Environmental Engineering - SAICE

August 2012 Vol 20 No 7

Environmental EngineeringHartbeespoort DamHartbeespoort DamRemediationRemediation

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Civil Engineering August 2012 1

F R O M T H E C E O ’ S D E S K

EVERYONE HAS A landmark day or

event that defi nes a breakthrough moment

or turning point in their professional or

personal lives. Interestingly, I have never

learned the distinction between professional

time and personal time; as though the tran-

sition between the two was triggered by the

fl ick of a switch – when living becomes a

resolute pursuit of purpose, then behaviour

and time can only be personal.

A landmark day or event – that mo-

ment that clearly marks a distinction be-

tween where one comes from and where

one is heading, from obscurity to signifi -

cance, and very often from impossibility

to hope, especially in the socio-economic

climate of modern South Africa.

For me this day was graduation day,

Th ursday 16 January 2003, at the Great

Hall at Wits University.

I am amazed at how American cinema

portrays student life as wanton enjoy-

ment of youthful recreation – sorority

and fraternity groups, abundant free time,

adventurous volunteer activities, and

other extramural activities. I do not iden-

tify with Hollywood’s depiction of student

life. While I had my fair share of play at

university, reading for a civil engineering

undergraduate degree at a prominent

school of civil and environmental engi-

neering was demanding and extremely

diffi cult. Suff ering is a strong word, but at

the time that is what it felt like.

Graduation day was a manifestation of

the joy of suff ering.

Being a civil engineering student was a

disciplined and focused four years, of ar-

duous academic training and development.

I also noticed that it was not the smartest

students in the class who passed, but the

ones who applied themselves consistently

and demonstrated commitment to study.

Th ey did the basic things – attended all

lectures well prepared, respected punc-

tuality and time, paid attention in class,

reviewed the day’s lecture notes on the

same day, completed tutorials, and asked

questions in class and in tutorial sessions.

On completion of the four strenuous years,

I proved that I had the potential to advance

to engineer status.

Invariably, students who do not put in

the eff ort and time fall by the wayside, but

there are those who appreciate the sac-

rifi ces required and who immerse them-

selves in the struggle to graduate. Sadly,

not all students reach graduation day. From

my visits to universities across the country,

and engaging with HoDs and Allyson

Lawless, author of the often cited Numbers

and Needs books, I have learnt that only

12% to 30% of current students complete

their qualifi cations in engineering in the

minimum time allocated. Th e reasons are

known – poor maths and science at high

school level, students having social diffi cul-

ties and the lack of consistent and reliable

funding.

It is particularly disconcerting when

students who complete the required

courses do not graduate because they are

unable to secure appropriate in-service

or experiential training, which is a key

requirement of the UoT (Universities of

Technology) engineering curriculum.

Without experiential training, there is no

graduation, and subsequently unemploy-

ment and the depressing demise of the

hopes of an individual, a family and a

community. Parents, often single parents,

from meagre blue collar wages make in-

credible social and economic sacrifi ces to

provide student fees. Students study till the

early hours of the morning, sometimes by

candlelight. Th ey take several taxis hours

before class begins, trying to be punctual.

Th ey go through exam stress, and they

pass those exams. Only to learn that there

is no employment. No graduation day.

Th e state of unemployment for students

extends to graduates – recently a prominent

civil engineering company released 15 of

its students from their contractual bursary

obligations after they had graduated, simply

because the company could not provide em-

ployment. During the presidential branch

visits, I have met numerous directors of

small- and medium-sized civil engineering

consulting fi rms who complain that they

are unable to employ because of the lack of

sustainable projects.

In a country where 25% of our

working population are unemployed, and

more than 40% of young people under

the age of 30 are unemployed, surely this

situation should not prevail – defi nitely

not in the construction industry.

SAICE has some 2 700 civil engineering

students on its database. At the six universi-

ties and eleven UoTs in South Africa, SAICE

has ten student chapters in operation.

Chapters are usually run by a committee

comprising civil engineering students, sup-

ported by an obliging lecturer who is usu-

ally active in the local SAICE branch. Th e

branches engage with the chapters on issues

relating to professional development, bursa-

ries, employment, SAICE special events and

other student-related issues.

I invite senior engineers throughout

the SAICE network and civil engineering

companies around the country, who are

not already engaged with student develop-

ment in the form of mentoring, coaching

or formal training, to adopt a student civil

engineer as your little project. E-mail me

your stories of graduation day.

And for those hundreds of students

who have shared their plight with me, and

who fi nd themselves in what appears to

be a hopeless situation, I would refer you

to the experience of countless other engi-

neering graduates around the world, and

more so to what the Prime Minister of the

United Kingdom, Winston Churchill, said

when he was invited to Harrow School on

29 October 1941 to address the learners.

Churchill stood before the students and

said: "…. never give up. Never give up.

Never, never give up."

Graduation day

ON THE COVERAfriSam’s innovative new road

stabilisation product, Roadstab Cement,

has been developed to achieve superior

stability across a broad range of road

material types, off ering enhanced

performance, even with soils that have

a high plasticity index. The product,

which has been successfully tested

on several contracts, provides an

excellent alternative for road design

ON THE COVER

PUBLISHED BY SAICEBlock 19, Thornhill Offi ce Park, Bekker Street, Vorna Valley, MidrandPrivate Bag X200, Halfway House, 1685Tel 011 805 5947/48, Fax 011 805 5971http://[email protected]

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EDITORVerelene de [email protected] 011 805 5947/8, Cell 083 378 3996

EDITORIAL PANELMarco van Dijk (chairman), Irvin Luker (vice-chairman), Martin van Veelen (president), Manglin Pillay (CEO), Dawie Botha, Wally Burdzik, Johan de Koker, Andile Gqaji, Gerhard Heymann, Jeffrey Mahachi, Jones Moloisane, Beate Scharfetter, Phuti Seopa, Marie Ashpole, Verelene de Koker (editor), Elsabé Maree (editor’s assistant), Barbara Spence (advertising)

ANNUAL SUBSCRIPTION RATESA R575.00 (VAT included), International US$ 122.00

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DESIGN AND REPRODUCTIONMarketing Support Services, Menlo Park, Pretoria

PRINTINGUltra Litho, Johannesburg

The South African Institution of Civil Engineering accepts no responsibility for any statements made or opinions expressed in this publication. Consequently nobody connected with the publication of the magazine, in particular the proprietors, the publishers and the 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.

ISSN 1021-2000


Environmental EngineeringHartbeespoort DamRemediation

FROM THE CEO’S DESKGraduation day . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

OPINIONGauteng e-tolling: it’s time, or is it? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

ENVIRONMENTAL ENGINEERINGHARTBEESPOORT DAM REMEDIATION Hartbeespoort Dam Integrated Biological Remediation Programme . . . . . . . . . . 9Brief history of the dam of dreams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Overview of the programme. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

Biomass removal and management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Food web restructuring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Food web and integrated biomonitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Shoreline remediation and fl oating wetlands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Sediment removal and management. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Reduction of the external nutrient load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Information, Communication and Knowledge Centre. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51

Future challenges and prospects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Siviele Ingenieurswese = Afrikaans

P4

South African Institution ofCivil Engineering


New road stabilisation product deliversoutstanding results in latest tests

AfriSam’s specialist new product, Roadstab Cement, has been

designed specifi cally for road stabilisation applications

F O R E X C E L L E N C E I N M A G A Z I N EP U B L I S H I N G A N D J O U R N A L I S M

AAP CA

R D SWW I N E R 2 0 0 7N W I N N E R 2 0 0 8

F O R E X C E L L E N C E I N M A G A Z I N EP U B L I S H I N G A N D J O U R N A L I S M

W I N N E R 2 0 0 9F O R E X C E L L E N C E I N M A G A Z I N E

P U B L I S H I N G A N D E D I T O R I A L

Winner of the 2009 Pica Awardin the Construction, Engineering and Related Industries category for the third year running

MORE ENVIRONMENTAL ENGINEERINGEnvironmental Management – grudge vs green. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56Durban’s Electron Road Waste Transfer Station –

effi cient cost-effective transportation of waste material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60Sabita commissions carbon measurement tool for

South Africa’s bituminous products industry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63

BOOKSIs Chernobyl dead? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64

WESTERN CAPESolar road studs: an innovative solution to increase

visibility and safety on South Africa’s roads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66MyCiTi innovations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69SAICE Western Cape Branch Website. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73

IN BRIEF 76 Solar revolution Considering the water cycle for sustainable operations

in Africa Perma clamp for joining HDPE pipes Kaytech GlasGrid used to

strengthen problem road On show at Electra Mining Africa: 10 – 14 September

SAICE AND PROFESSIONAL NEWSObituary: Faried Allie . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .81Obituary: Ross Parry-Davies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .82SAICE Training Calendar 2012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .84

P15

P25

P38

P60Civil Engineering August 2012 3

4 August 2012 Civil Engineering

O N T H E C O V E R

AfriSam’s new specialist road stabilisation product, Roadstab Cement, delivered

outstanding results in tests conducted on selected roads in the Free State and Gauteng

AFRISAM’S NEW specialist road sta-

bilisation product, Roadstab Cement,

delivered outstanding results in tests con-

ducted on the higher clay-containing soils

found in the Free State – during stabilisa-

tion projects on the N8 in Tweespruit in

the Free State, the N1 from Fonteintjie to

Wurasoord, the N6 at Smithfi eld and the

N5 from Bethlehem to Kestell.

Th e same excellent results have been

demonstrated on projects in Gauteng.

Th ese include the Kaalfontein Road in

Midrand, the R21 between Boksburg and

the OR Tambo International Airport, and

on runways at Lanseria Airport.

Stabilisation is the process of mixing ce-

mentitious material with granular material,

in predetermined proportions, to improve

the engineering properties of the granular

material. Soil stabilisation is therefore the

process of adding a stabiliser to soil that is

unsuitable for road construction, resulting

in a new, viable road construction material.

Compacting and curing the mix results in a

bound material with signifi cant strength.

Th is approach can prove extremely

economical, because it has the potential

to elevate sub-standard, in-situ soil to

levels that comply with the requirements

of a specifi c application. Strengthening

the lower layers of a pavement also creates

possible savings in the upper layers.

AfriSam’s Roadstab Cement, which

has been researched, developed and tested

for the past three years, is a composite

road-construction stabilising cement

specially formulated to improve the en-

gineering properties of soil by reducing

plasticity and enhancing the strength and

durability of road-base materials.

“Th e product indeed achieves superior

stability across a broad range of road

material types, even with soils with a

high plasticity index (PI), and off ers civil

engineers an excellent alternative for road

design,” says Mike McDonald, AfriSam

product manager.

PRIMARY REQUIREMENTSTh e binder composition of AfriSam’s

Roadstab Cement fulfi ls the three primary

requirements of a stabilising agent: reducing

the plasticity of soil; ensuring durability,

stability and strength; and working across

a range of diff erent road materials. It also

allows for longer setting times, as can be

found in the 32.5N strength class, making

it ideally suited for applications such as soil

stabilisation where longer time is needed to

place and compact the material.

“Stabilisation projects are almost al-

ways site-specifi c,” McDonald comments.

“Developing a solution requires standard

test methods, fundamental analysis and

design procedures. Th e selection of a

cement type and quantity for a project

should be based on laboratory tests of the

granular materials to be stabilised.

“In one of the tests, diff erent cements

are evaluated to assess their ability to

reduce the pH of the material to be stabi-

lised. Th is test gives a good initial indica-

tion of the quantity of cement required

to modify the soil characteristics to

render it suitable for road construction.

Laboratory testing provides performance

information about various cements, and

this information is used to determine a

cost-eff ective solution.”

APPLICATION OF AFRISAM ROADSTAB CEMENTTh e distribution of cement can be accom-

plished either by bag or bulk spreading,

and the uniformity of stabiliser applica-

tion must be verifi ed. Compaction should

start immediately after fi nal mixing and

should be completed within the working

time of the stabiliser. Th e working time,

defi ned as the time between placing and

compaction of the stabilised layer, is in-

fl uenced by the cement type, soil type and

ambient conditions.

Curing is necessary to ensure that

the required strength is achieved, that

adequate water is available for hydration

New road stabilisation productdelivers outstanding results in latest tests


and that drying shrinkage is limited at the

early stages. Th e stabilised layer is cured

for three to seven days after construction

to allow the layer to harden before subse-

quent layers are placed.

Curing is carried out by maintaining

the surface in a moist condition with light

sprinkling and rolling when necessary,

and sealing the compacted layer with a

bituminous prime coat.

“Th e selection of the cement type

infl uences the working time,” explains

McDonald. “Cement starts hydrating as

soon as it comes into contact with moisture.

If most of the hydration has occurred by the

time the material is compacted, the chem-

ical bonds that have been formed between

the cement and the soil will be broken down

by the compaction process and further

chemical bonding will be limited.

“Th is limitation may result in lower

in-situ strength of the stabilised layers,

and we recommend that 32.5N strength

class cement, with a slower rate of

strength gain, is used. Roadstab Cement

eff ectively meets these criteria.”

ENTIRE CEMENT PRODUCT PORTFOLIO REVISEDTh e release of Roadstab Cement follows

AfriSam’s recent across-the-board revi-

sion of its entire cement product portfolio.

Th e revised products are targeted at

specifi c end-users and have been devised

to achieve the most eff ective solutions for

their applications.

“Th e upgrade of our cement product

range forms part of our strategic vision

and positioning as a company committed

to sustainable innovation,” says Stephan

Olivier, chief executive offi cer of AfriSam.

A pace-setter in the fi eld of sustain-

ability, AfriSam invests signifi cantly in

product development, the upgrading of

plant and equipment, and the revision of

manufacturing processes to reduce the

impact of its business operations on the

environment. Making use of innovative

technologies has enabled the company to

reduce its carbon dioxide content per ton

of cement produced by more than 34%

over the last twenty years.

INFO

Victor Bouguenon

AfriSam

011 670 5520

[email protected]

www.afrisam.com

Use of Roadstab Cement in tests on selected roads

AfriSam’s innovative new product has been designed specifically for road stabilisation applications

BAG INFORMATION

32.5N A cement strength of 32.5 MPa will be achieved under standard test conditions.

LOA number Letter of authority number indicating that AfriSam is legally authorised to sell cement. It is required by law to display the LOA number on all cement bags and documents of sale.

SABS mark Shows compliance with the standards as set out in the SANS EN 197-1&2 specifications. Although no longer required, it is still displayed on all AfriSam cement bags.

e-mark A quantity control scheme within the legal prescriptions of the Trade Metrology Act and Regulations which ensures that consumers receive the quantity declared on the pre-packed bag.


O P I N I O N

Dr Werner Heyns

Senior Transport Planner

Arup

[email protected]

Gauteng e-tolling: it’s time, or is it?I ATTENDED the SAICE Civil Talk on

25 June where the Gauteng e-tolling issue

was discussed. I applaud the panel pre-

senting well-balanced for-and-against ar-

guments, as well as much needed history

and context. Leaving the venue, it dawned

on me just how divided opinion is.

E-tolling is not simply about demand

management. It cuts across a number of

complex transport planning, economic,

land use and traffi c engineering issues

that require a multi-disciplinary approach

for eff ective implementation. Neither is it

an off -the-shelf add-on to the transport

system. It is part of the wider transport

system and relies on other components

in the system to work eff ectively. I doubt

whether detailed consideration was given

to whether the supporting components

in the wider transport system are indeed

capable of supporting and or mitigating

the consequences of e-tolling. Th e wider

transport system must operate as a well-

oiled machine before e-tolling should be

considered.

Despite road pricing being an attrac-

tive policy tool, most attempts around the

world to introduce economic incentives

of this type in the transport sector have

failed, not due to technical diffi culties, but

rather because the public does not support

it. International evidence suggests that

road pricing is usually the fi nal tool in the

tool kit being reached for by the policy-

maker, as it is an extremely controversial

and blunt economic tool to manage traffi c

congestion and change road user behav-

iour. Only when the integration of con-

ventional Transport Supply Management

(TSM), Land Use Management (LUM) and

“softer” Transport Demand Management

(TDM) measures have failed, one considers

“hard” TDM measures, including tolling.

And even then the road pricing measure

should satisfy a number of operational

requirements before it is publicly palatable.

Th e requirements are grouped as follows:

■ From the road user’s point of view it

requires user-friendliness (simplicity),

transparency, anonymity (protection

from invasion of privacy) and pre- and

post-payment options for charging.

■ From the road authority’s point of view it

must pass the revenue–cost test, make

provision for occasional visitors, be

reliable, be secure and enforced, be

fl exible to allow variable pricing, and

fi nally enhance economic effi ciency

(the pricing system should be as close

as possible to the external cost arising

from the road use).

■ From the public/society’s point of view it

requires fairness and the availability

of alternatives, tolerance of a culture

of non-compliance, gradual introduc-

tion (a transitional phase) perhaps in

the form of a pilot study, provision for

mixed traffi c, passing the benefi t–cost

test, and fi nally, revenue recycling (the

dispositioning of the revenues collected

from the toll).

So, are we really meeting all the re-

quirements? Are circumstances such

that we are in a position to implement

e-tolling with the knowledge that the

wider transport system supports the

consequences of e-tolling? I think not. It

goes without saying that accessibility to

public transport and revenue recycling is

a prerequisite to introducing any type of

tolling system. Th e travelling public will

require a viable alternative once tolled

off the road, and the knowledge that

the revenue collected will be spent on

public transport and the infrastructure

they use. Th e problems associated with

introducing e-tolling and overcoming

the public and political implementation

problems are extremely hard to solve.

It is an intrinsically unpopular policy,

which will always meet opposition from

diff erent angles. Implementation will

therefore depend on striking a balance

between the determinants and obstacles

to implementation, and meeting a number

of requirements.

We therefore have some ground to

cover before we are in a position to intro-

duce e-tolling in Gauteng. E-tolling has its

rightful place in the TDM tool-kit, but it

is not the right time for it just yet. So what

is to be done about this situation? Maybe

the way forward is to:

■ Start with a pilot study – human behav-

iour does not change overnight. For

public acceptability and softening of

the full impact of the system, gradual

introduction may be necessary at

fi rst, as examples from Singapore, the

Netherlands, Norway and the United

States show. An incremental approach

to full e-toll roll-out is advisable to

increase the public appetite to tolling.

At the very least, a short section of the

GFIP road network should be piloted

to evaluate the impacts of the system

and allow for fi ne-tuning prior to full

roll-out.

■ Improve public transport – in Gauteng it is

not so much a problem of not having

public transport services, it is one of

not having an all-round organised,

integrated, safe, reliable, accessible and

user-friendly system. A step change is

needed in customer focus by all public

transport operators. Service improve-

ments are paramount, as is customer

information.

■ Apply a higher fuel levy in Gauteng in the

interim to fund the e-toll loans. Since

fuel consumption is proportional to

distance, given a certain engine class,

a fuel tax is perhaps the best proxy

for the amount of road usage. By uni-

formly taxing usage independently of

time and place, the fuel tax is unable

to diff erentiate between peak and off -

peak periods and usage in congested

and uncongested areas. Th e fuel levy

will do nothing to reduce congestion,

but it will generate signifi cant funding

to service loans until a well-considered

and permanent package of measures is

in place.


■ Introduce high occupancy vehicle (HOV) lanes

on the GFIP road network to encourage

a change in road user driving habits and

behaviour. Not only will we see a slight

reduction in traffi c congestion, we

will start infl uencing driver behaviour

incrementally to a stage where mode

shift to public transport becomes more

acceptable to the die-hard motorist.

■ Introduce a traffi c congestion management

plan (TCMP) – the introduction of a

TCMP will ensure that traffi c conges-

tion will be dealt with as part of a

holistic transport planning systems

approach. It will focus sectoral (de-

partmental) integration and alignment

more directly. Such a plan will ensure

that an appropriate package of meas-

ures is implemented in the right place

at the right time, with appropriate levels

of public transport, funding, informa-

tion provision and support, allowing

much greater public acceptability and

political appetite.

■ Introduce revenue recycling – whether as

part of the Gauteng e-tolling proposal

as a standalone scheme, or as part of a

TCMP, the disposition of the revenues

collected from e-tolling is crucial to its

success and acceptability, and should

be explicitly explained to the public.

Earmarking the proceeds would serve

as an important prerequisite to the ac-

tual implementation of marginal cost

pricing in the road sector. Key areas

of application of the proceeds should

be: funding and maintaining the e-

tolling system, road maintenance, and

improving and/or providing public

transport. Unless toll revenues are

ploughed back into the transport

system, policy-makers face an uphill

battle in convincing the public of the

merits of the proposal.

Th e approach outlined above suggests

an incremental approach to dealing with

traffi c congestion. As policy-makers we

must adopt a transport planning systems

approach to addressing traffi c congestion,

which goes beyond the introduction of

a single TDM measure. We desperately

need a package of measures to ensure

the acceptability of the scheme, which

in my view will be best addressed by

the outcomes of a Traffi c Congestion

Management Plan for Gauteng (Heyns

and Schoeman 2008). In the interim, ap-

plying a higher fuel levy in Gauteng may

be the most appropriate tool to service

e-toll loans. Th e introduction of HOV

lanes will be a good starting point to

encourage a change in road users’ driving

habits and behaviour in the run-up to full

implementation. As policy-makers our

approach to decision-making should re-

fl ect striking a balance between the many

confl icting and/or supporting disciplines

and stakeholders in transport to secure

public buy-in. Th e devil is in the detail; no

obstacle before us is insurmountable.

REFERENCEHeyns, W & Schoeman, C 2008. Positioning a Traffi c Congestion Management Plan within South African planning. 14th International Urban Transport Conference. Witpress: Southampton.

NOTEI take full responsibility for any of the views expressed in this article.

E N V I R O N M E N T A L E N G I N E E R I N G

In June 2006 the Department of Water Affairs, together with Rand

Water, started a programme to remediate the Hartbeespoort Dam,

which had over time become clogged by hyacinths, and polluted

with litter, debris and extensive algae growth during the summer months. The programme, known as Harties,

metsi a me (my water), has, since 2008, consistently created work

for between 80 and 140 workers who have so far removed at least

64 000 m3 of hyacinths, 2 400 tons of litter and debris, and 31 000 million

litres of algae soup, in addition to assisting with restructuring the

food web, removing 190 tons of unwanted fi sh species, rehabilitating

the shorelines (8 530 m2), and establishing fl oating wetlands of

4 800 m2. The immediate aim of the programme has been to restore the ecological balance

towards higher aquatic biodiversity in and around this strategically

positioned dam, which irrigates more than 15 thousand hectares of intensively farmed land in beautiful surroundings, and which is also a haven for anglers and water sport enthusiasts from all over Gauteng. The long-term aim is for full-scale

implementation of the programme at the Hartbeespoort Dam, and

eventual extension to other dams and catchments throughout South Africa. On the following pages we

look at some aspects of this inspiring project. For ease of reference we list the various articles with their

corresponding page numbers

Brief history of the dam of dreams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10Overview of the programme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15Biomass removal and management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25Food web restructuring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31Food web and integrated biomonitoring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35Shoreline remediation and fl oating wetlands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38Sediment removal and management. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42Reduction of the external nutrient load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48Information, Communication and Knowledge Centre. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51Future challenges and prospects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53

Hartbeespoort Dam Integrated Biological Remediation Programme

NOTEFor further information about any of the articles on the following pages, please contact the programme offi ce at Kurperoord (012 207 9911/2 or [email protected]). Alternatively contact Petrus Venter, Water Affairs Programme Leader of the Hartbeespoort Dam Integrated Biological Remediation Programme ([email protected]).


Managing the algae soup

Clearing hyacinths from the Hartbeespoort Dam


H A R T B E E S P O O R T D A M R E M E D I A T I O N

Brief history of the dam of dreamsVISION AND PERSEVERANCEGeneral Hendrik Schoeman carved his

place in history through the role he played

in the First Anglo Boer War, but more so

because of the controversy surrounding

his actions during the Second Anglo

Boer War. His violent death in May 1902,

caused by the explosion of a lyddite bomb

in an ashtray in his house in Pretoria,

sparked speculation that his death was

not an accident.

A lesser known titbit about the gen-

eral is the vision he had of a dam in the

Crocodile River that would serve as a

focal point for agricultural, industrial and

residential development. In fact, right up

to the time the war disrupted life in the

(then) Transvaal, General Schoeman did

his utmost to convince the government to

invest in such a project.

So strong were his own convictions

that he invested £10 000 in building a dam

near where the railway bridge in Meerhof

is today. Th e dam, which he named Sophia

after his wife, comprised a nine metre

high stone and concrete structure, built by

the engineer Emil Kunst. When the war

broke out, the general’s plans to interest

the government in building a bigger dam

went up in smoke. Not to be deterred,

Schoeman’s son, Johan Hendrik, revisited

the idea, and after the war put three thou-

sand hectares of farmland under irrigation

from the Sophia Dam. Th is proved the

viability of such a scheme, and in 1905 the

Swedish engineer August Karlson also

recommended that the government build a

dam. Th is fi nally prompted the Transvaal

Department of Water Aff airs to investigate

the proposition.

