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Sivhili Injhinyeringi June 2009 Vol 17 No 5
W I N N E R 2 0 0 8
FOR EXCELLENCE IN MAGAZINE
PUBLISHING AND JOURNALISM
FOCUS ON
WATER ENGINEERING
SA water resources – strategic planning
LHWP – overview of Phase II
The new SANCOLD
BOB PULLEN
RECEIVES NSTF AWARD
2010 FIFA World Cup 11 June – 11 July
COVER ARTICLE
Sivhili Injhinyeringi June 2009 Vol 17 No 5
W I N N E R 2 0 0 8
FOR EXCELLENCE IN MAGAZINE
PUBLISHING AND JOURNALISM
FOCUS ON
WATER ENGINEERING
SA WATER RESOURCES – STRATEGIC PLANNING
LHWP – OVERVIEW OF PHASE II
THE NEW SANCOLD
BOB PULLEN
RECEIVES NSTF AWARD
Xitsonga
ON THE COVER
On the cover
Sanyati’s full scope of works at a leading
mine in a remote area in the Northern
Cape’s Kalahari sands demonstrates the
JSE-listed company’s multi-disciplinary
capabilities and its extraordinary ability
to organise these capabilities into a Reinforcement of a conveyor culvert – part of Sanyati’s
unified construction entity capable of massive infrastructure contract for a mine in the Kalahari 2
competing with the best
WATER ENGINEERING BOOK REVIEW
Strategic planning for water Streams of Life by David Raymer 58
resources in South Africa 5
Vaal River System: Large Bulk Water
IN BRIEF 60
Two awards for UWP Consulting in Eastern Cape
Supply Reconciliation Strategy 9 CMA publishes sewer design manual Cape
Water Reconciliation Strategy for the Town partners with Dutch government to provide
Crocodile (West) River catchment 14
Sivhili Injhinyeringi June 2009 Vol 17 No 5
toilets for informal settlement Aqualiner – a new
Published by SAICE/SAISI process for the lining of water and sewer pipes
Block 19, Thornhill Office Park,
Bekker Street, Vorna Valley, Midrand Strategies to ensure sufficient water availability for Swagelining™ aids increase in oil production in the
the KwaZulu-Natal Coastal Metropolitan Area 20
Private Bag X200, Halfway House, 1685
Tel 011-805-5947/48, Fax 011-805-5971
http://www.civils.org.za Democratic Republic of Congo Hollow-core slab
civilinfo@saice.org.za
seminars to be held nationally Terraforce in Turkey
Editor An overview of the engineering components of
Verelene de Koker NASREC 2010 infrastructure developments
vdekoker@saice.org.za
Tel 011 805 5947/8, Cell 083 378 3996 the proposed Phase II of the Lesotho Highlands
Editorial Panel
Water Project: based on the feasibility study 28
Elsabé Kearsley (chair & SAICE president), Irvin Luker
(vice-chair), Marie Ashpole, Wally Burdzik, Johan de
Koker, Zina Girald, Huibrecht Kop, Jeffrey Mahachi,
SAICE AND PROFESSIONAL NEWS
Jones Moloisane, Hermien Pieterse, Eben Rust, Michelle Integrated water management of Recognition par excellence!
the Vaal River catchment 37
Theron, Marco van Dijk, Verelene de Koker (editor), Cathy
van der Westhuizen (editor’s assistant), Barbara Spence
(advertising), Dawie Botha (executive director) (Bob Pullen receives NSTF award) 72
Annual subscription rate
SA R560,00 (VAT included), International US$120,00
Current service delivery challenges for municipalities SAICE Annual General Meeting 2009 74
with regard to water management 41 Stalwart Paul Nicolaysen 80
Advertising
Barbara Spence, Avenue Advertising
barbara@avenue.co.za
Tel 011-463-7940, Fax 011-463-7939
Something for free!
Cell 082-881-3454
Mathematics versus pattern recognition
(Dr Graham Ross’s roads database) 81
in water resource studies 44
Design and reproduction
Marketing Support Services, Menlo Park, Pretoria
Printing Out and about – Online communication: is
Ultra Litho, Johannesburg
The South African Institution of Civil Engineering
The new SANCOLD 48 print media losing ground in the civil
50 82
accepts no responsibility for any statements made or
opinions expressed in this publication. Consequently
South African Register of Large Dams engineering industry?
nobody connected with the publication of the magazine,
in particular the proprietors, the publishers and the
SAICE Photo Competition 84
HISTORY AND HERITAGE
editors, will be liable for any loss or damage sustained
by any reader as a result of his or her action upon any
statement or opinion published in this magazine.
Upcoming fun events 85
ISSN 1021-2000
PU
B LIS HER
S
Past Master 22: John Hamilton Wicksteed 56 Nominations for election of Council for 2010 86
57
E
M AG A Z I N
Write down your memories for a special new book Diarise this! 88
SA
OF
IO
N
AS
S O C I AT
Civil Engineering | June 2009 1
ON THE COVER
Sanyati
a company of many talents
Whether the challenge is protection of the environment, Sanyati variety of work in remote areas. One such
finding and implementing complex and Construction, a JSE-listed construction example is a project at a leading mine in
unique engineering solutions, successfully company, has developed a reputation the Northern Cape. The mine is located
completing a wide range of construction with colleagues and clients alike for doing in the Kalahari sands and ‘remote’ is more
projects quickly and expertly, working things with a hefty dose of excellence. than an apt description of this location.
tirelessly with local communities close to Many recent contracts have demon- Sanyati’s full scope of works here in-
where the contracts are taking place or strated Sanyati’s ability to work under ex- cludes bulk earthworks and terracing for
fastidiously instituting practices for the treme time pressure and to take on a wide a railway siding, a haul road, access roads
and terraces, terracing for a coal fines
1 stockpile (–6 mm), an Eskom yard and
stockyards, and the construction of the
bulk water connection, conveyor culvert
and load-out silo.
The project started in November 2008
with the construction of the initial 4,2 km
of the eventual 7,2 km haul road. After
the clear and grub stage, 400 mm of
topsoil was removed to a width of 23 m
and spoiled. Thereafter a layer of Kalahari
sand, 500 mm deep and 19 m wide, was
also removed and spoiled. A three-sided
impact roller was used to compact the
bottom of the cut.
