), Red-footed Falcon (GT: NT) and Lesser Kestrel (NT); and (in the adjoining area) Eurasian Bittern (CE), Caspian Tern (V). The key potential impacts identified are, mainly, collisions, as well as disturbance and habitat modification/destruction. The entire area covered by the proposed power line is regarded as sensitive in terms of potentially negative bird and power line interactions, in view of the proximity of both natural wetland habitats (including the Zambezi River) and modified habitats that would be attractive to birds (including agricultural areas, an old fish farm, the municipal refuse dumping facility and the sewage ponds). Although bird mortalities may be recorded in low numbers, the cumulative impact of such negative interactions over the entire lifespan of the line is an important consideration. The following practical mitigation measures are recommended in order to reduce negative impacts and enhance benefits. Proactively mark the entire line with an appropriate design of bird flight diverter (e.g. double loop BFD), in order to increase the visibility of the line. "Flag" BFDs with phosphorescent components should be used in combination with the above, to EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line iv

5 increase the visibility of the line under conditions of poor light. The marking design should take the earth wires into account. Ensure that mitigation for bird collisions corresponds with the Botswana link-up at Sesheke. Before construction starts, inspect the proposed power line route for any signs of nests (e.g. of raptors) in large trees or on the existing power line, and avoid the disturbance of breeding birds. Where possible, avoid the unnecessary destruction of nesting habitat (i.e. large trees or shrubs) or degradation of the environment. Enforce anti-poaching measures strictly, and this should be emphasised during induction to contractors; regularly inspect accommodation quarters of construction workers for signs of poaching (e.g. feathers, bones); if there is reason to believe poaching may be taking place, enlist the services of the Ministry of Environment and Tourism or the police to investigate further. Promote ongoing awareness about the negative impacts of disturbance, especially to breeding birds; and of poaching. During induction, stress the need for reporting incidents, and clarify reporting procedures. The following monitoring initiatives are to be conducted by NamPower in collaboration with and with the support of other partners. It is essential that the entire line is monitored in an acceptable way for any signs of bird mortalities resulting from the construction and operation of the line; ideally, dedicated monitoring surveys should be carried out once a month for the first year after completion of the line; thereafter monitoring should be continued at least every quarter and at least up to five years after construction. All mortalities should be recorded and reported to the NamPower SHEW Section for follow up. The effectiveness of mitigation measures should also be monitored; if mortalities are still recorded in areas where mitigation has been fitted, existing devices may need to be replaced, or alternative means of mitigation may need to be investigated. It is also proposed that a dedicated monitoring survey be undertaken on the existing transmission lines near the Zambezi substation (for example within a 10km radius of the substation); the existence of one line already along the route of the proposed power line provides an ideal opportunity for comparative pre- and post-construction monitoring. The details of the survey should be based on the following principles: - The line patrols/monitoring visits should be dedicated to the bird survey work only; EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line v

6 - It is likely that the detection of bird carcasses will be very low in these habitats and densities of human settlement, therefore over-reliance on detecting carcasses may not provide a full understanding of impacts. The surveys should therefore cover both the gathering of data on bird collisions (i.e. carcass remains), as well as observations of live bird species (presence, abundance and movement) and their behaviour at the key focal sites in the area, such as agricultural lands, the river and floodplains, refuse disposal sites and sewage works. - The monitoring project should be designed and supervised by a qualified ornithologist in order to ensure that suitable returns are achieved from the resources invested. This supervision should include the necessary training for the relevant persons. - The surveys should be undertaken at least once-monthly, and on a continuous basis for at least three years prior to revisiting the ornithologist's recommendations. EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line vi

7 TABLE OF CONTENTS EXECUTIVE SUMMARY...iii TABLE OF CONTENTS... vii LIST OF FIGURES AND TABLES... ix ACRONYMS AND ABBREVIATIONS... x 1. INTRODUCTION Background Objectives of the specialist study and terms of reference Methodology Assumptions and limitations LEGAL AND REGULATORY REVIEW AFFECTED ENVIRONMENT Locality and habitats Protected land status Bird diversity Red Data bird species Endemic species Migrant and nomadic species Bird species recorded in power line incidents to date Species considered to be potentially at risk/involved in impacts associated with the project Habitats considered sensitive for bird species Sensitive/breeding times for power line-sensitive bird species IMPACT ASSESSMENT Rationale Identification of key impacts Mitigation/management and monitoring measures CONCLUSIONS AND RECOMMENDATIONS EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line vii

8 REFERENCES ACKNOWLEDGEMENTS APPENDIX 1. Checklist of bird species recorded for four QDS in the Zambezi - Wanela/ Sesheke study area, East Caprivi APPENDIX 2. Power line-sensitive bird species recorded for four QDS in the Zambezi - Wanela/ Sesheke study area, East Caprivi EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line viii

