pipeline wetlands report ver 1 - terratest - lombards kop reservoir... · this tool is a...
TRANSCRIPT
MAY 2015
Prepared by:
TERRATEST (PTY) LTD
PO Box794
Hilton
3245
033 3436700
D.J. Alletson
SURVEY OF THE WETLANDS AND DRAINAGE LINE ALONG
THE ROUTES OF LOMBARDSKOP PIPELINE UPGRADES AND
RELACEMENTS INTHE VICINITY OF LADYSMITH, KWAZULU-
NATAL TOGETHER WITH IMPACT ASSESSMENT
AND MITIGATORY RECOMMENDATIONS
VERIFICATION PAGE
Form
4.3.1
Rev 13
SURVEY OF THE WETLANDS AND DRAINAGE LINE ALONG THE ROUTES OF
LOMBARDSKOP PIPELINE UPGRADES AND RELACEMENTS INTHE VICINITY
OF LADYSMITH, KWAZULU-NATAL TOGETHER WITH IMPACT ASSESSMENT
AND MITIGATORY RECOMMENDATIONS
JGI NO. :
41556
DATE :
May 2015
REPORT STATUS :
Final
CARRIED OUT BY : COMMISSIONED BY :
Terratest (Pty) Ltd
P O Box 794
Hilton
3245
MBONA, SAUNDERS AND WIUM (PTY) LTD
28 St Patricks Road
Scottsville
PIETERMARITZBURG
South Africa
Tel: (033) 343 6789 Tel +27 (0) 33 395 0920
Fax: (033) 343 6788 Fax +27 (0) 33 395 0921
Email: [email protected] Email: [email protected]
AUTHOR : CLIENT CONTACT PERSON :
D.J. Alletson C. Mitchell
SYNOPSIS :
This report documents the findings of environmental studies done at the sites of stream and
wetland crossings along the routes of two bulk water pipelines to Lombardskop near Ladysmith,
KwaZulu-Natal. Both desktop studies and field surveys were undertaken. The findings were that
the project should not have any significant environmental impacts but that precautions will have to
be taken to ensure that the watercourses and wetlands are not impacted upon. Mitigation
guidelines are put forward.
KEY WORDS :
Pipeline upgrade, Environmental Studies, Impact Assessment, Mitigation Guidelines.
© COPYRIGHT: Terratest (Pty) Ltd.
QUALITY VERIFICATION
This report has been prepared under the controls established by a quality management system
that meets the requirements of ISO9001: 2008 which has been independently certified by DEKRA
Certification under certificate number 90906882
Verification Capacity Name Signature Date
By Author Specialist Ecologist D.J. Alletson
21/05/2015
Checked by Environmental Consultant J. Richardson
21/05/2015
Authorised by Executive Associate M. van Rooyen
21/05/2015
Terratest (Pty) Ltd
TABLE OF CONTENTS
1. INTRODUCTION ........................................................................................................... 1
2. PROJECT DESCRIPTION AND STUDY AREA ............................................................. 1
3. STUDY PROCEDURES ................................................................................................. 3
3.1 Study Outline .......................................................................................................... 3
3.2 Risk Assessment .................................................................................................... 3
3.3 Wetland Assessment .............................................................................................. 4
4 STUDY FINDINGS ......................................................................................................... 5
4.1 Desktop Studies ...................................................................................................... 5
4.1.1 Vegetation ....................................................................................................... 5
4.1.2 Conservation data ............................................................................................ 5
4.1.3 Wetlands .......................................................................................................... 5
4.1.4 Other data ........................................................................................................ 5
4.2 Site Studies............................................................................................................. 7
4.2.1 Existing Pipeline Crossing Points ..................................................................... 8
4.2.2 New Pipeline Crossing Points ........................................................................ 13
4.2.3 Proposed Alternative Pipeline Route Crossings ............................................. 21
5 CONSIDERATION OF RISK LEVELS AS PER THE DEPARTMENT OF WATER AND
SANITATION MODEL ......................................................................................................... 22
6 CONSIDERATION OF THE PRESENT ECOLOGICAL STATE OF THE LARGER
WETLANDS IN THE VICINITY OF THE PROPOSED PIPELINE ROUTE .......................... 23
7 CONSIDERATION OF POTENTIAL IMPACTS ON THE WETLANDS AS A
CONSEQUENCE OF THE PROPOSED PIPELINE UPGRADES AND COSTRUCTION .... 25
7.1 Impacts on Stream and Wetland Crossings ............................................................... 25
7.2 Impacts at the Klip River and Floodplain Crossing Sites ............................................ 27
8 SUMMARY .................................................................................................................. 29
9 REFERENCES ............................................................................................................ 29
APPENDIX I: DEFINITION OF TERMS USED IN IMPACT ASSESSMENT ........................ 31
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SURVEY OF THE WETLANDS AND DRAINAGE LINE ALONG THE ROUTES OF
PIPELINE UPGRADES AND RELACEMENTS INTHE VICINITY OF
LOMBARDSKOP LADYSMITH, KWAZULU-NATAL TOGETHER WITH IMPACT
ASSESSMENT
AND MITIGATORY RECOMMENDATIONS
1. INTRODUCTION
The Emnambithi/Ladysmith Municipality (the Municipality) is proposing to upgrade the bulk
potable water pipeline which links the Ezakheni Reservoir and a new Lombardskop Reservoir
which will be situated close to the existing one.
The proposed development of this water scheme triggers a number of activities listed under
the Environmental Impact Assessment Regulations (2014) which were promulgated under the
National Environmental Management Act (Act 107 of 1998). Prior to the commencement of
the proposed project, it will be necessary for the applicant (the Municipality) to obtain
Environmental Authorization, which is subject to a Basic Assessment being undertaken, from
the Department of Economic Development, Tourism and Environmental Affairs (EDTEA).
Terratest (Pty) Ltd have been appointed by the Municipality to apply for the required
authorization. This report is a part of that assessment process and is intended to provide an
understanding of the project in regard to wetlands and drainage line crossings.
The findings of this study are that most of the watercourses in the study area are already
degraded to varying degrees but that some features of environmental conservation value are
present. However, the existing pipelines have had very little discernible impact on the
watercourse crossings and hence there is little reason why the new lines should have impacts
provided that the construction is properly undertaken. Recommendations intended to help
reduce potential impacts along the routes are put forward.
2. PROJECT DESCRIPTION AND STUDY AREA
The project consists of the following components:
• The upgrading of the existing pipeline from the Ezakheni Reservoir to a point near the
Ntombi Spruit Crossing. The length of this section is 5.75 km;
• The construction of a new 450 mm – 500 mm steel pipeline from the Ntombi Spruit
crossing through to a new reservoir to be built on Lombardskop. This line will run very
close to an existing line for much of its length but will include some new sections
including a new crossing point under the Klip River. Its length, depending on the final
route option selected, will be approximately 7.7 km.