In 1909 the Sophia Dam was washed

away in a fl ood, and with the establish-

ment of the Union in 1910, plans for a

dam in the Poort were postponed. When

the Hartbeespoort Irrigation Scheme

Act passed through Parliament in 1915,

it seemed like Schoeman’s wish would

fi nally come true, but it was not to be, as

the First World War, and many legal and

technical diffi culties, delayed the start of

construction.

Not everyone was happy with the

government’s plans to expropriate land for

the storage area of the dam. Tough negotia-

tions ensued and the Schoeman, Scrooby

and Pretorius families refused to sell and

were only prepared to grant the govern-

ment ‘servitude of storage’. Th e issue turned

in court, the government lost and the

families retained their land, including the

submerged areas. Johan Schoeman obtained

power of attorney from his family and in the

end sold most of the submerged areas to the

government anyway. Th e land, described

by one evaluator as “some of the fi nest ir-

rigation land in the country”, was valued at

£85 000, but with the post-war economy in

depression, the state could off er Schoeman

only £35 000. To account for the diff erence,

Schoeman was off ered the retention of all

the commercial and riparian rights on the

water and foreshore. He would later estab-

lish the towns Schoemansville, Meerhof

and Kosmos on the shores of the dam.

Schoeman also ceded some of the boating

and fi shing rights to buyers of stands in

these areas and registered the commercial

rights on properties in Schoemansville and

Meerhof. When Schoeman retired in the

1950s, he sold these rights.

However, having resolved the property

issues in the dam basin did not mean the

end of the government’s legal problems

regarding the construction of the dam.

On the northern side of the Poort lay a

piece of ground that belonged to an E van

Maarseveen. Th e cantankerous Dutchman

wouldn’t succumb to the government’s

intimidation, no matter how much they

pressurised him for a small portion of land

needed for infrastructure (where Mount

Amanzi and Johann Rissik Estates are now

situated). It proved a serious hick-up, with

no access to the Poort from the south, since

the present road was only constructed much

later and the then existing road ran through

the Moot. Access therefore had to come

from the north over Van Maarseveen’s land.

After a long and costly dispute the matter

was eventually settled during an arbitration

case in September 1918, which gave govern-

ment the expropriation rights that it needed

and £500 to Van Maarseveen.

Th e construction of the dam eventu-

ally gained momentum in 1918, with

roads being diverted and engineering

plans compiled, and a logistics chain

being put in place to supply material to

the Poort by means of coco-pans via the

railway station at Brits.

With the Great War at an end, soldiers

were also returning from the front, and

the country found itself in the grip of a

recession, with widespread unemploy-

ment. Th e suff ering was compounded by

the Spanish Flu epidemic which caused

140 000 deaths in South Africa and more

than 50 million worldwide, as well as by

labour unrest and violent strikes on the

Witwatersrand mines. Poverty was rife,


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and the public were getting impatient

with the slow rate of progress at the dam

construction site, which was supposed to

be an employment-creating project.

Work on the dam commenced in all

earnest in 1920, but the project suff ered a

major setback when the coff erdams were

washed away during the fl oods of March

1921. Th e engineer resigned, and report-

edly many labourers also abandoned the

site. Dealing with these devastating set-

backs required major reorganisation and

the appointment of a new engineer, FW

Scott, to take the project to its completion.

THE ENGINEER WHO SAVED THE DAMTh e moment Scott came on board he

revised the plans and suggested that the

enormous gravity wall be changed to an

arched wall, which would be supported

against the rock faces on both sides of the

Poort. However, since the barrage had

already been placed, he could not build

it in the most ideal position. Th e com-

promise was thus a position where the

western side-support reached only half

Photo credit: Photostorm

Construction of the Hartbeespoort Dam in the early 1920s was done labour intensively to create employmentPhoto credit: Jack Seale


the height of the wall. Th e remaining sup-

port Scott obtained from broadening the

wall on that side, spanning the bridge that

stretched over the spillway and using the

weight of the ‘Victory Arch’.

Th e Hartbeespoort Environment

Heritage Association, in an unattributed

report on the history of the dam, states

that things progressed smoothly after

Scott's appointment. Th e coff erdams were

reinforced in April 1921 and on 24 May

the river was ‘tamed’ for the pouring of

concrete into the new foundations of the

wall on 26 July. On 7 September, the wall

stood two metres high, and in 1922 the

structure handled fl oodwater with ease.

At the height of the construction, to-

wards the end of 1924, 2 500 workmen and

19 engineers were directly employed in the

race to complete the Hartbeespoort Dam

by the end of that year, as reported in the

Irrigation Magazine of 15 June 1924.

Despite the scope of the project and the

many unskilled labourers involved, only

four fatal accidents were reported during

the entire period of hasty construction

– one lost his life at the tunnel while the

other three fell from the unfi nished wall

during diff erent periods of construction.

Th e completed Hartbeespoort Dam,

which was a major engineering feat

at the time, became, and still is, one

of the most distinctive features in the

Magaliesberg region.

HYDROELECTRIC POWER A thoroughly modern innovation incor-

porated in the wall of the dam must be

the small hydroelectric power plant. Th is

station operated for about 40 years, sup-

plying all the electricity for the pumps,

surrounding residences and the offi ces

of the Department of Water Aff airs. Th e

machinery arrived in March 1924 and on

13 June the plant replaced a 45 kW paraffi n

oil generator. It appears as if the plant sus-

tained lightning damage in December 1924.

Rumours did the rounds that the plant

had been decommissioned, but Ms Joanita

Norman remembers it diff erently. “My fa-

ther, an electrician, ran the plant from 1922

until he retired in 1949. He kept a diary of

everything concerning the plant, but never

mentioned the lightning strike of 1924.” Mr

Redelinghuys, the electrician, did make ref-

erence to another event though. “In 1944 we

had a fl ood and my father and his assistant

realised that the plant would bear the brunt.

Th ey did their best to save the equipment,

but in the end had to fl ee for their lives. I

still remember how Dad later dried the me-

tres in my mom’s oven.”

In the early 1960s ESCOM (Eskom

today) started supplying power to the

Department of Water Aff airs. Two local

businessmen, Jack Seale from the Snake

Park and Sydney Swarts from the then Lake

Hotel, made the Department an off er for

the rental of the plant, since in those years

private businesses and residences were

responsible for their own power supply.

Th e Department chose not to enter into an

agreement, and not long after ESCOM ex-

tended its services to the whole of the town.

Th e plant was decommissioned, but the

viability of once again generating electricity

from there is currently under discussion.

“Th e plant could be used to power the

equipment needed to pump sediments,

and it would possibly be more economical

to generate this power here,” said Petrus

Venter, Water Aff airs Programme Leader

of the Hartbeespoort Dam Integrated

Biological Remediation Programme, when

asked about the future of the power plant.

Th e plant would require refurbishment,

but when one weighs up the cost of Eskom

power and the new plant’s capability to sell

excess capacity to Eskom (the so-called

REFIT – Renewable Energy Feed In –

option), it could just be a viable option.

Text: Willie Meyer, Marlene McKay

Photos: supplied by Jack Seale

IMPRESSIVE SPECIFICATIONS

The specifications of the dam were impressive from the onset, with water released at the bottom of the wall via two sluices. This water then flows down the eastern and western canals, which are 78 km and 58 km long respectively. These impressive canals each handle 5.7 cumecs (5 700 litres per second), and the eastern canal runs along a rock face with its own sluice. This is to release water via the waterfall into the river and the ‘old furrows’. Much later, in 1970, ten steel radial crown sluices were added on top of the overflow, which increased the water level by 2.44 metres and the volume from 160 million cubic metres to 205 million cubic metres. As it stands today, water evaporates from the dam at approximately 18.9 million cubic metres per annum.

The completed Hartbeespoort Dam 1923/1924Photo credit: Jack Seale

Beautifully positioned, the Hartbeespoort Dam is one of the most distinctive features in the Magaliesberg regionPhoto credit: Photostorm

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BACKGROUNDSince the late 1960s the Hartbeespoort

Dam (HBPD) has become increasingly

eutrophic. In the mid-1970s the dam

reached a hypertrophic state due to

severe algae growth in summer months.

These blue-green algae blooms pose

a high risk to human health, and have

a detrimental impact on recreational

activities and the socioeconomic poten-

tial in the area. Secondary to the algae

blooms has been the prolonged growth

of hyacinths in the dam and upper

catchment over the last 30 years. Rapid

urbanisation, associated with increased

runoff, erosion, sedimentation and solid

waste entering the dam annually is a

growing threat. If this problem is not

addressed appropriately, it will result in

a further decline in the local tourism

industry, as well as negatively impact

economic growth and development in

the North West Province with regard to

agriculture, mining, industry, recreation

and entire aquatic ecosystems.

Since 2001 the Department of

Water Aff airs (DWA), the North West

Department of Agriculture, Conservation

and Environment (NWDACE), and local

residents have joined forces to fi nd the

most appropriate short- and long-term

solutions. Th is close collaboration, and

the inclusion of the Municipality of

Madibeng and the HBPD Water Action

Group (HWAG), resulted in a specialist

study undertaken during 2003/4. Th is

Overview of the programme Close-up of biomass accumulation at the dam wall

Crocodile River: litter, debris and hyacinths


study resulted in the NW Environmental

Series 5 Hartbeespoort Dam Remediation

Plan being published in 2005 by the

NWDACE. Th e Minister of Water

Aff airs at the time, Ms Buyelwa Sonjica,

launched the Programme in 2005

during her visit to the dam, and in the

spirit of cooperative governance re-

quired the DWA to take the lead with

the proposed integrated approach.

Rand Water, as the biggest Water

Services Provider to the upper catch-

ment of the HBPD, was appointment

as Implementing Agent. The inception

phase commenced in July 2006. The

social commitment from Rand Water to

waive management costs has played a

determining role in unlocking this com-

prehensive programme. To date this ac-

counts for a contribution of more than

R9 million over a five-year period. This

significant contribution has been a sub-

stantial building block in the develop-

ment and growth of the Hartbeespoort

Dam Integrated Biological Remediation

Programme (HDRP).

To ensure that the DWA meets its

objective of achieving a desired state

for the ever increasing trophic levels

of the HBPD, the HDRP developed

interdependent modules / focus areas

that are essential components linked

to the overall improvement of aquatic

health. The HDRP consists of activities

in and around the dam basin, and better

enforcement of improved land manage-

ment practices in the upper catchment

area. For the quickest and best results,

critical deliverables require the imple-

mentation of activities in parallel. This

needs to be aligned with certain legal/

policy processes which have, and still

will, add additional timing and budget

challenges to the programme.

Th e Director General of the DWA

identifi ed the HDRP as a national priority,

and in May 2007 his offi ce gave instruction

for the immediate fast-tracking of the entire

programme to facilitate the enhancement of

economic growth in the region and poten-

tial development in North West Province.

Th is directive to fast-track the programme

resulted in a tenfold increase of the pro-

gramme scope in terms of the extent,

scheduling and budget. Due to the com-

plexity of the biological systems and their

interdependent nature, on-going evaluation

is needed to ensure optimum cost benefi t.

In this dynamic environment, with its inter-

related water systems and environmental

conditions, special emphasis also has to

be placed on the diff erent components of

monitoring, tracking and reporting. Of

further importance is to keep stakeholders

informed and aligned to ensure their con-

tinued support and cooperation.

For the success of the programme

it was also required that all related

components and aspects be drawn into

the management of the programme. The

fisheries and food web restructuring,

mandated by the NWDACE, were the

first to be incorporated, followed by the

development and implementation of the

Resource Management Plan (with local

rules), later followed by activities such

as biomass-, litter- and debris removal.

This approach would prevent bottle-

necks and enable a speedy development

and roll-out of the HDRP.

THE SOLUTIONA three-pronged approach was adopted

to address the present state of the HBPD,

which needs to be managed on an on-

going basis:

■ The application of symptomatic

treatment, restorative action and the

creation of a biological, self-cleaning,

balanced ecosystem in the dam basin.

This entails removing the bulk of the

imbalances that are in exponential

growth (excessive external and in-

ternal nutrient loads with associated

sediments, algae, hyacinths, domi-

nating undesired fish species, litter

and debris).

■ Restoring and protecting the natural

filters (wetlands and riverbanks)

Close-up of litter, debris, algae and hyacinths


in the immediate catchment of the

HBPD to ensure that incoming pol-

luted water is filtered.

■ Regulating water use in the greater

HBPD catchment, enforcing regulations

regarding unlawful water use, and in-

tegrating the interdepartmental eff orts

across the catchment.

THE GUIDING PRINCIPLES OF THE PROGRAMME

■ Advocating anti-desertifi cation

and enhancing biodiversity for

ecological goods and services

■ A holistic approach to ensure bal-

ance and optimum conditions

within the overall programme and

between different components

■ Optimising waste minimisation

and re-use: ensuring reduction

of waste generation at source,

separation and re-use of water

and waste at source through re-

use and recycling techniques

■ Resource optimisation through

protection and remediation

■ Enhancing economic growth

and development through job

creation during remediation ac-

tivities, and thereafter ensuring

optimal local involvement, work

creation and reaching out to local

underprivileged communities

■ Knowledge transfer to, and em-

powerment of, designated groups

■ Improved water use effi ciency, in-

cluding optimising water use,

maximising water re-use, minimising

waste, and extending the use of water to

ensure concurrent multiple water usage

■ Frequent updating of execution

plans and optimum alignment with

Best Environmental Option (BEO)

■ Comprehensive and effective

stakeholder communication,

awareness and education

■ Ensuring continual improvement

through research and development.

Phase I of the HDRP consisted of the

development of a generic integrated

framework, and pilot implementa-

tion and testing of the feasibility, and

the outcomes thereof. The relatively

quick positive results experienced in

the overall condition of the dam, spe-

cifically with regard to the biological

succession, are considered sufficient to

warrant extension and duplication into

the second phase.

As far as Phase II is concerned, the

full-scale implementation and the ability

to extend to other dams and catchments

have been developed. Depending on the

availability of funds, the implementation

period for Phase II is from April 2012

to March 2017. To ensure consistency

Resource Management Plan zoning of surface use activities

BASIC DATA ON THE HARTBEESPOORT DAM

Catchment area 4 112 km2

Dam surface area full supply level* 2 060 ha*Storage volume (2008) to full supply level* 198 x 106 m3 (~82% of initial volume)Average depth 9.7 mNatural average annual runoff 164 x 106 m3/aCombined average annual runoff (2007) ~310 x 106 m3

(natural runoff + return water)* Full supply level – 1 162.34 m asl


during the continuation and extension

of the HDRP, alignment and collabora-

tion with other government departments

was included in the business plan, e.g.

other social upliftment programmes

like Working for Water, Working for

Wetlands, Public Works Programmes,

etc. Th ese are identifi ed as the 49 key

focus areas and six sub-programmes in

the HDRP structure (see Table 1).

Th e remediation programme is the

fi rst blueprint to concurrently implement

remediation and protection of diversity,

as embedded within the concept of the

reserve and aquatic ecosystems covered

in section 16 of the National Water Act

(Act 73 of 1998). Th is requires a strong

component of research and development

that started in Phase I of the programme

and will continue in Phase II.

A RESEARCH AND ENGINEERING CHALLENGEDealing with natural (lakes, wetlands,

etc) or artifi cially made (dams, reservoirs,

ponds, etc) stagnant water bodies requires

the knowledge and understanding of

their functioning, abiotic components

(such as mixing, stratifi cation, hydrology,

climate impacts) or biotic components

(such as local-specifi c food web, life cycles

of species, and the behaviour under a

variety of conditions occurring in the area,

signifi cance of biodiversity, the role of

particular living organisms in food chains,

and response to the external impacts, etc).

It is important to note that even a

stagnant water body is a living organism

that undergoes short-term (seasonal)

and long-term (human impact) changes

caused by a number of complex interac-

tions of chemical, physical and biological

factors. Th ese interactions follow the

general natural regulations, but occur in

local-specifi c conditions that should be

explored, recognised and applied when

tailoring solutions for successful manage-

ment, or when remediating a eutrophic

dam, as in the case of the Hartbeespoort

Dam. Th ere is no doubt that the collabo-

ration between scientifi c, research and

engineering capacities is a precondition

for the successful management and reme-

diation of eutrophic water bodies.

Th e Hartbeespoort Dam Integrated

Biological Remediation Programme

(HDRP), also known as the Harties,

metsi a me programme, is an excellent

Table 1: Hartbeespoort Dam Integrated Biological Remediation Programme

It is important to note that even

a stagnant water body is a

living organism that undergoes

short-term (seasonal) and long-

term (human impact) changes

caused by a number of complex

interactions of chemical,

physical and biological factors.

These interactions follow the

general natural regulations,

but occur in local-specifi c

conditions that should be

explored, recognised and

applied when tailoring solutions

for successful management, or

when remediating a eutrophic

dam, as in the case of the

Hartbeespoort Dam

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example of the importance of collabora-

tion between science and engineering in

solving environmental problems. Th is

project is a mixture of science focused

on environmental issues, research

focused on local-specifi c conditions,

and engineering that would develop

and implement tailored solutions.

Th e project comprises several stra-

tegic focus areas:

■ Biomanipulation and food

web restructuring

■ Harvesting of harmful biomass

and converting it to environ-

mentally valuable materials

■ Th e removal and recycling of debris

that fl oods in from the catchment

■ Reviving and restructuring

the dam shoreline and wet-

lands in the catchment area

■ Th e reduction of the internal

nutrient load through sediment

dredging and its benefi ciary uses

■ Th e reduction of the external nutrient

load, including improved catchment

management and the formation of a bar-

rier between the dam and the catchment

■ Public awareness and educa-

tion to encourage sustainable

environmental solutions.

Each of these tasks requires creativity,

whether in research or in engineering (or

both). It is a complex programme that re-

quires interaction between various scien-

tifi c disciplines and engineering branches.

Certainly there is no quick, easy and

cheap solution for the restoration of the

Hartbeespoort Dam – the problem has

been building for more than 85 years. Th e

remediation of the dam therefore com-

prises a series of planned and researched

environmental engineering eff orts both

in the dam basin and the catchment, and

can be summarised as follows:

External nutrient load reduction

■ Improvement of catchment management

■ Development of a barrier, and of

regulations concerning catch-

ment nutrient loads

■ Use of best available practices for

management of non-point sources

■ Development of methodology for catch-

ment nutrient release measurements

■ Streamlining of methodology for the

management of municipal and other

dams within the HBPD catchment

■ Streamlining of methodology

for stormwater management

within the HBPD catchment

Nutrient load and mass balance

■ River monitoring that respects the

complexity of the Crocodile River

catchment in terms of runoff and

nutrient release during storm events

■ Dam monitoring that respects

seasonal changes, dam opera-

tion, causes and responses

■ Research on the fate of nu-

trients within the dam

Biological and ecosystem changes

■ Research on algae growth and growth

rate under various conditions

■ Research on interactions

within the food web

■ Research related to ecosystem changes

caused by food web manipulation

■ Research on the aquatic fauna

health, including research on bioac-

cumulation and biomagnifi cation

Revival of shoreline and wetlands

■ Development of methodology for shore-

line revival and restructuring

■ Research on wetlands revival and reha-

bilitation within the catchment

■ Research on performance of fl oating

wetlands with regard to nutrient re-

moval and ecosystem changes

Biomass harvesting and transformation

■ Development of methodology and

equipment for biomass harvesting and

biomass processing

Sediment removal and management

■ Development of standards for river/

dam sediments and the improve-

ment of regulations for their hand-

ling, processing and disposal

■ Development of environmental

dredging methodology

■ Research on natural sediments

processing for various benefi ciary uses

■ Research on river water treat-

ment, as well as the treatment of

water separated from sediments

Dam and river modelling

■ Crocodile River hydraulics and hydro-

dynamics at inlet zone and river mouth

■ Methodology and models for

eutrophication processes in

HBPD-specifi c conditions.

Th e success of this project is scheduled

for future implementation to other similar

projects in the nationwide eff ort against

eutrophication. In addition, the fi ndings

and success of the programme would

certainly be well received and recognised

internationally, as has already happened

in Sweden, Finland and Serbia.

CAUSE AND EFFECTWater demand in the economic hub

of South Africa (Gauteng and its sur-

rounding areas) is provided by transfers

from the Tugela and Lesotho Highlands

water schemes to the Vaal Dam. Although

it is the smallest of the nine provinces,

covering only 1.4% of the land area of the

country, Gauteng contributes 33% to the

national economy, and a remarkable 10%

to the GDP of the entire African conti-

nent. To put matters further into perspec-

tive, the Crocodile (West) Marico Water

Management Area provides close to 30%

of the country’s economy. Th is economy is

maintained by water transfers from Rand

Water, which in turn represent more than

40% of their capacity.

Th e Gauteng province is essentially one

big city, with 97% of its population living

in urban centres. As the most densely

populated province it accommodates

some 9.6 million people (20.2% of the

total population). Th e northern part of

Gauteng, where 2.5 million people reside,

falls within the Crocodile (West) Marico

Water Management Area and drains to-

wards the Upper Crocodile (Hartbeespoort

Dam) and the Apies Pienaar River (where

another 2.5 million people reside). A wide

range / full spectrum of sanitation stand-

ards is applied in this area, although most

residences are serviced with waterborne

sewers, which is treated at technologi-

cally advanced nutrient removal plants

like the 420 Mℓ/d Northern Waste Water

Treatment Works (WWTW). Th e impacts

from informal settlements, sewer block-

ages, pump station overfl ows and storm-

water pollution result in the generation and

discharge of both grey and black water to

the water resources. If all the WWTWs in

the HBPD catchment (>720 Mℓ/day) fully

comply with effl uent standards of 1 mg/ℓ, a

total load of more than 280 tons of ortho-

phosphate and 3 000 tons of nitrogen per

annum, originating from waterborne sani-

tation, would still be discharged.

Since the implementation of the special

phosphate standard in 1985 (1 mg/ℓ), few

additional actions have been taken to deal

with the constant escalation of impacts

of increasing loads of nutrients from the

catchment. Th is has been going on for

almost 30 years with no action to curb the

internal load of the HBPD and the impacts


from the feeding rivers. Th e main rivers

fl owing to the HBPD are the Jukskei,

Hennops, Upper Crocodile and Magalies

Rivers – the Crocodile contributes 95%

of the total pollution load, of which 60%

originates from the Jukskei.

Even if the discharge from every waste

water treatment works in the area could

be stopped (seven WWTWs adding up to

>720 Mℓ/day), the eff ect on the eutrophic

state of the dam would take many years

to become evident, as the internal load of

phosphates trapped within the dam and

sediments amount to close on 2 000 tons.

Additional to this incoming load, the

internal load is constantly mobilised

by annual incoming stormwater and

fl ooding, and the continuous movement

by sediment-feeding fi sh (exotic carp

and barbel/catfi sh). Th ese mobilisations

of nutrients are curbed through the fol-

lowing dam basin programmes: (1) food

web restructuring, (2) biomass removal,

(3) establishment of biomass/shoreline

vegetation and fl oating wetlands, and

(4) proposed sediment removal.

LAND USE IMPACTSAny development ultimately impacts on

biodiversity and in many instances create

unsustainable environmental conditions.

Many of the anthropogenic impacts that

could be associated with development,

such as urbanisation, agriculture, mining

and industrialisation, contribute to global

warming, with desertifi cation becoming

the collective impact, resulting in more

and more of the world's land surface

turning into ‘deserts’. In all these cases

the common denominator is the eradica-

tion of natural vegetation and the associ-

ated destruction of the biodiversity. It is

estimated that 30 to 40% of the world’s

vegetation has disappeared over the last

150 to 200 years, i.e. since the industrial

revolution.

Th ese deserts are not necessarily hot,

dry sandy places, but are areas where

the soil has been modifi ed or mistreated

by humans to the extent that they

start taking on desert-like properties.

Deforestation in all its forms is a major

cause of desertifi cation, as not only are

nutrients lost when forests and woodlands

are removed, but the retention of water on

land is also drastically reduced. Th e entire

water cycle itself is disrupted. Th e initial

consequence is increased runoff from the

created hard surfaces, with associated

erosion. Due to the lack of vegetation

that acts as a ‘buff er’ to prolong the water

retention in the plants and soils, ground-

water recharge profi les are also changed

and less recharge occurs. Another likely

consequence is the long-term and irre-

versible decline in available water in the

region. A fundamental function of vege-

tation cover is to create microclimates

where shade cools soil down and reduces

evaporation, and where moisture is re-

tained and the soil fertilised, and where

water ingress is promoted and water

retention increased. Ultimately vegetation

infl uences air temperatures, and changes

weather patterns and rainfall.

Figure 1 illustrates the relationship

between desertifi cation and develop-

ment, with the associated destruction of

the natural environment and increased

impacts stemming from the various

land use activities. It is important that

integrated environmental management

focuses on the functionality of vegetation,

as it directly infl uences air temperatures,

evaporation and eventually sustains

biodiversity. Civilisation as seen from the

perspective of urbanisation, industrialisa-

tion and mining is a stimulus for deser-

tifi cation, as it promotes all the criteria

associated with this phenomenon, namely

hard surfaces, exposed soils, quick water

runoff / low retention, limited vegetation,

and extreme temperatures.