The material used for the construc-
tion of the haul road is known as “banded
ironstone formation” (BIF), which is
blasted in the mine. The layer works
consist of a layer of BIF 1 m thick and a
wearing course, 300 mm deep and 16 m
wide, of crushed BIF (G5) mixed with clay.
In December 2008, the construction
of the railway siding was awarded to
Sanyati Central. This crucial piece of
infrastructure consists of a 5 km railway
loop, which links up with the existing
railway that carries manganese to the
2 Civil Engineering | June 2009
1 Construction of conveyor footings
2
2 Three-sided impact roller being
used during road construction
3 Sanyati’s patented slipform equipment
being used on a silo at one of their other sites
harbour. Sanyati Central Operations
Director Louw De Bruin says that this
seven-month project includes railway track
construction, 3 kV dc electrification and
overhead track equipment, signalling and
radio communications, a load-out facility,
rail turnouts and fixings. At present it is on
schedule to be completed on time.
“An interesting feature of the railway
contract was the stipulation that all filling
be done with a G7 material, but because
the BIF from the mine is suitable for this
purpose, the specification was changed
accordingly,” says De Bruin. The proper-
ties of the material make it difficult to
process however. This is because BIF con-
sists of large stones with very sharp edges
which cut the tyres of the articulated
dump truck (ADT) and roller while they 3
are driving and working on the BIF.
For the railway project alone, more
than 100 000 m³ of rock fill (blasted
BIF) was required. The fill consisted of
500 mm layers of BIF (up to 3 m in places),
followed by the layer works consisting of
G5 and G2 (crushed BIF).
The construction of the load-out sta-
tion/silo was done by Sanyati’s Concrete
Division , Conform, which has developed
an enviable reputation for its specialist
skills in concrete work.
The silo, which has an internal di-
ameter of 14 m and will stand 37 m high,
will ultimately use 975 m³ of concrete and
145 t of reinforcing steel. Its foundation
consists of a ring beam resting on 72 con-
tinuous-flight auger-grouted piles, while
the thickness of the silo wall changes
from 800 mm at the bottom to 300 mm at
a height of 17,398 m.
There are also four 2 x 1,2 m columns
reaching a height of 17,398 m, which ac-
commodate a suspended slab 1,75 m thick.
André Coetzer, Sanyati Concrete
manager, says they are sliding continu-
ously on two 12-hour shifts with approxi-
mately 35 personnel on each shift.
“We slide both the columns and the
bottom-wall section for 10 days until we
reach the elevation height coinciding
with the change in wall thickness. At this
point we take five days to alter the inside
shutter to accommodate the change of
wall thickness and to ‘cut off’ the column
Civil Engineering | June 2009 3
4 Crushing BIF 20 hours per
4
day to meet the deadline
into the bedrock, which consists of calcretes
in this area. “This meant, inter alia, that a
powerful Bauer piling rig was required to
install the 162 piles into bedrock at varying
depths in order to support the loads for
which they were designed,” said Stoll.
He adds that from the outset logistics
was the key factor in this successful and
fast-track programme. “The excellent
working relationship between the various
Sanyati companies and divisions made the
logistics, planning and execution easier.”
This mine project is one of the most
successful and dynamic operations of its
kind in the world. Sanyati Construction has
amply demonstrated its multi-disciplinary
and organising capabilities and its ability to
function as a unified construction entity.
section of the slide. The remaining sec- structures on the mine project, including
tion of the slide takes a further five days those for the load-out silo, the railway cul- INFO
to complete,” says Coetzer. vert, the load-out bin and trestles. Jane Strijdom
Meanwhile, Sanyati Piling and Piling’s Anton Stoll says that the main Sanyati Civil Engineering & Construction
Geotechnical have been contracted to challenges from a geotechnical point of view 011 397 7462
install the piles for a number of different have been the sandy soils and the socket jane.strijdom@sanyati.co.za
4 Civil Engineering | June 2009
Text Johan van Rooyen
Director: National Water Resource Planning
Department of Water and Environmental Affairs
javr@dwaf.gov.za
Peter van Niekerk
Chief Director: Integrated Water Resource Planning
Department of Water and Environmental Affairs
Niekerk@dwaf.gov.za
Dirk Versfeld
Dirk Versfeld cc
WATE R E NG I N E E R I NG dirki@iafrica.com
Strategic planning
for water resources in South Africa
This article explains the thinking There is a growing emphasis on ways in on a strategic level to ensure sufficient
and planning of the Department of which water can make a difference to water resources for the country. Its
Water and Environmental Affairs people’s lives at all levels of economic work is aimed at providing raw water
(DWEA) (formerly the Department of growth and development. up to the point where this water is
Water Affairs and Forestry), and how it Recognising that water does not abstracted for purification and distribu-
seeks to meet its responsibility to recon- drive development, but is the resource tion to users.
cile growing water needs from a limited that underpins most, if not all, of it, it is The planning approach is to seek to
supply, now and in the future. the Department’s duty to be in a posi- reconcile the current and potentially
Historically the focus has been on tion to respond to the expected growth, available water resources with the
major dams, irrigation schemes and and to ensure, where economically growing requirements. Water quality,
inter-basin transfer schemes – all to viable, that water is available when and and the delivery of water fit for use,
meet agricultural, urban and indus- where it is required. is a very critical consideration in de-
trial demands. The resource situation The planning for water resources termining availability. All responsible
is very different now, with almost all must be done far in advance of the water management authorities need to
readily available water already being actual need. While planning for the understand the constraints that would
put to use. Water resource planning next 25 years is taking place, thinking be imposed by a lack of water so that
can no longer simply propose the de- has also to be extended beyond this to they too can work towards a conver-
velopment of new schemes to supply a time when there may no longer be gence of need and supply in their own
demand, but must work towards the ‘available water’ as we have come to planning and development initiatives.
careful management and optimisation know it. A long-term view is thus also An important cue for the Department
of existing uses. required. has been the National Spatial Development
The Department is required to Perspective, published by the Office of the
ensure that water can be supplied to STRATEGIC WATER RESOURCE PLANNING State President in 2006, which has identi-
all major development centres, while IN THE DEPARTMENT OF WATER fied 26 core growth areas in which most of
also serving industrial and agricultural AND ENVIRONMENTAL AFFAIRS the country’s wealth is generated. It stands
requirements on a regional and national The Directorate of National Water to reason that water resources need to be
scale. Planning must account for eco- Resource Planning, within the Chief planned into the growth scenarios.
logical imperatives, international obliga- Directorate: Integrated Water Resource Planning has followed a logical se-
tions and human needs at a local level. Planning, is responsible for planning quence in seeking to contextualise the
Civil Engineering | June 2009 5
water resource situation and to provide strategies were addressed as the next efficiently, shortages will develop
strategies and tools that can serve all core planning activity. and water restrictions will become
levels of decisions. The sequence has been inevitable. There is still enough time
as follows: RECONCILIATION STRATEGIES FOR to implement structured programmes
NNCompilation of the National Water LARGE METROPOLITAN AREAS to achieve greater efficiency, provided
Resource Strategy The objectives of these reconciliation these are well managed and given
NNDevelopment of the Department's studies are to: political support.