9 LIST OF FIGURES AND TABLES No. & title Page FIGURES 1 Map showing the Caprivi Link Interconnector route, linking Namibia to the Zambian/ Zimbabwean electricity networks (BID) Satellite image showing the locality of the proposed new Zambezi Wanela/ Sesheke 330 kv transmission line near Katima Mulilo Route for the proposed 330 kv power line from the Wanela/Sesheke border to the Zambezi substation Detail of proposed route for the proposed 330 kv power line from the Wanela/Sesheke border to the Zambezi substation Example of the proposed "guyed-v" structure to be used in this project Technical requirements for the "guyed-v" structure of the proposed power line The large Zambezi River is a key wetland feature of the study area in East Caprivi, providing habitat for a rich diversity of bird species Satellite image showing irrigated agricultural area, old fish farm, refuse disposal facility and sewage works in relation to the proposed power line Bird and power line collision incidents on record for the Caprivi Region A juvenile Bateleur involved in a collision incident on the 350HVDC power line near Kongola in August Large numbers of Marabou Storks attracted to a domestic refuse disposal site near Windhoek Distribution of power line-sensitive bird species in the greater study area in East Caprivi, in relation to thee proposed power line route Examples of potential flight paths for birds across the power lines in the study area Standard double loop bird flight diverters may be used to make the line more visible "Flag" bird flight diverters increase the visibility of the line, even under conditions of poor light TABLES 1 Assessment of key impacts relating to the proposed power line EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line ix

10 ACCRONYMS AND ABBREVIATIONS EIA IBA IUCN Environmental Impact Assessment Important Bird Area International Union for the Conservation of Nature IUCN Red List categories LC V NT E CE EW E Least Concern Vulnerable Near Threatened Endangered Critically Endangered Extinct in the Wild Extinct KAZA TFCA QDS SAPP Kavango-Zambezi Transfrontier Conservation Area Quarter Degree Square South African Power Pool EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line x

11 1. INTRODUCTION 1.1 BACKGROUND Figure 1. Map showing the Caprivi Link Interconnector route, linking Namibia to the Zambian/ Zimbabwean electricity networks (BID). NamPower has built a 350kV HVDC transmission link, known as the Caprivi Link Interconnector, between the north-eastern Zambezi Region and the power network in central Namibia (Figure 1 and 2). The Caprivi Link Interconnector provides an asynchronous link between the Namibian and Zambian/Zimbabwean electricity networks to ensure reliable power transfer capability between the east and west of the South African Power Pool (SAPP). The link was also specifically designed to ensure reliable power supply to the Eastern Zambezi that is now connected to the Namibian electricity grid. The ZIZABONA parties (power utilities ZESA, ZESCO, BPC and NamPower) have agreed to cooperate in the development of transmission infrastructure that involves the construction of a high voltage power transmission interconnection between Hwange 330kV substation in Zimbabwe, the proposed Victoria Falls switching station in Zimbabwe, the proposed Livingstone substation in Zambia, the proposed Pandamatenga substation in Botswana and the Zambezi substation in Namibia. The establishment of this specific infrastructure will allow full utilisation of the Caprivi Link interconnector, to the benefit of Namibia and the other SAPP member countries. EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line 1

12 ZAMBIA ANGOLA Katima Mulilo NAMIBIA BOTSWANA ZIMBABWE Figure 2. Satellite image showing the locality of the proposed new Zambezi Wanela/ Sesheke 330 kv transmission line (arrow) near Katima Mulilo; country borders are shown in yellow, and existing 350HVDC power line in Namibia in pink (NamPower/Google Earth 2013). Enviro Dynamics cc is conducting the Environmental Impact Assessment for this project on the Namibian side; Zambia has also appointed an environmental consultant to conduct a similar study on its side. The proposed route is illustrated in Figure 3 and 4. The new 330 kv power line will run from the Namibia-Zambia border approximately 3 km north-west of Katima Mulilo, to the Zambezi substation located approximately 3 km west of Katima Mulilo. The line will be approximately 3 km long, running parallel to an existing 220 kv power line. The structures to be used on the proposed line will either be a guyed or a selfsupporting structure, or a combination of both. An example is illustrated in Figure 5, with its technical requirements in Figure 6. The pylon height for the new line will be about 32 metres and the spacing between the pylons will be between 400 and 500 metres, depending on the wind and weight spans (BID). In contrast, the pylons for the existing 220 kv line are lower (23 metres) and the span of metres (K-H Wagner pers. comm.) is shorter. EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line 2

