tyalara qunu 132kv overhea im - gibb

_____

______

• • Tel: 0

__________

_________

Indwe Enviro043 726 6780

• Com

__________

__________

TY

OV

Avifau

nmental Cons0 • Cell: 083 76mpany Registr

_________

__________

ALARA

ERHEA

unal Im

July 20

sulting CC • 166 7514 • Faxration No.: 20

__________

__________

A QUNU

AD POW

mpact A

013 ‐ J201

12 Preston Avex: 086 513 97306/074394/23

__________

__________

U 132KV

WER LIN

Assessm

3‐19

enue • Vincen34 • Email: bre3 • www.indw

__________

__________

V

NE

ment

nt • East [email protected]

__________

__________

don • 5217 • econ.co.za •

1

___

____

2

TYALARA QUNU 132KV OVERHEAD POWER LINE BASIC ASSESSMENT (BA)

Avifaunal Impact Assessment CONTENTS

Chapter Description Page

1 EXECUTIVE SUMMARY 3

2 SPECIALIST DETAILS 5

3 INTRODUCTION 8

3.1 Background 8

3.2 Terms of Reference 8

3.3 Description of Proposed Activities 9

4 METHODS 11

4.1 Methodology 11

4.2 Sources of Information 11

4.3 Limitations & Assumptions 12

5 DESCRIPTION OF AFFECTED ENVIRONMENT 13

5.1 Study Area Vegetation Classification 13

5.2 Bird micro habitats 15

5.3 Relevant Bird Populations 18

6 ASSESSMENT OF IMPACTS 24

6.1 General Description of Impacts of Power Lines on Birds 24

6.2 Description of impacts of this proposed project 25

7 COMPARISON OF ALTERNATIVES 29

7.1 Power line 29

8 IMPACT STATEMENT 30

9 REFERENCES 31

APPENDIX 1 IMPACT ASSESSMENT METHODOLOGY

3

1 EXECUTIVE SUMMARY

Eskom is proposing to construct a new 132kV overhead power line between the Tyalara

substation near the Mbhashe River to the Qunu substation some 20km south of Mthatha

in the Eastern Cape. The power line route generally follows that of an existing 66kV

power line in a north easterly/ south westerly direction. This new power line is required in

order to strengthen the network in the area. The proposed power line is approximately

17.7 kilometres long and will require 58 pole structures to support the cables. The pole

structures will be guyed steel monopoles.

The alignment passes through communal subsistence lands covered by grassland and

some Bhisho Thornveld on the steeper sections. Vegetation has been cleared for arable

lands along the route and remaining grasslands are overgrazed. Rivers, streams and

wetlands are also highly degraded. The power line is however located approximately

11km from the Collywobbles Cape Vulture Colony which is a Birdlife Important Bird Area.

In bird terms, a reasonably low diversity of species could occur on site (at least 125

species recorded in the relevant quarter degree squares by Harrison et al, 1997, of which

four are Red Listed). This low diversity may be at least partially due to the study site being

poorly sampled in terms of the SABAP project. Additional species which are likely to be

found in the study area (based on authors’ knowledge) have therefore been included in

this assessment. The key species which are therefore important to this study are the Cape

Vulture Gyps coprotheres, Martial Eagle Polemaetus bellicosus, Denham’s Bustard Neotis

denhamii and Grey Crowned Crane Balearica regulorum.

Cape Vulture and Martial Eagle are both particularly vulnerable to electrocution on the

proposed power line, but the proposed pole structure (guyed steel monopole) will be

relatively safe for these birds particularly if used together with a standard Bird Perch.

The Grey Crowned Crane and Denham’s Bustard will be further at risk of collision with the

overhead cables, particularly in the grassland, arable lands and areas adjacent to stock

dams and wetlands where they are likely to forage. These sections of the line will require

bird collision mitigation in the form of line marking devices on the earth wire. It is

essential that once the exact route is finalized and individual pole positions surveyed, an

avifaunal walk‐through be conducted in order to identify the exact spans of power line

that will pose a collision risk. This walk through will also identify any sensitive breeding

species that may require special attention. None of these species can afford more

mortalities from power lines, and every effort should be made to mitigate these impacts

4

as effectively as possible. In addition, installation of mitigation for these large‐winged

species will also benefit various other non‐threatened bird species in the area.

Provided that the recommendations of this report, in particular the use of the Bird Perch

on every pole, and the carrying out of an avifaunal walk through as part of the site specific

Environmental Management Plan, are implemented, this project can proceed with

acceptable levels of avifaunal impact.

5

2 SPECIALIST DETAILS

Professional Registration

The Natural Scientific Professions Act of 2003 aims to “Provide for the establishment of

the South African Council of Natural Scientific Professions (SACNASP) and for the

registration of professional, candidate and certified natural scientists; and to provide for

matters connected therewith.”

“Only a registered person may practice in a consulting capacity” – Natural Scientific

Professions Act of 2003 (20(1)‐pg 14)

Role: Specialist Investigator Reviewer

Name: Brendon Steytler (Pr.Sci.Nat) Jon Smallie (Pr. Sci. Nat)

Qualification: BSc (hons) Wildlife Science –

University of Natal

M. Env. & Dev. (Protected Area

Management) ‐ University of

Natal

BSc (hons) Wildlife

Science – University of

Natal

M.Sc Env. Sci.

University of

Witwatersrand

Affiliation: South African Council for Natural

Scientific Professions

South African Council

for Natural Scientific

Professions

Registration number: 400304/06 400020/06

Registration: Professional Member Professional Member

Professional Experience

Brendon Steytler has been involved in avifauna impact assessments for the last five years

related to power lines, power stations and wind farms. Brendon was sub‐contracted by

the Endangered Wildlife Trust to assist as a specialist in the Bird and power interaction

programme. Brendon also attended the EWT/ Birdlife Wind Energy and Bird Interaction

course. Relevant projects include:

» Aggeneis – Helios 400kV power line, Avifauna Impact Assessment, Northern Cape

» Candover – Mbazwana 132kV power lines and substations, Avifauna Impact

Assessment. KwaZulu Natal

» Nondoboyu – Ndumo 132KV power line, Avifauna Impact Assessment. KwaZulu Natal

» Melkspruit – Patensie 132kV power line, Avifauna Impact Assessment, Eastern Cape

» Tombo – Mafini 132kV power line, Avifauna Impact Assessment, Eastern Cape

» Canyon Springs Wind Farm, Avifauna Impact Assessment, Eastern Cape.