The details of the above key points are indicated below and are shown in Figure 1.
• Ezakheni Reservoir. 28° 38' 23.0" S 29° 50' 18.5"E
This reservoir is taken as the starting point for the pipeline routes.
• Ntombi Spruit Crossing. 28° 35' 55.2" S 29° 49' 3.7" E
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The transition from older existing pipeline to a proposed new pipeline will take place at
a point near the Ntombispruit.
• Lombardskop Reservoir. 28° 33' 35.0" S 29° 51' 25.1" E
This reservoir is the endpoint of the pipelines.
Figure 1. Localities of the project area in relation to the town of Ladysmith.
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3. STUDY PROCEDURES
3.1 Study Outline
The study for the stream crossing sites along the pipelines was done in a series of phases
which were as follows:
• Desktop study. A preliminary investigation of the route was undertaken using aerial
and Google Earth imagery in order to determine possible sites of wetland or drainage
line crossings. Then attention was given to the Ezemvelo KZN Wildlife Minset planning
database, to the provincial wetland database, to the NFEPA (National Freshwater
Ecosystem Protected Areas) database, and to the vegetation type for the area. The
purpose of these database searches was to look for any recognised wetland-related
sites of conservation sensitivity. The terrestrial vegetation types and terrestrial fauna
were therefore largely ignored.
• Site surveys. The entire pipeline route, with the exception of a few points where it
passes over hilltops, which would not have wetlands, was traversed in order to gain
first hand understanding of the conditions on the ground. Each of the sites noted in
the desktop study was visited and assessed, and other sites, which had been missed,
were looked for. Attention was paid to the vegetation and to waterways and wetlands.
• Reporting. The findings of the above two phases were documented and the potential
impacts of the construction operations and associated mitigatory measures were
considered.
3.2 Risk Assessment
The National Water Act (Act 36 of 1988) and its regulations call for the issue of a Water Use
Licence under certain conditions where a development or other activity may impact on a water
resource. The two key Sections in this regard are Section 21 (c) which covers activities which
may “impede or divert” the flow of water in a watercourse. The key trigger distances for
consideration of an activity are 32m for a watercourse and 500m for a wetland.
In order for the potential impacts of the new pipeline to be assessed use was made of the
Department of Water and Sanitation’s Risk Assessment model to determine whether any
streams or wetlands were likely to be placed at risk as a result of the construction process.
This tool is a spreadsheet-based model which considers the possible impacts of an activity on
a water resource. Risks or other relevant conditions are assigned a numeric score and these
scores are then manipulated to produce a final rating. The ratings vary in value from 1 to 300
and are divided into three classes as shown in Table 1.
Table 1. Department of Water and Sanitation rating table for impacts on water resources.
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RATING CLASS MANAGEMENT DESCRIPTION
1 – 55 (L) Low Risk Acceptable as is or consider requirement for
mitigation. Impact to watercourses and resource
quality small and easily mitigated. Wetlands may be
excluded.
56 – 169 M) Moderate
Risk
Risk and impact on watercourses are notably and
require mitigation measures on a higher level, which
costs more and require specialist input. Wetlands
are excluded.
170 – 300 (H) High Risk Always involves wetlands. Watercourse(s)
impacts by the activity are such that they
impose a long-term threat on a large scale
and lowering of the Reserve.
3.3 Wetland Assessment
It is usual for an estimation of the Present Ecological State of each system to be made.
Normally this would be done by means of a model such as WET-Health and this has done for
the Klip River floodplain in the vicinity of the pipeline route. However, the model was not
applied to the whole of the system both as the system is so large and as the data available is
minimal. However, the potential changes of the pipeline construction are likely to be miniscule
and so, while the modelling of the system is not perfect, it is considered to be sufficient to
provide some understanding of the floodplain in that area. The classes generated by the model
are as indicated in Table 2.
Table 2. Wetland categories from the WET-Health model
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4 STUDY FINDINGS
4.1 Desktop Studies
4.1.1 Vegetation
The vegetation surrounding all the sites is transitional between Northern KwaZulu-Natal Moist
Grassland (Gs 4) and KwaZulu-Natal (Gs 6) by Mucina and Rutherford (2006). These two
types are in areas of moderate rainfall (750 mm – 850 mm per annum) are generally not rich
in wetlands other than in the lower lying area along river valleys. The vegetation descriptions
given make no reference to wetlands.
The wetlands which are present at some of the crossing points are classified as “Alluvial
Wetlands: Temperate Alluvial Vegetation” in the KZN Wetlands database and as “Natural” in
the NFEPA database.
4.1.2 Conservation data
The Ezemvelo KZN Wildlife Minset database was interrogated to search for wetland-related
conservation priorities. It was found that, other than for some of the wetlands in the area,
nothing relevant to this study was listed.
4.1.3 Wetlands
The Ezemvelo KZN Wildlife and NFEPA wetland databases contain the same spatial data and
so no differences are indicated. Two large wetland systems are indicated. The first of these,
in the direction of water flow, is an open valley bottom system in the Mbulwana area. See
Figure 2. It is immediately apparent that the mapping is inaccurate as the indicated area
includes a considerable amount of built development and roads which are on hillsides.
Despite this the site was marked for field investigation at a later stage.
The second wetland area indicated is the floodplain of the Klip River on the south-eastern
outskirts of Ladysmith. Again the mapping appears to be inaccurate in terms of the included
infrastructure and also of the ground contours in the demarcated area. It was apparent
however, that there are wetland patches present and that in situ inspection would be
necessary.
In addition to the large database-mapped wetlands, the desktop study also revealed a number
of smaller systems which are within 500m of the pipeline routes and these were also noted for
further investigation. It was found that those marked “1” and “2” in Figure 2 are on the opposite
side of the railway line and river to the pipeline and so will not be affected by the project.
4.1.4 Other data
(i) Transformation. All of the pipeline route with the exception of a small part of the
Klip River floodplain was classified as “Transformed”.
(ii) Threatened Ecosystems. No threatened ecosystems, as listed in the SANBI
database, are present anywhere near the pipeline routes.
(iii) Game Reserves, Nature Reserves, and Wildlife Conservancies. No nature
conservation areas are present anywhere near the pipeline routes.
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Figure 2. Distribution of wetlands along the pipeline routes. See text for
explanation of wetlands “1” and “2”.
(iv) Important Bird Areas. Important Birds Areas have been designated at sites where
the avifauna is of particular value, either in regard to bird diversity, or as habitat for
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migratory or rare bird species. No such areas are listed anywhere within a 20 km
radius of the pipeline and so no concern is raised in this regard.