13 Figure 3. Route for the proposed 330 kv power line from the Wanela/Sesheke border to the Zambezi substation (red line; BID). Figure 4. Detail of proposed route for the proposed 330 kv power line from the Wanela/ Sesheke border to the Zambezi substation (Enviro Dynamics). EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line 3

14 . Figure 5. Example of the proposed "guyed-v" structure to be used in this project (BID). Figure 6. Technical requirements for the "guyed-v" structure of the proposed power line (BID). EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line 4

15 The servitude will be 80 metres wide, but only approximately 12 metres width needs to be totally cleared of tall vegetation. However, the EIA team shall assess a corridor of 300m wide (150m on either side of the proposed centre line). Shrubs and grass will not be removed. The existing service road (constructed for the existing power line) will be utilised to provide access for the construction team and will be utilised for future maintenance works as well. The aims of the EIA for the proposed power line are to: Evaluate the suitability of the proposed route against the biophysical and socio-economic sensitivities of the area; Minimise the negative environmental impacts of the power line and the supporting infrastructure during construction and operational phases, as well as maintenance rounds; Consult all Interested and Affected Parties (I&APs), with specific emphasis on the communities in the affected area to ensure that their needs and concerns are taken into account; and Comply with relevant Namibian legislation, regional policies and procedures. Broad issues and potential concerns identified to date include: Loss of land for cultivation, grazing and other land uses; Loss of vegetation and habitat; Bird collisions and electrocution of birds; General environmental degradation during construction; Health, safety and technical hazards; and Visual impacts, especially with regard to tourism. This Bird Impact Assessment forms part of the above EIA. 1.2 OBJECTIVES OF THE SPECIALIST STUDY AND TERMS OF REFERENCE The Terms of Reference (TOR) set out the work required for a bird impact assessment which needs to be undertaken as part of the Environmental Impact Assessment for the proposed project. The Terms of Reference received from Enviro Dynamics for the Bird Impact Assessment are to undertake a desktop assessment of the potential impacts of the proposed project on birds within and surrounding the project area. EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line 5

16 The study is to be based on the initial Bird Impact Assessment for the EIA of the proposed Katima Ngoma 330 kv transmission line that was carried out in October 2011 by the same authors (Anon. 2011). As the area for the proposed new route is included in the above assessment, the present report will refer to the initial report where relevant rather than repeat the information. 1.3 METHODOLOGY The methodology for the initial study and the present study is provided in Anon Note that whereas 12 Quarter Degree Squares (QDS) provided the basis for the assessment in the initial study, only four QDS form the core area for the proposed new power line in the present study, due to the relatively shorter length of the line. These QDS are: 1724Ac, 1724Ad, 1724Ca and 1724Cb. 1.4 ASSUMPTIONS AND LIMITATIONS The assumptions and limitations for the initial study and the present study are outlined in Anon One further limitation in the present study is that the proposed new power line runs in parallel with an existing power line, which could increase the likelihood of collisions (see below); any mitigation measures fitted to the new line would thus be rendered less effective unless a holistic mitigation design could take both lines into account; however, this is not considered feasible in practice. EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line 6

17 2. LEGAL AND REGULATORY REVIEW The legal and regulatory review for the initial study and the present study is provided in Anon EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line 7

18 3. AFFECTED ENVIRONMENT 3.1 LOCALITY AND HABITATS Figure 7. The large Zambezi River is a key wetland feature of the study area in East Caprivi, providing habitat for a rich diversity of bird species. The study area in north-eastern Namibia within the Caprivi Region and its various associated habitats are described in detail in the initial report (Anon. 2011). One of the key landscape features is several large river systems including the Zambezi River (Figure 7), with their associated floodplains that cross through the Broad-leaved Tree-and-shrub Savanna Sub-Biome (Mendelsohn et al. 2006), the plant life being dominated by several species of large trees that can form a moderately thick canopy. Of additional relevance to the present report is the fact that land-clearing and other human developments have modified natural habitats, at the same time creating new habitats for birds. These include an agricultural area with circular irrigation systems, a fish farm (disused) and a Municipal refuse disposal facility adjacent or close to the power line; a sewage works south of Katima Mulilo (Figure 8); and rice fields near the Zambezi River to the north-east of the town. EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line 8

19 A B C D Figure 8. Satellite image showing irrigated agricultural area (A), old fish farm (B), refuse disposal facility (C) and sewage works (D) in relation to the proposed power line (yellow line; based on a Google map by Enviro Dynamics see Anon. 2011). 3.2 PROTECTED LAND STATUS Protected land status provides an indication of the biodiversity value of an area, and thus of the associated potential increase in risks to biodiversity. The study area has a relatively high conservation status, lying adjacent to three Namibian national parks, all to the west. It falls within the large KAZA TFCA (Kavango-Zambezi Transfrontier Conservation Area), formalised by Treaty in August 2011 and involving the five countries of Angola, Botswana, Namibia, Zambia and Zimbabwe. The Eastern Caprivi Wetlands are classed as an Important Bird Area (IBA), involving the entire area east of the Kwando River (Barnes 1998; Anon. 2011). These highbiodiversity conservation areas are complemented by a number of communal conservancies and several community forests. EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line 9