6

Jon Smallie has been involved in bird interactions with energy infrastructure for 12 years.

During this time he has completed impact assessments for at least 70 projects, many of

which involved Eskom distribution power lines.. A full Curriculum Vitae can be supplied

on request.

Declaration of Independence

The specialist investigator declares that:

» We act as independent specialists for this project.

» We consider ourselves bound by the rules and ethics of the South African Council for

Natural Scientific Professions.

» We do not have any personal or financial interest in the project except for financial

compensation for specialist investigations completed in a professional capacity as

specified by the Environmental Impact Assessment Regulations, 2006.

» We will not be affected by the outcome of the environmental process, of which this

report forms part of.

» We do not have any influence over the decisions made by the governing authorities.

» We do not object to or endorse the proposed developments, but aim to present facts

and our best scientific and professional opinion with regard to the impacts of the

development.

» We undertake to disclose to the relevant authorities any information that has or may

have the potential to influence its decision or the objectivity of any report, plan, or

document required in terms of the Environmental Impact Assessment Regulations,

2006.

Terms and Liabilities

» This report is based on a short term investigation using the available information and

data related to the site to be affected. No long term investigation or monitoring was

conducted.

» The Precautionary Principle has been applied throughout this investigation.

» Additional information may become known or available during a later stage of the

process for which no allowance could have been made at the time of this report.

» The specialist investigator reserves the right to amend this report, recommendations

and conclusions at any stage should additional information become available.

» Information, recommendations and conclusions in this report cannot be applied to

any other area without proper investigation.

» This report, in its entirety or any portion thereof, may not be altered in any manner or

form or for any purpose without the specific and written consent of the specialist

investigator as specified above.

»

S

» Acceptan

acknowle

Signed on th

nce of this

edgment of t

he 29 July 20

report, in

these terms

13, by Brend

any physic

and liabilitie

don Steytler

cal or digit

es.

in his capacit

tal form, se

ty as Special

erves to co

ist Investigat

7

onfirm

tor

8

3 INTRODUCTION

3.1 Background

Eskom is proposing to construct a new 132kV overhead power line between the Tyalara substation near

the Mbhashe River to the Qunu substation some 20km south of Mthatha in the Eastern Cape. The

power line route generally follows that of an existing 66kV power line. This new power line is required in

order to strengthen the network in the area. The proposed power line is approximately 17.7 kilometres

long and will require 58 pole structures to support the cables. The pole structures will be guyed steel

monopoles.

GIBB (Pty) Ltd. (hereafter referred to as GIBB) has been appointed to undertake the necessary Basic

Assessment (BA) investigations for the planned infrastructure. Indwe Environmental Consulting was

subsequently appointed as avifaunal specialists and a site visit was conducted during July 2013.

Approximately 125 bird species can be found within the study area using lists obtained from the South

African Bird Atlas Project (SABAP). Of the species likely to occur within the Tyalara Qunu study area, only

7 were recorded breeding. A total of 4 Red Listed species were recorded, comprising 2 Vulnerable and 2

Near‐threatened species. It is of note that the number of field card submitted under the SABAP project

for this study area is very low and hence the real diversity of bird species is likely to be higher. Much of

the authors’ knowledge in predicting potential bird species that are likely to occur within the study area

has therefore been employed in this assessment. The reality is that a lot more Red Listed species are to

be found within the study area.

Some of these Red Listed Species are particularly vulnerable to impacts associated with power lines. In

general terms, the impacts that could be associated with a project of this nature include: collision of

birds with the overhead cables; electrocution of birds whilst perched on the tower structures;

destruction of habitat; and disturbance of birds.

3.2 Terms of Reference

The following terms of reference were utilized for this study:

» Describe the current state of avifauna in the study area, outlining important characteristics which

may be influenced by the proposed infrastructure or which may influence the proposed

infrastructure during construction and operation.

» Identify Red Listed species potentially affected by the proposed power line.

9

» Assess the avifaunal status of the study area with the view to identifying sensitive areas and areas

that may be considered as “no‐go”. If appropriate deviations can be suggested, please do so, and

provide supporting reasons for the choice.

» Map all relevant aspects.

» Identify potential impacts (positive and negative, including cumulative impacts if relevant) of the

proposed development on avifauna during construction and operation. Particular attention should

be paid to bird collisions and preventative measures.

» Pay particular attention to wetlands.

» Identify mitigation measures for enhancing benefits and avoiding or mitigating negative impacts and

risks (to be implemented during design, construction and operation of proposed transmission lines.

» Identify and address any other aspects related to avifauna in the study area that should be

incorporated into the reports.

3.3 Description of Proposed Activities

The following are the proposed project activities (see Figure 1):

» Construction of a new 132kV overhead power line from the existing Tyalara Substation to the Qunu

Substation

» It is estimated that this power line will require approximately 58 pole structures to support the

cables.

» These pole structures will be guyed steel monopole structures.

» One potential route exists for the alignment of the power line.

Figur

Vultu

re 1. The Tya

ure Colony in

alara Qunu 1

n the south e

132kV streng

east.

gthening prooject. Note thhe close prooximity to th

10

e Collywobbbles

11

4 METHODS

4.1 Methodology

In predicting impacts of a proposed power line on birds, a combination of science, field experience and

common sense is required. More specifically the methodology used to predict impacts in the current

study was as follows:

» The various data sets listed below and the micro habitats within the study area were examined to

determine the likelihood of these relevant species occurring on or near the site.

» The potential impacts of the proposed facility on these species were described and evaluated.

» Sensitive areas within the proposed site, where the above impacts are likely to occur, were identified

using field work, various GIS (Geographic Information System) layers and Google Earth.

