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Study Name:
Orange River Integrated Water Resources Management Plan
Report Title:
Water Quality in the Orange River
Submitted By: WRP Consulting Engineers, Jeffares and Green, Sechaba Consulting, WCE Pty Ltd,
Water Surveys Botswana (Pty) Ltd
Authors:
T Coleman, A van Niekerk
Date of Issue: August 2007
Distribution:
Botswana: DWA: 2 copies (Katai, Setloboko)
Lesotho: Commissioner of Water: 2 copies (Ramosoeu, Nthathakane)
Namibia: MAWRD: 2 copies (Amakali)
South Africa: DWAF: 2 copies (Pyke, van Niekerk)
GTZ: 2 copies (Vogel, Mpho)
Reports:
Review of Existing Infrastructure in the Orange River Catchment
Review of Surface Hydrology in the Orange River Catchment
Flood Management Evaluation of the Orange River
Review of Groundwater Resources in the Orange River Catchment
Environmental Considerations Pertaining to the Orange River
Summary of Water Requirements from the Orange River
Water Quality in the Orange River
Demographic and Economic Activity in the four Orange Basin States
Current Analytical Methods and Technical Capacity of the four Orange Basin States
Institutional Structures in the four Orange Basin States
Legislation and Legal Issues Surrounding the Orange River Catchment
Summary Report

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TABLE OF CONTENTS
1
INTRODUCTION ..................................................................................................................... 1
2
DESCRIPTION OF CATCHMENT FROM WATER QUALITY PERSPECTIVE .................... 2
2.1
Upper Vaal WMA .......................................................................................................... 2
2.2
Middle Vaal WMA ......................................................................................................... 4
2.3
Lower Vaal WMA .......................................................................................................... 5
2.4
Lesotho ......................................................................................................................... 5
2.5
Upper Orange WMA ..................................................................................................... 5
2.6
Lower Orange WMA ..................................................................................................... 6
3
WATER QUALITY MANAGEMENT APPROACH .................................................................. 7
4
COLLECTION AND EVALUATION OF REPORTS ................................................................ 8
4.1
Water quality modelling reports.................................................................................... 8
4.2
Water quality situation assessment reports ................................................................. 8
5
OVERVIEW OF WATER QUALITY STATUS OF ORANGE RIVER BASIN........................ 10
6
ISSUES AND GAPS.............................................................................................................. 13
7
CONCLUSIONS AND RECOMMENDATIONS .................................................................... 19
8
APPENDIX A: REFERENCES .............................................................................................. 20
LIST OF FIGURES AND TABLES
Table 1: Summary of wastewater treatment plant discharge volumes in the Klip and
Suikerbosrand River catchments ............................................................................................. 3
Table 2: Average discharge volumes from gold mines in upper Vaal WMA .................................. 4
Table 3: Details of stations used in the water quality status overview ......................................... 10
Table 4: Concentrations associated with the different categories used in water quality status
assessment ............................................................................................................................ 11
Figure 1: Pie charts showing water quality status for EC in the Orange River Basin .................. 14
Figure 2: Pie charts showing water quality status for sulphate in the Orange River Basin ......... 15

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Figure 3: Pie charts showing water quality status for ortho-phosphate in the Orange River Basin
................................................................................................................................................ 16
Table 5: Summary of issues and knowledge gaps ....................................................................... 17

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Orange IWRMP
Task 9: Water Quality
1
INTRODUCTION
A desktop assessment of the surface water quality status of the Orange River catchment
was required as input into the development of the Integrated Water Resource
Management Plan (IWRMP) for the Orange River. The objectives of the study were:
· Collection and assessment of information in reports dealing with water quality
· Collection and assessment of water quality data on the Vaal and Orange Rivers
· Approach to water quality management
· Overview of water quality status
· Identification of issues and gaps.
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2
DESCRIPTION OF CATCHMENT FROM WATER QUALITY PERSPECTIVE
There are four countries making up the Orange River basin. These countries are Lesotho,
Botswana, Namibia and South Africa. The catchment area that falls in South Africa has
been divided into 5 Water Management Areas (WMAs) to facilitate the management of the
catchment. The WMAs are the Upper, Middle and Lower Vaal WMAs and the Upper and
Lower Orange WMAs. A brief description of the predominant land use in each of the
WMAs and Lesotho as it pertains to water quality is given in the following sections.