Most modern developments, often

involving extensive earth-moving op-

erations, result in ever-growing hard

Figure 1: Schematic presentation of the relationship between desertifi cation and development


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surfaces, which are not conducive to

stormwater retention, for example.

Conservation is diffi cult, and rehabilita-

tion is indeed rare and generally char-

acterised by a lack of species diversity,

poorly established vegetation and mainte-

nance practices that do not endorse sus-

tainability. Th e barren environments are

associated with extreme temperatures, in-

creased evaporation, reduction of ground-

water in perched aquifers, increased

runoff with concomitant erosion, gully

formation and silt load. It is thus evident

that desertifi cation reduces the ability of

land to support life, aff ecting wild species,

domestic animals, agricultural crops, and

people. Th e reduction in plant cover that

accompanies desertifi cation leads to ac-

celerated soil erosion by wind and water.

Reports suggest that South Africa loses

approximately 300 to 400 million tonnes

of topsoil every year.

Th e Hartbeespoort Dam Remediation

Programme has already greatly succeeded

in addressing eutrophication and some of

the impacts of desertifi cation. Given the

fact that the aff ected upstream catchment

area of the HBPD is developing at a stag-

gering rate, this programme is indeed of

national importance. Th e success of the

programme could prevent a serious set-

back in the development of this economic

hub. Seven dams in the Crocodile Marico

Water Management Area are already in

a similar hypertrophic state (of a total of

nine in SA), where excessive nutrients are

evident, and where the growth-limiting

factor is no longer the actual high nutrient

loads, but the physical and biological con-

ditions and drivers.

THE FUTURE OF THE PROGRAMME As mentioned above, the future of the

programme depends on external funding.

Th ree scenarios have been identifi ed:

■ Full-scale implementation and exten-

sion to other dams and catchments

■ Fast-tracking

■ On-going operation and maintenance.

In order to ensure that the current posi-

tive state of the dam is maintained, it

is of extreme importance that at least

the biomass management and food web

restructuring programmes continue.

Full-scale implementation will in-

clude the continuation of all identified

projects in order to alleviate adverse

effects, as well as preventing undesired

items from reaching the dam. This

will include a complete roll-out of the

programme as specified within this

business plan, including the long-term

projects, i.e. pre-impoundment and

litter trap. In addition it will include

providing assistance to the Department

of Water Affairs through the licensing

of the various water uses around the

Hartbeespoort Dam, as well as the

implementation of the Waste Discharge

Charge System (WDCS) initiative for

the entire catchment.

Should enough funding be available

to continue with fast-tracking, the pro-

grammes necessary to make the biggest

impact on the health and quality of the

Hartbeespoort Dam will be implemented,

which will include the litter trap and sedi-

ment management that will reduce the

internal load.

Petrus Venter

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INTRODUCTIONTh e eff ect of eutrophication in the

Hartbeespoort Dam manifests itself

through vast and excessive algae blooms,

as well as prolifi c growth of water hya-

cinths in all areas of the dam, although

concentrations occur along the shoreline

and in funnelled areas because of wind

action. Furthermore, the seeds of the

hyacinths also germinate from mid-July

along the shallow areas. Calculated from

the total incoming (external PO4 load

>420 tons/annum) and available nutri-

ents from the dam (internal PO4 load

>2 000 tons), the growth potential of the

photosynthesising biomass is much more

than the estimated 10 000 to 20 000 tons

of biomass which are produced over one

year from the 2 000 hectare full-level

surface area of the dam that is exposed

to the sun. Variably the Microcystis

blue-green algae and the exotic hyacinths

(category 1 aquatic weed) make up

most of the biomass. Biomass is man-

aged by harvesting and removing both

algae and hyacinths from the surface

of the dam. Th is does not only curb the

immediate growth, but also removes

nutrients already trapped in the biomass.

Th is approach results in an immediate

improvement of the visible and noxious

conditions in the dam.

ALGAEThe algae mass is not only unsightly, but

decaying material tends to emit a foul

odour, over and above producing potent

hepato-toxins (microcystine). Although

the algae grows over the entire surface

area of the dam, through wind action

it is concentrated along the northern

shoreline during summer months, and

in the direction of the more dominant

southerly wind during late autumn be-

fore the first temperature inversions in

the dam start.

Th e biggest concentration point is at

the dam wall, from where the concen-

trated algae clouds are removed with

Biomass removal and management

Magalies River, 2003 – different stages of algae blooms


the aid of fl oating pump stations. About

2 000 m of constructed fl oating curtains

(booms) are employed at three points

on the dam to control the movement of

algae, and facilitate concentration and

funnelling to the removal points, thereby

also alleviating hazardous conditions for

recreational users. Th is removal reduces

the sensory impact of the algae mass

during times of high concentration, as

well as the quantity of algae in the dam,

which helps to reduce the exponential

growth rate associated with the algae.

HYACINTHSHyacinths have a higher nuisance value in

terms of their coverage of the water surface

and the limitations their growth places

on recreational activities on the dam.

Th e invasive water plant can generally be

found on the surface of the dam, and a

vast quantity is transported into the dam

from the rivers feeding the dam. Similar

to the algae, the hyacinths, together with

organic and inorganic debris, also tend to

concentrate at the shore and the dam wall

areas. Hyacinths are removed mainly by

hand, and with great success at the 30 m

high radial sluices, and from all around the

dam, but particularly from areas that are

easily accessible from the shore.

Debris is also a nuisance as it is not

only unsightly, but has a detrimental

Algae boom refurbishment

A mass of hyacinths at the dam wall

Boom containing litter, debris and hyacinths during the December 2010 fl oods


impact on the greater environment, often

aff ecting bird- and other wildlife, as well

as posing a danger to recreational users

of the dam. Debris containment curtains

are constructed at the Crocodile River

inlet to the dam, and during periods

of normal rainfall most of the debris is

trapped and successfully removed.

To date the programme has removed

in excess of 44 280 m³ of hyacinths, at

least 1 625 m³ of litter and debris, and

pumped 16 million litres of algae soup.

The amount of hyacinths, litter and de-

bris prevalent in the dam is highly de-

pendent on environmental conditions,

such as rain or f looding. During 2008/9

the programme managed to remove

virtually all the hyacinth from the dam

during the winter months.

However, the high rainfall experienced

in the area during the summers of 2009/10

and 2010/11 meant that the dam level

remained at full capacity throughout the

winter of 2011. Th is high water level re-

sulted in previously exposed winter shore-

lines remaining underwater, and therefore

a signifi cant amount of hyacinth could not

be removed. In addition, the wind and rain

often hampered cleaning-up eff orts. Th ese

factors have now resulted in a vast amount

of hyacinth already being present in the

dam at the start of the August/September

2012 growth season.

Algae pumping at the dam wall

Hyacinths in a sluice gate (for removal)

Removal of hyacinths from a 30 m sluice gate at the dam wall

VERMICULTUREIn order to eff ectively deal with the

algae, hyacinths, litter and debris, the

Hartbeespoort Dam Integrated Biological

Remediation Programme (HDRP) has put

waste recycling and reuse principles in

place whereby organic matter is composted

through a process known as vermiculture

(earthworms). Th is method is simple, eff ec-

tive, convenient, noiseless; saves water, en-

ergy and landfi lls; and helps to recondition

degraded land. It is a value-added process

where the end products are sought after

compost and protein. Earthworms, or na-

ture’s friendly little helpers, have the ability

to convert organic waste into nutrient-rich

organic material, which also increases

water retention and soil moisture content

when applied to soil. In this programme

the vermicompost is used for shoreline

remediation, and in the construction of

fl oating wetlands. Worm husbandry pro-

duces premium soil and liquid products, as

well as protein.

Th e most common method of solid

waste disposal remains land spreading,

which results in polluted soil and surface/

groundwater. Vermiculture ensures that

none of this pollution occurs. Applying

vermicompost to aquaculture ponds re-

duces the input cost and ensures that no

harmful chemicals are introduced into the

system. Vermiculture technology is suited

to urban and rural communities and is a

sustainable way of dealing with waste.

Th e earthworm species Eisenia

Foetida is most commonly used for com-

posting of high organic content, but in the

HDRP indigenous African crawler species

are also used in combination (Eudrilus

Eugeniae; Eisenia Hortensis).

Th e use of earthworms in the biomass

composting process is an integral part in

reducing the total biomass, and in turn

physically reduces the sensory impact


Removing hyacinth around the dam

Vermiculture tunnel composting at the Hartbeespoort Dam

Vermiculture intensive units

Earthworm separation and compost sifting


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of eutrophication. Hyacinths have been

a problem on the Hartbeespoort Dam

since the mid-1970s, and by the late 70s

about 80% of the dam was covered by

the invasive plant. Th e Department of

Water Aff airs then decided to eradicate

the hyacinths through chemical spraying,

which continued until the HDRP placed

a moratorium on the chemical treat-

ment of hyacinths in 2007. Regrettably,

the chemical spraying and the rapid

development around the dam since the

1990s have contributed to the destruction

of up to 40 km of natural vegetation on

the shoreline around the dam.

Th rough the dam remediation pro-

gramme a nucleus has been established

at the Hartbeespoort Dam wall, also

housing the vermiculture hub, which

serves as a base for training, capacity

building and a skills and knowledge

transfer centre for earthworm breeding.

In addition to the valuable organic

fertiliser produced in the process, the

earthworm protein can be used as food

for chickens and fi sh.

Th e potential to produce protein

from organic ‘waste’ (like garden refuse),

is encouraging and a valuable option for

meeting the protein shortage in devel-

oping countries. Th is is a long-term objec-

tive for the future development of aqua-

culture and protein production through

vermiculure in parallel for the region.

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Food web restructuringINTRODUCTIONTh e food web manipulation pro-

gramme currently in operation in the

Hartbeespoort Dam aims to improve

the overall aquatic health of the dam by

facilitating improved aquatic ecosystem

diversity and services. An integrated bio-

monitoring protocol to manage aquatic

ecosystems for impoundments became

evident early in the programme and

serves as a comprehensive pilot initiative

which will guide similar future imple-

mentations in other dams.

Th e need to develop a Resource

Management Plan and to implement the

Local Rules (May 2009) was clear from

the commencement of the Harties metsi a

me programme. Th rough this, the entire

surface of the dam was zoned as a dedi-

cated fi shing area.

Food web restructuring entails the

restructuring of the fi sh population, as

well as the reconstruction and rehabilita-

tion of various aquatic habitats, in order

to achieve a balanced ecosystem. Th e

rehabilitation of aquatic fauna and fl ora

assemblages, with the aim to achieve effi -

cient nutrient and energy fl ow throughout

the food web in a dam does, however, not

come without its challenges.

Th e hypertrophic conditions of the

Hartbeespoort Dam favour certain un-

desirable fi sh species (mainly carp and

catfi sh), which have an adverse eff ect on

the ecological functioning of the dam

ecosystem.

Th ree fi sh species (coarse fi sh) were

identifi ed for removal as part of the food

web restructuring programme, due to

their dominance in the Hartbeespoort

Dam in terms of numbers and/or weight,

and their negative impact on the dam eco-

system. A fi sh removal permit was there-

fore issued by the North West Province

to Rand Water, and a fi shery contract was

awarded during 2007.

Th ese undesirable fi sh species are

responsible for the re-suspension of

nutrients into the water column due

to their benthic (bottom) feeding be-

haviour, when they churn the bottom

sediments and nutrients back into the

upper water layers of the dam in their

search of detritus and benthic organisms

as food source. Th e coarse fi sh species

also greatly rely on the zooplankton and

invertebrate population as food source

during various life stages, causing an inef-

fi cient energy and nutrient fl ow-through

in the natural food web. Catfi sh (Clarias

gariepinus), carp (Cyprinus carpio) and

canary kurper (Chetia fl aviventris) were

therefore selected for removal as part of

the food web restructuring programme,

due to their dominance in terms of num-

bers and weight, their negative impact

on the dam ecosystem, and the resulting

imbalance in the nutrient and energy fl ow

in the food web.

Th ese three fi sh species suppress other

fi sh species and aquatic biota in the dam

in terms of breeding success, recruitment

(survival of the young), feeding, habitat

and growth, thus resulting in competition

for the desirable fi sh species.

One hundred and ninety tons of

coarse fi sh were targeted for removal

during the fi rst period of the fi shery

(2008/2009). Th e removal of coarse fi sh

was set to continue until the fi sh eco-

logical studies indicated a shift in the

fi sh population, when a more desirable

table fi sh, the Mozambique tilapia (blou

kurper), would be harvested in continua-

tion with the coarse fi sh species.

Fishing quotas were, however, not met

by the fi shery contractor, and a parallel

fi shing operation was therefore initiated

to boost the fi sh removal programme.

Th is parallel fi shing operation has since


taken over the fi shery and is known as the

SMME Fish Harvesting and Scientifi c Fish

Removal Programme. Th is initiative makes

use of trained local fi shing rangers, who are

equipped with the necessary fi shing gear

to harvest the fi sh. A fi sh ecological survey

and study scheduled for later in 2012 will

provide information on the fi shery’s way

forward, i.e. shifts in the population, and

species to be targeted with quotas.

Parallel to this, shoreline remedia-

tion was developed, which also includes

fl oating wetlands. Th e remediated shore-

line, and more specifi cally the fl oating

wetlands, create a spawning and feeding

habitat, facilitating the establishment

and succession of all aquatic biota (i.e.

zooplankton, epi-biota, benthos, algae and

diatoms, aquatic macrophytes, and fi sh).

FOOD WEB MANIPULATIONTh e preferred indigenous fi sh species,

which were dominant in the dam as

recently as 25 to 30 years ago, include

yellow fi sh and the Mozambique tilapia

(blou kurper), especially due to their re-

creational value for angling and as table

fi sh (tilapia). Th e other smaller indige-

nous fi sh species (barbs), which may not

be of importance as angling species, are

of importance for the proper ecological

functioning of the dam (energy and nu-

trient fl ow in the food web). Yellow fi sh,

currently occurring in low numbers, is of

major importance in terms of the socio-

economics of the dam (angling), and as

a predator at the top of the food chain in

an artifi cial, man-made system, thereby

completing the energy and nutrient fl ow

in the food web.

Taking the above-mentioned in-

formation into consideration, a food

web manipulation and restructuring

programme was developed to achieve the

desired aquatic ecosystem, as depicted

in the sketch below. Following this is an

integrated biomonitoring programme

to consolidate the available and future

biological research data into a compre-

hensive document. Th is programme in-

cludes the fi sh, plankton and invertebrate

assemblages, incorporated and as associ-

ated with their habitats.

RESULTS Daily fi shery or fi sh removal

Fish removal occurs on a daily basis during

weekdays using scientifi cally predeter-

mined and prescribed fi shing methods,

which target the selected coarse fi sh spe-

cies. Th e types of fi shing gear prescribed

and used are selected particularly for the

Coarse fi sh species in the Hartbeespoort Dam


targeted species, with the desired results,

as is proved by a consistently low by-catch.

Fishery catches

Between February 2008 and June 2012,

190.4 tons of coarse fi sh were removed.

Th e sustainable annual yield for fi sh bio-

mass produced from the Hartbeespoort

Dam is estimated at 300 to 350 tons.

By removing fi sh within this quota, the

total fi sh stock in the dam is expected

to remain the same. No change in fi sh

behaviour is expected as a result of fi shery

activities, although a variation in size

distribution and species population, as

desired, is becoming evident. Fish move

around freely in the dam, and will con-

tinue to repopulate fi shed areas.

Scientifi cally selected gill nets

Training of the fi sh rangers

Recording the daily catch


Fishery team

Ideally a full fishery team for the

scale of work as proposed for the

Hartbeespoort Dam should consist

of around 32 personnel (four store

workers, 24 fishermen, and four skipper

managers). The four skipper managers

are needed to run the different fishing

operations independently (with rotation

of tasks). The fishery model has not

yet been fully implemented in terms of

staff, but has been up and running with

about half of the proposed personnel,

with relatively good outcomes. An in-

crease in the number of personnel will

further improve the fishery successes.

Fishing gear and operation

Th e following types of fi shing gear are

used/envisaged/implemented in accord-

ance with the fi shery model:

■ Scientifi cally selected gill nets are used

in the daily fi shery to catch the target

species.

■ Long lines are implemented to catch cat-

fi sh only, as ‘meat’ baits are used, such as

liver, which is not utilised by other species.

■ Electro-fishing is done with a

scientifically designed fish electro-

shocker, of which the design adheres

to international best practice. The

electro-fisher was designed not to

damage, harm, or kill, but to stun

fish, thereby allowing the operator

to selectively scoop target fish spe-

cies. The design and functioning

of the electro-fisher relies on the

principle of natural electron f low

from negative to positive, whereby

the fish are attracted to the positive

poles (anodes) of the electro-fisher

where it can be safely caught.

In addition to the above methods, a

purse seine net is also implemented.

The purse seine net is deployed from

a barge in the open water, which rules

out public interference (land owners

and anglers) and damage to the net (as

associated with land-based seine net-

ting). Targeted fish are removed from

the net on the water, and non-targeted

species are returned to the dam.

P Venter, Johan Koekemoer, Prof Gert Steyn

REFERENCESCJ Cilliers and CE van Ginkel,

Ecodynamics Report: Zooplankton of the Hartbeespoort Dam (2008)

JH Koekemoer, GJ Steyn, and WR Harding, Ecodynamics Report: in collaboration with DH Environmental: Fish Community Study of Hartbeespoort Dam, North West Province (2005)

JH Koekemoer and GJ Steyn, Ecodynamics Report: Fish Community Study for Hartbeespoort Dam 2008–2009 (2009)

J Kolding, A Database Package for Experimental Fishery Data from Passive Gears: An Introductory Manual. Department of Fisheries and Marine Biology, University of Bergen, High Technology Centre, N-5020, Bergen, Norway (1998)

GJ Steyn, JH Koekemoer, and WR Harding, Ecodynamics Presentation: in collaboration with DH Environmental: Fish Community Study of Hartbeespoort Dam, North West Province (2006)



Food web and integrated biomonitoringOVERVIEWTh is programme was developed to

quantify the collective improvements

in the Hartbeespoort Dam’s ecological

functioning after the implementation

of the Harties metse a me remediation

programme. Of particular interest, in

this instance, is the ecological response

to the food web restructuring initiative.

Th e integrated monitoring programme

consists of two components, namely

(1) Biomonitoring (monitoring of biotic

components) and (2) Integrated Water

Quality Monitoring. Monitoring is con-

ducted on a monthly basis at six represent-

ative localities in the Hartbeespoort Dam.

In biomonitoring, biotic components

are monitored to determine the increased

taxa (species diversity), changes in the

population size and composition, and

changes in species succession. Th e fol-

lowing components are covered:

■ Fish ecological studies are conducted to

determine certain aspects of the fi sh

population: species composition; spe-

cies dominance; fi shing gear effi cacy,

selectivity and selection for use in a

fi shery; biomass estimates and sustain-

able yield; presence of undesirable

species and their contribution to the

biomass; fi shery potential of certain

fi sh species (undesirable and desirable);

fi shery potential of certain sites on the

Hartbeespoort Dam; structure of the

fi sh population (population health and

length frequencies); progress of the

fi shery (to determine shifts in the fi sh

population after fi sh removal).

■ Open water phytoplankton monitoring is

a good indicator of any improvements

in the dam. Th e algae composition and

succession shifts in the population to-

wards desirable species are determined.

A trend towards reduced algae biomass,

reduction in microcystis biomass

(decrease in dominance during certain

periods), and increased clear water state

have been found since 2009.

■ Open water and fl oating wetlands zooplankton

monitoring. Th e zooplanton is part of

the food chain that can show changes

and responses within the system, and

monitoring has been done since 2008.

Th e fl oating wetlands create a habitat

that is similar to the littoral zone (close to

the shore), as many plant roots grow and

hang beneath the fl oating wetlands. Th e

fl oating wetlands create additional habitat

to that found in the limnetic zone.

■ Macro-invertebrate assessment aims to

determine whether changes occur in

the macro-invertebrate community

structure, including manipulation of

the fi sh population, lake shore habitat

rehabilitation, the introduction of

fl oating wetlands, as well as potential

water quality changes. Sampling is

conducted in three diff erent habitat

zones, namely that of the littoral zone,

benthic zone and fl oating wetlands.

■ Vegetation succession monitoring around

the dam to identify the movement to-

wards more desirable species.

■ Fisheries monitoring determines whether

targets are met and whether the fi shery

is on track. Data is used to make recom-

mendations to management regarding

the use of correct and prescribed gear,

the fi shing eff ort, fi shery plan, contin-

uous development of a fi shery protocol,

and fi shing areas.

■ The fi sh health assessment and suitability for

human consumption programme focuses

on the edible parts of the fi sh (muscle).

Toxin and microbiological analyses of

fi sh are done.

■ Aquatic health of the dam, which is divided

broadly into three categories: (1) macro-

scopic health assessment, (2) histological

evaluation and (3) the edibility of fi sh.

Since catfi sh and carp have been removed

to shift the fi sh community structure to

favour desirable fi sh species they have

been used for the fi sh health and edibility

part of the Resource Management Plan

for the Hartbeespoort Dam.


In Integrated Water Quality Monitoring,

data is used to analyse and explain certain

trends or changes in the dam with refer-

ence to the biotic components and overall

aquatic health.

OUTCOMES, RESULTS AND ACHIEVEMENTSA baseline data set for the Integrated

Biomonitoring has been recorded and a

three-year data set for comparison now

exists. Th e data sets of the two compo-

nents of the Integrated Biomonitoring (bi-

otic and water quality) will complement

each other, and with comparison and sta-

tistical analysis, will verify improvement

in the aquatic health of the Hartbeespoort

Dam. Th e Integrated Biomonitoring

Programme is a fi rst for dams in South

Africa and it is being developed for exten-

sion to other dams.

Th e results from the biomonitoring

shows an overall improvement in the dam,

with increased habitat and species diver-

sity and densities observed for certain

biota (some observations are seasonally

linked). In terms of the fi sh population a

reduction in carp was observed during

the last fi sh survey, and an increase in

Mozambique tilapia. Both zoo- and phy-

toplankton diversity and density have in-

creased, and aquatic vegetation succession

is also occurring during certain seasons.

Th e data is showing that the eco-

system of the Hartbeespoort Dam is gen-

erally becoming healthier, as an increase

in species diversity and densities has been

recorded. Increased diversity usually indi-

cates improved aquatic health.

Environmental conditions are also

noted at the time of sampling, such as

excessive algae at a site, which may hinder

sampling and species identifi cation, as well

as species colonisation. General weather

conditions and wind directions are also

noted. As a rule, monitoring is conducted

during sunny weather conditions.

Since the introduction of the shoreline

and food web reconstruction, clear water

states are more prevalent and prolonged,

with the dominant algae being the more

desirable long-stranded fi lamentous algae

Spirogyra sp (“paddaslyk” in Afrikaans).

A plant succession is currently occurring

with colonisation of previously barren

areas by Spirogyra sp, now being followed

by the true aquatic plants Potamogeton

pectinatus (fennel-leaved pondweed) and

Potamogeton crispus (curled pondweed),

which will become dominant over time

and utilise more nutrients, leaving less

nutrients available for blue-green algae.

Th e plants mentioned here are ‘soft’ plants

and are utilised by the plant-eating fi sh

species, as well as by waterfowl.

Monitoring of the zooplankton in-

dicates that, when comparing the open

water sampling sites to the island sites,

there is greater species variability at

the island sites, as expected, as a wider

habitat variety is provided by the fl oating

islands. Th e numbers of zooplankton

were, however, primarily higher at the

open water sampling sites than at the

fl oating island sites.

Visible positive results of the Hartbeespoort Dam Integrated Biological Remediation Programme


Public awareness is essential in terms

of the fi sheries and the management of

the Hartbeespoort Dam Remediation

Programme. In this regard the Harties

metsi a me programme has made huge

strides informing the public since the

start of the programme.

FUTURE CHALLENGES ■ Th e Integrated Biomonitoring

Programme for the Hartbeespoort Dam

is a fi rst for dams in South Africa and

it is being developed for extension to

other dams. A three-year data set is

currently being analysed and the results

from this analysis will verify the value

of such a monitoring programme as

part of a dam remediation or food web

intervention programme.

■ Bioremediation is an important tool

which can be used in the remediation

of eutrophic dams, or to adjust imbal-

anced fi sh populations (or the food

web). Th e challenge is to carry this mes-

sage through to all parties concerned,

as there is great potential in terms of

the improvement of the aquatic health

and aesthetics of dams as recreational

destinations and in terms of the mone-

tary value of viable fi sheries and SMME

development.

■ Any fi sh removal programme needs a

strategy for utilising the mass of fi sh re-

moved from the dam (i.e. slaughtering,

freezing and marketing), and this needs

to be in place before commencement of

such a programme.