20 3.3 BIRD DIVERSITY Namibia regularly hosts 676 bird species (Simmons et al. 1998; Simmons & Brown in press), or about 30% of Africa's and 6% of the world's birds. Of these, 73% of the terrestrial species breed in Namibia. East Caprivi as a whole, and its wetlands in particular, holds one of the richest diversities of bird species anywhere in Namibia. A total of 417 bird species has been recorded in the study area, representing 62% of the total number of species found in the country (Appendix 1; Anon. 2011). The most important features of the Eastern Caprivi Wetlands IBA are the swampy areas and floodplains, which are important breeding habitat for wetland birds (Simmons et al. 1998). The area is also rich in raptor species, while various other opencountry species also occur. 3.4 RED DATA BIRD SPECIES The Red Data Book applies the IUCN (International Union for the Conservation of Nature) criteria to determine conservation status of species. Sixty of Namibia s 676 bird species (9% of all bird species recorded for the country) are on the (draft) Red Data list for Namibia (Simmons & Brown in press) and classed by Namibian law as Specially Protected. Of the 417 species recorded in the study area, 28 (7%) are threatened in Namibia (Simmons & Brown in press); in addition, 17 (4%) are Globally Threatened (BirdLife International 2013; Appendix 1 of Anon. 2011), including one species not yet on the Namibian Red List. 3.5 ENDEMIC SPECIES Thirty (7%) of the total number of bird species in the study area are endemic or nearendemic, i.e. with a restricted distribution in southern Africa (Appendix 1; also see Anon. 2011). 3.6 MIGRANT AND NOMADIC SPECIES Of the 417 bird species recorded, 122 (29%) are migrant for at least some stage of their life and 131 (31%) are nomadic at some stage of their life (Appendix 1; also see Anon. 2011). Such movements in an unfamiliar habitat would increase the risk of collisions. EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line 10

21 It should be emphasised that both short and longer-distance bird movements are possible and highly likely between any of the wetland and other habitats (including man-modified parts) throughout the area for most if not all of the species. Environmental conditions may change dramatically, especially under flooding, thereby increasing the risk of negative interactions with power lines. 3.7 BIRD SPECIES RECORDED IN POWER LINE INCIDENTS TO DATE Although several hundred bird and power line interactions have been recorded formally in Namibia to date, relatively few of these pertain to the northern parts of the country (EIS 2013; NamPower/Namibia Nature Foundation Strategic Partnership unpublished data). This relatively low number is ascribed to the difficulty of detecting the remains of carcasses in the bushy habitat, and to scavenging and the high human population densities in settlements. The incidents on record include the following two, both on the 350HVDC line in Caprivi (Figure 9): Bateleur (juvenile): August 2012 near Kongola ( S E) Wattled Crane: December 2012 near the Kwando River ( S E) Figure 9. Bird and power line collision incidents on record for the Caprivi Region (EIS 2013; NamPower/Namibia Nature Foundation Strategic Partnership unpublished data). EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line 11

22 Figure 10. A juvenile Bateleur involved in a collision incident on the 350HVDC power line near Kongola in August 2012 (NamPower/Namibia Nature Foundation Strategic Partnership unpublished data). A number of incidents on the guyed-v structure for the proposed power line have been reported elsewhere in Namibia, involving (mainly) Ludwig's Bustard and Kori Bustard, and also Secretarybird, Black-chested Snake-Eagle, Secretarybird, a Lesser Flamingo and a heron. Incidents on two parallel power line structures are also relatively common; this is considered to be due to the fact that, with the differing heights of conductors involved, there is more potential for collision whether the bird flies upwards or downwards in order to avoid one particular line. Bird vision and power line collisions Recent research indicates that restricted binocular vision when flying forwards is likely to be a key factor in collisions of certain groups of birds on power lines (Martin 2007, 2011). With downward movement of the head of only 25 (e.g. to detect foraging or roost sites, prey or conspecifics), birds such as bustards and cranes may be blind directly ahead when flying (Martin & Shaw 2010) and therefore particularly susceptible to collisions on power lines; this also applies to vultures and eagles (Martin 2011; Martin, Portugal & Murn 2012). Although not yet proven, it is possible that this restricted vision may also apply to all types of korhaans. Thinner earth wires on top of power line structures, which are in any case less visible than the conductors, may be particularly lethal. EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line 12