2.1
Upper Vaal WMA
The Upper Vaal WMA is characterised by large urban centres, industrial areas, power
generation, mining and agriculture. This part of the catchment is the economic hub of
South Africa and is highly developed. The development has resulted in the local water
resources being unable to meet the water requirements. As a result water is transferred
into the catchment from surrounding WMAs and from Lesotho. Water is also transferred
from the Upper Vaal WMA to adjacent WMAs. These transfers of water into the Upper
Vaal WMA are often released into rivers for conveyance to Vaal Dam. These volumes of
water are substantial, the impact of these transfers on the water quality in the receiving
streams and the Vaal River System needs to be considered in the future water resource
planning of the Orange River basin.
The large urban centres are located around Johannesburg and on the east and west
Rand. These areas include industrial complexes and gold mining operations. There are
many gold tailings dams located in these areas. The water quality in these areas are
impacted on by discharges from the gold mines, seepages from the tailings dams,
discharges from industry directly to the river, urban runoff and discharges from the large
number of sewage treatment plants located in the urban areas. The return flows from
these sewage treatment plants have resulted in the flows in many of the river systems
exceeding the natural flows.
The largest sewage works are located in the Suikerbosrand and Klip River catchments. A
summary of the capacity of the major water treatment works run by Johannesburg Water
and Erwat are listed in Table 1.
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Table 1: Summary of wastewater treatment plant discharge volumes in the Klip and
Suikerbosrand River catchments
Catchment
Wastewater treatment plant
Nominal discharge volume (Ml/day)
Goudkoppies
105
Olifantsvlei
120
Bushkoppies
170
Klip River
Dekema
36
Rondebult
36
Vlakplaats
83
Waterfall
105
Total Klip River
655
Ancor
41.3
Benoni
18
Daveyton
16
Heidelberg
8
JP Marais
21
Jan Smuts Dam
9.1
Suikerbosrand
McComb
9.5
Ratanda
5
Rynfield
13
Tsakane
12.4
Herbert Bickley
10
Carl Grundling
6
Total Suikerbosrand
169.3
Total Discharge
824.3
The treatment works return a total volume of 824.3 Ml/d to the river system. This amounts
to an annual volume of 301 million m3. The discharge volume is a significant portion of the
naturalised Mean Annual Runoff (MAR) for the Vaal Dam of about 1800 million m3/a. This
represents a significant point source pollution load. The capacities of these plants will
expand in the future as the urban areas grow and the sanitation systems are upgraded.
The coal mining is located in the Waterval and Grootdraai Dam catchments in the upper
reaches of the Vaal River. The mining in the Waterval catchment supports the
petrochemical industries located at Secunda while the mining in the Grootdraai Dam
catchment supplies power stations with coal and coal for export. There is further coal
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Orange IWRMP
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mining along the banks of the Vaal Barrage below Vaal Dam. The coal mining supplies the
petrochemical industries located in Sasolburg and coal for power generation.
There are also industrial discharges into the Waterval catchment and directly to the Vaal
River from the petrochemical plants located in Secunda and Sasolburg respectively. The
other major industrial discharges are from the steel industry in Vanderbijlpark the pulp and
paper industry in the Suikerbosrand catchment.
The gold mines in the Upper Vaal WMA also discharge dewatering water into the Vaal
River and its tributaries. The average volumes and TDS concentrations of the mine
discharges are listed in Table 2.
Table 2: Average discharge volumes from gold mines in upper Vaal WMA
Mine
Average discharge volume
Average TDS concentration (mg/l
(Mld)
Grootvlei Mine
65
3153
ERPM
37
2780
Western Areas Gold Mine
3.1
880
Harmony Randfontein
60
450
Blyvaruitzicht Gold Mine
11
850
Driefontein Gold Mine
36
1047
Kloof Gold Mine
50
570
2.2
Middle Vaal WMA
The Middle Vaal catchment is less urbanised than the Upper Vaal WMA and more rural in
character. There are gold mines located in the Schoonspruit and Koekemoerspruit as well
as in the Virginia area of the Sand Vet River system. There is also some diamond mining
taking place in the WMA. There will be water quality issues related to the current
discharges and seepage from the mines. In the long term there are issues in dealing with
the decant from the mines post closure. Options of treating and re-using the mine water
are being investigated.
The larger urban areas of Klerksdorp-Orkney-Stilfontein and Virginia are associated with
the mining activities in the WMA. The point sources of pollution include the sewage
treatment plants associated with these urban centres. There are generally issues related
to the management of the sewage works and the sanitation systems in the urban areas.