SUMMARY AND CONCLUSIONThe food web monitoring at the

Hartbeespoort Dam entails the devel-

opment and updating of an Integrated

Biological Monitoring Programme

and Protocol Development to quantify

the collective impacts of food web

restructuring activities. The outcome

is to outlay the sampling protocol

for the food web monitoring of the

Hartbeespoort Dam, which will inte-

grate the collective impacts of the food

web restructuring activities. The bio-

monitoring will serve as a ‘barometer’

to indicate trends in the monitored bi-

otic components, and whether changes

occur as a result of food web manipula-

tion and bioremediation.

Th e restructuring of the food web is

necessary to balance the trophic structure

of the dam, and together with some of

the other projects of the remediation

programme, to improve the water quality

in the dam. Th e establishment of fl oating

wetlands to provide suitable habitat

for zooplankton populations and other

aquatic biota (such as invertebrates, fi sh

fry and diatoms), precipitation of bonded

phosphate and eradication of undesirable

fi sh species are synergistic actions in the

holistic process of food web manipulation.

Th e above-mentioned forms the

basis of a bioremediation programme

and can be applied to any other dam. An

Integrated Biomonitoring Programme

therefore also needs to run in unison with

a bioremediation programme in order to

assess improvements in the aquatic health

of a new target dam in response to reme-

dial actions, and to inform decisions.

JH Koekemoer, GJ Steyn, P Venter, C Cilliers,

C van Ginkel, IEJ Barnhoorn and GM Wagenaar



Shoreline remediation andfl oating wetlands

INTRODUCTIONDevelopment of criteria for habitat recon-

struction and rehabilitation aims to deliver

design criteria for habitat reconstruction

and rehabilitation in the littoral and riparian

zones for the following components:

■ Floating wetlands (littoral zone

and in open water in quiet bays)

■ Lake bank vegetation (including ter-

restrial shrubs and trees) (riparian zone)

■ Placement of gravel and rubble

beds (littoral zone)

■ Placement of additional structure in

the littoral zone, such as large rocks.

Habitat reconstruction and rehabilitation

in the context of the Hartbeespoort Dam

refers to the placement and replacement of

cover for aquatic biota. Cover in terms of

rocks and plants, etc, will provide habitat

for biota to feed from and to utilise as

habitat and protection. Th e aim of habitat

reconstruction and rehabilitation is:

■ To provide habitat for spawning, feeding,

establishment and the succession of all

aquatic biota (i.e. epi-biota, benthos,

algae, aquatic macrophytes, fi sh etc).

■ To achieve overall improvement and

an increase in diversity on all biological

levels to give eff ect to the aquatic eco-

system reserve in terms of the National

Water Act.

Example of eroded shoreline at the Hartbeespoort Dam

Shoreline remediation: berm stabilisation trials


■ To develop preliminary Resource Quality

Objectives for the Hartbeespoort Dam to

incorporate the aquatic ecosystem targets

(aquatic diversity).

■ To consider the preservation and opti-

misation of rivers, spruits and drainage

lines with their associated riparian vege-

tation and fl ood zones (in additional to

the Hartbeespoort Dam).

METHODOLOGYShorelines that have suff ered negative

impacts as a result of stormwater erosion,

vegetation destruction and the use of

non-selective herbicides to control alien

invader species are remediated in terms of

this key focus area. Habitats, which repli-

cate wetland ecosystem functionality and

resemble wet seepage zones, are created

to enable wetland plants to fl ourish. Th is

seepage zone typically includes a ‘buff er’

zone, which fi lters excess nutrients and

pathogens in stormwater runoff .

Floating wetlands are also aimed at

replicating wetland ecosystem function-

ality, thereby extending and maintaining

the functionality of shoreline vegetation

during fl uctuating water levels. Th e aim is

to mimic what occurs in nature, as in the

Okavango Wetland for instance, in terms

of naturally buoyant fl oating mats. Th ese

fl oating wetlands become a link from

deeper water to shallow water for fi sh

fry to travel – thereby becoming a vital

‘aquatic nursery migration zone’.

Certain prototype designs have been

trial-tested at the Hartbeespoort Dam

Kurperoord demonstration site. For fl oating

wetlands, the objective is to establish

designs which comply with two key as-

pects, namely functionality and stability.

Functionality includes above-the-water

vegetation growth, as well as below-the-

water root growth. Biodiversity is another

key component in terms of functionality, as

microbes, benefi cial bacteria and fungi colo-

nise the roots and matrix – all of which play

an active role in cleaning the water. Stability

is vital, as the fl oating wetlands need to be

fi rmly anchored to withstand very high

winds and wave action.

Shoreline rehabilitation trial prototype

designs at the Kurperoord demonstration

site utilise diff erent stabilisation methods,

which include hessian, netting and tyres.

Once the prototype designs have been ap-

proved, fl oating wetlands and shoreline re-

mediation will be implemented on all state

land (i.e. Kommandonek, De Rust, Oberon,

Schoemansville and Ifafi , etc). In conjunc-

tion with this, the required documentation

for implementation, such as operational

best practice (OBP), fi eld notes and concept

design documents will be compiled. Th ese

will then be rolled out to shorelines around

the dam within the legal framework of the

Department of Water Aff airs’ Integrated

Water Use licences requirements, the

Department of Agriculture, Conservation

and Environment EIA (Environmental

Impact Assessment) requirements, and the

Madibeng Municipality bylaws to all land

owners along the shoreline. Th e intended

roll-out areas include, as a fi rst priority,

the Hartbeespoort Dam, then the catch-

ment, and at a later stage other eutrophic

impoundments in South Africa.

Th e prototypes are monitored on an

on-going basis in respect of the growth

patterns of the various vegetation species

above and below the water. In addition,

a species’ ability to propagate sideways,

its natural buoyancy, and its ability to

fl ourish at local temperatures and with-

stand frost, are monitored. Th e compo-

nents in construction and assembly are

also documented. Th e combined data is

used in compiling lessons learned, and

designs are adapted accordingly.

TRAINING Th e fl oating wetland team receives

training on an on-going basis through

step-by-step explanations about fl oating

wetland and shoreline construction

methods, and about biodiversity (vegeta-

tion and wildlife species).

Site requirement fi eld notes capture

and incorporate information to assist with

construction and maintenance. Copies of

all the fi eld notes are supplied to the fl oating

wetland team and other interested parties.

PROTOTYPE DEVELOPMENT AND CONSTRUCTION PROGRESS Shoreline rehabilitation

Conceptual designs for the Ifafi shoreline

rehabilitation trial sites were compiled

in 2008/9, and since October 2010 various

prototypes were constructed employing

diff erent stabilisation methods, which

include hessian, netting and tyres. To

date a total of 8 540 m² of shoreline has

been rehabilitated – at Kurperoord,

Kommandonek and Ifafi .

Floating wetlands

Since 2008, various trials on fl oating

wetlands have been performed. In

October 2010 the tag numbering system, in

Shoreline remediation: berm stabilisation trials

terms of actual construction and compo-

nents within the numbering, was revised

and all the fl oating wetlands were tagged.

To date 5 000 m2 of fl oating wetlands

have been constructed and launched at

Kurperoord, Kommandonek, De Rust,

Lakeland, Leeuspruit and at the dam wall.

Quality control is essential, so the

criteria for fl oating wetland evalua-

tion include: checking bamboo growth

nodes to ensure that no water enters the

sealed end and causes rotting, ensuring

that all bamboo joints are tied together

securely with steel-rope, and that PVC-

coated wire-mesh cable ties are attached

(rusting remains a big concern), and

silicon-sealed ‘screwits’ are placed at

all mesh cut ends. To stop plants from

washing out at the sides of the fl oating

wetland a zigzag of steel-rope is attached


Close-up of fl oating wetland grid

Floating wetland being prepared and positioned along the shoreline

Launched fl oating wetland fulfi lling its purpose – longer periods of clear water have been experienced since mid-2009


on the sides between the top and bottom

frame. Lastly, regular monitoring of the

vegetation growth pattern, as well as of

the invertebrates present, is undertaken.

Maintenance

Regular maintenance is done on shorelines

and fl oating wetlands, and alien invader

species like hyacinth and snakeroot are

removed. Litter and debris that accumulate

are removed and any stormwater damage

is repaired.

Pecanwood Estate

Th e programme established a working

relationship with Pecanwood Estate when

they agreed to participate as a ‘beta’ site –

a Safety Health Environment and Quality

Management (SHEQ) term. In terms

of this, Pecanwood adopted the Waste

Minimisation and Recycling OBP, as well

as the Optimisation of In-lake Dams (in-

cluding stormwater dams and manmade

wetlands).

Pecanwood Estate was used as a

model to compile the OBP concept site

requirement fi eld notes and fact sheets,

and to capture aspects like ‘implementa-

tion challenges’ to which solutions are

added. Field notes and fact sheets com-

piled to date include:

■ Marina island wetland and shoreline

re-vegetation fact sheet

■ Wetland bird identifi cation fact sheet

■ Wetland golf estates and estates aims

and objectives fact sheet

■ A wetland poster

CONCLUSIONMany diff erent processes and procedures

have been put in place to optimise fl oating

wetland production, including the fol-

lowing:

■ Wetland vegetation iden-

tifi cation fact sheet

■ Wetland vegetation layout diagram for

proposed maintenance and management

■ Urban stormwater guidelines (four)

■ Jetty construction OBP concept

■ Golf course OBP concept

■ Shoreline activities (algae and hya-

cinth removal) OBP concept

■ Biomass removal: vermiculture wor-

mery for residential use OBP concept

■ Floating wetland quality

control OBP concept

■ Biomass removal: vermiculture wor-

mery tyre installation OBP concept.

Th roughout the pilot process many les-

sons have been learnt regarding technical

aspects of the designs, and these have been

incorporated into new designs in terms of:

■ Components: netting, PVC-coated galva-

nised mesh, steel-rope and frames

■ Plant species: papyrus, bulrush, giant

sedge and wetland mix

■ Construction: organic mulch, plant den-

sity, seed sausages, plant pockets, seed

blankets, upright placing of plants,

bigger frames, nursery designs, dia-

mond and square layouts, organic mate-

rial and anchoring

■ Production: templates, processes and pro-

cedures such as a ‘Production Wheel’.

Shoreline remediation and f loating wet-

lands will be rolled out to surrounding

land owners and other dams in the near

future.



Sediment removal and management THE SEDIMENT REMOVAL and Management Project deals

with nutrient-rich sediments that contribute to severe eu-

trophication in the Hartbeespoort Dam (HBPD), as well as with

sediments that should be retained and removed in future to

protect the dam from sediment infl ux and associated build-up

of nutrients.

About 40–45 X 106 m3 of sediments associated with nutrients

(phosphorus, nitrogen, carbon) have accumulated in the HBPD

for the more than 85 years of its operation (Figure 1).

Th e consequences of sediment build-up in the HBPD are

the loss of 21% of the dam’s initial storage capacity and the con-

tinuous release of nutrients (termed the Internal Nutrient load)

associated with the top layer sediments, and especially phospho-

rous as the pivotal nutrient in eutrophication abatement.

Th e top layer of dam sediments (volume ~ 5.5 X 106 m3)

that interacts with the overlaying water contains ~ 2 000 tons of

phosphorous that are trapped in particles, attached to the sur-

faces of particles, or contained in interstitial water. It is conserva-

tively estimated that 10–15% of this phosphorous mass trapped

in the dam top layer sediments is annually released/recycled to

the bigger water body. Th is is termed the Internal Phosphorous

load. Th e internal P load, coupled to the external nutrient infl ux

via tributaries, results in severe eutrophication of the HBPD and

excessive biomass growth.

In the context of internal loading a small (but very active

in nutrient recycling) part of the dam’s sediments is a buoyant,

gelatinous layer (generally termed the “jelly” layer) that is located

in the dam wall zone (shaded green in Figure 2). Th is layer is

composed of dead biomass (detritus) and fi ne clay particles rich

in nitrogen and phosphorous, and particularly in organic carbon

that provides energy for the fast decomposition of detritus and

the release of trapped nutrients back to the bigger water body.

x106

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Figure 1: HBPD sediment build-up as determined through bottom contours measurement and modellingDam bottom contours (1923) Dam bottom contours (2008)


Any serious approach to the remediation of the HBPD

should – inter alia – attend to a reduction of the excessive

Internal Phosphorous load.

Th e above-mentioned 40–45 X 106 m3 of sediments are distrib-

uted (Figure 1) over 25% of the dam’s area (full supply level). Th e

sediments are mostly settled in natural valleys that existed in the

area before the damming of the river.

An additional 1.25–1.5 X 106 m3 of sediments are accumu-

lated in the Crocodile River’s inlet zone (shaded red in Figure 3).

Th ereby the settling effi ciency and retention capacity of the

incoming sediments are considerably decreased.

Th e recovery of lost settling effi ciency and retention capacity

in this zone is of considerable importance within an overall

strategy for sediment removal and management – now and in the

future.

As estimated in the 1990s (Rooseboom 1993), about

300–500 x 103 m3 of sediments – associated with nutrients

– enter the HBPD each year, depending on precipitation and

runoff . Such data should be updated through monitoring of the

Crocodile River at DWAF’s Hydro Station A2H012 (Kalkheuwel)

within the Harties metsi a me programme. Currently available

monitoring data indicate that the Crocodile River sediments con-

tain a considerable mass of loosely-bound nutrients that should

be removed before entering the dam.

Contrary to previous initiatives and plans for the HBPD reme-

diation, the Harties metsi a me programme has recognised the im-

portance of the dam’s Internal P load, and has developed a present

and future strategy to deal with it. Data on the composition of top

layer sediments (as derived from a comprehensive research study

of HBPD sediments, Cukic 2008) indicates that such sediments

should be regarded as a resource and not a waste. Th ey could be

processed for reuse (land conditioning, tailings dam rehabilitation,

composting, etc), thereby serving environmental restoration and

protection, compensating for the environmental disturbances of

the catchment from which they originally derived.

Th e Sediment Removal and Management Project will focus

on: the removal of top-layer dam sediments rich in nutri-

ents, including the “jelly” layer; the removal of sediments

currently accumulated in the Crocodile River inlet zone and

river mouth; the future interception of incoming sediments

with associated nutrients; and the processing of removed

materials for benefi cial uses.

GOALSSeveral goals have been set for the project:

■ Reduction of historical Internal Nutrient load (i.e. recy-

cling), aiming to reduce the dam’s trophic levels.

■ Reduction of the current infl ux of sediments and as-

sociated nutrients, by the improvement of settling ef-

fi ciency and sediment retention capacity at the

inlet zone and mouth of the Crocodile River.

■ Reduction of future infl ux of sediment and associ-

ated nutrients to the dam, by an in-stream intervention

(conditionally foreseen as the pre-impoundment).

■ Processing of extracted materials for benefi cial uses (such as

soil amendments, compost, tailings dams rehabilitation) and

manufacturing of marketable products (such as bricks, blocks,

etc), thereby creating new jobs and recovering a portion of the

costs associated with sediment dredging and processing.

APPROACHTh e approach to sediment removal and management could be sum-

marised as follows:

■ Remove nutrient-laden top sediments from the aquatic en-

vironment – where they produce harmful eff ects – to ter-

restrial environments where they can be put to benefi t.

■ Carry out all operations in an environmentally safe, technically

feasible, fi nancially reasonable, and socially acceptable manner.

■ Use a part of the coarser sediments for the manufacture of con-

struction materials, thereby achieving more effi cient cost recovery.

■ Motivate and mobilise entrepreneurship (dredging op-

erations, processing of dredged materials, power plant

construction, extension of railway activity, etc).

■ Stimulate job creation based on the activities as envisaged.

OBJECTIVESAmong the many objectives set within the project, the most impor-

tant ones are the following:

■ Dredging of the dam’s nutrient-laden top sediment

layers (dam wall zone, dam main basin, Magalies River

mouth) for the reduction of Internal Nutrient load.

■ Dredging of sediments accumulated in the Crocodile River’s inlet

zone for recovery of its settling effi ciency / retention capacity.

■ Partial dredging of the Crocodile River mouth for the im-

provement of its settling effi ciency / retention capacity.

■ Processing of dredged materials for the sepa-

ration of solid and liquid phases.

Figure 2: Spatial distribution of sediments within the HBPD

Figure 3: Spatial distribution of sediments in the Crocodile River inlet zone and river mouth


■ Processing of separated solids for the production of top-

soil for agricultural use and tailings dam rehabilitation,

while providing new jobs and partial cost recovery.

■ Processing of separated sand and part of the coarser ma-

terials for the manufacture of marketable products (sand,

bricks, blocks, aggregate, etc) for the construction industry,

while providing new jobs and substantial cost recovery.

■ Collection and treatment (if needed) of separated water for dis-

charge back into the dam or for reuse in agriculture and industry.

■ Carrying out all operations in an environmentally safe

manner, without disturbance of neighbouring interests.

■ Job creation and establishment of small com-

munity projects (SMMEs), based on the dredging

and processing of dredged materials.

STRATEGYSeveral interconnected operations/activities will be involved

in the removal and management of sediments. Th ey should be

synchronised, optimised and completed within planned time

frames. Th ese operations include:

■ Dredging/extraction of sediments – present and future

■ Primary transport of dredged/extracted materials

■ Processing of dredged/extracted materials including:

separation of liquid and solid phases

dewatering of solids

collection and treatment (if needed) of sepa-

rated liquid phases for reuse or safe discharge

processing of solids for the manufacture of envi-

ronmentally valuable and marketable products.

■ Establishment of small community projects

(SMMEs) and creating new jobs.

Dredging/extraction of sediments

Th e dredging/extraction operation will include the extraction of

~ 5.5 x 106 m3 top layer nutrient-rich sediments within the dam’s

main basin – including the “jelly” layer and the Magalies River

mouth sediments as necessary steps for the reduction of the

dam’s internal nutrient load to a desired level. Th is will require

the extraction of deep-water top sediments.

An additional volume of ~ 2–2.25 x 106 m3 of sediments

from the Crocodile River inlet zone and river mouth should

be dredged in order to remove the nutrient-rich sediments, as

well as to recover sediment retention capacity and to improve

settling effi ciency in this zone. Combined deep-water sediment

Table 1 Volumes of sediments to be dredged/extracted

Area TypeVolume000 m3

Dam wall zone & northern dam basinJelly layer 300 – 500

Top layer 1 000 – 1 500

Central / southern dam basin Top layer 2 000 – 2 500

Crocodile River inlet zone Top layer and part of consolidated sediment 1 000 – 1 250

Crocodile River mouth All sediment 1 250 – 1 500

Magalies River mouth Top layer 300 – 500

TOTAL 5 850 – 7 750

Figure 4: Mobile, multi-purpose, shallow-water dredging equipment (to be purchased)

The purchase of contemporary multi-

purpose dredging equipment is intended. The

establishment of a dredging team within the

Harties metsi a me programme is envisaged

to assist with shallow water dredging, as well

as with shoreline/wetlands remediation and

the harvesting and removal of biomass


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extraction and shallow-water dredging (Figure 4) would be ap-

plied in this operation.

Th e purchase of contemporary multi-purpose dredging

equipment, similar to those depicted in Figure 4, is intended. Th e

establishment of a dredging team within the Harties metsi a me

programme is envisaged to assist with shallow water dredging, as

well as with shoreline/wetlands remediation and the harvesting

and removal of biomass.

Th e volumes of sediments to be dredged/extracted from the

indicated zones are presented in Table 1.

Dredging of the “jelly” layer from the dam wall zone (Figure 2)

and of sediments from the Crocodile River inlet zone and river

mouth (Figure 3) is considered a priority. Both schemes will be

examined through so-called bulk sampling and pilot runs before

actual operations will be fi nally designed and implemented.

About 5.85–7.75 x 106 m3 of sediments should be dredged/

extracted once-off in order to reduce the historical sediment

and internal nutrient load to target levels. Both deep-water

dredging/extraction and shallow-water dredging techniques

should be applied.

Th e dredging operation and hydraulic transportation of dredged

materials require energy. Th e construction of a small hydro-power

plant (~0.5 MW) in the dam wall zone is strongly recommended,

in order to provide energy for the dredging and ‘primary trans-

port’ of sediments, and for use by other consumers after the com-

pletion of dredging operations.

Transportation of dredged/extracted materials

Th e transportation of dredged materials (termed ‘primary trans-

port’) will be performed hydraulically in order to avoid environ-

mental risk, traffi c pressure, and social disturbance. Th e general

strategy is to transport dredged/extracted materials from the dam

wall zone and northern part of the dam basin, to mines and farms

situated northeast and northwest of the dam. However, materials

from the southern part of the dam basin should be transported to

the Oberon area.

Materials extracted from the Magalies River mouth would be

transported to Kommandonek. Materials dredged from the lower

part of the Crocodile inlet zone and river mouth would be trans-

ported to the Oberon area, but materials dredged/extracted from

the upper part of the Crocodile inlet zone would be transported to

the Roos se Oord area (refer to map on page 17 for orientation).

Dredged materials from the dam wall zone (~ 0.5 x 106 m3 of

“jelly” layer) and northern part of the dam’s main basin (~ 106 m3

of top layer sediments) would be transported towards farming/

mining areas north, northeast and northwest of the dam.

Th ree options for the hydraulic transportation of sediments

from the dam wall zone and northern part of the dam basin are

considered viable:

Option A: Transportation towards the Crocodile River Mine,

with possible (Option B) to the east (towards the

Eland Platinum Mine) and/or to the west (towards

mines in the Rustenburg area that are in need of

water supplies).

Option C: Transportation towards the Eland Platinum Mine

with possible extensions to the west towards the

Crocodile River Mine and/or towards mines in the

Rustenburg area that are in need of water supplies.


The processing of dredged/extracted materials

As mentioned above, sediments from the dam, as well as

water separated from them, are to be considered a resource.

Accordingly, strategies to process them and to establish

schemes for their benefi cial uses have been considered and

developed. Several operations are required for the processing of

dredged/extracted materials, including;

■ Separation of liquid and solid phases

■ Collection of separated liquid phases for reuse/safe discharge

■ Dewatering of solids

■ Processing of solids for the manufacture of environmentally valu-

able and marketable products.

In Figure 5 the general scheme is presented for the processing of

dredged/extracted materials to produce environmentally valuable

and marketable products (such as compost, soil conditioners, mate-

rial for tailings dam rehabilitation, etc); construction materials (such

as blocks, bricks, poles, agglomerates, etc); and water for reuse and/

or safe return to the dam.

All these products are marketable and could provide recovery

of costs associated with dredging/processing. It could also generate

80–100 new jobs over the next ten years. Th ere would be a multiplier

eff ect of 2–3, taking into account transportation, distribution and

application of fi nal products. It is roughly estimated that a recovery

of 50–150% could be achieved, depending on the scheme applied,

investments made and the market response.

Th e scheme as presented in Figure 5 would be modifi ed

depending on local-specifi c conditions and requirements as

envisaged for the areas where large portions of land are available.

Such a modifi cation will be made for the processing of dredged

materials from the dam wall zone and northern part of the dam’s

main basin that would be transported towards farming/mining

areas north, northeast and northwest of the dam. Parts of the

Eland Platinum Mine property and the HADECO fl ower farm

are primarily intended for processing of these dredged materials.

Th e irrigation scheme (refer to Figure 6) with reused water would

be developed to accomplish this operation.

Extraction

transport

TreatmentProcessing

Discharge Reuse

Sec. Transport

Transport

Market

Dr. Eng. Zoran Cukic

Construct.

SolidsWater

PR

OC

ESSI

NG

DR

EDG

ING

PRO

CE

SSIN

G

IrrigationPrimary

Separation

Dewatering

Land applicationTailings dams Rehab.Compostmaterials

Waterreuse

Crop, Grazing

SCREENING

DebrisSand

Construct.materials

SIEVING

Dr. Eng. Zoran Cukic

Storage

Extraction

Transport

Irrigation

Water

Soil

Use

Recharge

Aquifer

Pipe

Temporary

Sediments, Jelly Leyer

Land ConditioningEcosystem improvement

Grazing, Agiculture, Nursing

Tailings Dams

MarketPot Soil Construction

MateralsRehabilitation

Amendments

Amendments

Composting

Scraping

Mar

ket

Figure 5: The layout of a general scheme for the processing of dredged/extracted materials

Figure 6: The layout of the envisaged irrigation scheme for the processing of “jelly” layer and top-layer sediments from the dam wall zone and northern part of the dam’s main basin


Following a step-by-step approach for the design and imple-

mentation of the processing scheme, a pilot study to identify ele-

ments for the design and to assess the environmental impact will

be carried out at the Eland Platinum Mine and HADECO fl ower

farm. Th is would be done by materials provided through the bulk

sampling (extraction of a limited volume) of “jelly” layer and top

layer sediments from the dam wall zone.

Th e irrigation scheme (Figure 6), with site-specifi c modifi ca-

tions, will be applied at Kommandonek for ultimate disposal

of dredged materials from the Magalies River mouth and for

processing of separated water up to the levels required for dis-

charge back into the dam.

Th e top-layer sediments from the central and southern part

of the dam’s main basin, sediments from the Crocodile River

mouth, as well as sediments from the lower part of the Crocodile

River inlet zone will be processed for benefi cial uses in the

Oberon area, from where the fi nal products will be transported

to end users. Separated water will be processed to the levels

required for safe return to the dam, with possible use for agricul-

ture and various other water features.