Internal Strategic Perspectives, NNDevelop future water requirement NNThe reuse of water has been identified
addressing each of the 19 Water scenarios as a major potential source of water
Management Areas NNInvestigate all possible water resources for coastal cities. In some inland areas
NNIntensive reconciliation studies for the and other interventions this has now also become a necessity.
major metropolitan areas NNInvestigate all possible methods for Return flows from Gauteng have been
NNStudies focused on all other towns and reconciling the requirements for water identified as the best resource for de-
villages across the country, with the with the available resources velopments on the Waterberg coalfield
intention of having a holistic water re- NNProvide recommendations for the de- near Lephalale in Limpopo Province.
source picture and plan for the country velopment and implementation of the NNGroundwater resources are of par-
These aspects are discussed below. interventions and actions required ticular importance, not only for smaller
NNPropose a system for continuous up- towns, but also for larger cities such as
THE NATIONAL WATER RESOURCE STRATEGY dating into the future Cape Town.
(NWRS) (2004) The major reconciliation studies ad- NNFurther development of surface water
The first edition of the NWRS provides dressed thus far are listed below. The resources also has to occur.
a clear indication of the overall state Western Cape Reconciliation Study For each area the strategies and their
of the country’s water resources as in was described in the June 2007 issue of implementation will have to be adjusted
2000, with projections up to 2025. Many Civil Engineering (pp 16 – 19). The Vaal as the future unfolds. The strategies will
catchments are shown to be under River, Crocodile (West) and KwaZulu- be taken forward by Strategy Steering
stress, with water requirements and ex- Natal Coastal Metropolitan Areas Committees which will include important
isting allocations to users exceeding the Reconciliation Studies are covered in stakeholders in each area. These commit-
available supply. By 2025 the situation is detail elsewhere in this issue. tees are being set up to monitor actual
expected to worsen considerably. NNCompleted studies are: water use and the implementation of
The NWRS argued, nevertheless, Western Cape Water Supply System interventions, to assess the results from
that "In general, sufficient water can be Amatole Bulk Water Supply System further planning studies and to make rec-
made available at all significant urban Vaal River System ommendations on the approaches taken.
and industrial growth points in the NNStudies in progress are: This will happen annually and a 25-year
country for water not to be a limiting Crocodile (West) catchment, in- time horizon will be maintained.
factor to economic development." To cluding the Waterberg coalfields
achieve this, a number of reconciliation KwaZulu-Natal Coastal Metropolitan RECONCILIATION STRATEGIES
interventions were listed: Areas FOR ALL OTHER TOWNS
NNDemand management Algoa Water Supply Area A major planning thrust, which was
NNWater resource management Mangaung Municipality started in June 2008, is to extend the
NNManaging groundwater resources (Bloemfontein area) planning process discussed above to
NNReuse of water NNA study for the uMhlathuze Local cover all other towns in the country
NNControl of invasive alien vegetation Municipality, including Richards Bay, as well. This study intends to deliver
NNReallocation of water will start towards the end of 2009. a thorough situational analysis for all
NNDevelopment of surface water resources Municipalities, provinces and other towns, particularly those where water
NNInter-catchment transfers water management institutions are gen- resources are scarce. Typically, multi-
This clearly indicated that the time has erally providing excellent cooperation faceted strategies will be required in
come to consider many interventions and are assisting in dealing with the the search for solutions. Infrastructure,
other than just adding more dams. uncertainties in the planning process management and capacity problems
and the formulation of the planning will also be highlighted.
THE DWEA’S INTERNAL STRATEGIC scenarios.
PERSPECTIVES (ISPs – 2005) The most important conclusions WATER SUPPLY TO THE ENERGY SECTOR
In the Department’s ISPs the water re- arising from these studies are: The Department works very closely with
source situation was reviewed for each of NNWater-use efficiency measures (Water the large water users in the energy sector
the 19 Water Management Areas, thus at Conservation and Water Demand to ensure that existing and planned
a finer level of detail than in the NWRS. Management) must be implemented power plants and other energy indus-
The ISPs pointed to the need for water as a matter of urgency. For many of tries, as well as possible future power
reconciliation strategies to be conducted the systems investigated no other plants, are taken into account in its water
for all of the country’s major metro- measure can be implemented in time resource planning.
politan areas, these being the recognised to prevent shortages over the medium The planned power stations and
engines of growth of the economy. These term. If water is not used more coal-to-liquid plant in the Lephalale area
6 Civil Engineering | June 2009
will be supplied primarily from return most important feature to be distilled
flows from Gauteng in both the Crocodile from historical records.
(West) and Vaal catchments. A feasibility Climate change is an accepted
study is currently being done on the reality, although in South Africa the
pipelines, pumping stations and reservoirs actual impacts are not yet obvious. The
that will be required for these transfers. Department considers the long-term
predictions in its planning and makes
WATER SUPPLY TO THE allowances for these. At present climate
AGRICULTURAL SECTOR change can be viewed as an added
Even though South Africa has moved on uncertainty, with impacts that can be
to a diversified and modern economy, mitigated. The relatively gradual nature
irrigation still uses some 60% of the of climate change allows time for well-
country’s available water resources. considered adaptation measures. What
Agriculture’s (irrigated and dryland) is important is that the monitoring of
direct contribution to the GDP is rela- rainfall and runoff must be continued
tively small at 3%, although its indirect rigorously, and the hydrological moni-
contribution, in forward and backward toring network must be improved to
linkages, is indisputably much higher. ensure that the actual effects of climate
Given the very high consumption change are measured accurately and
demand of irrigation, it becomes a par- brought into the analysis of resources as
ticularly important strategy to increase quickly as possible.
agricultural water-use efficiency.