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Orange IWRMP
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The systems have become overloaded and there is further pressure on the works with the
possible replacement of dry sanitation systems with water borne sanitation systems.
The agricultural activities taking place in the WMA include dry land and irrigation farming
as well as stockwatering. The abstractions for agriculture are directly from the Vaal River
and dams constructed on tributaries of the Vaal River.
2.3
Lower Vaal WMA
The predominant land use in the Lower Vaal WMA is agriculture. There are extensive
irrigation schemes located on the Vaal River and along the Harts River. The water supply
for the schemes is supported with releases from the Bloemhof Dam. The Vaal-Harts
irrigation scheme draws its water from the Vaal Harts weir on the Vaal River. There are
substantial return flow volumes from these schemes particularly the Vaal-Harts Scheme.
These return flows impact on instream TDS concentrations and contribute significantly to
the nutrient loads.
2.4
Lesotho
The runoff from the Lesotho Lowlands drains to the west to the Caledon River while the
highlands drain to the south via the Senqu River to the Orange River. The lowlands area is
susceptible to erosion and the Caledon River has transported large sediment loads
causing extensive sedimentation of dams such as the Welbedacht Dam.
Lesotho is a source of significant quantities of good quality water. The transfer of water
from the Lesotho Highlands to the Vaal Dam catchment results in a reduction in the
volume of good quality water entering the Orange River. This will impact on the water
quality of the Orange River and must be considered in future planning.
2.5
Upper Orange WMA
The two major river systems that drain the Upper Orange WMA are the Modder-Riet and
the Orange River. The Modder-Riet drains to the Vaal River joining upstream of the
Douglas weir. Bloemfontein and Thaba `Nchu are the main urban and industrial
developments in the Upper Orange WMA.
Two large hydropower stations were
constructed at Gariep and Vanderkloof Dams in the Orange River. Mining activities have
significantly declined and currently mainly relate to salt works and small diamond mining
operations. The largest land use in the catchment is agriculture. There are a number of
dams on the tributaries of the Modder-Riet which are used to supply irrigation water.
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Task 9: Water Quality
Agricultural water requirements represent 80% of the water requirements in the Upper
Orange WMA.
2.6
Lower Orange WMA
The Lower Orange WMA is the lowest WMA in the Orange River Basin. The area is arid
with rainfall varying from 400 mm in the east to 50 mm on the west coast. The topography
of the area is flat with large pans or endoreic areas that do not contribute runoff to the
Orange River system.
The Orange River forms the border between South Africa and Namibia. The Vaal River,
the main tributary to the Orange River, has its confluence with the Orange River about
13 km west of Douglas. Other tributaries are the Ongers and Hartebeest Rivers from the
south, and the Molopo River and Fish River (Namibia) from the north.
Sheep and goat farming is practised over most of the area, with large parts falling within
conservation areas. Cultivation is restricted to isolated patches where somewhat higher
rainfall occurs, and extensive irrigation is practised in the fertile alluvial soils along the
Orange River valley. This irrigation is supplied with releases from the Vanderkloof Dam.
Large mining operations occur in various parts of the water management area. The return
flows from the irrigation areas contribute salinity and nutrients to the Orange River.
The water quality in the Lower Orange WMA is affected by upstream activities in the Vaal
and Orange River catchments.
Given the arid nature of the Lower Orange River and the high potential evaporation, the
evaporative losses result in an increase in concentrations along the length of the lower
Orange River.
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3
WATER QUALITY MANAGEMENT APPROACH
The water quality management approach adopted by the South African Department of
Water Affairs and Forestry is described in the Internal Strategic Perspective (ISP)
documents for the Vaal and Orange WMAs. The approach is to identify priority catchments
where water quality management is urgently needed. A two phase approach is typically
adopted to develop a strategy for the catchments.
The first phase involves a water quality situation assessment which is followed by the
development of a catchment management strategy (CMS) as the second phase.
The water quality situation assessment studies typically involve the following:
· Collection and assessment of instream surface water quality data;
· The studies may include an assessment of the groundwater;
· Identification of pollution sources;
· Assessment of compliance of discharges with licence conditions;
· Collection of information on water management on mines and industrial facilities;
· Division of study area into management units;
· Collection of hydrological and water requirement information;
· Setting of Resource Water Quality Objectives (RWQO);
· Design of monitoring systems.