Oberon is considered a key area for the processing of

dredged materials from the central and southern part

of the dam’s main basin, the Crocodile River mouth and

lower part of the Crocodile River inlet zone. Th e Crocodile

River sediments that should be retained and extracted in

the future could also be processed in the Oberon area, de-

pending on the option implemented. Revival of the railway

line between Pretoria and Magaliesburg to assist with the

transportation of fi nal products from the Oberon area is

highly recommended.

Th e dredged materials from the upper part of the Crocodile River

inlet zone will be processed in the nearby Roos se Oord area. Th e

fi nal products will be transported to end users and separated/

processed water returned to the Dam, or potentially reused in

agriculture if land would be made available.

Incoming sediments (~ 0.25-0.3 x 106 m3/y) that will be re-

tained in the envisaged pre-impoundment (yet to be considered),

will also be transported to the Roos se Oord area where they will

be processed for benefi cial uses. Th e fi nal products will be trans-

ported to end users and separated/processed water returned to

the dam for agricultural reuse.

Th e Roos se Oord/Pelindaba area is considered the key location

for the removal and processing of sediments from the upper

part of the Crocodile River inlet zone and, depending on the

options implemented, this would also be the area of choice for

the future handling of sediments that would be extracted from

the envisaged pre-impoundment.

A part of the Pelindaba property, next to the Roos se Oord

area, would potentially be used for the temporary disposal and

processing of sediments from the upper part of the Crocodile

River inlet zone and for the retention of incoming sediments.

A considerable portion of land available in this area holds posi-

tive potential for irrigation as the most suitable scheme for the

processing of dredged materials and water reuse.

Dr Eng Zoran Cukic, Petrus Venter



INTRODUCTIONIn South Africa the Hartbeespoort Dam (HBPD) is among the

water bodies most severely aff ected by eutrophication. It is po-

sitioned downstream of large industrial and densely populated

commercial centres (i.e. the Johannesburg and Tshwane Metros)

which discharge treated wastewater from sewage treatment

works (STW) and urban stormwater.

Runoff from natural and agricultural land, from mining

areas, and from townships and squatter camps with no sewerage

systems (hot spots), contributes to the HBPD’s additional nu-

trient load, which, combined with local climate characteristics

(high summer temperatures, high intensity of photosynthetic

active radiation) creates the worst scenario possible in favour of

eutrophication and its consequences.

Th e remediation of the HBPD has to address an excessive

nutrient load (dissolved and associated with sediments) either

accumulated historically in the dam (i.e. internal nutrient load)

or expected to be released from the catchment in the future (i.e.

external nutrient load).

In remediating the water quality and the ecosystem of

the dam the approach is to decrease the dam’s trophic levels

by controlling the phosphorous (P) load, phosphorous being

a pivotal nutrient in eutrophication abatement. Th is will be

achieved by the reduction of the dam’s Internal Phosphorous

load, originating from dam sediments (see article “Sediment re-

moval and management”) and by the reduction of the External

Phosphorous load, originating from the dam’s catchment. Th e

latter, which is the main cause of the severe eutrophication in

the dam, is the subject of this article.

Reduction of theexternal nutrient load

Table 1 Data on the effl uent discharge of STWs in the HBPD catchment

STWFlow 2007/8

ML/dFlow 2007/8

ML/yrSusp. Sol.

t/yrO-Phosphate

tP/yr

Randfontein 20 7 300 182.5 14.60

Percy Steward 29 10 585 370.5 39.69

Hartbeesfontein 40 14 600 146.0 7.30

Olifantsfontein 65 23 725 118.6 42.71

Sunderland Ridge 55 20 075 1 806.8 30.11

Driefontein 30 10 950 219.0 5.48

JHB Northern Works 400 146 000 2 920.0 146.00

TOTAL 639 233 235 5 763 286

Note: It was estimated that 75–80% of this discharge/load entered the HBPD


EXTERNAL PHOSPHOROUS LOAD TO THE DAMThe External Total Phosphorous load (ETP load) derives from

the dam’s catchment (point and non-point sources), where

the ETP load transferred by the Crocodile River contributes

more than 90% of the load. This means that future efforts to

reduce this load have to be focused on the Crocodile River

catchment.

Following available data on the STWs' effl uent discharge,

the composition of Phosphorous load and Suspended Solids load

from point sources range from 200 – 250 tP/yr (2010 data) and

from 5 500 – 6 000 t/yr respectively.

Th ere is no reliable data on non-point sources (agricultural

and urban runoff , squatter camps, spillage, etc) contribution in

Total P load (TP load), but it most probably ranges between 45

and 55% of total load (ranges from 350 – 650 tP/yr), as roughly

estimated from the mass balances performed. Th e major portion

(more than 90%) of non-point sources TP load is associated with

eroded soil particles or particles fl ushed out from urban surfaces

and municipal dams.

It should be emphasised that discharge from point sources

contains mainly dissolved P species, but TP load from non-point

sources contains mainly phosphorous incorporated into fi ne

particles, with a high probability of being released back into the

water under a variety of hydrological and bio-chemical condi-

tions in the dam.

Th e reduction of ETP load to the HBPD will result in dealing

with both point and non-point sources, comprising both dis-

solved and particle phosphorous species.

STRATEGIES FOR THE REDUCTION OF EXTERNAL PHOSPHOROUS LOADA comprehensive consideration of the need for reduction of

External Total Phosphorous (ETP) load to the HBPD, as well as

remedial actions to be considered within the Crocodile River

catchment, was done by Prof WA Pretorius (who regrettably

passed away in 2009) and his collaborators.

In principle, two approaches have been considered:

The improvement of catchment management, including:

■ Th e upgrade of STWs and the improvement of their operation

■ Th e implementation of stricter phosphorous

discharge standards

■ Stricter control on point sources of

pollution, including industrial effl uent

■ Improved control of non-point sources of pollution

■ Improved management of numerous

municipal dams and other retention dams that

exist within the Crocodile River catchment

■ Chemical removal of part of the phosphorus in

the Crocodile River infl ow to the dam

■ Th e revival, restructuring, protection and management of

natural treatment systems (wetlands, shoreline and in-stream

aquatic ecosystems, etc) which retain and absorb nutrients.

ETP load influx control where a barrier between the catchment

and the dam is implemented, and where at least 80% of the

ETP load to the dam would be retained and removed.

A combination of the above two approaches should be an

optimal strategy for the future management of ETP load to the

HBPD. A necessary part of this strategy is the formation of a

barrier (conditionally termed the “pre-impoundment”) which

will reduce that part of ETP and sediment load to the dam

that cannot be successfully controlled even by the implemen-

tation of the planned catchment management improvements,

and strict control of their sources within the Crocodile River

catchment.

The concept (and conceptual design) of pre-impoundment

with f low diversion was developed in 2008. It is based on the

assumption that the temperature of water in the Crocodile

River permanently exceeds that of surface water layers in the

dam, so no mixing (or partial mixing only) of incoming river

water and deeper layers of nutrient-rich dam water occurs.

Figure 1: Muddy sediment cloud observed during a fl ood on 20 Feb 2012Location: Crocodile River mouth, 200 m downstream of the railway bridge, 150 m from left river bank at Oberon


The opposite assumption was revealed through recent moni-

toring of water quality in the dam and Crocodile River at

the DWAF Hydrological Station AH012 (Kalkheuwel). The

temperature of the Crocodile River water appears to be lower

than that of water in the dam surface layers, meaning that a

plunger point exists in the river mouth, the distance of which

(from the mouth) varies depending on the incoming f low

energy. This assumption was confirmed during a relatively

small f lood (peak f low ~150 m3/s) which occurred on 20/21

February 2012 when the mobilisation of fine bottom sedi-

ments was observed (Figure 1).

In extreme flow conditions (peak f low >450 m3/s) the

whole main basin of the dam is partially f lushed, so most of

the fine top sediments are mobilised and turbid water rich in

nutrients can be observed at the dam spillway.

This observation has prompted an update of the previously

developed concept of pre-impoundment, and consideration

of other possible options for a barrier between the catchment

and the dam that would dissipate the river energy and would

reduce the ETP load to the dam.

The update of the pre-impoundment (with f low diversion)

project has not been done yet, but potential options have

already been considered. The preliminary conclusion is that

a barrier (conditionally termed the “pre-impoundment”) for

the reduction of ETP load should be installed between the

catchment and the dam. In general, this barrier could com-

prise a pre-impoundment (or series of impoundments) of an

appropriate size close to the dam. Alternatively the settling

processes in the river inlet section and the river mouth should

be improved, taking the river morphology and possible engi-

neering interventions into consideration. Both options should

be considered, and should provide:

■ Retention of at least 90% of the suspended

solids load associated with phosphorous

■ Removal of at least 80% of ETP load

from the incoming river fl ow

■ Removal of settled sediments on a regular basis with sub-

sequent processing of sediments at adjacent areas, and

■ Retention and removal of fl oating debris and litter.

Several localities in the Crocodile River zone stretching from the

dam to the Hennops River mouth are considered potentially suitable

for the formation of a barrier. Each of these localities should be ana-

lysed in terms of hydrology, geology, availability of land and required

volume, as well as in terms of impact on HBPD operations, residents,

the environment, infrastructure, etc. Th e successful implementation

of the barrier will be dependent on innovative engineering practices

serving environmental protection requirements through all phases

of the project, i.e. in the planning/study phase, the exploration phase

and during construction of the barrier.

Th e construction of a barrier should be synchronised with

activities around the reduction of the Internal Phosphorous load

(i.e. historical P load within the dam). Dredging of the Crocodile

River inlet zone, river mouth and the dam should therefore be

completed over the period required to design and to construct

the barrier.

CONCLUSIONIt should be recognised that there is no quick, easy and cheap

solution for the restoration of the HBPD. Th e problem has been

developing over more than 80 years and will take time to resolve.

Th e restoration of the dam can also not be considered as

a once-off action, but should rather be seen as a series of well-

planned integrated measures within the Crocodile River catch-

ment and within the dam basin itself, that should be strictly and

persistently carried out (now and in the future).

Improved catchment management, the formation of a barrier

between the dam and the Crocodile River catchment, as well as

interventions within the dam basin should be implemented in

parallel and run as long-term interventions.

Th e formation of a barrier between the HBPD and the

Crocodile River catchment is considered a necessary and im-

portant step to reduce a part of the ETP load that cannot be

controlled successfully even by the implementation of detailed

planned improvement of catchment management and stricter

control of sources of nutrients within the catchment.

If these actions are well planned, properly implemented

and persistently carried out, the HBPD could be successfully

remediated and converted from a waste trap to a beautiful body

of water. Successful remediation of the HBPD would also earn

international recognition of the successful interaction and co-

operation between South African water scientists, engineers and

decision-makers.

ACKNOWLEDGEMENTThe authors would like to express their gratitude to the late Prof WA Pretorius for his active promotion of the principles of external phosphorous load reduction and pre-impoundment at the HBPD.

Z Cukic, W Potgieter, C Claassen



INFORMATION HUBAt the onset of the Hartbeespoort Dam

Remediation Programme, the need for a

Communication and Knowledge Centre

was identifi ed as a vehicle to create

awareness and provide information, as

well as for capacity building and know-

ledge transfer. With this in mind, the

Information and Communication Centre

(ICC) fi rst opened to the public in 2008 at

the historic Tan’ Malie se winkel. Late in

2010, the fi rst Information Tent, situated

at the dam wall, was upgraded to a 310 m²

structure and opened its doors as an ex-

tension to the Communication Centre.

Th e information and education hub

increases public awareness by off ering infor-

mation and education on the Hartbeespoort

Dam and surrounding areas. Brochures,

pamphlets and exhibitions provide im-

portant and valuable information to the

public. Guided tours detail the remediation

programme, and science workshops off er

school children knowledge about environ-

mental protection and water conservation,

often combined with fun experiments.

Future developments around this in-

formation hub will see the buildings in use

as examples of green living. Materials and

measures will be put in place to demon-

strate sustainable living in practice. Waste

minimisation and reuse, in combination

with various infrastructure and soil man-

agement principles, will be demonstrated

and related to households, mining, agri-

culture, etc. Th e refurbishment process

(energy and water usage, for example) will

be appropriately documented with a view

to possible Green Star Accreditation for

the rehabilitated ICC.

Topics addressed at the ICC include:

■ Water conservation and protection, es-

tablishing and demonstrating biological

processes in biomass treatment (algae

and hyacinths), river basin manage-

ment, improved stormwater manage-

ment, protection and remediation of

wetlands and riparian and in-stream

river habitats, wastewater management

■ Waste minimisation, recycling and

reuse with organic enrichment of soil

■ Biodiversity functionalities and all the

advantages of associated ecosystem

services

■ Sustainable energy solutions, energy

effi ciency, energy saving, renewable

energy sources

Information, Communication and Knowledge Centre

The erection of the Information Tent in progress

School children visiting the Hartbeespoort Dam ICC; note the environmentally friendly walkway


■ Sustainable solutions to transport and air

pollution problems, promotion of public

transport and bike routes, energy-effi cient

and environmentally friendly transport

■ Public participation in decision-making,

protection of environmental rights

■ Green Consumerism International and

regional conferences and seminars on

sustainable wastewater technologies, ap-

plication of energy effi ciency and renewal

■ Training programmes and e-learning

courses on environmental education

for various target groups in partnership

with businesses, government bodies

and other institutions.

Th e centre is also used for conferences,

and many workshops and group sessions

have been hosted there. School groups

are encouraged to visit and more than

3 000 school children, and 1 850 members

of the public, have visited the ICC. Details

of the programme have been broadcast

over radio stations and national television.

Tshwane TV made a short documentary

about the successes of the Hartbeespoort

Dam Integrated Biological Remediation

Programme.

CORPORATE AND PRIVATE SUPPORTIt is important to take into account

that the Hartbeespoort Dam Integrated

Biological Remediation Programme

falls into two categories – preservation/

conservation and restoration/rehabilita-

tion. Current operational activities focus

on the rehabilitation of the dam with the

extension of the programme focusing on

eliminating and mitigating sources of pol-

lution in order to manage the dam and the

biodiversity in the catchment.

In developing a plan for the remedia-

tion of the dam, strategic conversations

with interested groups willing to cooperate

with the remediation team were held.

Th ereafter a tactical corporate and private

support (fundraising) plan was developed,

and a general analysis of the public involve-

ment drawn up. Th e roles, responsibilities

and needs of the public were outlined, as

was the capacity of stakeholders to con-

tribute to the programme.

Public/private support forms an inte-

gral part of the success of the remediation

programme. Although fi nancial contribu-

tions from diff erent organisations have

been received, a lot more support came

through positive attitudes. Th is includes,

for example, the off ering of manpower,

equipment and materials to assist with the

implementation of the programme. It is

one of the main aims of the remediation

programme to garner additional sources of

support, thereby extending ownership of

pollution prevention, waste minimisation

and sustainable green living principles.

SUPPORT TARGET Th e sourcing of funding and other sup-

port to cover costs for capital expenditure,

services and equipment forms part of the

corporate and private support strategy.

Th e aim is to carry these expenses by

means of sponsorships and donations, and

to involve the corporate sector (mines,

industry, fi nancial sector) and the private

sector (property owners around the dam

as key stakeholders in the remediation

programme). Th e legal requirements

for shoreline owners to comply with the

Resource Management Plan are in place,

although further engagement is required

in order to fully realize the potential of

this type of support. Assistance in some

form is needed in all of the following

areas of rehabilitation:

■ Floating wetlands – establishment,

monitoring and maintenance

■ Shoreline vegetation – clearing out

alien plants, re-establishment and

maintenance of indigenous vegetation

■ Biomass removal – removal of hyacinths

■ Waste minimisation and

recycling of waste material

■ Litter and debris removal –

removal, disposal and maintenance

■ Wetland rehabilitation and

establishment, and remediation

of riverbanks and shoreline

■ Sediment removal – recovery,

processing and disposing of

sediments from the dam

■ Pre-impoundment, river diver-

sion and river treatment

■ Waste minimisation and reuse, aligned

with organic reuse and soil conditioning.

CORPORATE AND INTERNATIONAL SUPPORTTh rough the initiatives of the remediation

programme some existing and potential

sponsors were mobilised, which include

all residents and home owners around the

dam, home owner associations (HOA)

and estates. A survey revealed that in

excess of R2 million per annum (for the

past three years) was spent collectively by

residents around the dam supplementing

the eff orts of the Harties metsi a me team.

Exposure is given to this kind of support

via acknowledgements at exhibitions, as

well as on the Harties website.

Corporate support, in terms of a

commitment of close to a million rand,

was received from Elands Platinum for

the pilot dredging of the jelly layer, and

close to R50 000 was donated by the Old

Mutual “Om die Dam” marathon over the

past two years.

International sponsorship and support

came from Lahti City in Finland, UNESCO

in Belgium, Novi Sad University in Serbia

and the Finnish Government with whom

the programme executors have a fi rm

working relationship to promote know-

ledge sharing. Finland has also contributed

towards the establishment and equipping

of the Communication Centre situated at

the dam wall.

Marlene McKay

A school group on a guided tour at the dam wall



Future challenges and prospectsINCREASING CHALLENGESTh e positive changes (more and longer

periods of clear water experienced since

2009, absence of bad odour, etc) recorded

within 18 months after the implementation

of the Hartbeespoort Dam Integrated

Biological Remediation Programme, are a

clear indication of the powerful potential

available within an integrated approach

towards unlocking nature’s ability to

restore healthy ecosystems through biodi-

versity. Th is principle to conserve, protect

and manage towards optimum biodiversity

is not only a requirement in the National

Environmental Management Act (Act

107 of 1998), but is echoed in the National

Water Act (Act 73 of 1998) through the

requirements of the Reserve to manage

towards aquatic ecosystem diversity.

Th e world has experienced tremendous

population growth over the past several

decades, a situation that is no diff erent in

South Africa. Water is essential for humans

in many ways, including water supply and

storage, land value enhancements, recrea-

tion, aesthetics and even transportation

(larger river systems). Communities there-

fore normally settle and grow near areas

where there is a relatively sustainable water

resource. However, the increasing popula-

tion growth is threatening the quality and

quantity of both surface and ground water,

especially in the highly developed urban

Flo

w (

mill

ion

m3/a

)

Date

Flow increases at Kalkheuwel

700

600

500

400

300

200

100

1920 1930 1940 1950 1960 1970 1980 1990 2000 20100

Figure 1: Flow increases in the Crocodile River (1923–2011)

Figure 2: Delineation of the Hartbeespoort Dam catchment


areas, posing signifi cant challenges when it

comes to sustainable water resource man-

agement, which is only possible if done in an

integrated manner.

It should be noted that the

Gauteng metropolitan area (covering

Johannesburg, Ekurhuleni, Mogale and

Tshwane) is one of the few large metro-

politan areas in the world not based near

an ocean port or a major river, and which

is therefore entirely, or to a great extent,

dependent on imported water.

Th e Gauteng municipalities have

experienced marked growth and develop-

ment over the last few decades, resulting

in signifi cant quantities of additional water

being piped into the region to satisfy water

demand. Th e present supply from Rand

Water to these areas amounts to about

2 900 Mℓ/d, of which about 50% is within

the Hartbeespoort Dam catchment. Th e

signifi cant increases in return fl ows from

these areas, as measured at the infl ow to

the Hartbeespoort Dam, can be observed

from Figure 1. Th e total volume of return

fl ows discharged upstream from the dam

ranges from 650 to >720 Mℓ/day, with an

increasing trend as depicted in Figure 1.

Th ese return fl ows have become an

important source of water supply to the

urban and bushveld mining complex

(platinum, chrome and base minerals)

developments north of the Hartbeespoort

Dam, and will in the immediate future

become even more important for supply up

to Lephalale (Ellisras Municipality) for the

extension of the Medupi Power Station.

To integrate and harmonise the

various environmental, biological, engi-

neering and socioeconomic aspects to

ensure sustainable solutions, requires

the involvement of a number of scientifi c

and engineering disciplines. With the

world population that has more than tri-

pled over the last century, the per capita

green footprint has increased between

9 and 50 times (third-world and fi rst).

Environmental impacts are still skyrock-

eting, with fewer resources available to

an ever growing modern civilisation. Th e

ability of eco-engineering to utilise and

integrate all disciplines to package the

best environmental option, might be seen

as the most appropriate way to go ahead.

Society needs to start taking respon-

sibility for the current level of environ-

mental degradation and water pollution.

The Waste Discharge Charge System

(WDCS) was established to promote

waste reduction and water conservation

under the National Water Act of 1998

(Act 36 of 1998). In terms of section 56

of the NWA, the WDCS endeavours to

introduce financial and economical in-

struments aimed at sustainable develop-

ment and utilisation of water resources,

Restoring the dam to its natural state

Floating wetlands form part of the HBPD remediation programme


internalisation of environmental costs,

and recovery of costs from the water

user/polluter. The WDCS forms part of

the pricing strategy where charges (in-

centives and mitigation charges) could

be levied from water users, based on the

polluter-pays principle.

Th erefore, the WDCS is primarily a

framework for charging for the discharge

of waste into water resources. It aims to

use economic instruments to encourage

polluters to internalise the social, eco-

nomic and ecological costs of discharges.

Th e ultimate objective is to reduce the

amount of waste that is discharged into

the country’s scarce water resources.

As part of the strategic development

of the system, testing will be done by

piloting the WDCS within the Crocodile

(West) Marico Water Management Area.

It is foreseen that the WDCS will cover

for a budgetary shortfall of 50% to meet

the required funding for catchment man-

agement. An estimated income in excess

of R400 million could be generated within

this sub-catchment, also providing funds

for the HBPD remediation projects.

FUNDNG SCENARIOSTh e future of the programme is de-

pendent on seeding funds from National

Treasury, and on external funding to be

recovered from waste discharge charges,

as discussed above. Th ree funding sce-

narios have been identifi ed, namely:

1. On-going operation and maintenance

(+R25 million/annum)

2. Fast-tracking (present 2012/2013 al-

location of +R50 million/annum)

3. Full-scale implementation of the

Hartbeespoort Dam Remediation

Programme, and extension of acquired

knowledge and experience to other

dams and catchments (+R120 million/

annum over three to fi ve years)

Ongoing operation will include the continu-

ation of tasks that will ensure the mainte-

nance of the current positive state of the

dam – biomass management (removal and

treatment of algae, hyacinths, litter and

debris, the establishment of fl oating

wetlands, and the remediation of the

shoreline) and food web restructuring (fi sh

removal) programmes. Th ese programmes

(which enhance the biodiversity and the

nutrient fi ltering capacity in the dam) will

be the least of the operations required to

ensure that the food web cycle within the

dam is managed in a manner that will pre-

vent the excessive hypertrophic state that

the dam is prone to.

Fast-tracking will include the tasks fo-

cused on the reduction of the dam’s internal

nutrient load (incoming sediment removal

and management) as a prerequisite to

making a considerable positive impact on its

ecosystem health and water quality.

Full-scale implementation will include the

continuation of all the identifi ed projects

in order to not only alleviate the eff ects of

undesired material reaching the dam, but

preventing them from reaching the dam in

the fi rst instance. Th is will entail a complete

roll-out of the programme as specifi ed

within the business plan, including the

long-term pre-impoundment and litter trap

projects. In addition it will include providing

assistance to the Department of Water

Aff airs through the licensing of the various

water uses around the Hartbeespoort

Dam, and the implementation of the Waste

Discharge Charge System (WDCS).

LAST WORDTh ere is no quick, easy and cheap solution

to rectify a problem that has developed

over more than 80 years. Th e restoration

of the Hartbeespoort Dam cannot be

considered a once-off action, but should

rather be seen as a series of well-planned,

integrated measures within the dam basin

and the Crocodile River catchment. Th ese

measures, the intensity of which would vary

depending on the programme’s implemen-

tation phase, should be strictly and persist-

ently carried out, now and in the future.

Currently these activities are

focused on the dam basin, and on de-

velopment of an improved catchment

management strategy, but future activi-

ties will mostly deal with catchment

management and maintaining of at-

tained trophic levels in the dam.

Petrus Venter

The state of the Hartbeespoort Dam has improved markedly since the start of the remediation programme


M O R E E N V I R O N M E N T A L E N G I N E E R I N G

Environmental Management –grudge vs green

THE AGEOLD ADAGE, where having to

undertake an environmental assessment

process in order to receive environmental

approval for a development was consid-

ered a strain on the project, appears to

have been diluted in recent years. In many

instances, environmental management is

now being seen by organisations as a valu-

able tool in ensuring that a development

or operation is both environmentally

sustainable and ‘green’ in nature.

Environmental Management is a

fi eld that is rapidly growing in im-

portance as a discipline of its own.

It is “the process of administering,

supervising or handling the environ-

ment in order to achieve a desired

outcome”. (Fuggle & Rabie 1999)

Globally, the implementation of environ-

mental management is not something that

has only come about in recent years, but

instead has been practised in countries

such as the US since the late 1940s, with

the drafting of legislation such as the

Federal Water Pollution Control Act (1948)

and the Air Pollution Control Act (1955).