New ‘greenfields’ irrigation projects CONCLUSIONS
will of necessity be very limited. The Are we keeping up?
expected trend is that the application Water resource planning is structured
of the water resources will move up the but flexible, with the Department being
value ladder, i.e. either that crops of guided by national policies, plans and
higher value will be produced, or that programmes. Flexible reconciliation
water will migrate from the irrigation strategies have been developed and will We can no longer afford
sector to other sectors of higher value. ensure water for the large metropolitan to stay in the world of one
The Department will continue to sup- areas if implemented in time. The Strategy
port viable irrigation projects but will Steering Committees will keep the strate- dam, one valve, one pump,
also facilitate agreed improvements in gies relevant and will monitor changes one pipe and one operator,
the application of the water resource and the implementation of interventions
asset base. to maintain a 25-year planning horizon. but have to work towards
the complex optimisation of
CLIMATE CHANGE There are challenges left
The planning of water resources re- Deterioration in water quality is a huge various distributed sources
quires the consideration of many uncer- threat and will have to receive much and savings. This may be less
tainties, including the extent and nature focused attention. Every sector and
of future requirements, and the inac- every individual needs to recognise the grand, but it is no less complex
curacy of our knowledge of both rainfall water resource limitations. Bringing
than the giant construction
and runoff. Climate change adds to the all South Africans up to an acceptable
uncertainty, with trends becoming the standard of water-related service and schemes of the past
Civil Engineering | June 2009 7
delivery remains a tough challenge in tary adjustments. The conservative view level, perhaps with the best of inten-
this context. Recognising the limits of of growth suggests that where people tions, in the paradigms of the past:
what is possible in water-scarce areas, live will be increasingly dominated by capture and store surface water; pipe
becoming more efficient, using less the availability of water and the cost of it; pump it; move it; and use it. We can
water, and in some cases moving water that water. The reuse of all water will no longer afford to stay in the world
from traditional uses such as agriculture be the norm. Desalination technologies of one dam, one valve, one pump, one
into urban and industrial development, will provide enough water to the coastal pipe and one operator, but have to work
are all challenges we shall have to face. cities, but desalinated sea water is un- towards the complex optimisation of
The reuse of water is both a technical likely to be affordable inland. Industries various distributed sources and savings.
and a social challenge. The National will lead the way by relocating where This may be less grand, but it is no less
Water Act demands that the environ- there are cheaper water sources and complex than the giant construction
mental standards of rivers be upheld for people will follow. Water may become schemes of the past. Indeed, systems
our own preservation. Technical and too valuable to continue using it in the are likely to be far more complex and
management skills in the water sector irrigation schemes we have nurtured far more demanding of detail and in-
are needed in both local and national in the past. It may be economical to novation. Engineers urgently need to
government. Above all else, neither the shift such agriculture north beyond our move into the new realms of water
Department nor the country can af- borders. If it is to grow as a populous conservation and demand management,
ford to slip on the long time horizons, industrial nation, South Africa may resource protection and the reuse of
and must retain the skills and capacity have to rely on importing ‘virtual water’ polluted and contaminated water in all
that will allow the identification and from the rest of Africa through the food its bewildering variety. They need to
implementation of necessary measures produced there. design and develop multiple conjunc-
in good time. tive sources, to improve desalination
Where does this leave the civil engineer? technology and to see that we are effec-
Gazing into the crystal ball The biggest challenge to the civil tive in bringing water to our country.
We do not know just where the planet is engineer is to adapt, and this is not The excitement lies in stripping off the
headed, whether ‘minor’ economic cor- happening fast enough. Far too many shuttering and getting immersed in
rections will yet become major plane- schemes are being planned at local solutions for the future.
8 Civil Engineering | June 2009
Text Seef Rademeyer
Chief Engineer: National Water Resource Planning
(Central)
Department of Water and Environmental Affairs
seef@dwaf.gov.za
Trevor Coleman
Golder Associates Africa (Pty) Ltd
tcoleman@golder.co.za
Pieter van Rooyen
Director: WRP Consulting Engineers (Pty) Ltd
pieterv@wrp.co.za
Willem Wegelin
Director: WRP Consulting Engineers (Pty) Ltd
willemw@wrp.co.za
Vaal River System:
Large Bulk Water Supply Reconciliation Strategy
The purpose of the Large Bulk The key objectives are: STUDY PROCEDURE AND METHODOLOGY
Water Supply Reconciliation Strategy NNUpdate the current and future water The overarching study approach was to
Study for the Vaal River System Study requirements develop reconciliation strategies in two
is to develop a strategy for meeting the NNAssess the water resources stages. The first stage involved developing
growing water requirements of the indus- NNFormulate reconciliation interventions and assessing scenarios of possible future
trial and urban sectors that are served by NNConsult stakeholders during the devel- reconciliation options. These scenarios
the Integrated Vaal River System (IVRS). opment of the strategies were presented to the management and
stakeholders of the Department of Water
1 and Environmental Affairs (DWEA, for-
merly DWAF, the Department of Water
Affairs and Forestry) for comments.
Further necessary investigations were
identified during the development of the
Second Stage Reconciliation Strategy and
the results are reported on in this article.
An essential part of the strategy
development process was the integration
of information from various processes in
order to arrive at a strategy that will ac-
count for all the major aspects that influ-
ence the bulk water supply situation in the
Vaal River System.
Information was sourced from the
following studies:
NNVaal River Reconciliation Strategy Study
1 Map of the Integrated Vaal River System
Civil Engineering | June 2009 9NNIntegrated Water Quality Management Mittal Steel, all of which provided water to address the increasing water needs
Plan Study for the Vaal River System requirement scenarios based on their resulting from significant future develop-
NNPotential Savings through Water respective future outlooks. ments planned in the area. Figure 1 shows
Conservation/Water Demand The Department did a thorough a geographical map of the water resources
Management (WC/WDM) in the Upper investigation of irrigation upstream of of the Integrated Vaal River System and
and Middle Vaal Water Management the Vaal Dam and found that as much as the respective inter-basin transfers.