» Recommendations were made for the management and mitigation of impacts.

4.2 Sources of Information

The study made use of the following data sources:

» Bird distribution data of the Southern African Bird Atlas Project (SABAP1 – Harrison, Allan, Underhill,

Herremans, Tree, Parker & Brown, 1997) obtained from the Avian Demography Unit of the University

of Cape Town, in order to ascertain which species occur in the study area. The relevant quarter

degree squares for this project are 3128CD and 3128DD. The more recent SABAP2 data was

consulted online (http://sabap2.adu.org.za/v1/gap_analysis.php), but sufficient coverage of this

study area is not yet available and the data is not necessarily fully representative. The relevant

pentads were recorded as follows: 3150_2825 (total of 1 card), 3150_2830 (total of 5 cards),) and

3145_2835 (total of 1 card). It is therefore only the data from pentad 3150_2830 which has been

incorporated into this assessment.

» The conservation status of all bird species occurring in the aforementioned degree squares was then

determined with the use of The Eskom Red Data book of birds of South Africa, Lesotho and

Swaziland (Barnes, 2000).

» A classification of the vegetation types in the study area was obtained from Mucina and Rutherford

(2006).

» Information on the micro‐habitat level was obtained through visiting the area and obtaining a first‐

hand perspective.

» Electronic 1:50 000 maps were obtained from the Surveyor General.

12

4.3 Limitations & Assumptions

This study made the assumption that the above sources of information are reliable. The following

factors may potentially detract from the accuracy of the predicted results:

» The SABAP 1 data covers the period 1986‐1997. Bird distribution patterns fluctuate continuously

according to availability of food and nesting substrate. (For a full discussion of potential inaccuracies

in SABAP data, see Harrison, Allan, Underhill, Herremans, Tree, Parker & Brown, 1997).

» The number of cards for the SABAP 2 data (of which only 1 card each was submitted for the

3150_2825 and 3145_2835 pentads) are not necessarily indicative of the avifauna of the region.

13

5 DESCRIPTION OF AFFECTED ENVIRONMENT

5.1 Land Use

The proposed power line will traverse communal land along its entire route. The dominant form of

agriculture is communal livestock grazing with cattle, sheep and goats. Villages and associated

settlement is scattered throughout. Crop cultivation exists on a largely subsistence scale. Common

crops grown include maize.

Infrastructure on route includes existing power lines (most noticeable is the new 400kV transmission

line and an existing 66kV line which this proposed line follows, the N2 National Road and gravel access

roads, houses and associated settlement .

The nearest major river system is the Mbhashe River which forms a steeply incised river valley to the

South of the proposed study area. A number of smaller rivers, streams and drainage lines occur on route

of the proposed power line. Small stock watering dams are scattered throughout as are seepage

wetlands.

There are no protected areas traversed by the proposed power line. The nearest Important Bird Area is

the Collywobbles Cape Vulture Breeding Colony which is some 11 kilometres southeast of the power line

route at its closest point (See Figure 1). The importance of this site in the context of this report is

explained in Section 5.4 of this report.

5.2 Study Area Vegetation Classification

The following description of the vegetation on the site focuses on the vegetation structure and not

species composition. It is widely accepted within ornithological circles that vegetation structure and not

species composition is most important in determining which bird species will occur there. The

classification of vegetation types below is from Mucina & Rutherford (2006). Three broad vegetation

types are traversed by the power line. These include Eastern Valley Bushveld, Bhisho Thornveld and

Mthatha Moist Grassland (see Figure 2).

The relevance of this classification for avifauna is that the vegetation present in an area will determine

which bird species are likely to occur there. For much of the route, grassland is dominant forming an

open landscape with a general absence of trees. The relevance of this is that the power line tower

infrastructure is often used as a bird perch. Grasslands are important for ground nesting species. Near

the Tyalara Mountain, the vegetation becomes more wooded with Acacia karroo and Aloe ferox as

common species.

Figurre 2. Vegetattion classificaation for thee Tyalara Quunu 132kV sttudy area (MMucina &Rut

14

herford, 20006)

55.3 Bird M

The a

occur

the s

habit

forme

other

ascer

study

Arab

Arabl

the fo

bulbs

cultiv

the d

dry la

south

visit.

Figur

areas

Micro Habita

above vegeta

r in the stud

tudy area ce

tats available

ed by a com

rs. These m

rtaining whe

y area are sh

le Lands and

le or cultivat

ollowing rea

s and other f

vated are oft

dry season a

andscape. Sm

h around Tya

Important s

re 3. A view

s will attract

ats

ation descrip

dy area. How

ertain specie

e to birds at

bination of f

micro habitat

re mitigation

own in Table

d Pastures

ted land repr

sons: throug

food sources

ten eaten the

rable lands

mall patches

alara Mount

pecies partic

of some ara

t species suc

ption partiall

wever, more

es will occur

a small spat

factors such

ts will be c

n is required

e 1. The follo

resents a sig

gh opening u

s readily acce

emselves by

often repres

s of arable la

ain. These a

cularly likely

able maize la

h as Grey Cr

y describes t

detail is req

and how su

tial scale are

as vegetatio

critically imp

d. The specie

owing micro

nificant feed

up the soil su

essible to bir

birds, or att

sent the only

and exist in

areas had be

to utilise thi

ands along th

rowned Cran

the habitat a

quired in ord

itable these

known as m

on, land use,

portant in r

es most likel

habitats wer

ding area for

urface, land p

rds and othe

ract insects

y green or a

the route of

een mostly p

s habitat inc

he power lin

nes.

available and

der to under

areas are fo

micro habitat

anthropoge

routing the

y to use eac

re observed

r many bird s

preparation

er predators;

which are in

attractive foo

f the power

planted to m

clude the Gre

ne route nea

d hence the s

stand exactl

or the releva

ts. These mic

nic factors, t

proposed p

ch micro hab

on site durin

species in an

makes many

; the crop or

turn eaten b

od sources i

line route e

maize at the t

ey Crowned

ar Tyalara M

15

species likely

y where wit

ant species. T

cro habitats

topography a

power line a

bitat within t

ng the site vi

y landscape

y insects, see

r pasture pla

by birds; dur

n an otherw

especially in

time of the s

Crane.