Nevertheless, the stringent implementa-

tion of such laws in the US only came to

the fore in the so-called ‘Environmental

Decade’ (1970-1980) with the signing of the

National Environmental Policy Act (1970).

Closer to home, the National

Environmental Management Act (NEMA)

(1998, as amended 2010) is the foremost

piece of legislation regarding environ-

mental regulation within the borders of

South Africa. Th e Act was necessitated

from Chapter 1 of the South African Bill of

Rights which says, “it is the right for every

citizen to have access to a clean environ-

ment” and it is on this foundation that

the subsequent NEMA Regulations were

drafted. Environmental management forms

a part of the White Paper on Environmental

Management Policy in South Africa and has

been written into the NEMA, and is thus

both formally and legally recognised.

Th e main aim of the Act is to provide

for cooperative governance by estab-

lishing decision-making principles on

matters aff ecting the environment, such

as sustainable development, an environ-

mental management approach, a polluter-

pays principle, a cradle-to-cradle develop-

ment responsibility, a precautionary fi rst

principle, and lastly, the involvement of

stakeholders in decision-making.

Of particular importance are the

Environmental Impact Assessment (EIA)

Regulations of the Act, which identify

activities that may have a substantially

detrimental eff ect on the environment. Th e

identifi cation of these activities results in

the proposed activity being prohibited, un-

less the competent authority has granted

written authorisation after consideration of

the environmental impacts.

An environmental impact can be

considered as being one of the three pil-

lars of sustainability (be it either positive

or negative), namely environmental, social

and/or economic impacts. But how does

one assess and manage these environ-

mental impacts?

Environmental Impact Assessment

(EIA) is predominantly a tool used in

order to assist authorities in ascertaining

whether development projects should pro-

ceed or not, based on the associated envi-

ronmental, social and economic impacts.

Typically, EIAs look at all the advantages

and disadvantages of any proposed project

in order to assist the decision-making

authority in arriving at an outcome. EIAs

Craig Allen

Project Environmental Manager

Strategic Environmental Focus (Pty) Ltd

[email protected]

The pillars of the sustainability triangle


When I say I’ll deliver... I deliver!Peter YamanGeneral Manager - Projects/Heavy Lift Division

Together, the Johnson team delivers a SMART liftSafety | Maintenance | Availability | Reliability | Total Cost Effectiveness

Tel: +27 (011) 455 9222 or 0860 CRANES | Fax: +27 (011) 455 9230

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by

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are the responsibility of both national and

provincial authorities where policy for-

mulation and coordination typically take

place at national level, whilst the approval

of EIAs for most developments has been

devolved to the provinces.

Th e assessment of the above-

mentioned environmental impacts is a

specialised fi eld of practice which, by law,

must be undertaken by an independent

environmental assessment practitioner

having no benefi t or pay-off from the

resulting authority decision. Following on

from the assessment of said impacts, the

accompanying management and mitiga-

tion thereof become critically important.

When considering the management

of the impacts that were identifi ed during

the EIA, environmental management

and its associated tools come to the fore.

As previously outlined, environmental

management is largely concerned with

fi nding the right balance between the

development/activity/operation and the

surrounding environment, i.e. the man-

agement thereof. Th e diff erence between

environmental management and EIA is

that environmental management is a whole

philosophy, as described above, whereas

EIA is just one tool or technique used to

gather and analyse environmental infor-

mation that is a part of the overarching

environmental management process. In

reality, environmental management is

supported by a wide range of tools and it

is imperative that the environmental man-

agement tools that are suited to the needs

of the organisation are chosen, adopted

and implemented in all facets of the de-

velopment/operation. Companies need to

decide which tools, or parts of the diff erent

tools, their businesses need to implement

in order to achieve business sustainability.

Companies need to decide which tools, or parts of the different tools, their businesses need to implement in order to achieve business sustainability


A framework of published guide-

lines is available from the Department

of Environmental Aff airs and these

guidelines attempt to ensure that envi-

ronmental considerations are taken into

account at every stage of the project,

process or policy. In other words, envi-

ronmental management is not only used

in looking at, for example, the environ-

mental impact of converting undeveloped

land to a sugarcane plantation (project),

but it also looks at the environmental

impact of increasing the sugarcane price

(policy), which may encourage more land

to be used for sugarcane-related activities.

Th e impact of social programmes is also

considered, for example the implications

of encouraging new sugarcane farms

(programmes). When implemented and

applied in a sustainable manner, environ-

mental management considers environ-

mental elements from the inception of

the idea right through to the decommis-

sioning or closure of the project.

When breaking environmental man-

agement down into its various compo-

nents, the complexity of the concept can

be further simplifi ed:

■ Planning tools include the assessment of

environmental, social and cultural im-

pacts, and life cycle assessment, as well

as planning for land and resource use,

waste management and environmental

emergencies.

■ Tools supporting the implementation of

environmental management include the

use of standards such as ISO14000, as

well as pollution prevention and cleaner

technologies.

■ Checking and improvement tools

include environmental monitoring,

accounting and auditing, whereas tools

for reporting and communicating

include public participation, risk com-

munication, confl ict management and

environmental assessment reports.

Environmental management and the

correct application thereof is signifi -

cantly based on the understanding and

experiences gained from similar previous

environmental management issues, and

as a result the future implementation of

corrective mitigation measures to prevent

such environmental problems can be in-

creased, based on previous experience.

So, the concept behind environmental

management seems rather simple once

broken down, and the implementation

thereof can be achieved relatively easily

by way of various tool applications. But

the question still remains: what benefi t

is there for an organisation to implement

environmental management measures

into its operations?

Th e answer is - sustainable de-

velopment! Th e phrase ‘sustainable

development’ has fast become an easily

brandished term when referring to the

impacts which a proposed development/

operation may have on the surrounding

environment. If one were to look on the

internet for a defi nition, one would be

swamped with a multitude of defi nitions,

but essentially what the concept implies

is a simple one. Sustainable development

is to invite one to evolve beyond pure

self-gratifi cation and short-term thinking

into awareness and an understanding

that harm to one will eventually cause

harm to all. Furthermore, it invites the

individual to step beyond current norms

of thinking and behaviour to become

conscious of the absolute intercon-

nectedness and inter-dependence of all

things in our surrounding environment.

Where there is a common thread

between environmental management

and sustainable development is that

both terms describe the implementation

of processes which run from start to

finish. By implementing environmental

management during the planning

process of a project, an organisation can

proficiently ensure that sustainability

is considered throughout the life of the

operation or activity.

Th erefore, by adopting a tailored

environmental management approach an

organisation can ensure long-term stra-

tegic visions, thus linking diff erent envi-

ronmental policies at diff erent business

levels to ensure coherency throughout the

organisation, ultimately ensuring that a

sustainable approach is being strived for.

In addition, environmental management

implies tackling related issues, such as

governance, spatial planning, social eco-

nomic wellbeing and environmental stew-

ardship, together in a holistic manner.

And without a doubt the easiest way to

achieve this sustainability approach is by

way of implementing an Environmental

Management System (EMS). More specifi -

cally, an organisational EMS, which would

serve as a tool to improve environmental

performance and provide a systematic

way of managing all environmental

Onllwyn turbines, an example of sustainable, renewable energy


aff airs, as well as improving the consist-

ency and coherence between diff erent

divisions/operations that may be present.

Th is needs to be outlined from an envi-

ronmental objective perspective, within

the available budget, in order to maximise

the eff ectiveness and implementation of

the organisation’s overarching objectives.

An EMS is the aspect of the organi-

sation’s overall management structure

that addresses immediate and long-term

impacts of its products, operations, ser-

vices and processes on the environment,

as well as giving order and consistency

for the organisation to address environ-

mental concerns through the allocation

of resources, assignment of responsibility

and ongoing evaluation of practices, pro-

cedures and processes. All in all an EMS

focuses on continual improvement of an

already functioning system.

An example of shifting an organisa-

tion’s existing EMS is how to manage the

ever-increasing pressure for power gene-

ration to meet a growing energy demand,

whilst still maintaining sound environ-

mental sustainability practices. As an

energy producing organisation, whether

it be wind, solar, tide or geothermal heat,

the era of harnessing renewable energy

should undoubtedly be the shift of their

focus. Why should a power-generating or-

ganisation choose not to exploit an energy

resource which is considered capable of

self-generation? A resource, furthermore,

which when exploited, ensures reduced

environmental impact in a society where

the concept of ‘environmental impact’ has

become progressively more important and

has shifted to the forefront of everyone’s

thinking. Th is is not to say that there

is currently no place for existing power

generating practices, but rather that a

gradual shift in thinking is needed if envi-

ronmental sustainability is to be ensured

for generations to come.

In conclusion, the term EIA has been

around for many years and most profes-

sionals are fully aware of what an EIA

entails and how one needs to go about the

process in receiving an environmental

approval. But should one’s environmental

onus ultimately end there? Th e answer is

NO for organisations that are adopting

an innovative approach to environmental

sustainability and are currently elevating

their level of environmental responsibility

to that of a change in employee thought

patterns and everyday operational man-

agement practices.


Durban’s Electron Road Waste Transfer Station – effi cient cost-effective transportation of waste material

THE eTHEKWINI MUNICIPALITY is busy constructing a

1 200 tonnes/day Waste Transfer Station to serve the Durban

area. Th is new waste management facility will provide a modern

and mechanised means of transferring municipal general solid

wastes to landfi ll sites effi ciently and cost-eff ectively.

Jeff ares & Green (engineering and environmental consultants)

were appointed to design a modern, mechanised Waste Transfer

Station (WTS) at Electron Road in Springfi eld Park, an industrial

and commercial area north of Durban, near the banks of the

Umgeni River.

Th e main structure, a refuse transfer station and compac-

tion hall, will be built on a site roughly 4 ha in size. Th is is where

waste will be off -loaded, compacted and containerised for bulk

transportation. Th e objective of the facility is to reduce the ex-

pense of having to transport solid waste to landfi lls, which are

sited further and further away from the point of generation.

At present, most of the waste in Durban City is disposed at

the Bisasar Road landfill site in Springfield Park, but this site

is reaching full capacity. When capacity is reached, waste col-

lection vehicles would have to travel to the Buffelsdraai land-

fill site approximately 33 km away, which is more than double

the distance (15 km) that is considered an economic travelling

cost for collection vehicles. These prohibitive transport costs

have made the provision of a WTS financially viable, particu-

larly since the Electron Road site is less than 1 km from the

Bisasar Road site. The reduced travelling will also reduce fuel

consumption and wear and tear on roads, and will hence con-

tribute to reduction in carbon emissions.

DESIGNTh e Electron Road WTS will comprise a main four-storey building

and some 4 290 m2 in plan, in which waste will be off -loaded into

compaction units, compacted into purpose-made containers for

bulk transportation, and then transported to the new Buff elsdraai

landfi ll site. Associated infrastructure will include a three-storey

offi ce block adjacent to the main compaction house, as well as an

auditorium for education and training purposes.

Th e upgrading of Electron Road itself entails, amongst others,

providing dedicated access to the site, and access roads to the

various handling areas within the site. Th e full contract involves

the construction of the refuse transfer station, a compaction

hall, container-handling operations, offi ces, weighbridge infra-

structure, and mechanical equipment and plant, in addition to a

workshop, wash bay, diesel storage facility, security facilities, and

the entrance building.

Th e design also includes the maximum use of natural lighting

and ventilation, stormwater treatment, and pollution control by

means of litter traps, silt traps and oil traps. Specifi c stormwater

treatment processes have been designed to control pollution and

allow discharge of an acceptable effl uent from the site.

Electron Road site in Durban at the start of construction in March this year


Editor and communications specialist Debbie Besseling

Out-of-sight Out-of-mind

IDUBE MEDIA

A unique feature of this project is the compaction process

that will be used for the fi rst time in South Africa. Th is system

was accepted as an alternative design proposed by the successful

bidder, Aveng Construction. Th e Husmann Compaction System,

imported from Germany, does not use conveyors, and provides

an extremely quick and clean answer to waste compaction.

CONSTRUCTIONConstruction on this R140 million project started on 12 March

this year and will continue for 78 weeks, although the con-

tractor is targeting an earlier completion date. Piling and layer

works are currently in progress. According to Brad Wyatt,

senior contracts manager, Aveng will be using a unique ap-

proach to the required 156 concrete columns: “Instead of doing

7.5 m columns in the conventional way, we will be pre-casting

them on the ground and then lifting them into place,” he says.

“Th is will result in outstanding quality, plus a safer and quicker

method than the conventional way.”

Another innovative construction approach will be the

tilt-up wall system which will be erected fully-formed on site.

Instead of conventional brickwork needing to be laid layer by

layer, these walls are cast in proprietary moulds that have the

same face-brick fi nish as a conventional wall and will then be

erected as complete units.

GEOTECHNICAL ENGINEERINGAs mentioned above, piling is currently under way, but in founding

conditions that are less than ideal, as the site is underlain by deep

alluvial deposits which are typical of the low-lying areas in and

around Durban. Th ese harbour beds comprise unconsolidated

sediments of sand, silts and clays in variable layer thicknesses

which extend to considerable depths. Th e soft-clay horizons have

a high organic content and are highly compressible, resulting in

long-term settlement of the clays once an imposed load is applied.

Specialist piezocone testing was undertaken across the foot-

print of the structure.Th e piezocone equipment is a modifi cation

from the original cone penetration test (CPT). Th e results of the

piezocone testing indicated that a competent founding medium

of dense coarse sand was encountered only at a depth of about

25 m below ground level.

Several piling options were investigated and the precast

driven pile was the one most suited to the site, as it is capable of

extending to signifi cant depths and is relatively quick to install.

Th e fi nal design includes more than 400 No 350 mm x 350 mm

A similar stormwater bio-swale as this one at the Kraaifontein Waste Management Centre in Cape Town will be built at the Electron Road site

The design also includes the maximum use of

natural lighting and ventilation, stormwater treatment,

and pollution control by means of litter traps, silt

traps and oil traps. Specifi c stormwater treatment

processes have been designed to control pollution

and allow discharge of an acceptable effl uent

from the site. A unique feature of this project is the

compaction process that will be used for the fi rst

time in South Africa. This system was accepted as

an alternative design proposed by the successful

bidder, Aveng Construction. The Husmann

Compaction System, imported from Germany, does

not use conveyors, and provides an extremely quick

and clean answer to waste compaction


precast driven piles to depths between 25 and 29 m, and even

beyond. Some recently driven piles have reached a depth of 39 m.

LANDSCAPINGDSW Cleansing & Solid Waste will apply the same award-winning

environmental approach at Electron Road as was used at the

Mariannhill Landfi ll Conservancy Site, just outside Durban, which

is today considered a best-practice ecosystem restoration project.

Th e successful process is driven by PRUNIT (Plant Rescue

and Relocation Unit), headed up by Richard Winn, a horti-

culturalist and rehabilitation specialist. Th is unit applies the

philosophy of moving plant species once only, and uses a reha-

bilitation nursery only as a backup when direct relocation is not

possible. Th e basic principles are:

■ To try and relocate species to an environment as close to the

original as possible.

■ To import no foreign soils.

■ To relocate grasslands together with original topsoil.

■ To relocate original watercourse species to wetland nurseries

for future utilisation.

■ To create similar habitat to what originally occurred.

■ To only relocate species within 50 km, as per international

biodiversity protocol, but preferably closer.

Th is ecosystem restoration project has created a large holding

nursery for storage of indigenous vegetation, which has been

“hardened-off ” to withstand rigorous conditions with little or no

maintenance. For example, a nursery of wetland plants has been

grown for the future establishment of “leachate through wet-

land” processes of returning water back into the environment,

and these plants have been specifi cally hardened-off for contami-

nants found in the waste industry.

Very little plant material could be salvaged from the Electron

Road site and DSW, PRUNIT and Jeff ares & Green worked

closely together to develop an Autocad design of what could be

provided by the holding nursery.

Clearly this is not a “plant by numbers” landscaping process,

but rather an attempt to create a sustainable ecosystem where

every plant is selected and planted to fulfi l a specifi c purpose.

Th e engineered stormwater swales, rainwater harvesting and

stormwater ponds have been designed to interlink, and are to be

planted with indigenous vegetation selected to help provide func-

tional solutions to issues identifi ed on site.

Street furniture, lighting, signage, benches, tables and water

points have been incorporated into the landscape design, together

with habitat creation opportunities, including bird totem poles,

structures for fl y traps, and bat and owl houses, linked to the ro-

dents, insects and reptiles that are likely to establish themselves

along with the operational activities of the site. A deck area has also

been included on the western stormwater attenuation pond, linked

to the offi ce building on site. Th e project is indeed an attempt to

soften the environmental impact with natural, green solutions.

OTHER GREEN ENGINEERING INITIATIVESVarious other green elements have been considered, over and above

those already mentioned. One such carefully designed aspect is the

bio-swale, which is a landscaped open stormwater system (channel)

to enhance the removal of solids, metals, and the like.

Other initiatives are, for example, stormwater inlets designed

to eff ectively remove litter and sediment before these reach other

systems. Rainwater, too, will be captured for benefi cial use and for

the washing of fl oors, containers and vehicles on site. Visual aids to

monitor energy consumption on site, are also being considered.

INFO

Charmagne Denny

Marketing and Communications Manager

Jeffares & Green (Pty) Ltd

[email protected]

An example of the materials recovery process


Sabita commissions carbon measurement tool forSouth Africa’s bituminous products industryA GUIDELINE DOCUMENT and

software system for the measurement

of carbon emissions by all operations

associated with the manufacture and ap-

plication of bituminous products in South

Africa’s roads industry is now available for

implementation.

Adapted for South African condi-

tions by the United Kingdom’s Transport

Research Laboratory (TRL), the Asphalt

Pavements Embodied Carbon Tool

(asPECT) facilitates the carbon foot-

printing of asphalt products and opera-

tions, and of product-to-product com-

parisons and project carbon assessments.

Th e system is made up of protocol and

guidance documentation and software ap-

plications, originally developed in the UK

in a collaborative undertaking between

national and local highway construction

clients, trade associations for mineral

products and bitumen, and the TRL.

Th e formal context for greenhouse

gas (GHG) reporting is rapidly being

established. At the world climate talks

in Copenhagen in 2009, South Africa as

a nation agreed to cut carbon emissions

by 34% by 2020 (based on 2009 levels),

subject to certain conditions. Th ese com-

mitments will inevitably fi lter down to

individual product supply chains, and the

prospect of a carbon tax provides further

incentive to measure and ultimately cut

carbon generation.

Th e asPECT protocol defi nes the

methodologies which are to be applied

to the calculation of carbon dioxide and

other GHG emissions from asphalt mix-

tures per tonne. Th e calculations are spe-

cifi c to individual mix formulations from

individual production units incorporating

all constituent materials. GHG contri-

butions as carbon dioxide equivalents

(CO2e) are accounted for whether they are

directly generated by the operator or indi-

rectly by sub-contractors or suppliers.

Th e accompanying asphaltCALC

software provides a framework which

contains the necessary formulae, emis-

sions factors and default data to calculate

the GHG emissions of asphalt products

in accordance with the protocol clauses

and the information provided here. Th e

guidance document, the protocol and the

software constitute the Asphalt Pavement

Embodied Carbon Tool (asPECT).

“Fundamentally the principle of

carbon footprinting remains the same

whether measured in the UK or in South

Africa,” Sabita CEO Saied Solomons says.

“Th e regulatory context for greenhouse

gas reporting is becoming ever more

rigorous, and in Europe large energy

consumers, local authorities and local

authority partnerships now have to report

carbon emissions to comply with various

statutory requirements.”

He adds that, while South Africa’s Air

Quality Act governing GHG emissions is

in place, the pending carbon tax legisla-

tion is a strong incentive for the bitumi-

nous products industry to be more aware

of emissions and better able to measure

and thereby control its production of

carbon dioxide by variation in the type

of energy used or the type of asphalt mix

produced.

“It must be remembered that the

South African bituminous products

industry has already made important self-

driven contributions towards minimising

GHG emissions through the development

of warm mix asphalt (WMA), which

signifi cantly reduces the temperature at

which the asphalt mix is manufactured

and applied, with measurable savings in

fuel usage and GHG emissions. Another

recent initiative is the implementation of

high-modulus asphalt (HiMA), a highly

durable long-life pavement system which

off ers reduced carbon footprint by sig-

nifi cantly extending the period before

maintenance and reconstruction would

be required,” Solomons says.

Th e asPECT software is a stand-alone

executable, built on the Microsoft .NET

platform, and users can download a free

copy, subject to a licencing and conditions

of use agreement, from the Sabita website

for use on their computers. Th e software

is able to analyse CO2e emissions associ-

ated with the fuel used in any specifi c

operation in the asphalt production and

application chain, from the production


and delivery of raw aggregate or bitumen

to the manufacture of asphalt, the prepa-

ration of road works layers and the paving

of the fi nal wearing course.

“In other parts of the world, it is be-

coming common for client organisations

to impose carbon awareness require-

ments on their suppliers for considera-

tion at the procurement stage, which

has made carbon awareness another

potential marketing tool for industry. It

is hoped that the outputs of the asPECT

project will assist in capturing the data

that will facilitate the necessary calcula-

tions for clients, industry and wider

stakeholders for product level assess-

ment,” Solomons says.

Th e asphalt life cycle includes the ten

steps indicated in Table 1.

INFO

Saied Solomons

CEO: Sabita

[email protected]

Table 1 The ten steps of the asphalt life cycle

Life cycle stage Description

1 Raw material acquisitionAcquiring raw materials from the natural environment with the input of energy

2 Raw material transportTransporting acquired raw materials to processing

3 Raw material processingCrude oil refi ning, rock crushing and grading, recycled and secondary material reprocessing

4Processed material transport

Transporting processed raw materials to site of manufacture of bitumen-bound highway components

5Road component production

Production of bitumen-bound mixtures

6 Material transport to site Delivery of materials to site

7 InstallationPlacing materials at the construction site, mobilisation of plant and labour

8 Scheme-specifi c worksInstallation of other specifi ed materials directly to site (e.g. aggregates and geosystems)

9 MaintenanceInterventions to maintain the road: overlay, surface dressing works, patching, haunching, etc

10 End of lifeExcavation and material management, mobili-sation of plant and labour

Use

THIS BOOK, a 302-page compilation of 51 essays regarding renewable and nuclear energy, is easy to read and very informative. The wide spectrum of topics covered in the book will enable the reader to gain a vast general knowledge about nuclear history, basic nuclear principles and major incidents and accidents that have shaped the future of this powerful and controversial energy resource.

Each essay is self-contained and ex-tensively referenced. The book is illustrated with over 100 pictures and fi gures, many of them rare and retrieved from international archives, with signifi cant historical interest.

The civil engineer who wants to broaden his/her general knowledge on nuclear and renewable energy resources will undoubtedly fi nd this publication

very interesting. As civil engineers we have to adapt to changing technology, and if more nuclear power stations are planned for the future in South Africa, it will certainly affect the way we design and construct.

Karin Jansen van Rensburg

Lecturer: Dept Civil Engineering

University of Pretoria

[email protected]

Author: CM Meyer

Publisher: EE Publishers (Pty) Ltd

First Edition: November 2011

ISBN: 978-0-620-51754-6

Price: R375.00 including VAT

and postage in South Africa

To order: www.eepublishers.co.za

Is Chernobyl dead?B O O K S

About the author Chris Meyer, who has a knack for ex-plaining technical concepts through writing, has written many popular articles on science and technology over the years, particularly during his years with the CSIR. He has since been working for the South African Bureau of Standards as an editor of a technical journal and as a technical publicity specialist, and currently as technical reviewer. Chris is also well-known for his historical articles on big game hunters.

DRIVING YOU TOWARDS A GREENER FUTURE.

SABITA SUPPORTS A SUSTAINABLE ROAD INDUSTRY THROUGH THE USE OF BITUMINOUS PRODUCTS

SOUND ENVIRONMENTAL ROAD DESIGN

DESIGNED TO BE MORE SUSTAINABLE

REDUCING ENERGY AT PRODUCTION REDUCES CO2

IT’S THE RIGHT THING TO DO

Southern African Bitumen Association

Tel: + 27 (0)21 531 2718 Fax:+ 27 (0)21 531 2606 e-mail: info@sabita .co.za www.sabita.co.za


INTRODUCTIONStatistics reveal that South Africa has al-

most double the global average road death

toll per capita, which is quite frightening

considering our socioeconomic circum-

stances (Vanderschuren et al 2011). South

Africa spends R52 billion on road crashes

and fatalities annually; it is therefore clear

that road safety investments are war-

ranted (Tsedu 2009). Clear demarcation

and visibility on our roads have proved to

reduce accidents.

However, since the 1960s road lighting

has remained largely unchanged, until

the past decade, which has seen a rapid

development in lighting, and technological

advances made possible by the development

of the LED (light-emitting diode). A LED

is a semi-conductor that emits visible light

when an electric current passes through it.