(v) Fish in the Klip River. Since the 1970s, Ezemvelo KZN Wildlife has conducted a
number of fish surveys in the Klip River. Other than for alien species only the
following indigenous species have been recorded downstream of the Windsor dam:
Sharptooth Catfish Clarias gariepinus
Mocambique Tilapia Oreochromis mossambicus
Chubby-headed barb Barbus anoplus
NOTE: All of these species are common and widespread. The Mocambique Tilapia
is classified as “Near Threatened” as the genetic integrity of the species is at risk
as a result of hybridisation with alien Tilapia species. However, the construction of
the proposed pipeline will not impact on it in any way.
It is recognised that the Tugela River, into which the Klip River flows, contains two
endemic fish species. One of these, the Natal Scaly (Labeobarbus natalensis), is
a KwaZulu-Natal endemic and the other, the Tugela Labeo (Labeo
rubromaculatus), is a Tugela River basin endemic. However, the Klip River has two
large waterfalls in its lower reaches (below Ladysmith) and the fish have not been
able to penetrate upstream past them.
4.2 Site Studies
As indicated, all of the pipeline route, with the exception of the hilltops, was visited. This was
made possible by the existence of roads and tracks along much of the route and only in a few
places was it necessary to walk any distance. Particular care was taken to visit the sites which
had been identified in the desktop study but further sites were also searched for. At each
wetland or stream crossing photographs were taken and note was made of the conditions.
The crossings listed below extend from the Ezakheni reservoir onwards.
NOTE: The sites within the Klip River floodplain area (Sites 9 to 14) and in other wide systems
(Sites 1, 2, 15, 16, and 17) are indicated by single points. However, since the floodplain is
expansive, consideration was given to, not just the point, but also to potential impacts along
the pipeline route on either side of the point.
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4.2.1 Existing Pipeline Crossing Points
See Figure 2 for the locations of the crossing points.
Figure 2. Pipeline crossing points along the existing pipeline route.
• Site 1
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Position: 28° 37' 56.2"S. 29° 50' 16.3"E
Description: This crossing point is on the Davelspruit. The stream is wide and has multiple
channels. Sediment infill as a result of catchment erosion is extensive. The area is
extensively grazed by livestock so, at the time of the visit the vegetation was low. The
stream channel is invaded by River Bean (Sesbania punicea). At the time of the visit the
system was largely dry.
Downstream of the crossing site the stream channel has been used as a borrow pit for
provision of a soil or rock material.
Crossing Details: No pipeline markers were seen at the site and there was no visible
evidence of any damage to the system as a result of the crossing.
Photograph 1. Site 1. Davelspruit
crossing point. The absence of
markers meant that the precise
point could not be determined.
• Site 2.
Position: 28° 37' 42.1"S. 29° 50' 14.6"E
Description: This site lies within a wetland area included in the NFEPA database. The
system is large and diffuse. The topography is generally low with gradients being very
gentle (<3.5%). It is apparent that it has been extensively transformed by human activities
including cultivation for production of crops. At present only parts are still cultivated but
some of the pipeline route has been used in this way.
An estimate of the Present ecological State (PES) has been made. See Section 6.
Crossing Details: No markers were found but there is no evidence of any damage to the
system as a result of the line being present.
• Site 3.
Position: 28° 37' 16.1"S. 29° 50' 11.5"E
Description: This site lies at the point where a small stream is crossed and is a short
distance (140 m) downstream of a dam whose primary function is now stock watering.
The stream probably has near perennial flow although the amount of water will be minimal
in the dry season and in dry years may cease altogether. Wetland obligate plants seen at
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the site included sedges (Cyperaceae), Knotweed (Persicaria sp.) and a tall grass
(Sporobolus sp?).
Crossing Details: The crossing point is marked with markers and a valve chamber is
present. A footpath/track crosses the stream immediately alongside the pipeline. The site
shows no indications of having been impacted upon by the line which is buried under the
stream.
Photograph 2. Site 3. A route marker
is visible and the valve chamber is
indicated by the arrow.
• Site 4.
Position: 28° 36' 36.7"S. 29° 50’ 8.3"E
Description: This site is the point at which the pipeline passes through the Hermanspruit.
The slopes on either side of the channel are moderately steep but appear to be stable. At
the time of the visit there was no surface water visible and so it is apparent that the system
is seasonal.
Photograph 3. Site 4. A route marker
(arrow) and a valve chamber are
visible.
Crossing Details: The stream channel is stable and is well armoured with boulders. The
pipeline is buried and does not appear to be affecting the channel in any way.
• Site 5.
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Position: 28° 36' 16.4"S. 29° 50’ 1.2"E
Description: This site is located on a very small drainage line which will only flow naturally
at times of high rainfall. A small dam has been constructed to retain some of these flows.
However, water leakage from a valve chamber on the line, as well as leakage from a
nearby tap, have led to a situation where there is permanent water and a community of
hygrophilous plants has developed below the crossing.
Crossing Details: The site lies alongside a narrow road/track and the pipeline route is
plainly indicated by the valve chamber and a marker. Apart from the changes arising out
of the two water leaks, the crossing does not seem to have affected the drainage line in
any way.
Photograph 4. Site 5. Note the zone
of green vegetation established as a
result of the leaks from the valve
chamber and from a running tap.
• Site 6.
Position: 28° 36' 3.2"S. 29° 49’ 20.6" E
Description: This site lies on a small unnamed stream. Flow, or at least standing pools of
water, are probably perennial. At the time of the site visit the vegetation in the channel
upstream of the crossing was green but a valve chamber at the site was full of water so it
is probable that some leakage is contributing to downstream flows. The vegetation was
heavily grazed by livestock but does appear to be dominated by grasses rather than by
hygrophilous species.
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Photograph 5. Site 6. The pipeline
marker and the valve chamber are
clearly visible. Leakage from the latter
may be contributing to the green
vegetation.
Crossing Details: The site is well marked by both a marker and by the valve chamber. There
is no erosion or other evidence to suggest that it is having any adverse impact on the drainage
line.
• Site 7.
Position: 28° 35' 55.8"S. 29° 49’ 4.6"E
Description: This site lies on the Ntombispruit and is immediately upstream of a road
crossing. A valve chamber is located within the macro channel of the stream but there is
no indication that leakage is having any effect on the system. After the crossing the line
continues northwards and a marker situated some 35 m north of the bridge is taken as
being the end point of the existing pipeline.
This site is indicated as being within a wetland system which is linked to the floodplain of
the Klip River. While the mapping is plainly inaccurate, the site is within a wetland system
and is likely to be inundated at times.
Crossing Details: The site is well marked by both a marker and by the valve chamber.
Access from the nearby road is readily available.
Photograph 6. Site 7. The
crossing point is to the left of the
road where a marker and a valve
chamber are visible. The arrow
indicates the positions of the
marker and is taken to be the end
of the “existing” pipeline.