23 3.8 SPECIES CONSIDERED TO BE POTENTIALLY AT RISK/INVOLVED IN IMPACTS ASSOCIATED WITH THE PROJECT Due to the relatively high number of species involved in the present study, risk assessment and mitigation efforts are directed towards those that have a high biological significance, i.e. primarily Red Data species (Van Rooyen 2008). Based on guidelines provided by Van Rooyen (2010), 31 Red-listed bird species could potentially be affected in a negative way by the development in the study area, and three more in the adjoining area (Appendix 1 and 2; see also Anon. 2011). Of these, the 19 species below are regarded as being at higher risk according to the criteria in Appendix 2: Twelve Red Data raptor species are considered to be at risk in the study area. Although generally fairly sedentary, they are also nomadic and/or migrant at times, which renders them prone to collisions with overhead lines. These species are: - Bateleur (E; GT: NT; breeding recorded) - Tawny Eagle (E; breeding recorded) - Martial Eagle (E; GT: NT) - Booted Eagle (E) - African Marsh-Harrier (E) - African Fish-Eagle (V) - Lappet-faced Vulture (V; GT: V) - White-headed Vulture (V; GT: V) - White-backed Vulture (NT; GT: NT; breeding recorded) - Pallid Harrier (NT; GT: NT - in the adjoining area) - Hooded Vulture (GT: E) - Secretarybird (GT: NT) Five Red Data aquatic/semi-aquatic bird species are also regarded as being at risk, largely due to their nomadic and/or migrant habits that render them prone to collisions with overhead lines, namely: - Wattled Crane (CE; GT: V) - Rufous-bellied Heron (E) - Saddle-billed Stork (E) - Lesser Flamingo (V; GT: NT) - Great White Pelican (V) Two Red-listed terrestrial species considered at risk from the proposed development are: EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line 13

24 - Marabou Stork (E; Figure 11), a scavenger species attracted in large numbers to refuse disposal sites and - Southern Ground Hornbill (E; GT: V), sensitive to collisions with stay wires, and disturbance/habitat destruction. Figure 11. Large numbers of Marabou Storks attracted to a domestic refuse disposal site near Windhoek. Thirteen other Red-listed species also occur in the study area, and two more in the adjoning area, but are regarded as being at a lower risk (Appendix 2); however, this does not imply that there is no risk. These species are: Pel's Fishing-Owl (CE), Blue Crane (CE; GT: V), Yellow-billed Oxpecker (E), Rock Pratincole (E), African Finfoot (E), Slaty Egret (E); Great Crested Grebe (E), African Skimmer (V; GT: NT), Peregrine Falcon (NT), Black-winged Pratincole (NT; GT: NT), Grey Crowned Crane (NT; GT: V), Red-footed Falcon (GT: NT) and Lesser Kestrel (NT); and (in the adjoining area) Eurasian Bittern (CE), Caspian Tern (V). Power line-sensitive Red Data species recorded within the greater study area, on a gradient of percentages, are shown in Figure 12 (Google Earth; EIS 2013). The distribution of such species in the QDS most relevant to the present study (1724Ac, 1724Ad, 1724Ca and 1724Cb) is relatively high. Further details on the species involved are included in Anon EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line 14

25 1724Ac 1724Ad 1724Ca 1724Cb 1724Da 1724Db 1725Ca 1724Cd 1724Dc 1724Dd 1725Cc 1824Ba Figure 12. Distribution of power line-sensitive bird species in the greater study area in East Caprivi, in relation to the proposed power line route (arrow and blue square); proportions of species range from high (dark) to low (light; based on a map by Google Earth/EIS 2013 also see Anon. 2011). Twenty-two other power line-sensitive bird species occur in the study area that are not on the Namibian/Global Rred lists but are also considered potentially cause for concern, with two more species in the greater study area. These species are listed in Appendix 2. Species involved in nest-induced faults A further group of birds to consider is those whose nesting on power line structures could result in nest-induced faults on electrical systems, including Pied Crow and Red-billed Buffalo-Weaver (Appendix 2; see Anon. 2011). EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line 15

26 3.9 HABITATS CONSIDERED SENSITIVE FOR BIRD SPECIES Figure 13. Examples of potential flight paths for birds (yellow arrows) across the power lines (blue line) in the study area (Google map/eis 2013). The entire study area is regarded as sensitive in terms of potentially negative interactions between birds and power lines, in view of the proximity of both natural wetland habitats (including the Zambezi River) and modified habitats that would be attractive to birds (including agricultural areas, an old fish farm, the municipal refuse dumping facility and sewage works). Potential flight paths between these habitats are suggested in Figure 13, indicatiing where they would cross power lines SENSITIVE/BREEDING TIMES FOR POWER LINE-SENSITIVE BIRD SPECIES Although the ideal would be to isolate any months that are relatively less sensitive in terms of the breeding season for construction activities, in practical terms this is not feasible given that this period in effect covers the full range of activities from courtship, nest-building, egg laying and incubation to hatching, chick-rearing, fledging and post-fledging dependence (see Anon. 2011). EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line 16