LEDs are used in television and computer

screens, and are now readily available as

a light source, for example as light bulbs,

down-lights, fl oodlights and for strip-

lighting. LEDs are environmentally friendly

and sustainable, as they are long-lasting

(with a lifespan of 30 000 plus hours), ef-

fi cient, cost-eff ective, cool, emit minimal

ultra-violet light and are mercury free.

The potential of LEDs for use in

the road environment is vast, exam-

ples of such applications being street

lights, traffic lights, LED road studs,

road signage and Intelligent Transport

Systems (which use LEDs in message

signs). LEDs have brought about a revo-

lutionary wave of change to the way in

which road lighting can be utilised. This

article is about the use of LEDS in road

studs and their potential to increase

visibility and safety within the road

environment.

LIGHT POLLUTIONConventional roadway lighting causes

considerable light pollution of between

35–50% of total light pollution of a

city (Boyce et al 2009). Although street

lighting provides increased visibility, it

is a major contributor to light pollution,

with up to 30% of roadway lighting not

reaching the roadway. Current lighting

options utilise vast amounts of electricity

and are unnecessary (Luoma et al 2011).

One method that is used to reduce elec-

tricity for street lighting is to switch off

every alternate light. Th is is, however,

more costly than the use of LEDs, as it

results in a 17% increase in accidents

and a 27% increase in roadside damage

(Elvik et al 2009). Light from LEDs, on

the other hand, can be directed to where

light is required, thereby limiting unnec-

essary light pollution.

W E S T E R N C A P E

Lucinda Holdridge

Earth Power Energy Solutions

[email protected]

Solar road studs:an innovative solution to increase visibility

and safety on South Africa’s roads

Illumination from raised solar road studs provides night-time visibility for up to 1 000 metres ahead

The solar cat’s eye, made of tough polycarbonate material, has a low profi le above the road surface and a 60-ton compression resistance


IMPROVING ROAD VISIBILITYA 2002 study indicated that the main road

factors contributing to road accidents

were poor visibility (34%), sharp bends

(17%) and slippery roads (17%) (Ojungu-

Omara & Vanderschuren 2006).

According to Th e Handbook of Road

Technology, “glare is formally defi ned as

luminance greater than to which the eye

is accustomed”. Headlights, strong road

lighting and high-pressure sodium lights

cause a certain amount of glare which is

distracting for drivers, dramatically af-

fecting their visual perception (Elvik et

al 2009). During the hours of darkness,

a driver’s visual environment and visual

sensitivity are severely diminished, and

these deteriorate further when glare is

experienced, commonly from oncoming

headlights (Elvik et al 2009). Drivers need

the navigational guidance provided by the

illumination of the roadway and its sur-

roundings, such as pavements, centre-line

and road edge delineation, to inform them

of the current vehicle position and to

navigate the road ahead (Elvik et al 2009).

Refl ective road studs (cat’s eyes) have

been in use on South Africa’s roads for

more than 40 years to improve visibility

at night. Th e problem with these conven-

tional road studs, however, is that they

only have a refl ective portion and rely on

car headlights for illumination. Refl ective

road studs do not allow the driver an ef-

fective reaction time, compared to solar

road studs which illuminate the roadway

for up to 1 000 m, thus improving the

driver reaction time to potential hazards

from three to thirty additional seconds

when travelling at a speed of 100 km/h.

Solar road studs would be helpful when

glare is encountered as they would assist

the driver in staying on the roadway by

providing illuminated guidance in the

event of glare from headlights, streetlights

or other sources.

WHEN ARE SOLAR ROAD STUDS USEFUL?At night

Statistics reveal a disproportionate

number of accidents at night, compared

to daylight hours, with multi-vehicle

crashes twice as likely to occur, and

pedestrian accidents four times more

likely to result in a fatality (Lay 2009).

At night a driver relies on light in order

to navigate a roadway. In urban areas

light is generally provided primarily in

the form of street lighting, but in rural

areas drivers rely solely on vehicle head-

lights to navigate the roadway ahead

(Lay 2009). Reflective road studs are

limited in their application as the reflec-

tive portion requires light to reach it in

order to increase visibility, and studies

done in America found that most

driving is done with dipped headlights.

The beam of a car’s headlight when

dipped is limited to 30–50 m (Elvik et

al 2009) and up to 90 m with headlights

on, and this is only made visible in the

direction that the car is travelling.

According to Boyce et al (2009), “a

bright road surface is obtained by di-

recting beams of light up and down the

road in such a way that sufficient light

is reflected off the surface to reveal ob-

jects of uneven surfaces, whilst keeping

glare at a minimum”. Solar road studs

effectively illuminate the road surface,

providing greater vision and viewing

distance at night. They do not require

electricity and can feasibly replace over-

head street lights.

In wet road conditions

Light is refl ected off a wet road due to

a water fi lm, but refl ections are further

increased on an uneven road surface, cre-

ating a mirror-like eff ect which decreases

visibility (Lay 2009). Certain street

lighting creates glare, such as that pro-

duced from high-pressure sodium (HPS)

The hardwired LED stud is a 24-hour operational road stud for use at pedestrian crossings, speed bumps and intersections

A pedestrian crossing fi tted with hardwired hybrid LED road studs


lights. Th ese patches form a T-shape if

lighting levels are sub-optimum, and

with a further drop in lighting levels

the illuminated areas form a contrast

between illuminated strips and darker

shadows (Lay 2009). If the roadway is wet

the illuminated strip transforms into a

hazardous strip of mirrored light, which

makes the detection of refl ective road

studs, traffi c markings and objects in the

roadway virtually impossible (Lay 2009).

Solar road studs off er a solution by in-

creasing visibility on roadways – they are

actively illuminated, remaining brightly

visible, even during wet conditions (Lay

2009). Car headlights illuminate objects

directly along the roadway, while solar

road studs provide the same function, but

are self-illuminated and improve visibility

for up to ten times the distance of the

road ahead (Boyce et al 2009).

In fog and mist

Fog and mist cause a scattering of light

particles, making light penetration harder.

Solar road studs will illuminate the road

for a minimum of double the visibility dis-

tance that car headlights provide in these

conditions (Boys et al 1997). In severe fog

conditions the increased visibility will

therefore provide a minimum of double

the time for a vehicle to react to potential

road hazards. Solar road studs are eff ec-

tive in fog conditions as they are placed

on the roadway and their (LED) light pen-

etrates fog better (Boys et al 1997).

At pedestrian crossings

Well marked pedestrian crossings alert

the driver to potential hazards, thereby

ensuring driver and pedestrian safety

(Zwahlen et al 1997). Solar road studs and

LED hardwired studs are ideal for this

purpose.

SOLAR ROAD STUD CASE STUDIESIn 2003 a two-year pilot project was

carried out in KwaZulu-Natal (KZN),

north of Durban along the R66, in which

7 800 solar road studs were installed

along a 34 km stretch of road. Seven

months prior to the installation 103 ac-

cidents had occurred, 88 of which were

serious and resulted in 27 fatalities, and

15 less serious accidents (Reed 2006).

Th e 103 accidents in question cost the

South African government an estimated

R27 million, while the solar road studs

cost R5 million! According to the KZN

transport department, night-time road

accidents were reduced by 70% within

12 months of the installation of the solar

road studs.

In Britain a six-mile unlit section

of the M25 was fi tted with 4 500 solar

road studs as an alternative cost-eff ective

solution to street lighting in providing

improved driver visibility. UK research

showed that when solar road studs are

used, drivers are signifi cantly less likely

to cross solid centre-lines or move out

of lanes on a dual carriageway, and they

brake earlier and more consistently

(Reed 2006). In addition to improved

driver guidance, its application reduces

carbon emissions and operating costs.

Th is study indicates that solar road studs

can provide the same functionality and

level of illumination required for accident

prevention as street lights, but at substan-

tially lower cost.

Planned hybrid LED

hardwired road stud test in Cape Town

Safety at pedestrian crossings needs at-

tention, as 45% of road accidents in South

Africa involve pedestrians (Tsedu 2009).

Earth Power has recently developed a

hybrid LED hardwired road stud to illu-

minate pedestrian crossings and improve

road safety in general; the LED light is

operational for both day and night to en-

sure safe crossing and increased visibility

for pedestrians. When hardwired LED

road studs are placed on either side of

pedestrian crossings, results indicate that

there is a reduction in the average speed

of approaching vehicles and an increase in

the number of motorists who stop at the

crossing (Bullough et al 2009).

Hybrid hardwired LED studs are

useful as they require minimal electricity

and can be powered by mounted solar

panels in remote locations if there is no

available power source. Th e studs op-

erate continually 24 hours per day, pro-

grammed by a controller that automati-

cally dims the LEDs at night to reduce

glare and provide eff ective illumination.

Earth Power is currently consulting with

a senior traffi c engineer at the City of

Cape Town to fi nalise a suitable trial site

within the City to test the hardwired

LED road studs.

CONCLUSIONS AND RECOMMENDATIONSRoad lighting is a crucial part of road

design, and designers need to ensure the

roadway is adequately lit to provide illu-

mination of the road ahead and increased

reaction time (Lay 2009). Solar road studs

off er numerous benefi ts, as mentioned in

this article.

Solar road studs should be of a high

quality, have a high compression resist-

ance and wide temperature range, and

should be correctly suited to their ap-

plication, be it on the road edge, curves,

intersections, pedestrian crossings or

centre-line markings.

Th e road sector should aspire to apply

automatic integration of safety measures,

as is standard in aircraft safety. Hence,

road studs should be incorporated into

designs as an additional safety measure.

Installing and upgrading roads with the

use of LED lighting and solar road studs

or hardwired studs will make a vital

contribution to the reduction in road ac-

cidents and the unacceptable burden they

impose on society.

NOTEThe list of references is available from the editor.

SOLAR ROAD STUD BENEFITS SUMMARISED

(Boyce et al 2009) ■ Maintenance-free and fully self-contained ■ Reliable and robust design ■ Proven reduction of night-time accidents by over 70% ■ Improved driver visibility – 10 times better than traditional refl ective road studs ■ Visible for up to 1 000 metres ■ Visible in adverse weather ■ Highlights sharp bends and road hazards well in advance ■ Allows substantially more time to react and anticipate road conditions ■ Eliminates the need for street lights, thereby reducing costs ■ Environmentally friendly ■ Reduces light pollution ■ Reduces wildlife road kill

Solar road studs have a lifespan of three to ten years, depending on battery type, quality of materials, the installation location, and the number of LEDs.


Ronald Haiden

Manager

Infrastructure and Development

IRT Implementation Department

City of Cape Town

[email protected] innovationsBACKGROUND AND AIMSCape Town needs a safe, aff ordable,

effi cient public transport system.

Capetonians make over one million trips

every day by train, bus and minibus taxi,

but these services are not safe, frequent

or predictable enough. Meanwhile,

those commuting by car are facing ever-

increasing delays due to congestion.

Th e City of Cape Town cannot continue

building roads to accommodate the rising

numbers of cars.

Bus Rapid Transit (BRT) costs four

to twenty times less than light-rail and

underground-rail systems respectively,

and is the best known way to effi ciently

transport relatively large numbers of

people as cost-eff ectively as possible

in developing countries. Th e City of

Cape Town has been infl uenced by, and

adapted, the successful BRT models fi rst

developed in the Curitiba in Brazil, and

Bogota in Columbia. BRT systems are

being developed in many cities worldwide

and Cape Town transport engineers are

keeping abreast of these.

Th e City aims to ultimately coordinate

train and bus services into a single effi cient

Integrated Rapid Transit (IRT) system,

which will be accessible on a network of

walking and cycling routes. Th e main

component of the system will be the new

network of safe, aff ordable, scheduled BRT

services. Th e aim is to eventually build a

reliable, safe and cost-eff ective transport

network within 500 m of 75% of all trip

origins and destinations in the city.

Th e brand name of the service is

MyCiTi.

Table View BRT – dedicated bus lanes allow MyCiTi buses to avoid traffi c congestion


BUS RAPID TRANSIT Th e key elements and design principles

of BRT, incorporated into the MyCiTi

service, include the following:

Infrastructure

■ Bus lanes (dedicated lanes, or shared

with mixed traffi c with ‘queue-jump’

lanes where justifi ed)

■ An integrated network of routes along

corridors

■ Closed median stations and open kerb-

side stops

■ Stations that are convenient, comfort-

able, secure and weather-protected

■ A universally accessible system

■ Improvements to the nearby public

space

Operations

■ A frequent, rapid service between

major origins and destinations

■ Ample capacity for passenger demand

■ Rapid boarding and alighting

■ Cashless, distance-based fare system

■ Predominantly pre-board fare

collection and verifi cation

■ Fare integration between routes,

corridors and feeder services

General

■ Technology including low-

emission, low-noise vehicles

■ Distinctive branding identity,

customer service excellence

■ Clear route maps, signage and

real-time information

PHASED IMPLEMENTATIONTh e MyCiTi network is being developed

in phases. Th e fi rst phase was set up for

the 2010 FIFA World Cup, which the City

had a contractual obligation to provide.

Th is consisted of routes between the Civic

Centre station in the CBD and the Airport

and Cape Town Stadium, and a route

around the inner city.

In May 2011 a trunk route was

launched along the dedicated red bus

lane on the R27 between Cape Town

and Table View, along with a network of

interconnecting services around the resi-

dential areas of Table View, Parklands and

Blaauwberg. At the same time a temporary

route was launched around the inner city.

Th ese services are enormously popular.

Th e buses are packed during peak hours,

and over three million passenger trips have

been made on the system.

In November 2012 eight new routes are

expected to be launched around the cen-

tral city, including the City Bowl suburbs

and the Atlantic Seaboard suburbs, and as

far as Hout Bay.

Th e second phase will connect the

southeast parts of the city, including

Mitchells Plain and Khayelitsha, to desti-

nations across the peninsula. Th is phase

will also cover the southern suburbs. Th e

third phase will include Bellville, Delft,

the rest of the northern suburbs and

Stellenbosch, and the fourth phase the

Greater Helderberg area.

Th e full system is expected to take about

15 to 20 years to implement, with each

phase being built as funds become avail-

able. Most of the funding comes from the

National Department of Transport’s Public

Transport Infrastructure and Systems

Grant, with the balance funded by the City.

PROJECT TEAM In 2007, the IRT project team started

its work under the City’s Transport

Department, to prepare for the launch of

the 2010 FIFA World Cup BRT service.

Following a successful World Cup pilot

project, two new departments were formed

within the City to implement the project on

a city-wide basis.

Th e IRT Implementation Department

is responsible for planning, designing and

developing the IRT infrastructure. Its

functions include system planning and

modelling; the design and construction

of the bus lanes, non-motorised transport

facilities, stations, stops and depots; and

the fi nancial management thereof.

MyCiTi trunk bus leaving the Civic Station; note indigenous landscaping

MyCiTi station; note Kassel kerbs and delineator kerbs


Th e IRT Operations Department

manages the operations of the service. It

is responsible for business development;

operations management, which includes

scheduling and controlling, service manage-

ment, facility operations and emergency

and risk management; industry transition,

strategy development, data management,

maintenance of the BRT buildings, fi nancial

management, and customer relations.

TECHNICAL INNOVATIONSContinuously reinforced concrete

Th e dedicated red bus lane between Cape

Town and Table View allows the MyCiTi

service to avoid the increasing traffi c

build-up along the R27, and to stick to

its schedule. Th e lane was constructed

from continuously reinforced concrete

(CRC), which is about 10% more expen-

sive (initial construction costs) than a

conventional fl exible road pavement of

similar design life. Th e CRC pavement

was chosen for the following reasons:

■ It requires signifi cantly less depth of

the pavement structure and associated

earthworks.

■ It has a red pigment, whereas a special-

ised surface treatment is necessary to

achieve a red surface on asphalt. Th is

asphalt treatment is expensive and

needs to be renewed frequently (every

four years approximately).

■ CRC road pavements require little to

no maintenance, yielding signifi cant

operational benefi ts over its design life,

and less risk of operational downtime.

■ Th e reduction in maintenance and op-

erational costs over the design life of the

asset far outweighs the 10% additional

capital investment (life cycle cost).

A CRC pavement (for the main bus lanes)

with a 40-year design life, in combination

with asphalt pavements utilising modifi ed

bitumen products (for local zones and

intersections) with a 20-year design life,

has been implemented.

Th e CRC pavements were designed

using local South African software

(cncPave), which was developed by the

Cement and Concrete Institute (C&CI).

Th e CRC pavements have equivalent lives

of between 30 and 100 million equivalent

80 kN axles (E80s).

Th e concrete used is designed for 28-

day fl exural strength of 4.5 MPa, which

when correlated to 28-day unconfi ned

compressive strengths, consistently

exceeded 35 MPa. Th e red colour is ob-

tained through the use of a 5% red oxide

which is added to the concrete mix.

Th e CRC lanes have continuous

longitudinal steel reinforcement with

minimum transverse steel. No transverse

expansion or contraction joints are con-

structed by design, and hence, by design,

the concrete cracks naturally under

shrinkage, controlled by the longitudinal

steel to form tight transverse cracks at

1 m to 2 m spacings in general. Th ese

naturally occurring joints typically do not

require joint maintenance.

Delineator kerbs

Delineator kerbs separate the bus lanes

from the general traffi c lanes and prevent

general traffi c from entering the bus lanes.

Th ese kerbs have the following features:

■ Th eir sloping profi le minimises the risk of

a vehicle rolling, should it strike the kerb.

■ Th ey are painted a retrorefl ective yellow,

with a 100 mm white line adjacent on

the side of the general traffi c, to demar-

cate the outer edge of the traffi c lane.

■ In some instances, the speed limit of

the general traffi c is reduced, for safety

reasons.

■ Th ere are 100 mm wide drainage gaps

every two metres. Th e gap width and

spacing were calculated using the

Rational Method, based on a worst-case

scenario that assumes crossfall towards

the bus lane, fl at terrain and a short

duration, high-intensity rainfall event.

Kassel kerbs

Kassel kerbs are used where the buses

dock at the stations and bus stops, to

guide the buses to the correct distance

from the platforms. The Kassel kerbs

also prevent the bus from hitting the

station platforms and minimise tyre-

wall wear by up to 40%. The kerbs were

patented by Profilbeton in Germany,

where the polyurethane moulds are

made. A local manufacturer was ap-

pointed through a tender process to

produce the kerbs. Buses must dock ad-

jacent to these kerbs in order to achieve

the goal of universal access.

Universal access

Universal accessibility allows people in

wheelchairs, others with disabilities, the

elderly, children and others with reduced

mobility to use the system with ease.

Boarding bridges are installed on

the buses to bridge any gap between the

bus and platform. Th is allows for level

boarding, with no need for stairs, and

ensures universal access.

Tactile paving and audible pedestrian

traffi c signals help visually impaired

New nine-metre buses are being assembled in Cape Town for MyCiTi residential services


people navigate their way across intersec-

tions and around stations and stops. Th e

buses also have special places reserved for

securing wheelchairs.

Tactile way-fi nding, signposting and

mapping are also being introduced en

route to, and at, BRT stations.

Signalised intersections

Th e placement of dedicated bus lanes

on the median side of the road poses a

problem at intersections. Th e obvious

confl ict is the through movement of buses

with right-turning general traffi c.

It was decided that right turns would

not be banned along trunk routes, as this

would lead to traffi c diversion and safety

concerns. Th e following two traffi c signal

prioritisation schemes have been adopted

to cater for both public transport and

general traffi c:

1 Default treatment: shared stop line

Signalised intersections have a shared

stop line, i.e. buses and general traffi c all

stop at the same stop line. A bus phase

runs in conjunction with the general

traffi c’s through phase, followed by a pro-

tected only-right-turn phase for general

traffi c. Th is treatment requires adequate

road reserve at the intersections to cater

for the general traffi c’s through lanes and

right-turn lanes, as well as the exclusive

bus lanes. It requires the use of special

bus signal aspects and ‘ST boards’ (sup-

plementary traffi c signal arrow signs

mounted above the signal heads).

2 Alternative treatment: pre-signal

Th e use of a secondary stop line in ad-

vance of the intersection is controlled by

a pre-signal. During the general traffi c

phase buses wait at the secondary stop

line. Th ereafter the bus phase commences

and general traffi c has to stop at the

secondary stop line, allowing the bus to

either travel through or turn left or right.

Th is alternative treatment may be used in

two cases:

a) in instances where there is inad-

equate space for both right turn

lanes and exclusive bus lanes, thus

right-turning traffi c and buses have

to share the same lane (separated in

time); and

b) to cater for bus turning movements.

BUSESTh e buses in use on the existing trunk

route to Table View, and residential

services, are 12 m and 18 m long Volvo

vehicles adhering to Euro 4 emissions

standards.

At a factory in Epping, Cape Town,

190 new nine-metre Optare Solo

buses are being assembled out of kits

produced in Leeds, UK. These will

serve the eight upcoming residential

routes around central Cape Town. The

buses have low floors, to allow for level

boarding from the kerbside bus stops.

They have no front overhang, which will

allow them to turn on residential roads.

The buses adhere to Euro 5 emissions

standards.

South African company Busmark

2000 won the tender to provide these

buses and as a result created about 120

jobs at its factory in Epping. Th e company

is importing the kits, as they are not avail-

able locally, but is helping to boost other

local industries by sourcing tyres, bat-

teries, windscreens, paint and seats from

local suppliers.

LANDSCAPINGWater-wise, indigenous plants were used

in all the landscaping, including the green

‘ribbons’ of space in the central strip

between the two bus lanes on the route to

Table View. Due to water being a scarce

resource in the city, irrigation is provided

by recycled water. A main effl uent line

from the Potsdam effl uent treatment plant

was installed.

Some of the larger stations have open

plazas around them with benches under

palm trees, and bicycle parking.

CONCLUSION MyCiTi is an extremely ambitious project,

and when complete, it will be the biggest

capital project the City of Cape Town has

ever undertaken. It was not an initiative

of the City alone, but was developed in

consultation and with the support of the

national government, which requires that

South Africa’s major cities develop IRT

systems.

Judging from the packed buses on the

existing routes, and the overwhelmingly

positive feedback from passengers, the

service is fulfi lling a desperate need for

high-quality public transport. We look

forward to the second, third and fourth

phases being equally successful. It is our

belief that the engineering innovations

being implemented will help ensure that

the service is as safe, effi cient and reliable

as possible.

TWO YEARS AGO the SAICE Western Cape Branch Committee developed a website with the aim of keeping SAICE Western Cape members informed of up-coming events, branch contacts, competi-tion entry forms, and providing feedback to branch members on events.

The site (http://saicewc.co.za) is con-tinually monitored and updated, and pres-ently provides the following information:1. Details of upcoming events, such as

branch lectures, branch awards, bridge building and water competitions.

2. Details of the current Western Cape Branch Committee and details on nom-ination and election to the committee at the end of each year.

3. A page dedicated to Continuing Professional Development where CPD numbers are listed and details of up-coming CPD opportunities, when avail-able, are given.

4. News pages where posts regarding past events are listed, as well as items of interest, such as liaison with other professional bodies, book reviews and newsletters.

The site has the capability to allow com-ments to be added to individual news items, or feedback to be given to the branch through a contacts page. Since the inception of the website, interest in involvement with the Branch Committee has increased fairly substantially, with several new committee members making contact with the branch via the website.

Also incorporated into the website are elements of social media, with links to Facebook, LinkedIn and Twitter. The web-site incorporates Quick Response Codes to provide linkages to the site via mobile devices for those on the move.

Coupled with the website is the branch’s email notifi cation system, aptly named efl ash. This is used to notify members via email of upcoming events. Members interested in being added to the notifi cation system can get in touch via the contacts page on the branch website.

The website is monitored using Google Analytics, which provides feed-back on traffi c, traffi c sources, visitor de-mographics, visitor behaviour and details of the technology used to visit the site.

Currently the website is funded by the branch, with the intent of becoming fi nan-cially sustainable in due course by elimi-nating the costs associated with printed communication, and possibly involving sponsors and advertisers.


Discover more about our expertise, meet out specialists and check out our projects at www.wspgroup.co.za or give us a call on 011 361 1300

WE BELIEVE IN SOUND INNOVATIVE

ENGINEERING SOLUTIONS

Heath Webb

Treasurer

SAICE Western Cape Branch

[email protected]

SAICE Western Cape Branch Website

PERI’s own biomass power station, is the symbol of closed cycles. The energy produced here contributes a substantial part

of the used energy mix. Is used for power production, for process heat xtraction, for heating and for hot water treatment.



About PERIIn 2011, the PERI Group successfully negotiated the takeover of Wiehahn Formwork and Scaffolding. Wiehahn has been

one of the market leaders in the South African formwork and scaffolding industry for over 40 years and the sole PERI

distributor for more than 10 years. PERI is a global, family owned and operated business based in Germany and one of

the leading brands in formwork worldwide. PERI Southern Africa is a global player with a strong local track record.

Sustainability with PERIEnvironmentally-conscious thinking and actions





The term sustainability stands for careful handling of resources and their conservation for future generations. Having the adaptability to meet future needs, as well as economic and eco-logical sustainability, play an essential role in all PERI processes.

