specialist botanical scoping study: proposed ......greenfields development of penhill (jacobsdal...

____________________________________________________________________

NICK HELME BOTANICAL SURVEYS PO Box 22652 Scarborough 7975

Ph: 021 780 1420 cell: 082 82 38350 email: [email protected] Pri.Sci.Nat # 400045/08

SPECIALIST BOTANICAL SCOPING

STUDY: PROPOSED GREENFIELDS

DEVELOPMENT OF PENHILL (JACOBSDAL

468), EERSTERIVIER.

Compiled for: Aurecon South Africa (Pty) Ltd

Client: Western Cape Government Department of Human

Settlements

13 Dec 2017

Draft: 5 Apr 2017

mailto:[email protected]

DECLARATION OF INDEPENDENCE

In terms of Chapter 5 of the National Environmental Management Act of 1998

specialists involved in Impact Assessment processes must declare their

independence and include an abbreviated Curriculum Vitae.

I, N.A. Helme, do hereby declare that I am financially and otherwise independent

of the client and their consultants, and that all opinions expressed in this

document are substantially my own.

NA Helme

ABRIDGED CV:

Contact details as per letterhead.

Surname : HELME

First names : NICHOLAS ALEXANDER

Date of birth : 29 January 1969

University of Cape Town, South Africa. BSc (Honours) – Botany (Ecology &

Systematics), 1990.

Since 1997 I have been based in Cape Town, and have been working as a

specialist botanical consultant, specialising in the diverse flora of the south-

western Cape. Since the end of 2001 I have been the Sole Proprietor of Nick

Helme Botanical Surveys, and have undertaken over 1200 site assessments in

this period.

A selection of work recently undertaken is as follows:

Botanical assessment of Rem Farm 643, Eersterivier (DBA 2017)

Botanical assessment of proposed petrol station at CTFS (Chand

Environmental 2016)

Botanical overview of possible development area near Darwin Rd (Gibb &

SEFSA 2016)

Botanical assessment of Diemersfontein, Wellington (Guillaume Nel

Consultants 2015)

Botanical assessment of proposed development on farm Palmiet Valley 54,

Wellington (Doug Jeffery Environmental Consultants 2015)

Botanical Scoping – Penhill Greenfields Development

ii

Ecological assessment of proposed Arcelor Mittal power station, Saldanha

(ERM 2015)

Ecological assessment of proposed Globeleq power station, Saldanha (ERM

2015)

Botanical assessment of proposed iGas pipeline Saldanha – Ankerlig (CES/

EOH 2015)

Botanical baseline of Communicare land, Morningstar (mlh architects

2015)

Botanical assessment of proposed industrial development, Frankendale

(Urban Dynamics 2015)

Ecological assessment of proposed refurbishment of 11kV powerline from

Kleinmond to Arabella, Western Cape (Landscape Dynamics 2015)

Botanical walkdown study of new Eskom 132kV powerline Ankerlig –

Sterrekus (EIMSA 2015)

Botanical assessment of Remainder of Farm Rietfontein 244, Piketberg

(Cederberg Environmental Assessment Practise 2014)

Botanical assessment of Remainder of Farm Draaihoek 293, Vredendal

(Cederberg Environmental Assessment Practise 2013)

Botanical assessment of Farm Gideonsooord 303, Klawer (Cederberg

Environmental Assessment Practise 2013)

Botanical assessment of Farm Patrysberg 344/1, Citrusdal (Cederberg

Environmental Assessment Practise 2013)

Assessment of Hartenbos Erf 3122 and Rem of Ptn 4 of Hartenbos 217,

Hartenbos (Boston Consulting 2012)

Botanical Scoping study for proposed Saldanha Municipality Desalination

Project (CSIR 2012)

Botanical scoping study for proposed crude oil tank farm, Saldanha

(WorleyParsons 2012)

Botanical inputs into proposed Saldanha IDZ (MEGA 2011)

Scoping and Impact Assessment for new West Coast District landfill site

(Anel Blignaut Environmental Consultants 2010)

Revised Botanical Scoping study for proposed Groot Drakenstein Rural

Housing Project (Arcus Gibb 2011)

Basic Assessment of proposed new Eskom 66kV powerline on the

Piketberg (ERM 2010)


iii

CONDITIONS RELATING TO THIS REPORT:

The methodology, findings, results, conclusions and recommendations in this report are

based on the author’s best scientific and professional knowledge, and on referenced

material and available knowledge. Nick Helme Botanical Surveys and its staff reserve the

right to modify aspects of the report, including the recommendations and conclusions, if

and when additional relevant information becomes available.