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4.2.2 New Pipeline Crossing Points
The section of pipeline which is considered below is designated as “new” although in situ
examination of the route revealed that an existing pipeline is already present along most of its
length. See Figure 3 for the crossing points along the new pipeline route.
The starting point of the new line has been indicated by the client as being at the end of the
existing pipeline covered in Section 4.2.1 above. While the alignment of this line was followed,
an alternative route is also suggested for a part of its length so as to avoid some wetland
areas.
Much of the new pipeline route, between Site 9 and Site14 lies within the Klip River floodplain.
This is a large wetland system but is now only inundated by exceptionally large flow events.
The soil is very clay-rich and is hard when dry. It is assumed to be alluvial in origin. Much of
the area has been cultivated in the past although, along the pipeline routes examined here,
there is now no such activity. However, the area is heavily grazed by livestock which consists
primarily of cattle and a lesser number of goats. The vegetation which now covers much of
the area is a species-poor medium-to-tall grassland community. Thatch grass (Hyparrhenia
hirta) and Turpentine grass (Cymbopogon sp.) predominate but short species such as Kweek
(Cynodon dactylon) and Buffalo grass (Paspalum sp.) are also widespread. Forbs are
generally scarce but a few scattered Hypoxis and Berkheya were noted. All were withered and
senescent and full identification was not possible. Scattered stands of tall Eucalyptus trees
are planted in rows and are probably remnant traces of past human activity.
Of importance on the floodplain are some wet areas. These may be small (<10 m2) or else
may be several hectares in extent. The origin of the water which sustains them is not apparent.
With the special exception of Site 12, no surface water was visible, and tall wetland plants are
generally absent. Thus the wet patches are considered to be unchannelled floodplain
hygrophilous grasslands. Their degree of wetness probably varies considerably, and some
may even be seasonal or ephemeral. Situated some 350 m from Site 9 is a vestigial oxbow
which probably remains permanently wet. However, it will not be affected in any way by the
proposed development.
Throughout the system it is common to find greener vegetation in the furrows left by the old
cultivation. In some cases these may be drawing water from the wet patches but most are
probably just localised reservoirs of pooled rainwater and are not linked to ground water in
any way. A large drainage canal, which originates in the housing area on the eastern side of
the floodplain, runs parallel to Mandela Drive and then turns southwards to pass across the
floodplain and into the Klip River.
The Klip River floodplain is considered further in Section 6.
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Figure 3. Pipeline crossing points along the “new” and alternate pipeline routes.
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• Sites 8a and 8b.
Positions: 28° 35' 54.9"S. 29° 49’ 3.7" E and 28° 35' 51.9"S. 29° 49’ 6.2" E
Description: These two sites are the locations of places where the new line would cross
channels of the Ntombispruit system. As such they are within the mapped wetland system
which is referred to above. Site 8a is visible in Photograph 6 and lies on the opposite side
of the road to the indicated marker. The channel in each case is open with a sand/gravel
bed and banks which are covered by tall grasses. They were dry at the time of the visit
and so only seasonal flows are indicated.
Crossing Details: Based on the observations made at Site 7, it appears that a pipeline
buried below the channel beds would have no impact on the system in the medium to long
term.
• Site 9.
Position: 28° 35' 49.6"S. 29° 49’ 9.6" E
Description: This site lies in an area which has some wetland characteristics. While the
soils were too hard to be augered, it was clear that they have a very high clay content and
are probably alluvial. The vegetation is dominated by tall grass species but they had been
trampled and grazed and identification could not be done. No evidence of the existing
pipeline could be found.
Crossing Details: The soils in the area are clay rich and were very hard at the time of the
visit. However vehicle tracks made in the wet season indicate that the surface is much
softer at that time. The soils are alluvial and are linked to the floodplain of the Klip River.
• Site 10.
Position: 28° 35' 41.0"S. 29° 49’ 12.6" E
Description: The site lies about 35 m off the indicated alignment of the new pipeline. It
does however mark the location of an existing pipeline marker and a valve chamber which
is leaking water to an extent which is sufficient to have created a small wetland. The
leakage has been persistent enough for a stand of bulrushes (Typha capensis) to have
developed. This plant is a wetland obligate species and it is thought that propagules would
have been brought to the site by water birds.
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Photograph 7. Site 10. The stand of
bulrushes near the pipeline marker
and valve chamber is indicated.
This wetland patch was delineated and has an area of 0.25 ha. It is, however, totally
unnatural and termite mounds situated a few metres away from its edge are dry to a depth
of at least 1,5 m, thus indicating that the ground water is not widespread.
Crossing Details: Apart from the wetland at the site of the valve chamber there are no
other traces of the pipeline. It can therefore by assumed that no long term environmental
damage is being done.
• Site 11.
Position: 28° 35' 30.3"S. 29° 49’ 17.0" E
Description: Site 11 is the point at which the existing pipeline crosses the Klip River
although the new pipeline route is some 75 m to the east. There are markers on both
banks and so the placement of the old line is clear. The active channel is deeply incised
and the present water surface is approximately five metres below the surrounding
floodplain area. The vegetation on the banks of the primary channel is greener than that
on the upper floodplain and so a deep (2 m from surface) ground water surface is
suggested. The vegetation along the crest of the channel is dominated by grasses
including Thatch grass (Hyparrhenia hirta) but the lower banks also have a variety of small
bushes and some trees. Species noted included Willows (Salix Sp.), Silver poplar
(Populus x canescens), Paperbark thorn (Acacia sieberiana), Pale-bark Sweet Thorn (A.
natalita), and Gum trees (Eucalyptus sp.).
Crossing Details: Other than for the two pipeline markers, there is no trace of the pipeline
at the site. It is therefore apparent that the line is now having no impact at that point. On
the basis of this observation there is no clear cause for concern if the new line is placed
75 m further downstream.
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Photograph 8. Site 11. Site of the
present pipeline crossing. The
picture was taken from the site of
a marker and the marker on the
opposite is indicated (arrow).
Otherwise there is no visible trace
of the line.
• Site 12.
Position: 28° 35' 17.7"S. 29° 49’ 22.6" E
Description: This site marks the location of an existing marker and valve chamber while
the indicated new pipeline route is some 65 m to the east. The pipe within the chamber
leaks and a large (± 2 ha) wetland has developed in the area. This wetland is well
developed and now supports populations of several bird species which are either wetland
obligate or near obligate. Included are Grey Crowned Cranes (Balearica regulorum), Red-
billed Teal (Anas erythrorhynca), Black-headed Heron (Ardea melanocephala), Great
Egret (Egretta alba), Sacred Ibis (Threskionis aethiopicus) and a variety of weavers,
bishop birds, and warblers. The greater part of the vegetation consisted of sedges and
grasses. The crane species is Red Data listed.