The setting of instream RWQO is based on the South African Water Quality guidelines and
the water users in the study area. The RWQO were specifically developed to protect the
water users and to guide the management of pollution sources. The RWQO were set as
ideal, acceptable, tolerable and unacceptable. The
second phase involves the
development of a CMS to specifically develop strategies to meet the RWQO.
The RWQO have to date been developed for the priority catchments to protect the users
within the catchment. The impacts of managing water quality in the individual catchments
have not been aligned with the water user requirements of downstream water users. In
other words the RWQO have not been integrated across the Orange River Basin. This was
identified in developing the ISP for the Vaal and Orange Rivers. As a result a study to
develop an integrated water quality management plan for the Vaal River has been
commissioned by the South African Department of Water Affairs and Forestry and a study
of the Orange River is planned.
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4
COLLECTION AND EVALUATION OF REPORTS
Reports were collected from the library of the South African Department of Water Affairs
and Forestry (DWAF) as well as from other sources such as Water Boards and Water
Service Providers.
The assessment of the reports showed that the findings can be presented in two broad
categories viz findings dealing with modelling and those describing the water quality
situation. The list of reports collected is given in Appendix A.
4.1
Water quality modelling reports
The modelling reports described the calibration of the WQT hydro-salinity model on the
Orange and Vaal Rivers. The model operates at a monthly time step and models total
dissolved solids (TDS). The WQT model operates closely with the Water Resources
Planning Model (WRPM). The water quality algorithms used in the WQT are replicated in
the WRPM which allows the calibrated input parameters for the WQT to be used in the
WRPM. This modelling system has been used to investigate blending and dilution water
quality management options for the Vaal Barrage system.
Further models such as the NaCl suite of models has been applied to the Blesbokspruit
and the Klip River to assess the impact of sewage treatment plant discharges on the
receiving rivers. This work was done for ERWAT as part of the impact assessment
process. The NaCl suite of models runs at a daily time step and models TDS. Nutrient
modelling has also been undertaken on the Blesbokspruit and Klip River (Vaal Barrage
Catchment) as part of the impact assessment process.
4.2
Water quality situation assessment reports
The water quality situation assessments have been undertaken on a number of
catchments in the Orange River basin. The majority of the studies have been undertaken
in the heavily mined areas of the Vaal River catchment. The results of the studies are that
sets of RWQO have been established for a number of catchments. The water quality
variables of concern differ between catchments but in general salinity as represented by
EC, sulphate in the mining areas and nutrients as they relate to eutrophication are the
common water quality variables of concern. The algae resulting from eutrophication has
led to odour and colour problems in the intake water to water treatment plants which are
not geared for dealing with eutrophic waters.
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The presence of toxic algae has been reported in the Lower Orange River passing
Upington. A monitoring system has been established to check on the development and
movement of algal blooms in the lower reaches of the Orange River. The results of the
monitoring program are communicated to the role players through the Lower Orange River
Remediation Forum (LORRF) which has been established in the Lower Orange WMA.
Along the main stem of the Vaal organics has been raised as an issue by the water
boards. Their monitoring programs have identified increases in Dissolved Organic Carbon
(DOC) in the raw intake water to the water treatment plants.
This gives concerns regarding disinfection technologies used as the traditional chlorine
disinfection can give rise to trihalomethanes if excessive organics are present in the intake
water.
The Water quality monitoring programmes in the different areas of the Orange River Basin
vary in frequency of measurement and water quality variables tested for. The water quality
variables tested for depends on the sources of pollution present in the catchments. In
general monthly grab samples are taken and at minimum the concentrations of the major
cations and anions are determined.
At this stage there is limited continuous monitoring of water quality in the Orange River
Basin. Attempts have been made in the past to install electrical conductivity probes and
data logging systems at key points in the system but theft and vandalism has limited the
life of the installation and precluded extensive use of these systems.
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5
OVERVIEW OF WATER QUALITY STATUS OF ORANGE RIVER BASIN
A brief overview of the water quality status in the main stem of the Vaal and Orange Rivers
was undertaken. The approach used was to collect water quality data at key stations on
the Vaal, Caledon, Fish (Namibia) and the Orange Rivers. The water quality data was
accessed from the South African Department of Water Affairs and Forestry, Windhoek
Consulting Engineers and the Lesotho government databases and the details of the
stations used in the analysis are listed in Table 3.