Mountain. Th

y to

thin

The

are

and

and

this

sit:

for

eds,

ants

ring

wise

the

site

ese

Grass

As m

obser

speci

which

grass

Bellie

1.

Figur

the n

lines.

River

Most

speci

these

study

Mbha

Furth

route

have

sland

mentioned ab

rved to be

es. In addit

h are reside

slands in this

ed Korhaan,

re 4. A view

newly constr

.

rs, Drainage

t rivers in so

es of water

e species cor

y area of the

ashe River s

hermore a nu

e. The crossi

been identif

bove, much

highly overg

tion ground

nt in the ne

s study area

Southern Gr

of the open

ructed 400k

Lines and Fa

outhern Afric

bird are mos

rrelates with

e proposed

uch as the Q

umber of ea

ing of rivers

fied and disc

of the stud

grazed by sh

nesting bird

eighbouring

is an attract

round Hornb

n grasslands

kV overhead

arm Dams

ca are in the

stly restricte

the river co

power line

Qunu and B

rthen dams

by the propo

cussed elsew

dy area is co

heep and ar

s are advers

villages and

tive habitat f

bill, and poss

typical of t

transmissio

e east and e

d to riverine

urses in sout

is the Mbha

uwa Rivers

exist, some

osed power

where in this

onsists of op

re short pro

sely affected

predate on

for Denham’

sibly some o

he northern

on line, and

extreme sout

e habitat in s

thern Africa.

ashe River to

are traverse

which are in

line and the

report.

pen grasslan

oviding little

d by the high

eggs and fl

’s Bustard, G

of the other s

n section of

existing 66

th, in the hig

southern Afri

. The most s

o the south

ed by the po

n very close p

proximity to

nd. These g

e cover for g

h number of

ledglings. N

Grey‐Crowne

species men

the propose

kV and 132

gher rainfall

ica. The map

significant riv

. Smaller tri

ower line at

proximity to

o farm dams

16

grasslands w

ground nest

f domestic d

Nonetheless

ed Crane, Wh

ntioned in Ta

ed route. N

kV distribut

l areas. Vario

p distribution

ver along in

butaries of

various poin

the power l

s are issues t

were

ting

ogs

the

hite

able

ote

tion

ous

n of

the

the

nts.

line

that

Figure

result

Figure

water

e 5. The Buwa

t of erosion an

e 5. An earthe

r birds includi

a River which

nd has little in

en farm dam

ing Grey Crow

is crossed a n

ntact riparian

located along

wned Crane.

number of tim

n habitat.

g the power li

mes by the po

ne route nea

ower line. The

r Qunu. Such

e river is high

h areas will at

17

hly disturbed a

tract a variety

as a

y of

5

Figure

Harrie

Table

area.

lands

norm

time

the a

5.4 Relev

Table

degre

reaso

subm

the a

Repo

used

our c

penta

perce

times

e 5. Typical s

er.

e 1 below sho

It must be s

scape from t

mal habitats.

– so logically

uthors’ exte

vant Bird Po

e 1 lists the

ee squares c

onable numb

mitted per sq

rea but due

orting rates h

as an indicat

onfidence in

ads have bee

entages of th

s that square

seepage wetla

ows the mic

stressed that

time to time

These locat

y that is whe

nsive experi

pulations

Red Listed b

covering the

ber of cards.

quare is also

to poor sam

have been ex

tor of our co

n the data is

en poorly co

he number o

e was count

and which w

ro habitats t

t birds can a

e. However, t

tions are wh

ere impacts

ence gained

bird species

e study area

The total nu

shown. Bas

mpling the nu

xtracted from

onfidence in

higher, and

unted, so ou

of times a s

ted. It is imp

will attract spe

hat each Red

and will, by v

the analysis

ere most of

on those sp

through per

recorded by

a and by th

umber of all

sed on these

mber of spe

m the SABA

that particul

vice versa. In

ur confidence

species was

portant to n

ecies such as

d Listed bird

virtue of the

below repre

f the birds o

ecies will be

rsonal observ

y the SABAP

ose pentads

species reco

e two data se

cies is likely

P1 and SABA

lar report rat

n this study

e in the data

recorded in

note that thi

s Grey Crown

species typi

ir mobility, u

esents each

of that specie

e most signif

vations.

P1 (Harrison

s which wer

orded and th

ets, at least

to be signific

AP2 data. T

te. If lots of

all of the Qu

is not high.

the square,

s data provi

ned Crane an

ically freque

utilise almost

species’ mo

es will spend

icant. Table

et al, 1997)

re counted S

he number of

125 species

cantly highe

he number o

cards have b

uarter Degree

Report rates

, divided by

ides an indic

18

d African Ma

nts in the stu

t any areas i

ost preferred

d most of th

1 makes use

) in the quar

SABAP2 wit

f cards (coun

s could occu

r.

of cards can

been submit

e Grid Cells a

s are essenti

the number

cation of wh

arsh

udy

in a

d or

heir

e of

rter

h a

nts)

r in

be

ted

and

ally

r of

hich

19

species could occur on the proposed site. Based on the authors’ experience, additional red data species

which are likely to occur in the area have been added to the table.

In total only 4 Red Listed species were recorded by the SABAP data across the relevant pentads and

quarter degree squares, comprising 3 Vulnerable and 1 Near‐threatened species (Table 1, Barnes, 2000).

This is more than likely due to poor sampling. Several other Red Listed species are likely to occur in the

study area (based on author’s knowledge) and the total is more likely to be 10 Vulnerable species and 4

Near Threatened species. In addition, the White Stork Ciconia ciconia is highly likely to occur within the

study area and has been included in the Table as it is afforded protection internationally under the Bonn

Convention on Migratory Species.

Using this data in combination with the assessment of the micro habitats available to birds in the area –

an effective assessment of potential impacts of the proposed power line has been made as described in

Section 4.

