Appendix F: Impacts Assessment
CONSTRUCTION OF AN ADDITIONAL RAND WATER 200ML
RESERVOIR IN BRAKPAN, EAST RAND, GAUTENG PROVINCE:
IMPACT ASSESSMENT
The assessment of impacts will largely be based on the Department of Environmental Affairs and
Tourism’s (1998) Guideline Document: Environmental Impact Assessment Regulations. The
assessment will consider impacts arising from the proposed decommissioning activities of the project
both before and after the implementation of appropriate mitigation measures.
The impacts will be assessed according to the criteria outlined in this section. Each issue is ranked
according to extent, duration, magnitude (intensity) and probability. From these criteria, a
significance rating is obtained, the method and formula is described below. Where possible,
mitigation recommendations have been made and are presented in tabular form.
The criteria given in the tables below will be used to conduct the evaluation. The nature of each
impact was to be assessed and described in relation to the extent, duration, intensity, significance
and probability of occurrence attached to it.
Table 1: Impact assessment methodology
Status of Impact
The impacts are assessed as either having a:
negative effect (i.e. at a `cost' to the environment),
positive effect (i.e. a `benefit' to the environment),
or
Neutral effect on the environment.
Extent of the Impact
(1) Site (site only),
(2) Local (site boundary and immediate surrounds),
(3) Regional (within the City of Johannesburg),
(4) National, or
(5) International.
Duration of the Impact
The length that the impact will last for is described
as either:
(1) immediate (<1 year)
(2) short term (1-5 years),
(3) medium term (5-15 years),
(4) long term (ceases after the operational life span
of the project),
(5) Permanent.
Magnitude of the Impact
The intensity or severity of the impacts is indicated
as either:
(0) none,
(2) Minor,
(4) Low,
(6) Moderate (environmental functions altered but
continue),
(8) High (environmental functions temporarily
cease), or
(10) Very high / Unsure (environmental functions
permanently cease).
Probability of Occurrence
The likelihood of the impact actually occurring is
indicated as either:
(0) None (the impact will not occur),
(1) improbable (probability very low due to design
or experience)
(2) low probability (unlikely to occur),
(3) medium probability (distinct probability that the
Significance of the Impact
Based on the information contained in the points
above, the potential impacts are assigned a
significance rating (S). This
rating is formulated by adding the sum of the
numbers assigned to extent (E), duration (D) and
magnitude (M) and
multiplying this sum by the probability (P) of the
impact.
S=(E+D+M)P
impact will occur),
(4) high probability (most likely to occur), or
(5) Definite.
The significance ratings are given below
(<30) low (i.e. where this impact would not have a
direct influence on the decision to develop in the
area),
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(30-60) medium (i.e. where the impact could
influence the decision to develop in the area unless
it is effectively
mitigated),
(>60) high (i.e. where the impact must have an
influence on the decision process to develop in the
area).
The impacts of the proposed project were assessed and rated as follows:
1
CONSTRUCTION PHASE IMPACTS
Direct Impacts:
1.1.1 Loss of biodiversity and habitat
During construction some plants species may be removed on the proposed site footprint. No red
data species have been detected or anticipated to occur on site. Most of the flora noted on site is
heavily disturbed, with low alien infestation, however, very little natural vegetation is remaining
along the proposed route. The fauna identified were birds, rodents, and other small flying and
crawling insects. The impact on flora and fauna will be insignificant as very little vegetation will be
removed to clear the site for construction. The proposed development is unlikely to have a
significant negative impact on any threatened plant species or vegetation community, however, the
following potential impacts on fauna and flora might occur as a result of the proposed project:

Site preparation could result to loss of vegetation from the construction footprint; and

Loss of habitat for animal species from the building footprint.
Every effort must be made to minimize the disturbance to the surrounding vegetation. It is however
noted that the scale of this development is not likely to have a significant impact on the biodiversity
of the area or even within the property boundary. It is anticipated that the loss of biodiversity for
the proposed site and its surroundings will be of a low negative significance due to the scale of the
proposed development and the already disturbed nature of the proposed alignment.
Implementation of the suggested corrective measures will ensure that this impact has a low level of
significance.
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1.1.2 Soil erosion
The loss of topsoil in South Africa is a national concern and thus erosion control must be taken
seriously. Soil erosion may occur during the construction phase due to:

Excavations

Ineffective storm water management
The impact will be limited due to the fact that the site has already been cleared due to past
development activities; therefore any additional erosion is expected to be minimal. Provided that
adequate soil erosion measures are implemented during the construction phase of the proposed
activity, this impact can be deemed to be of low significance. Where soils are highly erodible,
adequate measures must be implemented to prevent undue soil erosion.
1.1.3 Air pollution
Construction activities on the site will lead to land clearing and disturbance of the soil resulting in
dust creation. Potential air pollutant during construction may result from dust emanating from site
preparation and excavations. Furthermore movement of construction vehicles also represents
temporary, but important sources of particulates and dust deposition that can be respired. Given the
nature and magnitude of the proposed project it is anticipated that minor dust will be generated from
the construction activities. The potential impact on air quality will be short term and can be controlled.
Proper implementation of recommended corrective measures will reduce the impact to become
insignificant and of very low probability. It is therefore anticipated that this impact will be limited and
of low negative significance.
1.1.4 Noise pollution
There will be an increase in noise levels during the construction period. There are no major sources
of noise adjacent to the site. Noise from construction vehicles, machinery, workers can be a nuisance
during the construction phase. The level of noise and the distance it will travel will depend entirely
on the prevailing construction activities within the site. An increase in noise is expected due to
construction, which might have an impact especially on the neighbouring schools and residential
settlements. Noise associated with the construction activities can be mitigated by limiting the
construction operation to business, during which noise will not be of such a big concern to
surrounding residents. The impact of noise will also be reduced to almost insignificant levels given
the small scale of the development.
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1.1.5 Employment Creation
The construction requires input from various individuals, resulting in employment opportunities for
such persons. This employment would include direct opportunities for Contractors, Engineers,
Project Managers and Planners. The project will yield opportunities for skilled and unskilled labour,
although minimal. The extent and magnitude of this impact is relatively low and short term in duration
compared to the other economic impacts, and is typically restricted to a limited number of skilled
individuals. The significance is rated as medium and no mitigations were identified for this project.
All the identified alternatives are likely to result in the same level of significance for this impact. Only
the No-go Alternative would differ in that this impact would not occur.
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Appendix F: Impacts Assessment
IMPACT
IMPACT RATING CRITERIA
SIGNIFICANCE
MITIGATION
Vegetation clearing must be limited to areas to be
occupied by the development footprint.
Where possible large trees must be left intact.
No hunting and killing of fauna is allowed.
Only indigenous plant species must be planted in areas
where rehabilitation is required.
Implementation of anti-erosion measures such as the
construction of berms to reduce the water velocity is
essential.
 Storm water runoff shall be considered and its flow
controlled at the construction site.
 In the event of significant erosion occurring, adequate
corrective measures must be implemented to prevent
any further soil loss.
Unnecessary clearing of vegetation must be avoided.
 All exposed surfaces subjected to dust generation must
be managed with appropriate dust suppression
methods including amongst others, the use of water
tankers etc.
 Vehicles travelling on the site must not be allowed to
reach sufficient speeds so as to cause dust to rise from
the roads.
It must be ensured that all vehicles used during
construction are appropriately maintained.
 Surrounding residents must be notified in advance of
construction schedules.
 Working hours must be restricted to daytime only (8am
– 5pm).
NATURE
EXTENT
DURATION
MAGNITUDE
PROBABILITY
Loss
of
biodiversity
and habitat
negative
1
5
3
5
45 - Medium
Soil erosion
Negative
2
2
6
2
20 - Low
Air pollution
Negative
2
1
4
4
26 - Low
Noise
pollution
Negative
2
1
4
3
21 -Low
 Should there be a need for the contractor to work
overtime, neighbours must be informed.
Employment
creation
Positive
3
2
8
4
30-60 Medium
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Appendix F: Impacts Assessment