Table 3: Details of stations used in the water quality status overview
Station
Station name
Lat
Long
Beg Date
End Date
number
DIH003Q01
Aliwal North
-30.679722
26.7125
29/01/1972
18/08/2004
D2H036Q01
Caledon
-30.279167
26.654167
12/05/1993
14/07/2004
D3R002Q01
Gariep Dam
-30.623056
25.507222
08/01/1971
12/10/2004
D3R003Q01
Vanderkloof Dam
-29.991111
24.731667
24/07/1971
29/10/2004
D7H002Q01
Prieska
-29.651389
22.746389
28/09/1965
08/05/2001
D7H005Q01
Upington
-28.460833
21.248889
01/11/1965
23/08/2004
D8H003Q01
Vioolsdrift
-28.760833
17.730278
11/11/1965
10/10/2004
C1R002Q01
Grootdraai Dam
-26.918056
29.295
18/11/1982
20/10/2004
C1H017Q01
Inflow Vaal
-27.0225
28.594444
16/11/1975
28/10/2004
C2R008Q01
Vaal Barrage
-26.853611
29.326111
06/06/1980
19/01/2005
C9H021Q01
Bloemhof Dam
-27.669167
25.618056
23/11/1972
19/10/2005
C9R003Q01
Douglas Barrage
-29.043333
23.836944
03/10/1977
26/10/2005
Naute Dam on
Fish River
-
-
-
01/02/1997
01/09/2005
(Purification plant
raw water)
South
-
Phuthiatsana
-
-
20/10/1997
12/10/2002
River
The data covering the period 1994 to 2004 was analysed. The following water quality
variables were analysed to give an overview of the water quality status of the basin:
· Electrical conductivity which gives an indication of the salinity or TDS of the river
system. The EC was compared to the South African water quality guidelines for
agriculture (most sensitive crops) and domestic. (Class 0, Class 1 and Class 2)
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water uses to give an indication of the fitness for use of the water as far as salinity
is concerned.
· Sulphate which gives an indication of the extent of mining pollution. The sulphate
concentrations have been compared to the Class 0, Class 1 and Class 2 water
quality guidelines for domestic use.
· Ortho-phosphate (as P) which gives an indication of the nutrient levels and the
potential for eutrophication of the river system. The South African Water Quality
guidelines give the trophic status associated with different concentrations of
inorganic phosphorus
The concentrations associated with the different categories used in the water quality status
assessment are summarised in Table 4.
Table 4: Concentrations associated with the different categories used in water
quality status assessment
Water Quality
Ideal
Acceptable
Tolerable
Unacceptable
variables
EC (mS/m)
<40 (irrigation)
40-70 (Class O)
70-150 (Class I)
>150 (Class II)
SO4 (mg/)
<200 (Class O)
200-400 (Class I)
400-600 (Class II)
>600 (Class III)
PO4 (mg/)
<0.005
0.005-0.025
0.025-0.25
>0.25
(Oligotrophic)
(Mesotrophic)
(Eutrophic)
(Hypertrophic)
The results of the analysis have been represented as pie charts on a map of the
Orange River Basin. The sectors of the pies represent the fraction of the total
samples that fall in the different concentration ranges used to assess the water
quality. The results are given in,
Figure 1,
Figure 2 and Figure 3 for EC, sulphate and ortho-phosphate respectively.
The results of the analysis can be summarised as follows:
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· The upper reaches of the Vaal River upstream of Vaal Dam has good quality
water as far as salinity is concerned. The EC and sulphate concentrations meet
Class 0 domestic water quality guideline. The general consensus as far as users
are concerned is that the salinity aspects of the water quality meet their
requirements but should not deteriorate any further.
· The salinity deteriorates along the stretch of the river from Vaal Dam to the
Douglas weir. There is a significant deterioration in water quality from the Vaal
Dam to the Vaal Barrage. This is due to the contributions from the Suikerbosrand,
Rietspruit and Klip River catchments. This is largely driven by mine water sewage
and industrial discharges as well as runoff from urban areas.
· The salinity in the Orange River from Lesotho to the confluence with the Vaal
River is of good quality.
· The salinity deteriorates downstream of the confluence of the Vaal and Orange
Rivers but still remains good. There is an increase in EC from the Prieska station
to Vioolsdrift along the reaches of the lower Orange River. This is due to irrigation
return flows and evaporative losses along the river.