Crossing Details: The leak from the pipeline has contributed to the formation of a large
wetland with areas of open water. Apart from this feature there is no other evidence of the
line since there is no soil erosion of any sort.
Photograph 9. Site 12. The open
water near the valve chamber is
visible and the body of the wetland
lies in the background.
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Photograph 10. Site 12. The
valve chamber which is leaking the
water, and the pipeline marker are
shown.
• Site 13.
Position: 28° 35' 22.0"S. 29° 49’ 41.1" E
Description: Site 13 is taken to be at the point where some yellow painted stones were
seen and is assumed to be the point where the pipeline turns toward the north. These
stones were the only marker found and are situated some 50 m from the drainage canal
leading from the direction of Mandela Drive.
Crossing Details: There is no soil erosion of any sort visible at the site and the vegetation
is the same as that in the surrounds.
Photograph 11. Site 13. The
painted stones which mark the site
are shown.
• Site 14.
Position: 28° 35' 13.1” S. 29° 49’ 45.2” E
Description: Site 14 is the point where the pipeline passes under Mandela Drive and then
passes under the drainage canal there. No markers or other traces of the line were found
and so no description is given.
• Site 15.
Position: 28° 35' 8.8” S. 29° 49’ 51.1” E
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Description: Site 15 is the point where the pipeline passes under the road coming in from
Colenso (P325). No markers were found but it is clear that no erosion has been caused
to that area.
South and east of the site are areas of wetland which discharge toward the nearby
floodplain. However, since the elevation above the river is too great for water in the area
to be derived from riverine flooding, it is apparent that the flows are from Mbulwana Hill to
the east. The drainage from the higher areas is largely in discrete channels but on the
lower slopes the system becomes very diffuse in its lower areas and, as with the floodplain,
much of it has been cultivated in the past. Recent human activities have greatly
transformed the area but it was probably originally an unchannelled toeslope seepage
system. However, it is now partially channelised, either as a consequence of soil erosion
gullies, or as a result of deliberate drain excavation.
Photograph 12. Site 15.
Drainage ditch/channel alongside
Road P325. No markers were
seen but the pipeline is thought to
be just to the right of the ditch.
Crossing Details: No pipeline markers were found but, since no impacts which could be
considered to have arisen from the pipeline were seen, it is taken that conditions are
conducive to problem-free construction.
• Site 16.
Position: 28° 34' 4.9” S. 29° 50’ 7.2” E
Description: From Site 15 the pipeline route runs up the hill and parallel to the road. At
Site 16 it must pass through a broad (± 250 m) drainage line which consists of multiple
small channels and gullies. The largest of these is at the point indicated but others emerge
from the nearby housing area and from the open space to the north of the primary channel.
This drainage line flows down to the Pound Spruit. At the crossing site much of the surface
is open and it is clear that soil erosion is taking place. The substrate of the system is
generally fine silts and gravels which overlie shales and mudstones.
Crossing Details: The existing pipeline route is clearly indicated by markers and by valve
chambers. The route of the proposed new line lies very close to the existing line and so it
is assumed that the same servitude will be used. There are no indications of any erosion
or other damage which may have resulted from the existing line and so it is clear that
construction can be done in an impact-free manner.
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Photograph 13. Site 16. View
along the pipeline route at Site 16.
Two markers and a valve chamber
are visible. Water leaking from the
chamber is supporting a small
hygrophilous plant community.
The primary channels flows under
the bridge which is visible.
• Site 17.
Position: 28° 33' 52.2” S. 29° 50’ 11.7” E
Description: The drainage line which is crossed at Site 17 is a further tributary of the Pound
Spruit. The primary channel is crossed by means of a pipe bridge but secondary channels
to the north near some houses result in the whole crossing being some 350 m wide. As
with Site 16, vegetation is sparse and the bare soils are being eroded.
Crossing Details: The route of the new pipeline is shown as being exactly along that of the
old line. This implies that the pipe bridge will be used again and so there will be no new
impacts arising out of the construction process.
Photograph 14. Site 17. Pipe
bridge at Site 17. The sparse
vegetation and some bare soil
areas are shown.
• Sites 18a to 18d.
Description: Over a distance of approximately 650 m along Road P32 the pipeline route
traverses four minor drainage lines which are no more than local dongas. These are all
very small and, as they have not been impacted upon in any way by the existing line, are
further ignored.
Following on from the Site 18 points, the pipeline route encounters no further stream or
wetland crossings.
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4.2.3 Proposed Alternative Pipeline Route Crossings
It appears that sections of the proposed new pipeline route will pass through wetlands that
could be avoided. Since this situation is undesirable from an environmental perspective, some
small re-alignment alternatives are suggested below. See Figure 4 for detail of the proposed
alternative pipeline route. it is to be noted that this proposal is conceptual only and that the
position of the line could be easily shifted.
Figure 4. Detail of the proposed alternative route for the new pipeline in the vicinity of the
Klip River.
• Site 8c.
Position: 28° 35' 50.2” S. 29° 49’ 4.5” E
Description: This site is on a part of the same drainage line as are Sites 8b and 8c and is
similar to them.
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Crossing Details: Based on the observations made at Site 8, it appears that a pipeline
buried below the channel bed would have no impact on the system in the medium to long
term.
From this site, the alternative route would proceed directly to Site 10. In doing so it would
pass through an area that does not include the wetland system that is present at Site 9.
Instead it would pass through an area of scrubby woody vegetation and grassland. Then
from Site 10 the route would continue on a line close to the cemetery boundary and, at the
corner post, would swing across to use the same crossing point, at or near Site 11, as the
given new line alignment.
• Site 19.
Position: 28° 35' 27.4” S. 29° 49’ 21.2” E
Description: Some 80 m to `100 m after crossing the Klip River the alternative route would
turn eastwards and continue for some 150 m before turning north again to join the given
new alignment at Site 20.
The purpose of this detour would be to route the line around the large wetland area
associated with Site 12. It is recognised that the wetland will largely dry out if the present
pipeline is decommissioned but there is some evidence that the area was a wet patch prior
to 2010 which is when the spread of the new wetland is first apparent in Google Earth
images. If this was in fact the case, then the alternative route suggested here will avoid a
wet area that is likely to persist in the future.
5 CONSIDERATION OF RISK LEVELS AS PER THE DEPARTMENT OF WATER
AND SANITATION MODEL
The Department of Water and Sanitation risk assessment model was applied to each of the
seven crossing sites and the results are indicated in Table 3 below.
The table suggests that the risk of impacts on the crossing sites, with the exception of Site 11
is “Low”. The risk at Site11 is rated as being “Medium” for the following reasons:
• The Klip River is a large perennial river and has the capacity to carry contaminated
water further than does a small stream or a wetland which has diffuse flow.