In general, the study area is fairly densely settled and highly populated with a fairly substantial amount

of arable agriculture taking place. Grasslands are overgrazed and wetlands and rivers are degraded with

high levels of erosion. There is little undisturbed habitat along the proposed power line route. The

most pristine is that associated with the more remote slopes along the Tyalara Mountain range/ ridge

area. The resultant bird diversity is rather low but none the less includes some species which are

sensitive and are worthy of conservation.

Several large‐winged red‐data species have been recorded or are likely to be found in the study area,

which are known to be impacted by power lines from a collision and electrocution risk perspective.

These include Cape Vulture, Martial Eagle, Secretarybird Sagittarius serpentarius, Denham’s Bustard,

Grey Crowned Crane, Blue Crane Anthropoides paradiseus and Southern Ground Hornbill Bucorvus

leadbeteri. In terms of reporting rates recorded in bird atlas data (SABAP1 and SABAP2), more common

species are Cape Vulture and Grey Crowned Crane.

Cape Vulture has been recorded in fairly high reporting rates in those pentads affected by the proposed

power line. Two Cape Vulture individuals were observed crossing the proposed route of the power line

during the field visit. This is the priority species for this study as the former Transkei is a regional strong

hold for the species. The nearest breeding colony is at Collywobbles, some 11 km of the power line at

its nearest point. The Collywobbles site is one of 15 key breeding colony sites for this Globally

Threatened Species and has over 100 active nests (Allan, 2011). Previously the Collywobbles site was

regarded as one of the largest most successful breeding sites for Cape Vulture. Bird counts undertaken

in 1989 show that the site had over 800 birds. There has since been a dramatic decline in the number

of birds over the last 20 years. Botha, et. al.(2011) note that the construction of power lines running

along ridges in the vicinity of the Collywobbles site could pose a particular threat to these vultures

20

frequenting the area. The current proposed power line is close enough to this important colony to

warrant concern.

The primary impact of concern for the vultures is electrocution, which is relatively straight forward to

mitigate for, as explained elsewhere in this study. This species is particularly at risk of electrocution due

to its large physical size (having a wingspan of up to 2.5 metres, and a height of up to 1.18 metres).

These large dimensions increase the likelihood of these birds bridging the critical clearances on power

lines, thereby causing a short circuit and electrocution. Another factor which renders this species

particularly vulnerable to electrocution is its’ gregarious nature. Instead of birds perching individually on

poles (as do large eagles) these birds tend to try to perch together, with multiple birds on one pole

structure. This results in some birds perching in sub‐optimal, and hence more dangerous, positions on

the pole structures. Another factor which renders this species at risk in this particular study area is the

relative absence of large, tall trees to serve as natural perches for the birds. This means that power lines

are probably the tallest structures in this landscape and will be selected as perches by these birds. These

factors in combination make the Cape Vulture the species for which the most birds have been reported

killed through electrocution in South Africa (Eskom‐Endangered Wildlife Trust Central Incident Register).

In addition, Cape Vultures are increasingly reported as colliding with power lines. This is most likely to

occur where the birds congregate either to feed or at roosts or breeding colonies. The current proposed

alignment should not pose a significant collision risk to this species.

A second species for which there is concern is the Grey Crowned Crane. This species has a reasonably

high report rate in the area, and will frequent the arable lands and floodplain areas of the proposed

power line. Cranes are extremely vulnerable to collision with overhead lines. It is assumed that this is

due to their relatively high wing loading (ratio of mass to wing area) which influences their ability to take

evasive action mid‐flight once obstacles are seen. Recent research on bird vision and power line

collisions found that the Grey Crowned Cranes’ close relative, the Blue Crane may be particularly

vulnerable to collision with power lines as its frontal vision is particularly poor (having a small binocular

field of vision – the field within it can judge distance, which is critical to obstacle avoidance), and worse

still, it may not even look forward sufficiently during flight (Martin & Shaw, 2010). It is reasonable to

expect similar factors to influence the Grey Crowned Crane’s vulnerability to collision. It is important to

note at this point that the Grey Crowned Crane has just been up listed from Vulnerable to Endangered

on the 2012 IUCN Red List for birds, due primarily to the impacts of overhead power lines.

Denham’s Bustard has been observed in the open areas (grasslands, and arable lands) in the northern

section of the study area by the authors. This species is at risk of collision with the power line.

Other Red Listed species found in the study area include African Marsh Harrier Circus ranivorus

(observed during field visit), Secretary Bird Sagittarius serpentarius, Lanner Falcon Falco biarmicus

(which are known to breed near Collywobbles as is Black Stork Ciconia nigra.) and White Bellied Korhaan

21

Eupodotis senegalensis. Due to the low abundance of these species the potential impact from the

power line is unlikely.

Due to the large numbers of these birds killed through electrocution and collision throughout their

range, these priority species can ill afford further mortalities on this new proposed line. These impacts

will therefore require mitigation as explained in this study.

It must be noted that many “non‐Red Listed” bird species also occur in the study area and could be

impacted on by the power line. Although this impact assessment focuses on Red Listed species, the

impact on non‐Red Listed species is also assessed, albeit in less detail. Furthermore, much of the

mitigation recommended for Red Listed species will also protect non Red Listed species in the study

area.

22

TABLE 1 – Abundances of Red Listed bird species in the study area (3128CD, 3128DC Harrison et al, 1997), SABAP 2 & their preferred microhabitats.

Species Conservation status

3128CD Report rate (%)

3128DDReport Rate (%)

SABAP2 – 3150_2830 Report Rate (%)

Preferred micro habitat in this study area

Likelihood of occurrence on site

Likely importance of this study area for the species

# cards 15 15 5

Total # species 100 125

Breeding species 7 6

Cape Vulture Gyps coprotheres V 53 40 Grassland Confirmed during field work

High. There are large numbers in the former Transkei area and this study area falls within the southern reaches of the species foraging range. The Collywobbles breeding colony is situated 11 kilometres away and is a source of large numbers of this species.