· The measured EC data at Naute Dam on the Fish River (Namibia) showed that
93% of the EC reading met the Class 0 domestic water use guideline.
· The analysis of the water quality in the South Phuthiatsana River showed that the
EC of the river is low with a maximum value of 25mSm. However, the ortho-
phosphate concentrations are high with 43% exceeding 0.25 mg/l i.e. falling in
the hyperthrophic range. The source of the ortho-phosphate is from the runoff
from the settlements scattered throughout the Lesotho lowlands catchment.
· The ortho-phosphate pie charts show that the ortho-phosphate concentrations are
indicating potential for eutrophic conditions throughout the catchment and a
possibility of hypertrophic conditions in the Vaal Barrage. There are a number of
factors however that determine the extent of algal growth. These include the
availability of other nutrients such as nitrogen, adequate sunlight and suitable
temperatures. The turbid waters experienced in the catchment is limiting sunlight
penetration and limiting algal growth. The pie charts shown in Figure 3 can only
be considered indicative. However the indications are supported by observations
and reports of algal blooms in impoundments, the Vaal Barrage and along the
lower reaches of the Orange River downstream of the confluence of the Orange
and Vaal Rivers.
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6
ISSUES AND GAPS
The issues and knowledge gaps identified during this desk top overview of the water
quality in the Orange River Basin are discussed in Table 5 below. Measures to address
the gaps identified are also proposed for inclusion in the future phases of the development
of the IWRMP for the Orange River Basin.
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Task 9: Water Quality
Figure 1: Pie charts showing water quality status for EC in the Orange River Basin
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Task 9: Water Quality
Figure 2: Pie charts showing water quality status for sulphate in the Orange River Basin
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Task 9: Water Quality
Figure 3: Pie charts showing water quality status for ortho-phosphate in the Orange River Basin
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Table 5: Summary of issues and knowledge gaps
Issue
Description of issue and gap
Proposed measure to address gap
Insufficient water quality data and
During the analysis of the water quality data collected
A coordinated monitoring programme needs to be
data management
in the Orange River Basin, a number of issues related
developed to address :
to data collection were identified :
The establishment of monitoring objectives
Data collection is fragmented between countries and
The monitoring point locations
institutions.
Frequency of monitoring and water quality variables
The location of the water quality monitoring points are
to be tested for
not optimal.
The current network of continuous water quality
The water quality variables analysed for are not
monitoring stations needs to be reviewed and
consistent between institutions.
expanded. In designing the system consideration
The sampling frequency and the water quality
should be given to real time management of both
variables. analysed for are insufficient to manage the
water quality and quantity
Orange River Basin successfully.
Database systems, data management and
There is no single or standard data management and
reporting
reporting systems.
Institutional responsibilities and implementation
Lack of information on discharge volumes and
program
qualities from sewage treatment works, mines and
A series of workshops involving the major role
industries.
players is the approach recommended to achieve
the objectives listed above.
Eutrophication
The analysis of the water quality data showed that
A project should be initiated that will investigate the
nutrient levels in the Vaal River, particularly in the
nutrient mass balance and pathways. The Vaal
Vaal Barrage, are such that there is a potential for
Barrage catchment is the most impacted and the
eutrophic conditions to develop. The problems with
largest source of nutrients. A pilot scale project to
excessive algae development are already reported by
determine the fate of nutrients within this catchment
Sedibeng and MidVaal Water. The following gaps
is proposed. If the pilot scale project proves to be
have been identified :
successful the model can be rolled out to the entire
A lack of understanding of the fate of nutrients once
catchment.
they are discharged to the river. The pathways for the
nutrients, organics and algae growth need to be better
understood.
A planning level nutrient model needs to be developed
and set up for the Orange River Basin. The model
should allow for cause and affect modelling so that
nutrient management strategies can be developed.
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Issue
Description of issue and gap
Proposed measure to address gap
Integrated RWQO
The RWQO are being set in isolation in priority
The IWQMP for the Vaal River study needs to be
catchments. The integration of the RWQO for the Vaal
extended to include the Orange River.
River is being addressed in the Integrated Water
Quality Management Plan (IWQMP) that is being
developed for the Vaal River by the South African
Department of Water Affairs and Forestry. The link
between the Vaal and the Orange river needs to be
addressed
Mine water closure planning
The gold mine dewatering discharges contribute a
Projects are being initiated by the South African
significant salt load to the Vaal River System. The
Department of Water Affairs and Forestry and the
time frames for the continued mining depend on the
Water Research Commission in South Africa to
gold price. Mines are starting to close down and flow
address the mine closure and water management
of water between mines and the management thereof
issue.
is becoming an issue. A management strategy for the
mine water currently and post closure need to be
developed.