Areas 174 million m3/annum of the year 2005
NNCrocodile (West) River Reconciliation irrigation water use could be unlawful. BULK AUGMENTATION OPTIONS
Strategy Study This is an unacceptable situation that The Vaal Augmentation Planning Study
An integrated stakeholder-engagement puts the other users from the Vaal River (VAPS), completed in 1996, concluded
process was followed for the three Vaal System under a very high risk of shortages that either a further phase of the Lesotho
River studies, which ensured the coordi- and water restrictions. The Department Highlands Water Project (LHWP) or
nation of interdependent activities. has already started with actions to remove further water resource developments in
the unlawful irrigation. the Thukela River System could be con-
WATER REQUIREMENTS AND In addition to the above, the water sidered as alternatives for augmenting the
RETURN FLOW SCENARIOS balances for the Crocodile (West) System water resources of the Vaal River System.
The system provides water to one of the and the Lephalale Area indicated that Further parallel feasibility and com-
most populated and important areas in additional raw water transfers will be parison studies were carried out for these
the country as reflected by the magni- necessary from the Vaal. The necessity for two options.
tude of the developments located in the this transfer results from the proposed
Upper and Middle Vaal, the Olifants developments on the Lephalale coal- PERSPECTIVE ON WATER
and the upper portion of the Crocodile fields, which include new power stations QUALITY MANAGEMENT
West/Marico Water Management areas. planned by Eskom and a possible new A water quality situation assessment of
These developments include many coal-to-liquid plant planned by Sasol. the Vaal River System was carried out
of the country’s power stations, gold as part of the Integrated Water Quality
mines, platinum mines, petro-chemical WATER CONSERVATION AND WATER Management Plan (IWQMP). It was
plants, sprawling urban development, DEMAND MANAGEMENT SCENARIOS found that salinity (represented by total
and various other strategic industries. The focus of the WC/WDM assessment dissolved solids), eutrophication and
The water requirements in the area are was on the nine largest urban water users, microbiological water quality were the
therefore very important to sustain the which in total used 1 186 million m3/annum major water quality issues that need to be
economy of the country and the well- of water in 2004. A standard water balance addressed by the strategy.
being of its people. was compiled for each municipality; these The salinity in the Grootdraai Dam
Urban water requirement scenarios were built up from assessments of water and Vaal Dam catchments is currently ad-
were developed for the Rand Water supply zones in their respective supply areas equate and meets the water user require-
supply area by applying the Water to represent the actual conditions in each ments. However, the water quality in both
Requirement and Return Flow Model zone. From this water balance the potential these dams is influenced by the water
for the planning period up to 2030. savings were determined, with the focus quality of the transfers from the Lesotho,
Three population scenarios were devel- on the components billed but not paid Thukela, Zaaihoek and Usutu transfer
oped as main drivers of the model. for consumption and potential savings on schemes. Currently, this transfer water is
The Water Requirement and physical leakage. of good quality and assists in maintaining
Return Flow Model was configured for Based on detailed assessments of the present water quality in these dams,
47 sewage drainage areas (SDAs) and the specific situation in each municipal but the water quality in Grootdraai Dam
calibrated for the census year 2001. area, the potential savings, coupled with is under threat from mining, in particular
The calibration involved changing a range of WC/WDM measures, were from decants from closed mines in the
model parameters to match both the determined and costed. catchment. The salinity deteriorates sig-
water use and the return flows ob- nificantly downstream of the Vaal Barrage
served for each SDA. WATER RESOURCES due to urbanisation, return flows from
Water requirement scenarios for The core of the Integrated Vaal River wastewater treatment works, and indus-
Sedibeng Water and MidVaal Water System consists of the Upper, Middle and trial and mine dewatering discharges. The
Company were obtained from the re- Lower Vaal River Water Management current status does not meet the Resource
spective organisations. For all the other areas. However, due to the numerous Water Quality Objectives (RWQOs) set
urban areas the water requirement inter-basin transfers, reconciliation plan- for this reach of the river.
projections were determined using the ning has to include the linked systems. The water quality assessment
growth rates from the National Water Significant water transfers occur to water showed that the Vaal Dam, the Vaal
Resource Strategy (NWRS). users in the Crocodile (West) River catch- Barrage and the Bloemhof Dam are
There are three main industries ments through the Rand Water system. eutrophic to hypertrophic. The average
receiving water in bulk from the Vaal In addition, a scheme is proposed to phosphorus concentrations exceed the
River System: the electrical power transfer water from the Crocodile (West) proposed RWQOs significantly. The
utility Eskom, the petrochemical River Management area to the Lephalale eutrophic conditions in the middle
(coal-to-liquid fuel) industry Sasol and area (Mokolo River System) in order reaches of the Vaal River have affected
Civil Engineering | June 2009 11the performance of the water treat- WC/WDM measures. The unlawful ir- RECONCILIATION STRATEGY
ment plants of Midvaal and Sedibeng rigation water use was removed, as shown Ensuring that sufficient water is available
Water. Additional treatment processes by the reduction in the system demand to meet the future water requirements in
to deal with the colour and odour have between 2008 and 2011. This scenario the supply area of the Vaal River System
had to be installed. The major source results in significant shortages (deficits) requires a six-pillar strategy consisting of
of the nutrients is the effluent from in supply until 2021 when the Polihali the following main components:
wastewater treatment works (WWTWs) Dam (Lesotho Highlands Water Project 1. Enforcement of compliance with water
and the maintenance of the sewerage Phase 2) will be able to deliver its full use arrangements to eradicate unlawful
systems. A number of WWTWs are not yield. Jana Dam in the Thukela River has water use
performing according to specifications. to be implemented shortly thereafter to 2. Water conservation and demand man-
The findings from the IWQMP were commence delivery in 2025. agement measures to reduce losses and
used to formulate a number of manage- The effect of implementing meas- improve efficiency
ment measures to improve the water ures to reduce water loss through 3. Utilisation of treated effluent and
quality in the system. WC/WDM activities is illustrated in other discharges, especially those
The proposed immediate to Figure 3. This shows significant reduc- from the mines
short-term management strategy is: tion in the shortages up to 2021 and 4. Implementation of the infrastructure
NNContinue with dilution of the Vaal that only the Polihali Dam and the augmentation option
Barrage water with releases from the much smaller Mielietuin Dam in the 5. Management of the water quality in the
Vaal Dam and levy waste-discharge Bushmans River (a tributary of the system
charges to offset the economic disben- Thukela River) are needed to achieve a 6. Constitution of a Strategy Steering
efit of the downstream users. water balance up to 2030. Committee
NNSelect target schemes for treating saline The remaining shortages indicated for The reasons behind these and other rec-
effluent. 2015 to 2020 could be alleviated by desali- ommendations for water resource man-
NNIncorporate additional dilution releases nation of mine water effluent for reuse. agement are given below:
to manage the algal blooms in the
middle reaches of the Vaal River. 2
NNAudit WWTWs and develop perspec-
tives on hotspots requiring urgent
action.