27 4. IMPACT ASSESSMENT 4.1 RATIONALE In a recent review of causes and mitigation of avian collisions with power lines (with a South African perspective), Jenkins, Smallie and Diamond (2010) summarise: "Many large terrestrial and wetland birds and some smaller fast-flying species are prone to colliding with overhead wires associated with power infrastructure. A high proportion of these are threatened species and for some, collision with power lines and other man-made structures is a significant and damaging source of anthropogenic mortality... Cranes, bustards, flamingos, waterfowl, shorebirds, gamebirds and falcons are among the most frequently affected avian groups, and collision frequency is thought to be an influential factor in ongoing population declines in several species of cranes, bustards and diurnal raptors... ". This high frequency of bird collisions on power lines, especially involving species of biological significance, underlines the need for impact assessment and the proposal of management/mitigation measures. 4.2 IDENTIFICATION OF KEY IMPACTS METHODOLOGY The methodology for the impact assessment is described in Anon POTENTIAL IMPACTS AND KEY IMPACTS IDENTIFIED The following potential impacts have been identified for the proposed power line route. Note that the likelihood of detection of bird carcasses is considered to be relatively low due to factors such as vegetation cover and scavenging of carcasses; this means that bird mortalities could go unreported (Smallie et al. 2009). DIRECT CONSERVATION IMPACTS Bird collisions on power lines A bird collision occurs when a bird in mid-flight does not see the overhead cables until it is too late to take evasive action (Smallie, Diamond & Jenkins 2009; see also Anon for details of the collision process). EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line 17

28 All of the nineteen Red-listed birds identified as being at risk during the present study are potentially threatened by collisions on power lines and/or power line structures (including stay wires; also see Appendix 1. Bird electrocution on power line structures (poles and in substations) A bird electrocution occurs when a bird is perched or attempts to perch on the electrical structure and causes an electrical short circuit by physically bridging the air gap between live components and/or live and earthed components (Van Rooyen 2004; Smallie et al. 2009; see also Anon for further details). In the case of the structure of the proposed transmission line with its relatively large clearances, the risk of electrocution is considered to be low. Electrocution on substations is also not relevant as no new substations will be constructed. Nesting and roosting space for birds on power line structures Direct (positive) conservation impacts include the provision of nesting and roosting space for birds on poles, including eagles and other raptors. INDIRECT CONSERVATION IMPACTS Physical disturbance of birds and modification/destruction of bird habitat During the construction phase and maintenance of power lines and associated structures, a certain amount of disturbance to birds, as well as habitat destruction and/or alteration, inevitably take place (Smallie et al. 2009). Birds may be disturbed while going about their daily activities, such as feeding, roosting and in particular breeding (see Anon for further details). The half kilometre section of the line closest to the Zambian border has tree and bush habitat that could potentially be affected. Southern Ground Hornbill is potentially vulnerable to the above impacts, as well as most raptors (see Appendix 2 for species); DIRECT BUSINESS IMPACTS Electrical faulting caused by birds Birds are able to cause electrical faults on power lines through a number of mechanisms incuding bird streamers, bird pollution and bird nesting (Smallie et al. 2009). The incidence of records of such bird streamer/pollution in Namibia is low. However, nest-induced faulting could be caused by crows and Red-billed Buffalo- Weavers nesting on pylons; to date there is no known effective mitigation for the latter. The potential for such faulting is considered low on the proposed power line. KEY IMPACTS IDENTIFIED The key impacts identified thus comprise collisions, and physical disturbance and habitat modification/destruction (potentially affecting 19 species; Table 1). Although EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line 18