Black Stork Ciconia nigra NT ‐ ‐ ‐ Riverine and cliffs Possible. Observed breeding near Collywobbles site

Low

White Stork Ciconia ciconia Bonn ‐ ‐ ‐ Grassland, wetland, arable land

Probable Low to medium

Secretarybird Sagittarius serpentarius

NT ‐ ‐ ‐ Savanna, variable Probable Medium

Lesser Flamingo Phoenicopterus minor

NT ‐ ‐ ‐ Open water bodies Unlikely Low

Martial Eagle Polemaetus bellicosus V ‐ ‐ ‐ Savanna, variable Possible – known breeding pair in Kei River Cuttings

Low

African Marsh Harrier V ‐ 7 ‐ Grassland, wetland Confirmed during site visit.

Low

Black Harrier Circus maurus NT ‐ ‐ ‐ Grassland, wetland Possible grasslands in north

Low

23

Species Conservation status

3128CDReport rate (%)

3128DDReport Rate (%)

SABAP2 –3150_2830 Report Rate (%)

Preferred micro habitat in this study area

Likelihood of occurrence on site

Likely importance of this study area for the species

Lanner Falcon Falco biarmicus NT 33 40 ‐ Grassland, arable land Confirmed , seen breeding in broader area. Observed during site visit

Medium – breeding in area

Lesser Kestrel Falco naumanni V ‐ ‐ ‐ Grassland, arable land Unlikely

Denham’s Bustard Neotis denhami V ‐ ‐ ‐ Grassland, arable land Highly probable Low to medium

White‐bellied Korhaan Eupodotis senegalensis

V ‐ ‐ ‐ Grassland, savanna Possible, although not yet recorded by these authors

Low

Blue Crane V ‐ Savanna, arable lands Possible Low to Medium

Grey Crowned Crane Balearica regulorum

V 7

27

‐ Wetland, arable lands Probable – there is a fairly high report rate for this species and ample suitable habitat.

Medium to high

Southern Ground Hornbill Bucorvus leadbeteri

V ‐ ‐ ‐ Grassland and savanna Probable Low to Medium

24

6 ASSESSMENT OF IMPACTS

6.1 General Description of Impacts of Power Lines on Birds

Because of its’ size and prominence, electrical infrastructure constitutes an important interface between

wildlife and man. Negative interactions between wildlife and electricity structures take many forms, but

two common problems in southern Africa are electrocution of birds (and other animals) and birds

colliding with power lines. (Ledger & Annegarn 1981; Ledger 1983; Ledger 1984; Hobbs & Ledger 1986a;

Hobbs & Ledger 1986b; Ledger, Hobbs & Smith, 1992; Verdoorn 1996; Kruger & Van Rooyen 1998; Van

Rooyen 1998; Kruger 1999; Van Rooyen 1999; Van Rooyen 2000). Other problems are electrical faults

caused by bird excreta when roosting or breeding on electricity infrastructure, (Van Rooyen & Taylor

1999) and disturbance and habitat destruction during construction and maintenance activities.

Electrocutions

Electrocution of birds on overhead lines is an important cause of unnatural mortality of raptors and

storks. It has attracted plenty of attention in Europe, USA and South Africa (APLIC 1994; van Rooyen &

Ledger 1999). Electrocution refers to the scenario where 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). Electrocution is possible on 132kV

lines such as that proposed, depending on the exact pole structure used. While vulture electrocutions

have been recorded on steel monopole structures previously, if used with the standard Eskom Bird

Perch, the risk of electrocution should be acceptably low.

Collisions

Collisions are the biggest single threat posed by transmission lines to birds in southern Africa (van

Rooyen 2004). Most heavily impacted upon are bustards, storks, cranes and various species of water

birds. These species are mostly heavy‐bodied birds with limited manoeuvrability, which makes it difficult

for them to take the necessary evasive action to avoid colliding with power lines (van Rooyen 2004,

Anderson 2001). Unfortunately, many of the collision sensitive species are considered threatened in

southern Africa. The Red Listed species vulnerable to power line collisions are generally long living, slow

reproducing species under natural conditions. Some require very specific conditions for breeding,

resulting in very few successful breeding attempts, or breeding might be restricted to very small areas.

These species have not evolved to cope with high adult mortality, with the results that consistent high

adult mortality over an extensive period could have a serious effect on a population’s ability to sustain

itself in the long or even medium term. Many of the anthropogenic threats to these species are non‐

discriminatory as far as age is concerned (e.g. habitat destruction, disturbance and power lines) and

therefore contribute to adult mortality, and it is not known what the cumulative effect of these impacts

could be over the long term. Collision of certain bird species, particularly in the grasslands, arable lands,

25

river crossings and areas adjacent to wetlands and farm dams is anticipated to be an impact of the

proposed power lines and should be prevented as far as possible.

Habitat Destruction

During the construction phase and maintenance of power lines, some habitat destruction and alteration

inevitably takes place. This happens with the construction of access roads and the clearing of servitudes.

Servitudes have to be cleared of excess vegetation at regular intervals in order to allow access to the

line for maintenance, to prevent vegetation from intruding into the legally prescribed clearance gap

between the ground and the conductors and to minimize the risk of fire under the line which can result

in electrical flashovers. These activities have an impact on birds breeding, foraging and roosting in or in

close proximity of the servitude through modification of habitat.

Habitat destruction is unlikely to be a major impact with this project as the study area is mostly open

grassland with little tall vegetation that would warrant any clearing. Furthermore tracks were created

during the construction of the 400KV transmission line which follows the route of the power line in the

northern section. Should these tracks be utilised during the construction phase, then this impact is also

considered fairly insignificant.

Disturbance

Similarly, the above mentioned construction and maintenance activities impact on bird through

disturbance, particularly during bird breeding activities.

6.2 Description of Impacts of this Proposed Project

The impacts of the proposed power lines and substation were rated in the tables below. The criteria

used for this rating can be seen in Appendix 1.

Table 2. Assessment of electrocution of birds on the Tyalara Qunu 132kV power line.