NNEffect the control of pollution sources
through licensing and integrated water
and waste management plans.
The medium to long-term management strategy is:
NNImplement schemes for treating saline
effluent.
NNImplement the system of charging for
waste discharge.
NNImplement WWTP retrofit and up-
grading projects in the ‘hot spot’ areas.
WATER BALANCE AND RECONCILIATION
Given the water requirements and return
flows and the potential saving scenarios,
the need for intervention was deter- 3
mined by assessing the water balance
situation over the planning period. This
was undertaken by firstly defining the
planning scenarios and, secondly, car-
rying out scheduling analysis to deter-
mine the dates when further intervention
may be required.
The water balance situation in the
Vaal River System is presented in Figure 2
for the high water requirement scenario
without the implementation of further
2 Reconciliation scenario
excluding further WC/WDM
3 Reconciliation scenario with WC/
WDM loss management measures
12 Civil Engineering | June 2009NNEradication of the unlawful water tion and continuous revision of the
use is essential in order to rectify Reconciliation Strategy.
the current deficit in the Vaal River
System. The Department has already CONCLUSIONS
started a process in which legal and The recommended strategy provides
compliance enforcement measures the focus for water management in the
are being investigated for an enforce- Integrated Vaal River System. Successful
ment campaign. implementation of the strategy will
NNThe continuation of further WC/ require the commitment of and sub-
WDMs is essential to maintain a stantial resources from the Department
positive water balance in the Vaal of Water and Environment Affairs
River System over the next ten years. (DWEA, formerly DWAF) and other
Savings of about 15% are required. institutions.
NNThe results from detailed simulation The interdependency of the Vaal
analysis indicated that the reuse of River and Crocodile (West) River
mine water effluent, in combination systems will require coordinated and
with other interventions, could have a synchronised planning in future to en-
significant benefit by postponing the sure coherent management of the water
need for further augmentation after resources.
the implementation of Phase II of the Cooperation among water service
Lesotho Highlands Water Project. A providers, municipalities, industries and
feasibility study will be carried out to the DWEA in the implementation of the
evaluate all the options to find an op- strategy will be essential to foster the
timum solution. principles of integrated water resource
NNCabinet has given its approval that management and to achieve the objectives
the Department should proceed with of the strategy.
negotiations with the Government
of Lesotho for the implementation
PROJECT TEAM
of Phase 2 of the Lesotho Highlands
Water Project. This scheme consists The study was undertaken for the
Directorate of National Water Resource
of the construction of the Polihali
Planning by DMM Development
Dam and a conveyance tunnel to
Consultants, Golder Associates Africa,
transfer water under gravity to the
SRK, WRP Consulting Engineers and
Katse Dam, from where it will be
Zitholele Consulting, supported by
delivered to South Africa via the ex-
various subconsultants, collaborating
isting delivery tunnel.
institutions and DWEA directorates.
NNThe Strategy Steering Committee Project status Completed in March 2009.
(SSC) will oversee the implementa-
Civil Engineering | June 2009 13Text Tendani Nditwani
Chief Water Resources Planner (North)
Directorate: National Water Resource Planning
Department Water and Environmental Affairs
nditwanit@dwaf.gov.za
Dr Thinus Basson
Director: BKS (Pty) Ltd
thinusb@bks.co.za
Johan Rossouw
Director: BKS (Pty) Ltd
johanr@bks.co.za
Water Reconciliation Strategy for the
Crocodile (West) River catchment
1 INTRODUCTION
The Crocodile (West) River catchment area
is one of the most developed river catch-
ments in the country. It is characterised by
the sprawling urban and industrial areas
of northern Johannesburg and Pretoria,
extensive irrigation downstream of the
Hartbeespoort Dam and large mining
developments north of the Magaliesberg.
As a result, the Crocodile River is one of
the rivers in the country that has been most
influenced by human activities, and one for
which more specific management strategies
are of paramount importance.
The purpose of this study was to for-
mulate a detailed strategy to ensure the
sufficient and reliable supply of water of
appropriate quality to all existing, as well as
future users. This should be achieved within
the framework of the best utilisation of
water resources, at the lowest cost and in an
environmentally sustainable manner.
The strategy caters for both existing
and future needs, and is sufficiently com-
prehensive and flexible to enable a quick
response to changing circumstances. It
takes cognisance of possible future sce-
narios and impacts, and identifies preferred
options and interventions that could be
implemented as being most appropriate
to the situation. Although a chronology of
events and time scales is considered, the
strategy should not be viewed as a rigid
single plan with fixed sequencing and time
scales. The development of the strategy
was facilitated in an open process and one
1 Map of the study area
14 Civil Engineering | June 2009of the mechanisms employed will be a regulated. Because of the extensive de- NNUrban, which consists of (i) domestic or
steering committee which is representative velopments and level of human activity household use of water and (ii) commer-
of sectors important to the study. in the catchment, water use in the catch- cial, industrial and public use of water
ment far exceeds the water available NNRural water requirements, which include
THE STUDY AREA from the local sources – already more domestic use and stock watering
The study area covers the whole of the than fourfold. Most of the water used in NNIrrigation requirements for commercial
Crocodile (West) River catchment as shown the catchment is supplied from the Vaal agriculture
in Figure 1. The Mokolo River catchment, River System via Rand Water, mainly to NNMining water requirements
where water supplies to the large mining, serve the metropolitan areas and some NNPower generation in the Crocodile catch-
power generation and petrochemical devel- mining developments. This in turn results ment
opments in the Lephalale area need to be in large quantities of effluent from the NNTransfers of water to neighbouring areas;
augmented from or via the Crocodile River urban and industrial users, most of which this relates mainly to the Lephalale area,
catchment, is also included. is discharged into the river system after for which different development scenarios
Currently, roughly 70% of the GDP treatment for reuse downstream. In many were also considered, mostly for the en-
for Gauteng Province is generated in the of the streams and impoundments, water ergy sector
Crocodile River catchment. Also about 80% quality is severely compromised by the Urban water requirement scenarios
of the GDP for the North West Province, proportionately large return flows. were developed by applying the Water
mostly from platinum mining, and in the These influencing factors are inex- Requirement and Return Flow Model for
order of 20% compared with Limpopo tricably linked together through various the planning period up to 2030. One of the
Province, is generated in this catchment. In complex inter-relationships and are not to driver variables in the model is population.