Presence of pesticide and
There is extensive irrigation practised in the Vaal and
A pesticide and herbicide monitoring program
herbicides in the Vaal and Orange
Orange Rivers where herbicides and pesticides are
should be initiated to determine the extent of the
Rivers
used. These could be present in the return flows and
problem
conveyed in the surface runoff to the river systems.
The current water quality database does not support
the identification of pesticides and herbicides in the
rivers.
13/11/2007
Final
18

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Orange IWRMP
Task 9: Water Quality
7
CONCLUSIONS AND RECOMMENDATIONS
The following conclusions and recommendations can be made as a result of this desktop
study:
· The water quality has to be managed in conjunction with the development of the
water resource for supply. The reduction in flow from Lesotho due to transfers to
Vaal Dam could affect the water quality in the lower Orange. Similarly the
management of the system to meet water requirements and generate hydropower
should be coupled to the management of water quality;
· The salinity is currently being managed with releases of water for dilution from
Vaal Dam. The modelling tools have been set up to manager the salinity aspects
of the water quality of the Orange River Basin. The consensus is that the salinity
aspects of the water quality meet user requirements. However the water quality
must not be allowed to deteriorate further.
· Many of the coal and gold mines are closing down and the workings are starting
to fill and will decant some time in the future. Management strategies have to be
developed to manage the filling process and the decants.
· Nutrients and the resulting algal growth are an issue. The modelling of nutrients
has not reached the same level as salinity and the nutrient pathways are not well
understood. Attention will have to be given to the development of modelling tools,
management of point sources such as sewage works as well as diffuse sources
associated with runoff from urban areas and agriculture. A nutrient management
strategy needs to be developed.
· Currently very little information is available on pesticides and herbicides in the
river systems. There is extensive agriculture on the banks of the Vaal and Orange
Rivers. The presence of these pollutant types should be determined by designing
and carrying out a round of monitoring.
· An integrated water quality monitoring programme and data management
systems need to be developed for the Orange River Basin. The monitoring
programme should include discharge information.
13/11/2007
Final
19

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Orange IWRMP
Task 9: Water Quality
8
APPENDIX A: REFERENCES
Title
Document No.
Author
Date
Water Quality Modelling for the
Stewart Sviridov&
PC 000/00/8688
1988
Vals and Renoster Rivers
Oliver
Preliminary estimation of the
Stewart Sviridov&
impact of air pollution on the
PC 000/00/8989
1989
Oliver
water quality in the Vaal Dam
Stewart Sviridov&
Kromdraai Option
PC 000/00/9089
1990
Oliver
Internal Strategic Perspective for
PDNA,WRP, WMB
the Vaal River System
PC 000/00/0103
March 2004
and Kwezi-V
Overarching
Development of Resource
Sub-Series No.
Directed Water Quality
DWAF
February 2005
WQP 1.5
Management Policies
Internal Strategic Perspective for
PWMA
PDNA, WMB, V3 and
March 2004
the Upper Vaal WMA
08/000/00/0304
WRP
Preliminary evaluation of options
Stewart Sviridov&
for improving the Quality of the
PC 000/00/9189
November 1989
Oliver
Water Supplied to Christiana
Blending options for the Western
Transvaal Regional Water
Stewart Sviridov&
Company and the OFS Goldfields
PC 000/00/8788
July 1989
Oliver
Water Board based on Rietfontein
Dam and Klip Dam
The potential effects on the
NC
Eutrohpication of the Middle Vaal
DWAF
March 1991
200/00RPQ/2790
River
PMFG Teurlings, DJ
Initial Environmental Impact
Otto,M Matsabu, CE
Report of the status quo of the
Final report
Herold, G Schoeman,
February 1997
existing wastewater infrastructure
Mr. Howard, J Rall
and HNS Wiechers
Practical Implications of the
Stewart Sviridov&
PC 000/00/2885
May 1985
Blending Option
Oliver
Summary of the data acquisition
and assimilation carried out by
Stewart Sviridov&
PC 000/00/10190
July 1991
the consultants for the Southern
Oliver
PWV Catchment
The Development of techniques
for the evaluation and effective
Institute for Ground
WRC Report No.
management of surface and
Water Studies-
June 1996
224/1/92
ground water contamination in the
University of OFS
OFS Goldfields
Impact of the Mining Industry on
reference to the Impact of Gold
JVW-0024-WPD
DWAF
June 1996
mine Residue Deposits
13/11/2007
Final
20

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Orange IWRMP
Task 9: Water Quality
Title
Document No.