Nature: Electrocution – likely to affect the Cape Vulture in particular

Without mitigation With mitigation

Extent 1 1

Duration 4 4

Magnitude 6 2

Probability 4 2

Significance 44 (medium) 14 (low)

Status (positive or negative) Negative Negative

Reversibility Low – birds are killed

Irreplaceable loss of resources? Yes – birds killed

Can impacts be mitigated? Yes

26

Mitigation: Build the proposed guyed steel monopole with the standard Eskom Bird Perch on top of the pole to

provide sufficient safe perching space for vultures above the dangerous hardware. Every single pole on the line

should be fitted with the Bird Perch as affected species could occur anywhere along the line.

Cumulative impacts: Cape Vulture in particular cannot afford more mortalities as a result of power lines. Elsewhere

in their range they are significantly impacted by this factor.

Residual Impacts None – if power line were decommissioned the impact would cease.

Table 3. Assessment of collision of birds on the Tyalara Qunu 132kV power line.

Nature: Collision – likely to affect the large terrestrial species such as Grey Crowned Crane, Denham’s Bustard and

White Stork


Extent 1 1

Duration 4 4

Magnitude 6 4

Probability 4 3

Significance 44 (medium) 27 (low)

Status (positive or negative) Negative

Reversibility Low – birds are killed

Irreplaceable loss of resources? Yes – birds are killed

Can impacts be mitigated? Yes – partially – current collision

mitigation is not 100% effective

Mitigation: The high risk sections of the power line will need to be installed with a suitable Eskom approved anti bird

collision line marking device on the earth wire to increase the visibility of the cables. This report has identified those

areas likely to be of high sensitivity on a preliminary basis (see Figure 8). However it is essential that an avifaunal

walk‐through be done on the route once the exact tower positions are surveyed and finalised. This walk through

will identify the exact spans of power line requiring mitigation. At this stage this report has identified a fairly

extensive section of line for marking, but it is likely that this can be reduced based on the avifaunal walk‐through.

Cumulative impacts: High nationally for species such as the cranes

Residual Impacts Medium – even after decommissioning, habitat would not regenerate fully or immediately

Table 4. Assessment of habitat destruction on the Tyalara Qunu 132kV power line.

Nature: Destruction of bird habitat


Extent 1 1

Duration 4 4

Magnitude 2 2

Probability 4 4

Significance 28 (low) 28 (low)


27

Reversibility Medium – certain habitat may be

rehabilitated

Irreplaceable loss of resources? Partially

Can impacts be mitigated? Partially, but a certain amount of

impact is unavoidable

Mitigation: The most sensitive areas of this alignment are the river crossing, the dense thicket areas and the plateau

grassland. As little as possible of the natural vegetation should be removed for the purpose of construction and

existing roads must be used for access purposes where possible.

Cumulative impacts: Low

Residual Impacts Medium

Table 5. Assessment of disturbance of birds on the Tyalara Qunu 132kV power line.

Nature: Disturbance of birds


Extent 1 1

Duration 1 1

Magnitude 2 2

Probability 3 3

Significance 12 (low) 12 (low)


Reversibility Fully reversible

Irreplaceable loss of resources? No

Can impacts be mitigated? Partially

Mitigation: Similar to that proposed for habitat destruction in Table 4. In addition, the avifaunal walk through

recommended elsewhere in this report will identify any sensitive nesting species close to the alignment, and case

specific recommendations on how to manage these situations will be supplied.

Cumulative impacts: Low

Residual Impacts Medium

Figure 9.

measures

High risk se

s (red circles

ctions of the

s).

e Tyalara Quunu 132kV poower line reequiring colli

28

sion mitigat

tion

29

7 COMPARISON OF ALTERNATIVES

7.1 Power Line

This assessment considers one power line route only (Figure 1). From the Qunu Substation (some 20km

south of Mthatha town), the route travels in a southerly direction, following the route of an existing

66kV power line where it crosses communal grazing and arable lands through to the existing Tyalara

Substation (located near the Mbhashe River).

No other alternative routes were assessed.

30

8 IMPACT STATEMENT

The proposed power line can be built with acceptable levels of impact on avifauna should the

recommendations in this report be followed. Of particular importance are: using the correct pole or

pylon structure to avoid electrocution of Cape Vultures; using bird marking devices in the areas

illustrated in Figure 9. An avifaunal walk down to identify exact marking areas and additional mitigation

is further recommended on the approved route.

31

9 REFERENCES

Allan, D.G. 2011. Report on Trip to Collywobbles Cape Vulture Colony on 08 August 2011.

Anderson, M.D. 2001. The effectiveness of two different marking devices to reduce large terrestrial bird collisions

with overhead electricity cables in the eastern Karoo, South Africa. Draft report to Eskom Resources and

Strategy Division. Johannesburg. South Africa.

Avian Power Line Interaction Committee (APLIC). 1994. Mitigating Bird Collisions with Power Lines: The State of the

Art in 1994. Edison Electric Institute. Washington D.C.

Barnes, K.N. (ed.) 2000. The Eskom Red Data Book of Birds of South Africa, Lesotho and Swaziland. BirdLife South

Africa: Johannesburg.

Botha, A., Allan, D.G., Field, I., Vernon, C. 2011. Report and Recommendations following the site visit to the

Colleywobbles Cape Vulture Breeding Colony, Eastern Cape.

Harrison, J.A., Allan, D.G., Underhill, L.G., Herremans, M., Tree, A.J., Parker, V & Brown, C.J. (eds). 1997. The atlas

of southern African birds. Vol. 1&2. BirdLife South Africa: Johannesburg.

Hobbs, J.C.A. & Ledger J.A. 1986a. The Environmental Impact of Linear Developments; Power lines and Avifauna.

(Third International Conference on Environmental Quality and Ecosystem Stability. Israel, June 1986).

Hobbs, J.C.A. & Ledger J.A. 1986b. “Power lines, Birdlife and the Golden Mean.” Fauna and Flora, 44, pp 23‐27.

Kruger, R. & Van Rooyen, C.S. 1998. Evaluating the risk that existing power lines pose to large raptors by using risk

assessment methodology: the Molopo Case Study. (5th World Conference on Birds of Prey and Owls: 4 ‐ 8

August 1998. Midrand, South Africa.)