• Because the river is larger than any other in the study area, any long term instream
impacts will be difficult to determine.
• Impacts at the site could easily spread and affect a larger area.
Table 3. Risk assessment criteria at crossing sites. Scoring based on both the desktop study
findings and the field survey.
Crossing
Site
Impact Risk
Rating Severity Consequence Likelihood Significance
1 1 4 8 32 L
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2 1.25 4.25 8 34 L
3 1 4 8 32 L
4 1 4 8 32 L
5 1 4 8 32 L
6 1 4 8 32 L
7 1 4 8 32 L
8 1 4 8 32 L
9 1.25 4 8 34 L
10 1 4 8 32 L
11 1.75 6.75 10 67.5 M
12 1.5 5.5 8 44 L
13 1 4 8 32 L
14 1 4 8 32 L
15 1 4 8 32 L
16 1 4 8 32 L
17 1 4 8 32 L
18 1 4 4 16 L
19 1 4 8 32 L
20 1 4 8 32 L
The table suggests that the risk of impacts on the crossing sites, with the exception of Site 11
is “Low”. The risk rating at Site11 is rated as being “Medium” for the following reasons:
• The Klip River is a large perennial river and has the capacity to carry contaminated
water further than does a small stream or a wetland which has diffuse flow.
• Because the river is larger than any other in the study area, any long term instream
impacts will be difficult to determine.
• Impacts at the site could easily spread and affect a larger area.
6 CONSIDERATION OF THE PRESENT ECOLOGICAL STATE OF THE LARGER
WETLANDS IN THE VICINITY OF THE PROPOSED PIPELINE ROUTE
As indicated in Section 3 above, only that section of the floodplain around the pipeline route
was subject to actual WET-Health modelling. The area considered was 55 ha in extent and
the following assumptions were made:
• Inundation of the floodplain as a result of flooding by the Klip River has been very
severely curtailed as a consequence of the Windsor Dam and the Qedusizi Dam Flood
Retention Wall.
• In the past, almost the entire selected area was subject to cultivation but now most has
been abandoned.
• Canalisation of floodplain flows is negligible. The presence of the Mandela Drive
drainage canal is recognised but the greater part of the flow through it is derived from
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the hinterland. It does, however, contribute to reduction of lateral inputs and also to
some limited drying of the floodplain in its vicinity. The latter impact is likely to have
been reduced as the soils in that area are clay-rich and so will be relatively
impermeable.
• Invasion by alien weed species is minimal.
• Grazing by livestock keeps the grass sward lower than might otherwise be the case
and so water losses by surface evaporation are likely to be slightly enhanced.
The outputs from the assessments are split into three categories which are Hydrology,
Geomorphology, and Vegetation and are shown in Table 4. The categories are derived from
Table 3.
The wetland at Site 2 was assessed on the basis of professional experience and was scored
as shown in Table 4. The following assumptions were made:
• The wetland in its natural state would be classified as an unchannelled hillslope seep.
• The hydrology in the system has been adversely affected by both a dam and by erosion
of the stream channel banks at its base.
• There are now erosion gullies within the wetland.
• Parts of the area have been cultivated.
• Much of the original vegetation has been replaced by grasses which are encouraged
by regular veld burning.
The wetland at Site 15 was assessed on the basis of professional experience and was scored
as shown in Table 4. The following assumptions were made:
• The wetland in its natural state would be classified as an unchannelled hillslope seep.
• The hydrology in the system has been adversely affected by residential development
and a school.
• There are now erosion gullies within the wetland.
• Parts of the area have been cultivated.
• Much of the original vegetation has been replaced by grasses which are encouraged
by regular veld burning.
Table 4. WET-Health scores for the three larger wetland systems.
Floodplain Crossing Site 2
Wetland Area
Crossing Site 15
Wetland Area
Score PES
Category PES Category PES Category
Area modelled (ha) 55 n/a n/a n/a
Hydrology 10.0 F C D
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Geomorphology 9.0 F E E
Vegetation 3.8 C D D
Mean Score 7.6 n/a
n/a n/a
Health Class E D D
The systems are regarded as being stable over the next five years and no change in the
trajectory of change is anticipated.
The modelling process suggests that the primary driver of the condition of the primary wetland
in the study area is reduction inundation of the floodplain as a result of the two named dams.
The past agriculture and consequent loss of indigenous vegetation were found to have a far
lesser effect on the score. The poor condition of the site, together with the observation that
the present pipeline has had virtually no impacts on the system other than to make it wetter
as a result of leakage, suggest that the new pipeline should also have very few impacts if
construction is done with due care.
NOTE: The best developed wetland patch in the area modelled exists primarily as a result of
water leakage. Presumably the water losses will cease with the new pipeline and so the wet
area will largely dry out. As the site supports a Red Data listed bird species (Grey Crowned
Crane Balearica regulorum) the change may be regarded as a negative impact on biodiversity.
7 CONSIDERATION OF POTENTIAL IMPACTS ON THE WETLANDS AS A
CONSEQUENCE OF THE PROPOSED PIPELINE UPGRADES AND
COSTRUCTION
Since there are already pipelines in the ground along all of the study area routes it is possible to consider the long term consequences of the previous construction operations by using the existing conditions as a guideline. In no instance was it possible to find impacts on wetland or stream crossings, or elsewhere, which could be attributed to the pipelines. Thus it is possible to state that, if the new construction work is done correctly, the impacts that will arise as a consequence of the proposed upgrades are likely to be minor or even negligible. As a part of the impact assessment process, attention was given to the scores derived in the risk rating model (Section 7 above). However, since the term “Risk” is not precisely defined it was unclear as to where to apply it in the more conventional impact assessment framework. Finally it was determined that it would be most useful to align it with the “Significance” assessment since a risk which is rated as “High” may logically be assumed to be “Significant”.
7.1 Impacts on Stream and Wetland Crossings
The key issue at the stream and wetland crossing sites is the need to undertake excavations within the various watercourses. The foreseen potential impacts associated with such work are as follows:
• Deposition of soil or other sediment into the watercourse where it will be washed
downstream into either wetlands or the Klip River.
• Possible damage to the riparian surrounds.
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• Possible spillage of wet cement/concrete into the watercourse.
• Deposition of solid waste such as plastics, scrap metal and the like into the
watercourse.
These impacts are assessed as shown in Table 5.
Table 5. Assessment of potential impacts at stream and wetland crossing sites. Refer to
Appendix I for definitions of the terms used.