Author
Date
Water Quality Monitoring
Requirements for salinity
PC 000/00/92
DWAF
December 1992
Modelling
Assessment of the feasibility and
impact of alternative water
WRC Report
JAC Cowan & P
pollution control options on TDS
Sep 1993
No.326/1/93
Skivinngton
Concentrations in the Vaal
Barrage and Middle Vaal
An assessment of Water related
problems of the Vaal River
TR 121
DWAF
between Barrage and Douglas
Weir
Water Quality Management Plan:
Rand Water & DWAF
April 1996
Phase 1 scoping Report
Hydro-Salinity model calibration:
PC 000/00/18096
DWAF
December 1998
upper Vaal Catchment
Grootdraai Catchment Water
Quality Situation Assessment
5005/6965/2/W
Golder Associates
February 2006
(Draft)
Annual Operating Analysis for the
2003/2004
DWAF
5 August 2003
Integrated Vaal River System
16 November
Vaal river Liaison Forum
PC000/00/0193
DWAF
1993
Surface water Quality of South
Africa( 1979-1988) Volume 3:
TR 145
DWAF
November 1990
Drainage Region C and D
Hydro-Salinity Model Calibration:
PC 000/00/18196
DWAF
April 1998
Vaal Barrage Catchment
Hydro-Salinity Model Calibration:
PC 000/00/18296
DWAF
January 1999
Middle Vaal Catchment
A Model to simulate the daily
Hydrological
Water and Salt balance un the
Report No.5/81
Research Unit-WITS,
May 1981
Vaal River Water Supply System
Johannesburg
Vaal Dam Salinity Assessment
with particular reference to
D Stewart
February 1991
Atmospheric Deposition
Mooi river Catchment
Management study: Phase 1,
16/14/231/1
DWAF
October 1998
Situation Analyses
Vaal River Water Quality
Management Study: Kroomdraai
PC 000/00/9089
Sviridov& Oliver
March 1990
Option
13/11/2007
Final
21

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Orange IWRMP
Task 9: Water Quality
Title
Document No.
Author
Date
Development of a water Quality
Management Plan for the Klip
4117
DWAF
August 1999
River Catchment, Situation
Analyses (Phase 1)
Pulles Howard and
Evaluation of the Quantity and
de Lange, Greater
Quality of purified effluent
Johannesburg
discharged from Johannesburg
August 1996
Transitional
Drainage Basin Waste water
Metropolitan Council
Treatment Works: volume 4
and Stewart
Situation Analyses of
Eutrophication related Water
DWAF
February 1995
Quality
Pulles Howard and
de Lange, Greater
Southern Waste Water treatment
Johannesburg
Works on the Klip River, Volume
August 1996
Transitional
7
Metropolitan Council
and Stewart
Pulles Howard and
de Lange, Greater
Hydrology of the Klip River
Johannesburg
August 1996
System: Volume 6
Transitional
Metropolitan Council
and Stewart
Pulles Howard and
de Lange, Greater
Johannesburg
Overview Report, Volume 1
August 1996
Transitional
Metropolitan Council
and Stewart
Development of a Waste Water
Quality Management Plan for the
4117
DWAF
August 1999
Klip River Catchment: Situation
Analyses, Phase 1
Practical Implication for the and
Blending Option
DWAF
September 1997
(Development of water
management Plan) volume 6
Background to the study and
Pulles Howard and
overview of the study area and
de Lange, Greater
Greater Soweto Water Quality
Johannesburg
August 1996
Monitoring programme and
Transitional
Assessment of available data:
Metropolitan Council
Volume 2
and Stewart
Land use/ Diffuse pollution
Pulles Howard and
surface relationships( Part 1), klip
de Lange, Greater
August 1996
River Water Quality Situation
Johannesburg
13/11/2007
Final
22

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Orange IWRMP
Task 9: Water Quality
Title
Document No.
Author
Date
Analyses (part 2), point and
Transitional
Diffuse source pollution load
Metropolitan Council
projection: volume 6
and Stewart
Selection, Cal