This report may not be altered or added to without the prior written consent of the author,

and this also applies to electronic copies of this report, which are supplied for purposes of

inclusion in other reports, including in the report of EAPs. Any recommendations,

statements or conclusions drawn from or based on this report must cite this report, and

should not be taken out of context, and may not change, alter or distort the intended

meaning of the original in any way. If these extracts or summaries form part of a main

report relating to this study or investigation this report must be included in its entirety as

an appendix or separate section to the main report.


iv

TABLE OF CONTENTS

1. INTRODUCTION 1

2. TERMS OF REFERENCE 4

3. LIMITATIONS, ASSUMPTIONS AND METHODOLOGY 5

4. REGIONAL CONTEXT OF THE VEGETATION 6

4.1 Description of the study area 8

5. THE VEGETATION AND ITS SENSITIVITY 9

5.1 Rehabilitation Potential 14

5.2 Botanical Sensitivity 15

5.3 Botanical Sensitivity – Associated Infrastructure 16

6. CONCLUSIONS AND RECOMMENDATIONS 18

7. REFERENCES 19


1

1. INTRODUCTION AND PROJECT DESCRIPTION

This specialist botanical input was commissioned in order to help inform planning

and the environmental authorisation process being undertaken for the proposed

greenfields development of Penhill (Jacobsdal Farm 468), Eersterivier. The site is

192ha in extent, and is located immediately east of Van Riebeeck Road (see

Figures 1 and 1b).

The site is comprised of ten state owned land units and is currently characterised

by small scale farming, including dwellings and fields, plus a number of other land

uses (including illegal dumping, rubbish sorting, etc). There are numerous gravel

and sand roads that traverse the site, which are used to access the plots and the

infrastructure. Eucalyptus (gum) trees line some of the internal roads on the site,

and adjacent to the site. There are multiple servitudes, the most significant being

the 400KV lines. There are also servitudes for 11kV, 66kV and 132kV overhead

lines, and two water pipelines, but there is no sewage infrastructure. A series of

five stormwater detention ponds are prominent features adjacent to but west of

the site, between the site and Van Riebeeck Road. Also outside the site to the

north is a water treatment works with associated sludge drying beds, with the

Welmoed Cemetery to the south, and a railway line to the west, on the opposite

side of Van Riebeeck Road.

Figure 1: Satellite image showing study area and proposed associated

infrastructure.


2

Associated infrastructure that will be required includes an access road, bulk water

reservoir and pipeline, and a bulk sewer connection (see Figure 1). It has recently

been proposed by the engineers that the stormwater channel that feeds the

wetlands in the northwestern corner of the site be diverted along the northern

boundary of the site, and a temporary wastewater treatment package plant has

also been recently proposed. A series of stormwater detention ponds exist

adjacent to the site, between the site and van Riebeeck Road. Additional

stormwater generated by the development will need to be accommodated on site

and the estimated area required for this is 8ha. The CoCT has confirmed in

principle that the existing stormwater ponds can be expanded to accommodate

this capacity, and the possibility of accommodating stormwater in the Eskom

servitude is also being investigated. Details of stormwater management on the

site is to be investigated during the detailed design phase, which will establish to

what extent stormwater is piped versus channelled along open drains. The option

of capturing water upslope of the agricultural area, for potential use for

agriculture, will also be investigated during detailed design.

Two proposed development layouts have been provided for initial assessment

(see Figures 2 & 3).

Figure 1b: February 2017 satellite image with the study area

superimposed.


3

Figure 2: Alternative A layout


4

Figure 3: Alternative B layout

A botanical baseline study of the site was undertaken by Helme in 2013, and has

been used to help inform the current study.