total, about 25% of the national GDP is gen- be viewed in isolation. Three population scenarios were developed,
erated in the Crocodile River catchment. with the information from Statistics SA
The water resources that occur WATER REQUIREMENTS AND (2007) forming the base scenario, and two
naturally in the Crocodile River catch- RETURN FLOW SCENARIOS further alternative scenarios (high and low).
ment have already been fully developed Estimates were made of the current and The 2005 urban population in the
and most of the tributaries, as well as future requirements for water for the fol- Crocodile River catchment of about
the main stem of the river, are highly lowing sectors: 4,5 million people is expected to grow to
Civil Engineering | June 2009 152
2 Hartbeespoort Dam additional water will be required by the WATER RESOURCES
time the third unit of the plant is com- The following main components were
between 5,3 and 7,1 million by 2030. The missioned. Three more Eskom power sta- considered with regard to the availability of
2005 rural population of just more than tions are likely to be built and proposals water:
1,0 million people is expected to grow to for the establishment of power stations by NNLocal resources, which comprise (i) sur-
between 1,1 and 1,2 million by 2030. As a independent power producers are under face water, (ii) groundwater and (iii) in-
consequence, the 2005 urban water require- consideration. Sasol is investigating the creases in runoff from paved urban areas
ments are expected to grow from the cur- feasibility of a coal-to-liquid fuel plant NNReturn flows from urban areas and from
rent 570 million m3/a to between 640 and in the area. All these and consequential irrigation
850 million m3/a in 2030. The rural require- secondary and tertiary developments are NNTransfers of water from the Vaal River
ments are expected to grow from 15 mil- expected to increase the water require- System
lion m3/a to between 40 and 44 million m3/a ments substantially in the Lephalale Due to the high degree of development and
during the same period. area from about 20 million m3/a to over regulation of the water resources in the
The existing irrigation requirements are 185 million m3/annum by 2030. catchment, and to the large quantities of
about 450 million m3/a and are expected return flows to many tributaries and eventu-
to remain at that level. Mining water WATER CONSERVATION AND WATER DEMAND ally to the main stem of the river, the natural
requirements are expected to increase MANAGEMENT SCENARIOS flow regime of streams in the catchment has
from about 90 million m3/a to between Specific consideration was given to been greatly altered. This will limit the extent
140 and 150 million m3/a in 2030. The ex- Water Conservation and Demand to which natural variability can be reinstated
isting water requirements for power genera- Management (WCDM) and the influ- through the implementation of the reserve.
tion at the three power stations are 34 mil- ences of different levels of WCDM were
lion m3/a, and stock watering requirements investigated. The focus was on the urban BULK AUGMENTATION OPTIONS
have been estimated at 22 million m3/a. No water users, which already represented It was assumed that Rand Water’s cur-
change in these requirements is expected. over 50% of the water use in the catch- rent water users will continue to be
In total, the water requirements of all ment in 2005. supplied by them. Local water sources
the users within the Crocodile River catch- Based on the detailed assessments (including return flows) will be used to
ment are expected to grow from about made of numerous supply zones in each meet the growing water requirements in
1 100 million m3/a in 2005 to between 1 300 municipal area, the potential savings, those areas not supplied by Rand Water.
and 1 500 million m3/a in 2030. coupled with a range of water conserva- With these assumptions, the water
Future transfers of water to the tion/water demand management (WC/ transfers from the Vaal River System to
Lephalale area will significantly influence WDM) measures were determined. the Crocodile River catchment are ex-
the water balances in the subareas of the With the knowledge that these meas- pected to increase from 550 million m 3/a
Crocodile River catchment. The exten- ures will require substantial financial in 2005 to as much as 800 million m3/a
sive developments associated with the and human resources to implement, a in 2030. Proper synchronisation between
Waterberg coalfields in the Lephalale area schedule (projection) of future savings the reconciliation strategies for the
were planned for. Construction of the was made, resulting in the development Crocodile (West) and Vaal River Systems
Medupi Power Station started in 2007 and of four scenarios. was therefore done.
16 Civil Engineering | June 2009PERSPECTIVE ON WATER QUALITY cile the requirements for water with the the Lephalale area. The water balance for
Although the reconciliation strategy is fo- availability thereof, there are different this scenario is shown in Figure 4.
cused mostly on water quantity (with water scenarios of growth in demand, each of The blue line indicates the avail-
quality being dealt with in detail in other which will again have an impact on the able yield from the Mokolo Dam. The
studies), some key perspectives on water availability of effluent. Different WCDM black line represents the combined
quality are given below: measures will also have different impacts Mokolo Dam yield plus the surplus in
NNThe water quality in streams and im- on the quantity of effluent. Various com- the Crocodile River catchment for the
poundments downstream of the major binations of WC/WDM measures and scenario of high population growth
urban areas is poor as a result of the growth scenarios were tested, and one of with medium-efficiency water demand
return flows and urban wash-off. This has these scenarios is shown in Figure 3. The management in the Crocodile River
serious environmental impacts and can scenarios are the same as those for the catchment. The red line represents the
also limit the potential for reuse. The poor Vaal River System Reconciliation Strategy. expected future water requirements in
quality of water in the Hartbeespoort The top black line indicates the total water the Lephalale area. For this specific sce-
Dam is a major concern. availability and the bottom red line indi- nario the Mokolo Dam should be able to
NNIrrigation return flows and runoff from cates the total water requirements of the meet the growing water requirements in
highly fertilised rain-fed cultivation areas Crocodile River catchment. The difference the Lephalale area until about 2011, after
also impact on downstream water quality. between the two lines represents the sur- which the supply will have to be supple-
NNAs a result of these impacts, the plus volumes of water available for transfer mented from the Crocodile River (where
Hartbeespoort and Roodeplaat Dams are to the Lephalale area. the blue and red lines cross). After 2013
highly eutrophic. On the Lephalale side various sce- (where the red and black lines cross) the
narios were also considered. The high Crocodile River resources will have to be
WATER BALANCES scenario is currently being used in the supplemented by a transfer from the Vaal
The main growth in the available water planning for the transfer pipeline, taking River System.