Assessment parameter Extent
CERTAINTY Moderate to High
PROBABILITY Highly Probable
IMPACT Moderate
SIGNIFICANCE Moderate to High
SPATIAL EXTENT Site to Local
TIME PERIOD Construction Phase to
Short Term
EFFECT Negative
NEED FOR MITIGATION High
LOCALITY OF
MITIGATION On Site
Such impacts would be unacceptable without mitigation. Therefore, in order to minimise
(mitigate) the impacts the following recommendations are put forward:
• Prior to the start of operations the contractor must produce a method statement
indicating how the construction process will be undertaken. Most important in this
statement will be consideration of the impacts on the watercourse crossings and the
associated mitigation measures.
• The construction camp(s) may not be sited within 100 m of a wetland.
• Ideally, the construction work should be done in the dry season when plants are
senescent and stream flows are at their lowest.
• If concrete or cement are to be mixed at the site then it must be done in a place where
no uncured product can flow into a watercourse in an uncontrolled manner.
• Precautions are to be taken in regard to spillage of any hydrocarbon (fuels, oils,
greases) on the site. Care must be taken in their use but spill clean-up facilities must
also be on hand at all times.
• The watercourses and their surrounds must be protected against inputs of soil or other
sediment through proper use of stormwater management structures along the pipeline
route.
• Where sections of pipe are to be decommissioned they should be left in the ground
unless the new pipe will be laid in the same place. The reason for this recommendation
is that of avoiding opening unnecessary second trenches through the crossing areas.
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• At the end of the construction phase, the entire pipeline servitude, including the various
working areas, must be fully revegetated to match the pre-construction condition.
• The site must be kept clear of alien weeds species until such time as the area is fully
covered with a viable sward of grasses and other indigenous vegetation.
• A monitoring programme must be set up to keep a check on the condition of the site
for at least two years after the completion of construction. During this time all sites
should be checked at least twice per annum. Any observed impacts from the operation
must be corrected with immediate effect. Responsibility for the monitoring and the
follow-up operations must lie with the pipeline operator who may appoint a contractor
to do the work.
• All conditions and requirements of the project Environmental Management Plan (EMP)
must be adhered to.
If the mitigatory measures are adhered to then the impacts will be reduced as indicated in
Table 6.
Table 6. Assessment of potential impacts at stream and wetland crossing sites.
Assessment parameter Extent
CERTAINTY Moderate to High
PROBABILITY Highly Probable
IMPACT No Impact to Low
SIGNIFICANCE Low
SPATIAL EXTENT Site to Local
TIME PERIOD Construction Phase
EFFECT Negative
NEED FOR MITIGATION n/a
LOCALITY OF
MITIGATION n/a
7.2 Impacts at the Klip River and Floodplain Crossing Sites
The Klip River and its associated floodplain areas on both banks must be regarded as being
of especial environmental sensitivity. The reasons for this are for both the intrinsic values of
any river and floodplain, and for the fact that impacts there could potentially expand and affect
extensive downstream areas. The following impacts may be anticipated:
• Loss of biodiversity at the site, particularly through allowing the establishment of alien
plant species.
• Deposition of soil or other sediment into the system from where it will be washed
downstream.
• Possible damage to the riparian surrounds.
• Risk of initiating erosion gullies which could spread into the floodplain.
• Possible spillage of wet cement/concrete into the watercourse.
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• Deposition of solid waste such as plastics, scrap metal and the like into the
watercourse.
These impacts are assessed as shown in Table 7.
Table 7. Assessment of potential impacts at Crossing Site 5. Refer to Appendix I for definitions
of the terms used.
Assessment parameter Extent
CERTAINTY Moderate to High
PROBABILITY Highly Probable
IMPACT High
SIGNIFICANCE High to very High
SPATIAL EXTENT Site to Regional
TIME PERIOD Construction Phase to
Long Term
EFFECT Negative
NEED FOR MITIGATION Obligatory
LOCALITY OF MITIGATION On Site
• Prior to the start of operations the contractor must produce a method statement
indicating how the construction process will be undertaken. Most important in this
statement will be consideration of the impacts on the river and the associated
mitigation measures that will be used.
• It is recommended that the bulk of the construction work at this site be done in the
winter season when the risk of flooding is at its lowest.
• The working servitude is to be kept as small as possible. It is recommended that an
appropriate specialist demarcate the working area and that an exclusion fence be set
up so as to contain the operations.
• Precautions are to be taken in regard to spillage of any hydrocarbon (fuels, oils,
greases) on the site. Care must be taken in their use but spill cleanup facilities must
also be on hand at all times.
• The river must be protected against inputs of soil or other sediment through proper use
of stormwater management structures.
• The section of pipeline which is to be decommissioned must be left in the ground so
as to minimise the extent of excavations in the area.
• Especial care must be taken in regard to the stability of the river banks once the
pipeline has been installed. It is strongly recommended that the rehabilitation
measures be undertaken with emphasis on the use of plants to protect the river bank.
Hard structures such as gabions and mattresses should be avoided if possible since
they may well lead to bank erosion in the long term.
• At the end of the construction phase, the site must be fully revegetated to match the
pre-construction condition.
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• The site must be kept clear of alien weeds species until such time as the area is fully
covered with a viable sward of grasses and other indigenous vegetation.
• A monitoring programme must be set up to keep a check on the condition of the site
for at least two years after the completion of construction. During this time the sites
should be checked at least three times per annum. Any observed impacts from the
operation must be corrected with immediate effect. Responsibility for the monitoring
and the follow-up operations must lie with the pipeline operator who may appoint a
contractor to do the work.
• All conditions and requirements of the project Environmental Management Plan (EMP)
must be adhered to.
If the mitigatory measures are adhered to then the impacts will be reduced as indicated in
Table 8.
Table 8. Assessment of potential impacts at Crossing Site 5. Refer to Appendix I for definitions
of the terms used.
Assessment parameter Extent
CERTAINTY Moderate to High
PROBABILITY Highly Probable
IMPACT No Impact to Low
SIGNIFICANCE Low
SPATIAL EXTENT Site
TIME PERIOD Construction Phase to
Short Term
EFFECT Negative
NEED FOR MITIGATION n/a
LOCALITY OF MITIGATION n/a
8 SUMMARY
This study on the stream and wetland crossings along the designated pipeline routes has
found no potential impacts that could be considered to be fatal flaws. Despite this, there is
substantial environmental sensitivity, with the watercourses and their surrounds being the
primary features of concern. The potential impacts on the systems have been assessed. Key
concerns include damage to the wetland and riparian vegetation, and to the deposition of
sediment and waste materials into the systems. It will be possible to mitigate against the
impacts and recommendations in this regard have been put forward. In order to assist the
future contractor(s), some distinction has been made between the smaller systems and the
Klip River and floodplain, and each is dealt with according to its characteristics. If the
recommendations are adhered to then the road upgrade project should have no long lasting
effects at all.
9 REFERENCES
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MACFARLANE, D.M., KOTZE, D.C., ELLERY, W.N., WALTERS, D., KOOPMAN, V.,
GOODMAN, P., and GOGE, C. 2008. WET-Health: A technique for rapidly assessing wetland
health. WRC Report TT 340/08. Water Research Commission. Gezina.