2. TERMS OF REFERENCE

The Terms of Reference for the study were to:

undertake a site visit to assess the vegetation on site

describe the vegetation in the study area and place it in a regional

context, including its status in terms of the relevant CBA maps,


5

identify and map any plant Species of Conservation Concern in the study

area

provide an overview and map (providing Google Earth kmz files) of the

botanical conservation significance (sensitivity) of the study area, showing

and describing the reasons for any No Go areas

identify likely botanical impacts of the proposed project

and make recommendations for minimising the botanical impacts of the

proposed development.

3. LIMITATIONS, ASSUMPTIONS AND METHODOLOGY

The original site visit was undertaken on 25 October 2013, and the most recent

site visit was undertaken on 23 February 2017. Most of the available tracks were

driven and observations were made at various points along these tracks. Most of

the better quality remnants were surveyed on foot, and a full species list was

compiled on site. The latest site visit was undertaken at the peak of the summer

dry season, which is the worst possible time of the year for botanical observations

in this strongly winter rainfall area. There were thus potentially constraints in

terms of the botanical observations, in that very few of the potential geophytes or

annuals were evident, but given the heavily disturbed nature of the habitat in the

area, and the previous site visit in late spring, this is not considered to be a

significant constraint, due to the lack of undisturbed habitat in the area, and the

fact that a survey was undertaken four years ago in late spring. The likelihood

that significant indigenous plant species were overlooked on both occasions is

considered to be low to moderate, and confidence in the findings is high. The

heavy grazing on much of the site means that even if indigenous bulbs, annuals

and small shrubs are present on parts of the site that they may not have been

evident during either of the site visits, having been grazed to ground level.

Fenced off plots and aggressive dogs prevented access to about 15% of the area,

and this is regarded as a small but possibly significant limitation on the overall

accuracy of the survey, as some of these unsurveyed patches may be of higher

conservation value than the areas surveyed, leading to an underestimation of the

overall conservation value of these areas, but this was to some extent mitigated

by the use of the recent satellite imagery (see Figure 1).

The associated infrastructure shown in Figure 1 was not surveyed on site, as it

was added to the project outline after the date of the site visits, and is at any rate

still conceptual. Any assessment of these routes and areas is thus based on

previous knowledge and still needs to be groundtruthed at the IA stage. The


6

proposed bulk sewer connection corridor is assumed to be 15m wide (from

current road edge), this being the likely disturbance width during construction. It

is intended that the pipeline would be located largely within the road reserve, but

the construction footprint may extend outside the road reserve onto adjacent

properties, and this would require landowner approval. The final routing could be

either side of the road. Sensitivity mapping focuses on an area within about 20m

of the current road edge. The potential pump station would be at the corner of

Forest Drive and Van Riebeeck road, and will have a footprint of about 100m2.

The proposed temporary wastewater treatment package plant would be located in

the southwestern corner of the site, being the lowest point, and will have a 2ha

footprint.

All references are as noted in the report.

Botanical sensitivity (also known as conservation value for purposes of this study) is

understood to be a product of species diversity, rarity of habitat, rarity of species,

ecological viability and connectivity, vulnerability to impacts, and reversibility of threats

(ease of rehabilitation). Extensive previous work in the region has allowed the author to

make conclusions regarding the overall and relative sensitivity of the vegetation in the

area, and the author has a high level of confidence in the findings.

Google Earth imagery dated October 2017 (and earlier) was used to verify

vegetation patterns and for mapping.

4. REGIONAL CONTEXT OF THE VEGETATION

The site is part of the Fynbos biome, located within what is now known as the Core Region

of the Greater Cape Floristic Region (GCFR; Manning & Goldblatt 2012). The GCFR is one

of only six Floristic Regions in the world, and is the only one largely confined to a single

country (the Succulent Karoo component extends into southern Namibia). It is also by far

the smallest floristic region, occupying only 0.2% of the world’s land surface, and

supporting about 11500 plant species, over half of all the plant species in South Africa (on

12% of the land area). At least 70% of all the species in the Cape region do not occur

elsewhere, and many have very small home ranges (these are known as narrow

endemics). Many of the lowland habitats are under pressure from agriculture,

urbanisation and alien plants, and thus many of the range restricted species are also

under severe threat of extinction, as habitat is reduced to extremely small fragments.