29 the abundance of some of these bird species in the relevant QDS may be relatively low at times, it should be borne in mind that conditions may change dramatically under flooding, resulting in unusual and unpredictable bird movements and an increase in diversity and numbers; and that the cumulative impact of such negative impacts over the entire lifespan of the line is an important consideration. TABLE 1: ASSESSMENT OF KEY IMPACTS RELATING TO THE PROPOSED POWER LINE Project Phase 1. BIRD COLLISIONS ON POWER LINES Construction phase + Operational phase Nature Activity Aspect Criteria Rating without mitigation / enhancement Mortality of birds due to collisions with power line Power line route near a major river and floodplains; also routed through habitats modified for agriculture, aquaculture, a refusedisposal site and a sewage works Risk for rich diversity of birds in these habitats, including many Redlisted species Extent: Local Local Rating with mitigation / enhancement Duration: Permanent Permanent Intensity: Moderate Low Probability: Probable Improbable Significance Moderate Low Degree of confidence in predictions: 2. PHYSICAL DISTURBANCE TO BIRDS AND HABITAT MODIFICATION/DESTRUCTION Construction phase Sensitive species are disturbed in their feeding/ roosting/ breeding areas even though the habitat has been manmodified Construction of new power line; physical disturbance of vehicles and people in area, noise, dust (road mortalities; poaching) Risk for rich diversity of birds in these habitats, including many Redlisted species High 95% High 90% Extent: Local Local Duration: Permanent (should the affected bird species abandon the area) Temporary (should bird species return after activities completed) Intensity: Moderate Low Probability: Probable Improbable Significance: Moderate Low Degree of confidence in predictions: High 95% High 95% EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line 19

30 4.3 MITIGATION/MANAGEMENT AND MONITORING MEASURES The following practical mitigation measures and management actions are recommended in order to reduce negative impacts and enhance benefits. RECOMMENDED MITIGATION MEASURES The following practical mitigation measures are recommended in order to reduce negative impacts and enhance benefits. Proactively mark the entire line with an appropriate design of bird flight diverter (e.g. double loop BFDs; Figure 14), in order to increase the visibility of the line. "Flag" BFDs (Figure 15) with moving black and (phosphorescent) white sections should be used in combination with the above, in order to increase visibility of the line under poor light conditions. The marking design should take the earth wires into account. Figure 14. Standard double loop bird flight diverters may be used to make the line more visible (Anon. 2011). Figure 15. "Flag" bird flight diverters increase the visibility of the line, even under conditions of poor light (Ribe). EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line 20

31 Ensure that mitigation for bird collisions corresponds with the Botswana link-up at Sesheke. Before construction starts, inspect proposed the power line route for any signs of nests (e.g. raptors) in large trees or on the existing power line, and avoid the disturbance of breeding birds. Where possible, avoid the unnecessary destruction of nesting habitat (i.e. large trees or shrubs) or degradation of the environment. Enforce anti-poaching measures strictly, and this should be emphasised during induction to contractors; regularly inspect accommodation quarters of construction workers for signs of poaching (e.g. feathers, bones); if there is reason to believe poaching may be taking place, enlist the services of the Ministry of Environment and Tourism or the police to investigate further. Promote ongoing awareness about the negative impacts of disturbance, especially to breeding birds; and of poaching. During induction, stress the need for reporting incidents, and clarify reporting procedures. MONITORING The following monitoring initiatives are to be conducted by NamPower in collaboration with and with the support of other partners. It is essential that the entire line is monitored in an acceptable way for any signs of bird mortalities resulting from the construction and operation of the line; ideally, dedicated monitoring surveys should be carried out once a month for the first year after completion of the line; thereafter monitoring should be continued at least every quarter and at least up to five years after construction. All mortalities should be recorded and reported to the NamPower SHEW Section for follow up. The effectiveness of mitigation measures should also be monitored; if mortalities are still recorded in areas where mitigation has been fitted, existing devices may need to be replaced, or alternative means of mitigation may need to be investigated. It is also proposed that a dedicated monitoring survey be undertaken on the existing transmission lines near the Zambezi substation (for example within a 10km radius of the substation); the existence of one line parallel to the route of the proposed power line provides an ideal opportunity for comparative pre- and post-construction monitoring. The details of the survey should be based on the following principles: - The line patrols/monitoring visits should be dedicated to the bird survey work only; EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line 21

32 - It is likely that the detection of bird carcasses will be very low in these habitats and densities of human settlement, therefore over-reliance on detecting carcasses may not provide a full understanding of impacts. The surveys should therefore cover both the gathering of data on bird collisions (i.e. carcass remains), as well as observations of live bird species (presence, abundance and movement) and their behaviour at the key focal sites in the area, such as agricultural lands, the river and floodplains, refuse disposal sites and sewage works; - The monitoring project should be designed and supervised by a qualified ornithologist in order to ensure that suitable returns are achieved from the resources invested. This supervision should include the necessary training for the relevant persons; and - The surveys should be undertaken at least once-monthly, and on a continuous basis for at least three years prior to revisiting the ornithologist's recommendations. EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line 22