Kruger, R. 1999. Towards solving raptor electrocutions on Eskom Distribution Structures in South Africa. M. Phil.

Mini‐thesis. University of the Orange Free State. Bloemfontein. South Africa.

Ledger, J. 1983. Guidelines for Dealing with Bird Problems of Transmission Lines and Towers. Escom Test and

Research Division Technical Note TRR/N83/005.

Ledger, J.A. & Annegarn H.J. 1981. “Electrocution Hazards to the Cape Vulture (Gyps coprotheres) in South Africa”.

Biological Conservation, 20, pp15‐24.

Ledger, J.A. 1984. “Engineering Solutions to the problem of Vulture Electrocutions on Electricity Towers.” The

Certificated Engineer, 57, pp 92‐95.

32

Ledger, J.A., J.C.A. Hobbs & Smith T.V. 1992. Avian Interactions with Utility Structures: Southern African

Experiences. (Proceedings of the International Workshop on Avian Interactions with Utility Structures, Miami,

Florida, 13‐15 September 1992. Electric Power Research Institute.)

Martin, G.R. & Shaw, J.M. 2010. Bird collisions with power lines: Failing to see the way ahead? Biological

Conservation 143: 2695‐2702.

Mucina & Rutherford. 2006. The vegetation of South Africa, Lesotho and Swaziland. Strelitzia 19. South African

National Biodiversity Institute, Pretoria.

Van Rooyen, C.S. & Ledger, J.A. 1999. “Birds and utility structures: Developments in southern Africa” in Ferrer, M.

& G..F.M. Janns. (eds.) Birds and Power lines. Quercus: Madrid, Spain, pp 205‐230

Van Rooyen, C.S. 1998. Raptor mortality on power lines in South Africa. (5th World Conference on Birds of Prey

and Owls: 4 ‐ 8 August 1998. Midrand, South Africa.)

Van Rooyen, C.S. 1999. An overview of the Eskom ‐ EWT Strategic Partnership in South Africa. (EPRI Workshop on

Avian Interactions with Utility Structures 2‐3 December 1999, Charleston, South Carolina.)

Van Rooyen, C.S. 2000. “An overview of Vulture Electrocutions in South Africa.” Vulture News, 43, pp 5‐22. Vulture

Study Group: Johannesburg, South Africa.

Van Rooyen, C.S. 2003. Mitigation programme for Avian Collisions with Eskom Transmission Lines. Unpublished

Progress Report, September 2003. Endangered Wildlife Trust, Johannesburg, South Africa.

Van Rooyen, C.S. 2004a. The Management of Wildlife Interactions with overhead lines. In The fundamentals and

practice of Overhead Line Maintenance (132kV and above), pp217‐245. Eskom Technology, Services

International, Johannesburg.

Van Rooyen, C.S. 2004b. Investigations into vulture electrocutions on the Edwardsdam‐Mareetsane 88kV feeder,

Unpublished report, Endangered Wildlife Trust, Johannesburg.

Van Rooyen, C.S. & Taylor, P.V. 1999. Bird Streamers as probable cause of electrocutions in South Africa. (EPRI

Workshop on Avian Interactions with Utility Structures 2‐3 December 1999. Charleston, South Carolina)

Verdoorn, G.H. 1996. Mortality of Cape Griffons Gyps coprotheres and African Whitebacked Vultures Pseudogyps

africanus on 88kV and 132kV power lines in Western Transvaal, South Africa, and mitigation measures to

prevent future problems. (2nd International Conference on Raptors: 2‐5 October 1996. Urbino, Italy.)

33

APPENDIX 1

Direct, indirect and cumulative impacts of the issues identified through the scoping study, as well as all other issues identified in the EIA phase must be assessed in terms of the following criteria:

» The nature, which shall include a description of what causes the effect, what will be affected and how it will

be affected.

» The extent, wherein it will be indicated whether the impact will be local (limited to the immediate area or site

of development) or regional, and a value between 1 and 5 will be assigned as appropriate (with 1 being low

and 5 being high):

» The duration, wherein it will be indicated whether:

the lifetime of the impact will be of a very short duration (0–1 years) – assigned a score of 1;

the lifetime of the impact will be of a short duration (2‐5 years) ‐ assigned a score of 2;

medium‐term (5–15 years) – assigned a score of 3;

long term (> 15 years) ‐ assigned a score of 4; or

permanent ‐ assigned a score of 5;

» The magnitude, quantified on a scale from 0‐10, where 0 is small and will have no effect on the environment,

2 is minor and will not result in an impact on processes, 4 is low and will cause a slight impact on processes, 6

is moderate and will result in processes continuing but in a modified way, 8 is high (processes are altered to

the extent that they temporarily cease), and 10 is very high and results in complete destruction of patterns

and permanent cessation of processes.

» The probability of occurrence, which shall describe the likelihood of the impact actually occurring. Probability

will be estimated on a scale of 1–5, where 1 is very improbable (probably will not happen), 2 is improbable

(some possibility, but low likelihood), 3 is probable (distinct possibility), 4 is highly probable (most likely) and 5

is definite (impact will occur regardless of any prevention measures).

» the significance, which shall be determined through a synthesis of the characteristics described above and can

be assessed as low, medium or high; and

» the status, which will be described as either positive, negative or neutral.

» the degree to which the impact can be reversed.

» the degree to which the impact may cause irreplaceable loss of resources.

» the degree to which the impact can be mitigated.

The significance is calculated by combining the criteria in the following formula: S=(E+D+M)P S = Significance weighting E = Extent D = Duration M = Magnitude P = Probability The significance weightings for each potential impact are as follows:

» < 30 points: Low (i.e. where this impact would not have a direct influence on the decision to develop in the

area),

34

» 30‐60 points: Medium (i.e. where the impact could influence the decision to develop in the area unless it is

effectively mitigated),

> 60 points: High (i.e. where the impact must have an influence on the decision process to develop in the area).

tyalara qunu 132kv overhea im - gibb

Documents