Data from the nationwide plant Red Listing process undertaken is that 67% of the

threatened plant species in the country occur only in the southwestern Cape, and these


7

total over 1800 species (Raimondo et al 2009)! It should thus be clear that the

southwestern Cape is a major national and global conservation priority, and is quite unlike

anywhere else in the country in terms of the number of threatened plant species.

The study area lies within what has been termed the Southwest Fynbos bioregion,

and this bioregion is characterised by relatively high winter rainfall and poor,

sandstone derived soils, with intensive agriculture and large urban areas. Due to

this combination of factors the loss of natural vegetation in this bioregion has

been severe (>80% of original extent lost within the lowland regions), and the

bioregion has the highest number of threatened plant species of any bioregion in

the country (Raimondo et al 2009).

The lowland regions of the Cape metropole (stretching from Atlantis southeast to

near Somerset West, and thus including the study area), generally known as the

Cape Flats, are under enormous pressure, and the area has been described as a

“conservation mega-disaster” (Rebelo et al 2011), in terms of the number of

severely threatened plants (some already extinct) and habitats within the area.

The study area falls within one of the fastest growing areas within the City, and it

is thus essential to plan for and conserve the key remaining natural habitats

before they are all lost.

The City of Cape Town’s Biodiversity Network shows that about 40% of the study

area is mapped as a CBA2 (Critical Biodiversity Area 2; Holmes et al 2012), with

the remainder not indicating any remaining natural vegetation of importance

(see Figure 4). The CBA2 category is described as “Restorable Irreplaceable Site;

Irreplaceable Low Condition Site; Critically Endangered vegetation of restorable

condition; Restore and Conserve” (Holmes et al 2012). There is a fairly large

area (about 55ha) to the south of the study area that is mapped as “Conservation

Area; Protected in Perpetuity”. This area is known to support some high quality

habitat and various threatened and localised plant species (CREW Rares GIS

layer; Maze & Rebelo 1999). The botanical sensitivity mapping undertaken of the

current study is regarded as more up to date, and more accurate, than the CoCT

BioNet mapping, and it is recommended that the former thus be used for any

biodiversity offset calculations that may be required.


8

Figure 4: Extract of the current City of Cape Town Biodiversity Network map for

the area, showing that most of the eastern half of the site is mapped as Critical

Biodiversity Area 2.

Very little high conservation value natural vegetation (i.e. vegetation in good

condition with viable populations of threatened plant species) remains in the

immediate vicinity (within 1km) of the site, with the notable exception of the

fairly large (about 55ha) area immediately south of the site, and shown as

“Protected in Perpetuity” in Figure 4 (2ha of this area was recently impacted by

the adjacent cemetery developments). There is relatively little remaining

ecological connectivity in the region, which is rapidly shifting from undeveloped or

agricultural to an area of human settlement. Virtually all ecological processes on

the site are already likely to have been impacted to a greater or lesser degree by

habitat fragmentation, hardened surfaces, too frequent fire, dumping, heavy

grazing and alien plant invasion (along with other lesser factors).

4.1 Description of the study area

The study area is largely flat, and generally slopes from east to west. To the west

of the site are five extensive detention ponds, which themselves drain north to

south. The area is now essentially peri-urban, and is heavily impacted by human

activities, and the vegetation has been significantly degraded since the initial

botanical survey in 2013 (Helme 2013). The entire study area is today home to a

large number of homesteaders and small scale farmers, each with small plots of

land, ranging in size from 1ha to about 10ha. Landuse in these plots ranges from


9

low intensity grazing to high intensity cultivation, and virtually all of them have

built various structures on their plots. There appears to have been a rapid and

substantial increase in the number of people living on and working this area since

2008 (Google Earth time series imagery), presumably along with a parallel

increase in livestock numbers on site.