MUCINA, L. & RUTHERFORD, M.C. (eds) 2006. The vegetation of South Africa, Lesotho and
Swaziland. Strelitzia 19. South African National Biodiversity Institute, Pretoria.
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APPENDIX I: DEFINITION OF TERMS USED IN IMPACT ASSESSMENT
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Assessment
Consideration Description
CERTAINTY
This criterion applies to the confidence of the assessor in making the assessment.
Low. The present degree of confidence in the relevant statement is less than 40%.
Moderate. The present degree of confidence in the relevant statement is between 40% and 80%.
High. The present degree of confidence in the relevant statement is greater than 80%.
PROBABILITY
This criterion applies to the likelihood of the anticipated impact actually happening. It may also be used in assessing the likelihood of success of a mitigatory action. Unlikely. The probability of the anticipated impact happening is low (Less than 20% probable).
Probable. The probability of the anticipated impact happening is moderate (20% - 60% probable).
Highly Probable. The probability of the anticipated impact happening is great. (60% - 99% probable).
Definite.
It is definite that the impact will take place.
IMPACT
This criterion refers to the impact in relation to its effect on a (stipulated) feature.
No Impact. There will be no discernible impact on the feature or issue under consideration.
Low. The impact on the feature or issue under consideration will be limited in terms of effect or in time.
Moderate. The impact on the feature will be such that there will be some damage done but that the feature will not be totally destroyed and that it will recover if the cause of the impact is removed.
High. The impact on the feature is such that the damage done will be considerable and enduring. Recovery from the impact could, at best, be only partial.
Very High. The impact on the feature is such that the feature will be totally destroyed and that no recovery is possible.
Unknown.
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The nature of the impact on the feature is not understood or cannot be predicted in any reliable fashion.
SIGNIFICANCE
This criterion refers to the effect of the impact "in the larger scheme of things". EG: If a proposed dam will inundate a particular patch of vegetation then the impact on that patch of vegetation is very high as it will be totally destroyed but, if the vegetation is of a common type which has low conservation priority, then the significance of the impact is reduced.
No Significance. The impact is so inconsequential that it is of no significance at all.
Low. The impact is of low intensity or consequence. It is probably Local in effect.
Moderate. The impact is of sufficient intensity to warrant concern. There will be considerable disturbance to either the natural biota and/or to humans. Ecological processes will be only slightly affected. The impact may be apparent for some time.
High. The impact is of considerable intensity. There will be severe degradation of the environment and localised losses of entire plant and animal assemblages may occur. Ecological processes are strongly disrupted. Social impacts may be severe. Recovery will only be possible in the Long Term.
Very High. The impact is of potentially devastating intensity to both the natural environment and/or to human residents of the area. There will be total or near-total failure of ecological processes. It is unlikely that mitigation is possible in any reasonable human time scale and hence that full recovery from the impact may not be possible in any reasonable human time scale. Thus the impact must be regarded as being Permanent.
Unknown. The consequences of the impact are not understood or cannot be predicted in any reliable fashion. Probably the precautionary principle should be applied.
LEVELS OF
SPATIAL EXTENT
This criterion refers to the space within which the impact will be of consequence.
Site Level. The physical impacts of the development will not extend beyond the immediate development site. If relevant, visual impacts will only be apparent to viewers on or close to, the site.
Local Level. The impacts of the development will only be felt or be significant at the site of the development or within a short distance (roughly 500 m) of it. In the case of visual impacts the distance may be increased to about 2 kilometres but is restricted to a narrow viewscape.
Regional Level. The impacts of the development may be felt or be significant at a distance which is well removed from the site. In the case of visual impacts the viewscape may be increased to landscape width and breadth.
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Provincial Level. The impacts of the development are sufficient so as to be significant throughout the province.
National Level. The impacts of the development are sufficient so as to be significant throughout the Republic of South Africa.
International Level. The impacts of the development are sufficient so as to be significant beyond the borders of the Republic of South Africa.
TIME PERIODS
This criterion refers to the length of time for which the impact may be apparent or in effect.
Construction phase. The time period during which geotechnical surveys and/or construction or other such work is done. Note: This phase will include all the time from the start of any geotechnical work that is done to the end of the construction period and includes any associated rehabilitation work that may be called for.
Operational phase. The time period for which the operation or development continues to function. This is of particular relevance for developments which have a very large footprint, such as timber plantations or urban expansion, or opencast mines which keep on expanding as they operate.
Short term. A period of time including the Construction Phase and up to two years further. Note: This time period is defined as it is considered that it covers the period in which the footprint of the construction operation will be sustainably revegetated and wildlife will return to the disturbed areas.
Medium term. A period of up to five years from the end of the Construction Phase. Note: This time period includes the criteria described for the Short Term but includes the time necessary for woody vegetation, if appropriate, to become established on the development area.
Long Term. A period of at least ten years, but possibly more, from the end of the Construction Phase or the Operational Phase. Note: This time period includes the criteria described for the Medium Term but includes the time necessary for trees to reach a "fair" size at which they will largely soften the appearance of the development.
Permanent. The change which would be brought about by the development cannot in any way be reversed in situ. The only mitigation options which may be available will be those which are conducted off site.
EFFECT This criterion refers to the nature of the change brought about by an impact.
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Positive. The impact will have predominantly beneficial results or connotations.
Negative. The impact will have predominantly detrimental results or connotations.
Neutral. There will be a change but it cannot be described as being either particularly beneficial or particularly detrimental.
NEED FOR
MITIGATION
This criterion refers to the extent to which an anticipated impact will require that mitigatory action is taken.
Low. The need for mitigation is slight but the conditions demand that some effort be made.
Moderate. The need for mitigation is definite but there is not requirement for major and costly works. Any proposed mitigatory measure must have good potential to reduce the impact.
High. The need for mitigation is such that major and costly works are justifiable. Any proposed mitigatory measure must have definite and demonstrable potential for reduction of the impact before the proposed development may be given authorisation to proceed.
Obligatory. The nature of the impact is such that, unless mitigation can very largely nullify the consequences, it must be regarded as a potential fatal flaw which will halt the proposed development. If such mitigation cannot be achieved, it will be necessary to modify the development so that the impact will be reduced or even obviated.
LOCALITY OF
MITIGATION
This criterion refers to the place at which the stipulated mitigation must take place.
On Site. The necessary mitigation must be undertaken at the site of the impact.
Off Site. The necessary mitigation need not necessarily be at the site of the impact. Compensatory action may be undertaken at another, preferably similar, site on the property. Eg. Loss of a wetland due to construction of a dam may be mitigated by rehabilitation of a similar wetland in the immediate vicinity.