33 5. CONCLUSIONS AND RECOMMENDATIONS East Caprivi as a whole, and its wetlands in particular, hold one of the richest diversities of bird species anywhere in Namibia. A total of 417 bird species has been recorded in the study area, representing 62% of the total number of species found in this country (676). This includes 28 species (7%) that are threatened in Namibia, and 17 (4%) that are Globally Threatened. The latter include one species not yet on the Namibian Red List. Thirty (7%) of the total number of species in the study area are endemic or near-endemic. One hundred and twenty-two species (29%) are migrant for at least some stage of their life and 131 (31%) are nomadic at some stage. It should be emphasised that both short and longer-distance bird movements are possible and highly likely between any of the wetland habitats throughout the area for most if not all of the species. Environmental conditions may change dramatically, especially under flooding, thereby increasing the risk of negative interactions with power lines. Of the total in the study area, 27 (5%) have been recorded as breeding species.(5%) Due to the relatively high number of species involved in the present study, risk assessment and mitigation efforts are directed towards those that have a high biological significance, i.e. primarily Red Data species. Thirty-four Red Data bird species are regarded as potentially at risk in these habitats, in particular the following 19 species. These include twelve raptor species, potentially at risk due to their nomadic and/or migrant habits at times, and to restricted binocular vision in some cases, namely Bateleur (E; GT: NT; breeding recorded); Tawny Eagle (E; breeding recorded); Martial Eagle (E; GT: NT); Booted Eagle (E); African Marsh-Harrier (E); African Fish-Eagle (V); Lappet-faced Vulture (V; GT: V); White-headed Vulture (V; GT: V); White-backed Vulture (NT; GT: NT; breeding recorded); Pallid Harrier (NT; GT: NT - in the adjoining area); Hooded Vulture (GT: E) and Secretarybird (GT: NT). Five Red Data aquatic/semi-aquatic bird species are also at risk largely due to their nomadic and/or migrant habits namely: Wattled Crane (CE; GT: V), Rufous-bellied Heron (E); Saddle-billed Stork (E); Lesser Flamingo (V; GT: NT); and Great White Pelican (V). Two Red-listed terrestrial species considered at risk from the proposed development are: Marabou Stork (E), a scavenger species attracted in large numbers to refuse disposal sites and Southern Ground Hornbill (E; GT: V), sensitive to collisions with stay wires, and disturbance/habitat destruction. Thirteen other Red-listed species also occur in the study area but are regarded as being at a lower risk, due to their relatively lower probability of occurrence within the study area. However, this does not imply that there is no risk. These species are: Pel's Fishing-Owl (CE), Blue Crane (CE; GT: V), Yellow-billed Oxpecker (E), Rock Pratincole EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line 23

34 (E), African Finfoot (E), Slaty Egret (E); Great Crested Grebe (E), African Skimmer (V; GT: NT), Peregrine Falcon (NT), Black-winged Pratincole (NT; GT: NT), Grey Crowned Crane (NT; GT: V), Red-footed Falcon (GT: NT) and Lesser Kestrel (NT); and (in the adjoining area) Eurasian Bittern (CE), Caspian Tern (V). The key potential impacts identified are, mainly, collisions, as well as disturbance and habitat modification/destruction. The entire area covered by the proposed power line is regarded as sensitive in terms of potentially negative bird and power line interactions, in view of the proximity of both natural wetland habitats (including the Zambezi River) and modified habitats that would be attractive to birds (including agricultural areas, an old fish farm, the municipal refuse dumping facility and the sewage ponds). Although bird mortalities may be recorded in low numbers, the cumulative impact of such negative interactions over the entire lifespan of the line is an important consideration. The following practical mitigation measures are recommended in order to reduce negative impacts and enhance benefits. Proactively mark the entire line with an appropriate design of bird flight diverter (e.g. double loop BFD), in order to increase the visibility of the line. "Flag" BFDs with phosphorescent components should be used in combination with the above, to increase the visibility of the line under conditions of poor light. The marking design should take the earth wires into account. Ensure that mitigation for bird collisions corresponds with the Botswana link-up at Sesheke. Before construction starts, inspect the proposed power line route for any signs of nests (e.g. of raptors) in large trees or on the existing power line, and avoid the disturbance of breeding birds. Where possible, avoid the unnecessary destruction of nesting habitat (i.e. large trees or shrubs) or degradation of the environment. Enforce anti-poaching measures strictly, and this should be emphasised during induction to contractors; regularly inspect accommodation quarters of construction workers for signs of poaching (e.g. feathers, bones); if there is reason to believe poaching may be taking place, enlist the services of the Ministry of Environment and Tourism or the police to investigate further. Promote ongoing awareness about the negative impacts of disturbance, especially to breeding birds; and of poaching. During induction, stress the need for reporting incidents, and clarify reporting procedures. The following monitoring initiatives are to be conducted by NamPower in collaboration with and with the support of other partners. EIA Study for the Proposed Zambezi Wanela/Sesheke 330 kv Transmission Line 24