A possibly natural drainage channel crosses the northwest corner of the site, evidently fed

by runoff from the water treatment works north of the site. There is evidence of shallow

groundwater in various areas, notably in the southern parts of the site, where there also

appear to be a few small marshy areas, now heavily grazed and mostly degraded. Large

quantities of livestock are present on site, which graze the remaining vegetation almost

continually – some of this livestock is restricted to individual, fenced plots, but some is

also free ranging. Soils are deep sands, with a mix of granite derived sands and both acid

and alkaline sands of marine origin. No natural bedrock is present on site. This is a

strongly winter rainfall area, with the bulk of the approximately 500mm annual rainfall

falling between May and September.

5. THE VEGETATION AND ITS SENSITIVITY

According to the SA Vegetation Map (Mucina & Rutherford 2006, and 2012

update) the study area would have supported mostly Cape Flats Sand Fynbos,

with a minor element of Swartland Shale Renosterveld along the eastern edge

(see Figure 5). According to the National List of Threatened Ecosystems (DEA

2011) both these vegetation types are Critically Endangered on a national

basis, with less remaining habitat (19% of original total extent in the case of

Cape Flats Sand Fynbos) than the national conservation target (30%; Rouget et

al 2004). Less than 1% of the original total extent of Cape Flats Sand Fynbos is

formally conserved (Rouget et al 2004), and the remainder is thus very

vulnerable to ongoing loss and transformation.


10

Figure 5: Extract of the SA vegetation map (Mucina & Rutherford 2006) showing

that most of the site would have supported Cape Flats Sand Fynbos, which is now

a Critically Endangered vegetation type (DEA 2011).

There is currently no evidence of any Swartland Shale Renosterveld on site, and

all extant remnants would be best classified as Cape Flats Sand Fynbos.

The majority of the site supports little or no vegetation of any conservation

significance. This is due to the fact that parts of the site may well have been

previously cultivated (more than thirty years ago), but also due to the heavy,

ongoing disturbances previously noted, including human settlement, heavy

grazing, alien plant invasion, dumping and small scale cultivation. However, even

though most of the remaining vegetation is of Low conservation value (or

sensitivity) it is estimated that more than 20ha of natural vegetation remains on

the site, although much of this is the tough perennial pasture grass Cynodon

dactylon (fynkweek), and resilient, unpalatable species such as Trachyandra

divaricata, Conicosia pugioniformis (vetkousie), Pelargonium capitatum

(kusmalva) and Carpobrotus edulis (suurvy). Additional indigenous species noted

in the Low sensitivity areas include Helichrysum moeserianum, Oncosiphon

suffruticosum (stinkruid), Willdenowia incurvata (zonkwasriet), Stoebe plumosa

(slangbos) and Aspalathus hispida.


11

Overall botanical diversity on site is Low, due to the high levels of disturbance,

and it is particularly low in the Low sensitivity areas, where less than 5% of the

original species complement is now present.

Invasive alien plant species are common on site (making up at least 40% of the

plant cover on the site as a whole), and are dominant in many areas, and include

a wide range of species, including Acacia saligna (Port Jackson), Echium

plantagineum (Patterson’s curse), Plantago lanceolata (ribwort), Trifolium

angustifolium, Brassica tournefortii, Raphanus rapistrum (wild mustard), Ricinis

communis (castor oil), Chrysanthemum sp., Lagurus ovatus (rabbit tail), Lolium

sp (rye grass), Bromus diandrus (ripgut brome), Briza maxima (quaking grass),

and Avena sp. (wild oats). There are also some significant avenues of planted

gum trees (Eucalyptus sp), that are probably at least sixty years old.

Plate 1: View of a grassy part of the study area, dominated by the tough

perennial pasture grass Cynodon dactylon (fynkweek). The shrubs in the

foreground and behind the houses are the alien invasive Acacia saligna (Port

Jackson).


12

Plate 2: Heavily grazed area with no remaining grass, and two unpalatable,

indigenous species still present (Carpobrotus edulis and Trachyandra divaricata).