resources is expected from the growth in into account five Eskom power stations, a
water requirements, which in turn will coal-to-liquid fuel plant, the water require- RECONCILIATION STRATEGY
generate effluent. Given the underlying ments of the coal mines and consequential The strategy is not intended to be a single
purpose of the strategy, namely to recon- secondary and tertiary developments in master plan with fixed sequencing and
Civil Engineering | June 2009 173 1 600
1 550
1 500
Total water availability
1 450
Volume (million m3/a)
1 400
Total water requirements
1 350
1 300
1 250
1 200
1 150
1 100
2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030
Year
Total water requirements Total water availability
4 200
180
Lephalale area requirements
160
140
Mokolo Dam yield + Crocodile catchment surplus
Volume (million m3/a)
120
100
80
Mokolo Dam yield
60
40
20
0
2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030
Mokolo Dam yield Mokolo Dam yield + Crocodile catchment surplus Lephalale area requirements
3 Water balance for the Crocodile River will be supplied to the Lephalale other key stakeholders. It will be a vol-
catchment: high population, medium area. Future projected deficits untary body operating at a strategic level
water demand management will be made up with transfers and ensuring that the technical aspects
4 Water balance at Lephalale from the Vaal River. It has already of the strategy are transparent, open and
been decided that effluent from consultative, and that cooperative gov-
time scales, but should cater for a spec- Johannesburg Water Treatment ernance is embraced.
trum of plausible future scenarios, and Works situated south of Soweto
also be both flexible and robust under could be used for this. This part of STATUS OF THE STRATEGY
changing conditions. the strategy is also covered in the The information and perspectives given
The strategy can be broadly clas- Vaal Reconciliation Strategy. above were taken from Version 1 of the
sified under the following three key Reconciliation Strategy for the Crocodile
geographic areas: IMPLEMENTATION OF THE STRATEGY (West) Water Supply System, and are
(i) Gauteng North, which is mainly the For this strategy to be implemented therefore subject to review and refinement.
part of the catchment south of the and to serve its purpose properly in Some of the information is still being veri-
Magaliesberg: Water for urban and the future, the water balance situation fied and a final version of the strategy is
industrial use in the Gauteng North needs to be monitored continuously planned for the end of 2009.
area will continue to be supplied by and the strategy must be regularly up-
Rand Water. dated and maintained in general. This PROJECT TEAM
(ii) The Crocodile River catchment north will ensure that intervention planning The study was undertaken on behalf of
of the Magaliesberg: Growth in water can be adjusted to take account of any the client, Directorate: National Water
requirements in this area will be met changes that may have an impact on the Resource Planning of the Department
from the growing effluent return flows projected water balance. of Water and Environmental Affairs (for-
from the urban and industrial users A Strategy Steering Committee will merly the DWAF), by BKS and by Arcus
south of the Magaliesberg. be constituted, with members from the Gibb, supported by various subconsult-
(iii) The Lephalale area: Surplus effluent Department of Water and Environmental ants, collaborating institutions and
from the Crocodile River catchment Affairs (DWEA, formerly DWAF) and DWEA directorates.
18 Civil Engineering | June 2009Text Niel van Wyk
Chief Engineer
Directorate: National Water Resource Planning
Department Water and Environmental Affairs
vanwykn@dwaf.gov.za
Pieter van Rooyen
Director: WRP Consulting Engineers (Pty) Ltd
Strategies to ensure sufficient
pieterv@wrp.co.za
Colin Talanda
WRP Consulting Engineers (Pty) Ltd
colint@wrp.co.za
Willem Wegelin
Director: WRP Consulting Engineers (Pty) Ltd water availability for the
KwaZulu-Natal Coastal
willemw@wrp.co.za
Trevor Coleman
Metropolitan Area
Golder Associates Africa (Pty) Ltd
tcoleman@golder.co.za
The water requirements of the Strategy Study for the KwaZulu-Natal tainty, due to the numerous factors that
KwaZulu-Natal (KZN) metropolitan Coastal Metropolitan Areas, which is in can influence such demands. It is also
areas have been growing rapidly as the process of being completed. important to identify the actions and
a result of the expanding economy, The aim of the Reconciliation responsibilities required to implement
urbanisation, several large new infra- Strategy Study is to identify, evaluate the strategy.
structure projects and a general im- and prioritise interventions to recon- The study area extends from
provement in the existing water supply cile the water requirements with the Pietermaritzburg to Durban (west to
services. These trends are expected available water resources up to 2030. east) and from KwaDukuza (Stanger) in
to continue in future and to deal with All key stakeholders were included in the north, to Amanzimtoti in the south.
this situation the Department of Water the development of the Reconciliation It includes the eThekwini Metropolitan
and Environmental Affairs (DWEA, Strategy and the recommendations were area and the Msunduzi and iLembe
formerly DWAF), in collaboration with derived through a transparent and open Municipalities – as reflected in
all major water services organisations, process, resulting in collective endorse- Figure 1. This is one of the most densely
has developed strategies on how to ment. The strategy must be sufficiently populated areas in South Africa with
meet future water needs up to 2030. flexible to accommodate future changes approximately 5,2 million people and
The proposed strategies were devel- in actual water use since it is impossible is the third-largest contributor to the
oped through the Water Reconciliation to predict the future demands with cer- national economy.
1 WATER REQUIREMENTS AND
RETURN FLOW SCENARIOS
The urban sector is the largest water
user in the study area and has experi-
enced continuous growth in water use
over a period of many years, which can
be attributed to the favourable socio-
economic conditions in the region. The
economic prospects, coupled with the
rising living standards of the popula-
tion, as well as other factors such as
HIV AIDS, will have a significant influ-
ence on the future water requirements.
Sophisticated models were used to
assist in developing water requirement
and return flow scenarios for each
sewer drainage area (SDA) – delineated
to represent the area contributing to
1 Map of the study area and river systems
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