The best quality habitat seen in the study area is shown in Plates 3 and 4. Areas

like this are small (generally


13

Even in the better quality patches of vegetation (assessed as being of Medium

botanical sensitivity) the indigenous plant diversity is low in comparison to what it

would have been prior to disturbance, and is typically only 10-15% of the original

diversity. Additional indigenous species noted in the two main patches of Medium

botanical sensitivity on site include Wachendorfia paniculata, Hebenstretia repens,

Asparagus rubicundus (katnaels), A. capensis, A. undulatus, Cotula turbinata,

Isolepis spp., Monopsis purpurea, Ursinia anthemoides, Phylica cephalantha,

Lampranthus explanatus, Pentameris pallida, Scirpus nodosus, Cyperus textilis,

Muraltia spinosa, Senecio burchellii, Brunsvigia orientalis, Trichogyne ambigua,

Thesium sp., Trichocephalus stipularis and Ehrharta calycina (rooisaadgras). Very

few indigenous woody shrubs were seen on site, presumably having been lost to

previous cultivation, heavy grazing and regular fires.

A single plant Species of Conservation Concern (SCC; Raimondo et al 2009) was

observed on site, and the likelihood of other such species persisting in the

disturbed habitats on site in viable populations is deemed to be very low. The

SCC recorded was the vygie Lampranthus explanatus, which is Redlisted as Near

Threatened (Klak et al 2012). The population on site occurs only in the southern

quarter of the main Eskom servitude, and consists of less than 40 plants. This is

deemed to be a viable population, but it is relatively insignificant in a regional

context, as the species is still present at more than 20 localities between here

and Redelinghuys, and the population on site constitutes


14

Plate 4: Remnants of Cape Flats Sand Fynbos in the Eskom servitude, showing

the red flowered bulb Brunsvigia orientalis (tolbos) and the only threatened

species recorded on site – the creeping vygie Lampranthus explanatus. This is

one of only to areas on site that are mapped as being of Medium botanical

sensitivity.

5.1 Rehabilitation Potential

The passive rehabilitation potential of the area is likely to range from poor to moderate

(see Table 1), but this rehabilitation potential is essentially theoretical as it would require

removal of all livestock and people, and active management in terms of fire control and

alien invasive vegetation management to achieve any significant, conservation worthy

results. It would of course be desirable to manage the better quality parts of the site for

conservation, as the vegetation type is Critically Endangered and thus already below

national conservation targets in terms of remaining extent, but this would require a very

significant budget, and from a species perspective it is of uncertain value. Active

rehabilitation (replanting with various suitable locally indigenous species) would

significantly enhance the area, but this would of course be even more costly. Alien

invasive plant management, and land invasions by people, would be an ongoing issue.


15

5.2 Botanical Sensitivity

About 90% of the study area is considered to be of Low or Low to Medium

botanical sensitivity, with the remainder being of Medium and Medium – High

botanical sensitivity (Figure 6). No portions of the site are deemed to be of High

or Very High botanical sensitivity.

A single plant Species of Conservation Concern (Lampranthus explanatus; Near

Threatened) has been recorded on site, and no others are expected to occur

within the study area in viable numbers. This species was recorded only in the

area of Medium – High sensitivity (Figure 6).

Rehabilitation potential is poor to moderate, due to the long history of soil

disturbance and likely future disturbances. Indigenous plant diversity in the Low

and Low to Medium sensitivity areas is very low (see Table 1), and consists only

of weedy, widespread species. Indigenous plant diversity in the Medium and

Medium to High sensitivity areas is also low, although approximately double what

it is in the Low sensitivity areas (see Table 1), and these areas have a much

higher rehabilitation potential than the Low and Low – Medium sensitivity areas.

Figure 6: Botanical sensitivity map of the primary study area. Unshaded areas

within the study area are of Low sensitivity.

About 60% of the area is not mapped as a significant remnant in the City of Cape

Town’s Biodiversity Network, and the remainder is mapped as a CBA2, which


16

indicates that it is a restorable area of Critically Endangered vegetation needed to

meet conservation targets (see Figure 4).

Table 1: Summary table for the areas of different botanical sensitivity and

various attributes thereof. This table applies equally to the primary development

site and to all ancillary infrastructure.

5.3 Botanical Sensitivity – Associated Infrastructure

The proposed access road is likely to traverse a 2.2ha area of mostly Low –

Medium botanical sensitivity and it is unlikely that any plant SCC occur in the

area.

The proposed water reservoir and pipeline are likely to be within an area of Low

botanical sensitivity that has been previously cultivated, and it is unlikely that any

plant SCC occur in the area.

The temporary wastewater treatment plant (2ha) would be located within an area

that is about 60% Low – Medium sensitivity and about 40% Low sensitivity. No

plant SCC are likely to occur here.

The proposed pump station for the bulk sewer line is located within an area of

Low botanical sensitivity, and no plant SCC are likely to occur here.

The proposed bulk sewer pipeline corridor traverses a distance of almost 6000m,

and for the northern and eastern side of the corridor about 4000m of this (66%;

6ha) is likely to be of Medium, High or Very High botanical sensitivity (Figure 7).

Botanical sensitivity Criteria Recognisable

elements of

vegetation/ flora

strongly support

presence of Cape

Flats Sand Fynbos

Restoration potential –

recovery of spp diversity to

a point where supports at

least 20% of original

diversity (excluding

consideration of external /

human influences)

Qualifies as CBA2

(irreplaceable,

restorable)

Significance of

loss of such

areas

Low


17

The southern and western side of the corridor is of significantly lower sensitivity,

with all of it being Low sensitivity, except for a 1.7km section (28%; 2.5ha) which

is of Medium sensitivity. At least six plant SCC are known from the Very High

sensitivity section of the proposed route within the Vergenoegd Farm section of

the route (southern end, but mostly more than 15m from current road edge),

which is also a recognised site of high botanical conservation value (CoCT BioNet;

pers. obs., Maze et al 2003). This element of the project is likely to have the

highest negative botanical impact (possibly High negative) of all the project

elements and is thus significant, but if the footprint can be restricted to the area

within 15m of the current road edge the botanical impact could be minimised, and

may be no more than Low or Medium negative. A single plant SCC is known from

the Medium sensitivity portion of the corridor. It may not be possible to

adequately or fully mitigate the likely botanical impacts associated with

construction of this large pipeline in the High and Very High sensitivity areas

(about 700m in total), and a biodiversity offset would be recommended to help

reduce the residual botanical impacts in this case. Proper rehabilitation of these

areas would help mitigate some of the negative botanical impact, as would

detailed design phase input, but there may still be a residual Medium or Medium

– High negative botanical impact in these areas. It is possible to mitigate the

likely botanical impacts in the Medium sensitivity areas (by Search and Rescue of

the relevant bulbs).

Figure 7: Map showing the botanical sensitivity of the proposed sewer pipeline


18

route. The mapping shows the sensitivity both sides of the existing roads, up to

about 20m from existing road edge.

6. CONCLUSIONS AND RECOMMENDATIONS

The study area presents a difficult situation in terms of assessing the

botanical conservation value, as the underlying vegetation type is Critically

Endangered and largely restricted to the City of Cape Town, and urgently

requires additional conservation, but the site itself has been significantly

degraded both in the past and more recently, and this degradation is

ongoing.

Only two patches of Medium and Medium – High sensitivity vegetation

were mapped on site, totalling about 9ha. The likelihood of being able to

conserve and manage these relatively small and isolated portions for

conservation is considered negligible to very low in the long term, and

consequently it is recommended that these areas be considered for

development, but with some form of biodiversity offset. The remainder of

the site is deemed to be of Low or Low – Medium botanical sensitivity, and

there are no serious botanical constraints associated with development of

these areas, although the latter may need to be mitigated via a

biodiversity offset, as the overall significance of the loss of the large areas

of Low – Medium sensitivity is likely to be Medium negative, and cannot be

meaningfully mitigated any other way.

A single plant Species of Conservation Concern was found on site

(Lampranthus explanatus; Near Threatened), under the Eskom powerlines,

and no others are likely to persist here in viable populations. This species

could feasibly be translocated, perhaps to the nearby Penhill conservation

area.

Although at least parts of the study area have moderate rehabilitation

potential this would be difficult, time consuming and costly to achieve,

particularly in the prevailing environment.

The footprints of the associated infrastructure have not been finalised, but

it would appear that the most important botanical impacts would be

associated with the High and Very High botanical sensitivity portions of the

bulk sewer pipeline, which are together about 700m long. The northern

and eastern option would have a significantly greater botanical impact

than the western and southern option, and the latter is consequently

strongly preferred, as it would avoid all the High and Very High sensitivity


19

areas. However, if the entire footprint could be restricted to an area within

15m of the current road edge, even in these High and Very High sensitivity

areas, much of the botanical impact could be avoided, and it is

consequently recommended that the botanist work closely with the

engineering design team when it comes to planning the works in these

areas, and perhaps also in the actual construction phase.

All other ancillary infrastructure (access road, reservoirs, water pipeline,

wastewater treatment plant and sewer pumpstation) will be located in Low

or Low – Medium sensitivity areas and these areas present no constraints

to the proposed project.

On balance this author believes that the site offers potential for the

proposed development, but notes that this will come at a significant

environmental cost, in terms of the permanent loss of rehabilitation

potential of a large area of Critically Endangered vegetation. Overall the

loss of all vegetation on the primary site is likely to have a Medium

negative botanical impact, prior to mitigation.

A biodiversity offset may need to be considered to help reduce the

unavoidable Medium negative overall botanical impacts of the proposed

project

7. REFERENCES

DEA. 2011. Threatened Terrestrial Ecosystems in South Africa. Government

Gazette Vol. 1002: No. 34809. National Printer, Pretoria.

Helme, N. 2013. Botanical baseline and constraints study – Penhill Farm.

Unpublished report for The Environmental Partnership. Nick Helme Botanical

Surveys, Scarborough.

Holmes, P., J. Wood and C. Dorse. 2008. Updated (2016) and groundtruthed

CoCT Biodiversity Network, together with City of Cape Town – Biodiversity

Report. Environmental Management Branch, City of Cape Town. Available from:

www.iclei.org/lab

Klak, C., Helme, N.A., Raimondo, D. & von Staden, L. 2012. Lampranthus

explanatus (L.Bolus) N.E.Br. National Assessment: Red List of South African Plants

version 2017.1. Accessed on 2017/03/31

http://www.iclei.org/lab


20

Manning, J. and P. Goldblatt. 2012. Plants of the Greater Cape Floristic Region 1:

The Core Cape flora. Strelitzia 29. South African National Biodiversity Institute,

Pretoria.

Mucina, L. and M. Rutherford. Eds. 2012 update. Vegetation map of South Africa,

Lesotho, and Swaziland. Strelitzia 19. South African National Biodiversity

Institute, Pretoria.

Raimondo, D., Von Staden, L., Foden, W., Victor, J.E., Helme, N.A., Turner, R.C.,

Kamundi, D.A., and Manyama, P.A. (eds.) 2009. Red List of South African Plants

2009. Strelitzia 25. South African National Biodiversity Institute, Pretoria.

Rebelo, A., P. Holmes, C. Dorse and J. Wood. 2011. Impacts of urbanization in a

biodiversity hotspot: Conservation challenges in metropolitan Cape Town. S.A. J.

Bot. 77: 20-35.

Rouget, M., Reyers, B., Jonas, Z., Desmet, P., Driver, A., Maze, K., Egoh, B. &

Cowling, R.M. 2004. South African National Spatial Biodiversity Assessment

2004: Technical Report. Volume 1: Terrestrial Component. Pretoria: South

African National Biodiversity Institute.

Wood, J., A. Low, J. Donaldson and A. Rebelo. 1994. Threats to plant species

diversity through urbanization and habitat fragmentation in the Cape Metropolitan

Area, South Africa. In: Huntley, B (ed.). Botanical Diversity in Southern Africa.

Strelitzia 1. SANBI, Pretoria.

specialist botanical scoping study: proposed ......greenfields development of penhill (jacobsdal...

Documents