Engineering and product development

are targeted towards minimising demand

for raw materials: Our product develop-

ment aims to achieve the best utilisation

of materials but with the minimum of

material use. Furthermore, customised

and economically-optimised formwork

and scaffolding solutions reduce material

usage on the construction site and

make a valuable contribution to waste

avoidance.

Raw material selection and procurement

is organised with respect to the envi-

ronment: Procurement takes place in

accordance with ecological sustainability.

Procurement processes are taken into

consideration and optimised for current

and future environmental costs. Further-

more, they are incorporated in the quality

management system in accordance with

EN ISO 9001. Substitution of hazardous

or harmful substances by environmen-

tally-friendly alternatives is and has been

company strategy for decades.

High product quality ensures long-term

durability: PERI constantly invests in

the very latest production processes.

The expertise of the workforce, efficient

production processes and very strict

quality inspections are a guarantee for

reliable products which are well-suited

to handle tough site conditions on a

daily basis, and are characterised by a

log service life.

Logistics organisation focusses optimised

shipping volumes and transportation

routes: Strategically-positioned logistics

sites guarantee short delivery distances

whereby transportation is continuously

optimised through an intelligent logistics

network.

PERI procures timber material mainly

from certifi ed growing regions. The

PEFC certifi cate confi rms that harvested

forest areas are constantly reforested.

Intelligently designed formwork and

scaffolding systems minimise material

use. Moreover, longer life spans and

increased reusability of PERI systems

also reduce the overall demand for raw

materials.

PERI offers its customers compre-

hensive logistics services at more than

100 high-performance logistics sites

around the world. This ensures small

distances to the sites of our customers.












avoidance.























log service life.







network.










materials.






FormworkScaffoldingEngineering

www.peri.co.za












avoidance.























log service life.







network.










materials.

















avoidance.























log service life.







network.










materials.







IN BRIEF

SOLAR REVOLUTION LIKE THE INFORMATION technology revolution of the past few decades, we are on the brink of a solar revolution that will transform the way in which we use en-ergy. Solar power and business are fi nally moving forward together as viable, sustain-able partners and for a simple reason – solar power has become cost effective.

Spearheading the industrial solar revolu-tion in South Africa, AEG Power Solutions, the local division of the global solar giant, is providing the technology and the business model to make the vision of a sustainable energy future a reality. “Over the past few years there have been some signifi cant breakthroughs in solar energy, specifi cally in reducing production costs of solar. The difference in the cost of a kilowatt from a solar array compared to a kilowatt from Eskom has grown smaller,” explains AEG Power Solutions’ Trevor de Vries. “As things currently stand, it already makes good business sense for companies to invest in solar solutions, and things will continue to shift until the ability to generate electricity at an affordable price would be limited only by the amount of space you have. Got a big enough roof? You need never want for electricity again.”

And this is not a dream of a far distant future. This future is already here, with the solar power equivalent of an on-site utility being used by customers of AEG Power Solutions around the world. South Africa,

with its plentiful supply of sunshine, is fast gaining an industrial solar consciousness, with a number of the country’s larger com-mercial and industrial concerns looking into solar as their primary energy source.

“Each company that implements this system is not only taking some of the load off the national electrical utility grid, but also has the potential to generate power back into the grid. Solar energy can fl ow directly from the source to the consumer, and any excess can be sold back to Eskom. This changes the whole dynamics of how we view and use power,” de Vries points out.

As sustainability issues become more prominent in the business environment, renewable energy sources like solar are increasingly coming to be viewed as neces-sary additions to any company’s corporate social responsibility portfolio. AEG Power Solutions, as a global leader in this tech-nology, walks the sustainability talk as far as its products are concerned, while also investing heavily in the societies in which it operates.

In South Africa, the company not only sponsors a number of community upliftment projects, but has invested mil-lions into the local economy by building a state-of-the-art factory that produces the photovoltaic technology for its green energy solutions. This facility, based in the Western Cape, provides employment for hundreds of people – most of them from previously disadvantaged backgrounds.

“The construction of this factory strengthens our ability to offer solutions that benefi t South Africa’s economy as a whole, and demonstrates our dedication to providing sustainable, effi cient outcomes for our entire ecosystem,” says de Vries.

“AEG Power Solutions is fully committed to making this planet a better place – and this doesn’t just involve the environment. We are proud that our investment has enabled the empowerment of so many people, and we will continue to invest in our community in the future.”

INFO

www.aegps.com

CONSIDERING THE WATER CYCLE FOR SUSTAINABLE OPERATIONS IN AFRICA WATER IS A VITAL resource. It is essential for human life and wellbeing, healthy eco-systems, global food security, energy and industry. Without it, human existence and the development of the global economy are doomed. Never before has the issue of water security and availability received such focus, and rightly so. Economic development, population growth, food security and climate change are all likely to contribute to severe shortages and degra-dation of global water supplies and eco-systems over the next 30 years, particularly in the developing world.

In recent years, African countries have demonstrated a renewed commitment to industrialisation as part of a broader agenda to diversify economies as a critical vehicle for growth and poverty reduction in the region. This has seen a rapid accelera-tion in growth on the continent, generating with it new opportunities for investment. When it comes to future global investment strategies, Africa is high on the agenda for investors and entrepreneurs. However, this also brings with it substantial challenges – particularly in the realm of water availability and security.

Water is critical for many businesses, and by its nature is non-substitutable. All goods and services require water in their production, and water is used in some way in all manufacturing processes. Companies are increasingly being faced with physical

Trevor de Vries from AEG Power Solutions


water shortages or quality issues, which cause disruptions to continuity and volume of production, and reduced revenues, as well as posing potential regularity and reputational consequences. Business sectors such as agriculture and bever-ages face even more direct challenges, as sustainable sources of good quality water, particularly in regions characterised by growing water stress, become harder to fi nd. Although Africa is a continent en-dowed with rich natural resources, many parts of the country have limited access to water due to insuffi cient infrastructure and poor governance. Where water is available, habitually in the more populated areas, the quality is often severely compromised due to lack of adequate sanitation or waste disposal services, mining discharges, industrial effl uent and agricultural run-off. Consequently, available fresh water (both ground and surface water) becomes heavily polluted chemically and pathologi-cally.

Furthermore, water sources in Africa are predominantly trans-boundary and are exposed to signifi cant agricultural, mineral and industrial extraction across a number of competing regions. The water sector is also strongly infl uenced by, and sensi-tive to, changes in climate and prolonged climate variability. Climate change will not have uniform impacts on water issues across the continent, but will aggravate water stress in some areas while reducing it in others. As pressure from demographic and economic growth intensifi es and the competition for food, energy and water multiplies, it is going to become increas-ingly critical for companies to look to innovative solutions for not only identifying

and assessing water-related risks, but for optimising available water sources to ensure operational and business longevity. Additional motivation for this is that the responsibility of urban and industrial water supplies is not typically a government priority, as is the case in more developed countries. Therefore the challenge of en-suring a sustainable water source of ad-equate quality for use in operations is likely to remain a responsibility of companies operating in Africa.

During the development and applica-tion of water management practices and technologies, the entire operational water cycle should be considered, including sourcing adequate quality water for use in operations, in factory water management practices and wastewater treatment and discharge. Opportunities for biogas re-covery as a green energy source and water recovery for reuse become viable options, particularly in companies situated in Africa where these needs are not easily met by current infrastructure.

In a region expected to experience severe water scarcity by 2025, the potential for reusing wastewater in Africa cannot be ignored. The effectiveness of such initia-tives relies largely on successful partnering with reputable water and wastewater man-agement companies (like Talbot & Talbot). Effective partnering offers companies the best chance for a water management solu-tion and technology selection that will suit the company, their operations and industry best, and that will ensure a sustainable supply of good quality water and optimal operational and maintenance costs. As treatment requires sophisticated technolo-gies, the risk of failure is particularly high,

especially given the challenges associated with construction, operation and mainte-nance of such facilities in Africa. Effective management from the outset is funda-mental and allows for timeous delivery of critical information and feedback.

Although initial investments in such treatment technologies may be substantial, the pay-back is justifi ed in terms of security of supply and continued operation, water loss control and use effi ciency. Further benefi ts include improved corporate repu-tation, as infrastructure investments service local communities, thereby also aiding in protecting environmental resources.

INFO

Megan Schlebusch

Talbot & Talbot

033 346 1444

[email protected]

[email protected]

PERMA CLAMP FOR JOINING HDPE PIPES THE PERMA CLAMP is a South African designed and patented coupling for joining HDPE pipes. No welding or preparation of pipe ends is necessary, and installation is simple and quick. A 160 mm coupling, weighing approximately 5 kg, can be installed in three to fi ve minutes. The only tools necessary to install a coupling are two ring spanners, and installation can be done by unskilled labour.

In sizes from 450 mm upwards it may be necessary to torque the bolts by means of a torque multiplier. Once the Perma coupling has been correctly fi tted, it cannot leak or pull out. In every instance the pipe will always burst while the coupling holds.

A documented test by Klamfl ex was carried out on 160 mm and 250 mm pipes. Two 160 mm pipes were coupled and hung from a crane. When a weight of 3.7 tons was suspended from the pipes, the cou-pling held. The same test was done with 250 mm pipes and a weight of 6.5 tons, with similar results. The bolt holes in the pipes for attaching the weights did, under-standably, elongate under the load.

The Perma coupling has no O-rings or oil seals that could be lost during

Water goes through various treatment phases before it is potable


installation. When the coupling is installed and the bolts are tightened, the concept uses its own material on the inside of the pipes to create a seal, the life span of which will be equivalent to the life span of the pipe.

The standard coating for the whole coupling is hot-dipped galvanising, but other coatings are also available. The whole coupling is foundry-cast in SG 42 ductile iron. The size range is from 110 mm OD to 1 200 mm OD.

The Perma coupling, which can be installed in all weather conditions and even under water, carries the SABS mark and has been approved by a major South African fuel company.

INFO

Ian Cartledge

Perma Marine Pipeline Components (Pty) Ltd

083 453 4766

[email protected]

KAYTECH GLASGRID USED TO STRENGTHEN PROBLEM ROAD WHEN STEMELE BOSCH, specialist con-sultants for eThekwini Municipality, needed expert advice on the maintenance and rehabilitation of a sector of road in Malvern, Durban, they called on Kaytech. Impala Road had sustained various cracks to the existing asphalt due to crocodile, longitu-dinal and transverse cracking. Investigation

by Kaytech engineers revealed that the layers below the asphalt were not strong enough to support the traffi c loading, hence the existing road surface had been severely compromised.

The Kaytech technical team recom-mended a 50 x 50 kN/m GlasGrid solution for this application. The product has been specifi cally developed to address the reha-bilitation challenges of refl ective cracking distress on roads, airport aprons, runways and parking lots. The GlasGrid pavement reinforcement system extends road life by up to 200% and provides additional support to resist the migration of refl ective cracks in roadway applications. This reliable interlayer system is composed of a series of fi bre-glass strands formed into a grid structure and coated with an elastomeric polymer. Additionally, each strand has a remarkably high tensile strength with a high modulus of elasticity. This combination, weight for weight, renders the GlasGrid system stronger than steel.

Another advantage of using GlasGrid is its ease of installation, helping speed up the time spent on road works. In the Impala Road case, the system was applied to the existing surface with the pressure sensitive adhesive ensuring a good bond. After the tack coat had been applied, the fi nal 35 mm layer of asphalt was laid.

The GlasGrid system is considered the most expedient interlayer system rela-tive to installation time. Moreover, when the GlasGrid system is placed between a levelling layer and the surface asphalt, it becomes the hidden strength in the road, as it is designed to dissipate vertical crack stresses horizontally.

In addition to being cost effective, GlasGrid is an environmentally friendly system, too, as its main component is silica, which is a natural substance.

INFO

Kaytech

031 717 2300

www.kaytech.co.za

ON SHOW AT ELECTRAMINING AFRICA: 10 – 14 SEPTEMBERA number of leading mining and mining re-lated industry suppliers will be launching the latest new products and technologies at this year’s Electra Mining Africa trade exhibition from 10–14 September at the Expo Centre in NASREC, Johannesburg. This interna-tional mining, industrial, construction, power generation and machine tools show enjoys global recognition. It is the second largest mining show in the world, and the biggest trade exhibition in southern Africa.

The Multotec Group will exhibit a com-prehensive showcase of process and mate-rials handling equipment, services and tech-nical know-how, as well as existing, new and value-added technology. Never seen before at the show will be a working demonstration of Multotec’s self-driven trommel, a well-proven trommel for high capacity screening applications, together with the latest version of the company’s sievebend, manufactured from HDPE. The stand will also feature a range of panels which are process-specifi c in their application. Injection-moulded rubber screen panels will be shown for the fi rst time.

Another new product at Electra Mining Africa will be Multotec’s new cast iron CL115 cyclone, developed specifi cally for the coal industry to combat the tramp iron which is damaging to traditional ceramic linings. Multotec’s Cy-i suite of cyclone sizing and selection software, developed to equip cus-tomers with a scientifi c approach to making the initial selection of a cyclone for any given application, will also be demonstrated.

Sew Eurodrive will showcase their new electrifi ed monorail system for the fi rst time in South Africa. Although the technology

Applying an asphalt layer over GlasGrid reinforcement

The Perma clamp, a South African designed and patented coupling


has been available internationally and is currently used in some of the local auto-motive plants, these installations have been via European OEMs. For SEW Eurodrive South Africa this is a fi rst in terms of ex-hibiting this model locally. The Movitrans contactless energy transfer system offers the operator an effi cient, fl exible complete package at his or her disposal. Drive solutions for electrifi ed monorail systems can be combined with many options from the Sew Eurodrive modular concept. The system is often used for automatic, guided vehicles in various industries.

MMD Minerals Sizing Africa specialises in the design and development of sizing and ancillary equipment for the mining and allied industries. The company will exhibit its patented Twin Shaft Mineral Sizer, the only breaking system specifi cally designed for mobile installation. In addition to classic static units for mineral production and processing, MMD produces a wide range of high capacity semi- and fully-mobile sizing stations for IPCC installations.

Global high technology engineering group Sandvik will introduce new tech-nology alongside a selection of its world-renowned core products at Electra Mining Africa. Mining equipment highlights on the stand will include the company’s new DM300 mobile bolter, the DR580 surface mining drill, a compact hybrid crusher and, from its construction range, the DI550 con-struction drill and the DS210L-M low-profi le mechanised roof bolter.

Xylem will be exhibiting a total solu-tion for the dewatering of mines. The company’s extensive rental fl eet of 720 units in Africa and its robust stock-holding of new units enable it to satisfy customer demands immediately. This is backed up by spare parts availability, back-up service, and on-site mainte-nance and repairs on and off site. A selection of Xylem pumps and mixers for the mining and minerals processing industries will be on display, designed to perform in the most severe applications and incorporating a wide range of corro-sion and abrasion-resistant offerings.

MBE Minerals South Africa, formerly Humboldt Wedag, will exhibit static scale models showcasing key elements of its broad range of technology. These will include its Pneufl ot fl otation, BATAC jig, ROMJIG, Jones Wet High Intensity Magnetic Separator (WHIMS), PERMOS (LIMS), a Palla Vibrating Mill, TESKA HMS Separator and a wide va-riety of screens and feeders.

Expressing the Zest Weg Group’s focus on green energy effi ciency, Zest Electric Motors will showcase the motor-drive combination of the Weg W22 electric motor coupled with its WEG CFW11 variable speed drive technology. Also on show at the Zest Weg Group stand will be the WEG SSW7000 medium voltage soft starter, which uses state-of-the-art technology to provide start/stop control and protection for three-phase medium voltage induction motors in the 2.3 kV to 6.9 kV range. Zest Weg Group’s switchgear division will be introducing its new range of miniature contactors and motor pro-tection circuit breakers with spring-loaded terminal connection. Also on show will be the recently upgraded range of DWA moulded case circuit breakers along with a full range of capacitors and also Weg’s state-of-the-art SRW01 smart relay.

Machine Tools Africa and Elenex Africa will be co-located with Electra Mining Africa 2012. Exhibitors at Machine Tools

Africa include Talmac Machine Tools, which are the sole agents for Faccin, Gasparini, Omera, SIMASV, Mecome and Rolleri from Italy. The company has a large variety of the best machine tools on the market, and will welcome all clients to its stand with a good Italian espresso!

Also part of Machine Tools Africa, Toolquip and Allied will exhibit their latest range of industrial equipment, including abrasives, band saw blading, HSS and carbide cutting tools, measuring equip-ment, CNC and conventional machine tools, industrial hand tools, specialised products, toolroom equipment and welding machines and accessories.

Events taking place at Electra Mining Africa 2012 include an Exhibitor Soapbox hosted by the South African Institution of Mechanical Engineering (SAIMechE). The Exhibitor Soapbox will give exhibitors a 30-minute opportunity to present their products and services to a captive audi-ence in a separate presentation room, with no restriction on either the format or the content of the presentation. Attendance at the Exhibitor Soapbox will be free to all Electra Mining Africa visitors.

The Southern African Institute of Mining and Metallurgy (SAIMM) will be hosting a Surface Mining Conference at Electra Mining Africa between 10-12 September. The main focus of the conference will be to review advances and best practice in surface mining. The Surface Mining 2012 Conference aims to provide a practical forum to showcase the direction in which the industry needs to move in order to un-lock current and future mineral potential.

Another exciting event taking place at Electra Mining Africa this year is the International Infrastructure & Investment Convention (IIIC), organised by Hannover Fairs International, together with the Southern African-German Chamber of Commerce and Industry. The event, which will run between 12-13 September, will cover the topics of energy effi ciency, smart grids, renewable energy, water and wastewater, mobility and transportation infrastructure, highlighting the importance of infrastructure investment in these industry sectors.

INFO

Visitor pre-registration:

www.electramining.co.za

Further information:

Specialised Exhibitions Montgomery

011 835 1565

[email protected]

New at the show: Multotec’s self-driven trammel

The Sandvik DM300 mobile bolter will be on show


SAICE Honorary Fellow Faried Allie, who

passed away on 6 June after a long illness,

was not only SAICE’s centenary presi-

dent in 2003, but served the Institution

in various other capacities over many

years. He was the fi rst president to

come from the ranks of the engineering

technologists after the merger of SAICE

and SAICET (South African Institute

of Civil Engineering Technicians and

Technologists) in the early nineties.

Faried also served two consecutive

terms on the ECSA Council, i.e. from

2001 to 2010, and was active in various

ECSA committees, chairing the ECSA

Technology Programme Accreditation

Committee. Over the years Faried was

visit leader during ECSA accreditation ex-

ercises at many universities of technology,

as well as leader of the team who, at the

Queensland University in Australia, ac-

credited the qualifi cations covered by the

Sydney and Dublin Accords, which cater

for the international recognition of tech-

nologists and technicians respectively.

Faried was also nominated by ECSA to

serve on the international Engineering

Technology Mobility Forum (ETMF),

where he was elected as chairman in 2010

– a position he held until his passing.

On the work front Faried con-

tributed substantially to many key per-

formance areas with the amalgamation

of seven administrations under the City

of Cape Town, where he was Manager

Infrastructure Maintenance of the City’s

Roads and Stormwater Department.

A previous personal assistant of

Faried’s says, “He commanded such re-

spect because he himself had infi nite re-

spect for every person with whom he dealt,

both in the offi ce and broader community.”

And it is indeed on the more personal

level that SAICE members and National

Offi ce staff will remember this unas-

suming and gentle man who made such an

enormous contribution to the professional

lives of civil engineering technicians and

technologists, and to SAICE as a whole.

Zina Girald, SAICE’s previous

Communications Offi cer, speaks for most

SAICE staff members when she says:

“Th e most striking thing about Faried

was his smile. It was contagious, and even

if you were having a frustrating day, you

couldn’t help but smile along with him.

Faried always took time to fi nd out how

you were truly feeling on a given day, and

actually listened to what you had to say.

In my opinion, he was one of the most

easy-going, hassle-free SAICE presidents

who still got the job done, and with en-

thusiasm and passion.”

Carla de Jager, previous SAICE

Education and Training Manager, says,

“Faried was one of those very special

people who did not lose his genuineness

when he became a person of distinction.”

Sam Amod, SAICE 2006 president, re-

members Faried as “one of the few people

who could light up my day with just a

smile or a look, he so overfl owed with

warmth. His empathy and compassion,

his ability to relate without judgement

and his sincerity were unusual. He gave

so much more to his profession and this

world than he ever demanded from it.”

Ron Watermeyer, SAICE 2004 presi-

dent, says: “I always valued his passion

and enthusiasm for the profession, and his

quiet and diplomatic disposition to issues

of the day.”

Rodney Nay, president of SAICET

before its merger with SAICE, also re-

members Faried’s “smiling and laughing

face. All the troubles and challenges we

faced in the early 1990s never seemed to

get him down. He retained his focus and

always saw things from the other person’s

perspective. Faried’s professional ethics,

attitude to life and the fact that he re-

mained an ordinary person are character-

istics that made him an ideal role model.”

Trueman Goba, SAICE 2002 president

was most saddened by the news of Faried’s

passing, and said: “I always thought highly

of Faried’s selfl ess contribution to the civil

engineering profession, his intellect and

his friendliness to so many of us. We have

lost a really good person.”

Previous SAICE executive director,

Dawie Botha, remembers Faried as “the

man with the forever-smile; the man who

playfully called me Dr Botha; the man

who had a selfl ess passion for SAICE, the

civil engineering profession and South

Africa; the man who was there when

we crafted the Africa Engineers Forum

Protocol and who kept the peace between

arguing countries; the man who respected

our diverse cultures and steadfastly

practised his; the man who took the sup-

porting role and pushed me to take the

fl oor in international meetings, saying he

was ‘only’ the president.”

We have lost a true friend who had

a keen sense of humour, and who was a

comrade in the quest for the recognition

of technicians and technologists – indeed

a diplomat and a gentleman.

Johan de Koker Pr Tech EngSAICE President 2008

[email protected]

ObituaryFaried fondly remembered

S A I C E A N D P R O F E S S I O N A L N E W S


REFERRED TO BY COLLEAGUES as “South Africa’s principal

ground anchoring expert” and a “trailblazer in geotechnics”, Dr

Ross Parry-Davies passed away peacefully, aged 88, in his home

on 27 July 2012. He is survived by his much loved wife of sixty

years, Renée, their children Janice, Megan and David, and their

close, loving family.

A formidable man at times, with a sturdy moral compass,

Ross Parry-Davies will be remembered not only as a distin-

guished academic, leading contractor, consultant and arbitrator,

renowned nationally and internationally, but as a man of high

intelligence, true integrity and sincerity, genuine love, quick wit,

and a belief in “right doing, and steadfastly pursuing the pathway

of duty in life's checkered career”.

After matriculating from Queens College, Queenstown,

in the Eastern Cape, at the end of 1941 and winning the Bailey

Bursary, which was a princely sum of £60 awarded to the top

student in the area towards tertiary studies (it covered most

of Ross’s fi rst year study fees), Ross Parry-Davies, although

knowing little about civil engineering, commenced studying at

the University of Cape Town in 1942. In his personal memoirs

Ross writes that “Civil Engineering was a four-year course, but

very, very tough and the failure rate was extremely high. I could

not aff ord to fail, either academically or fi nancially.” Friendships

formed then were as strong in 2012 – a testament to the man

Ross Parry-Davies.

Not one to let anything stand in the path of his convictions,

Ross was bitterly disappointed and deeply hurt at being denied (he

tried fi ve times) enrolment in the army at the end of 1942 as he was

deemed “medically unfi t” – due to impaired vision in his right eye.

Engineering studies were tough and Ross used to say that “if

the lights were still on at 02h00 in the morning, it was either an

engineering student working or a medico playing cards.” At the

end of the second year Ross got his fi rst paying engineering project

on the graving dock being built in Cape Town, earning about £5 a

week. Although the rest of his university years consisted of work,

work and more work, Ross’s managerial and leadership abilities

were already in evidence, as he showed in ably organising the UCT

Rag Procession in 1945, and graduating that same year.

Ross spent the next nine years contracting, mainly on water

supply projects and dams, before he worked for two years with

FE Kanthack & Partners on the design of the Kafue Hydro-

electric project incorporating dams, tunnels, penstocks and

underground power stations.

After a two year consultant stint (1954-1955) as Design

Engineer with Knight Piesold, Ross joined Th e Cementation

Company of South Africa, the only grouting contractor in the

country, in September 1955, where his indoctrination into the

intricacies of grouting began, and it was during that time that

the technology of protecting ground anchors against corrosion

surfaced.

He worked for Cementation Co (Africa) from 1956 to 1970,

initially as Contracts Manager and eventually as Division

Manager of Civil/Geotechnical Divisions, involved in foundation

grouting and stressed strengthening/raising of 12 dams, lateral

support of excavations by anchoring, and the building of the fi rst

through-fl ow rockfi ll dam in SA.

Ross returned to the Cape to build the Apostles Tunnel and

various harbour works, but at the same time he was working on

innovative techniques, such as vibrofl otation, dynamic consolida-

tion, specialised grouting and ground improvement techniques.

He was the fi rst person in the world to use ground anchors for

ObituaryPr Eng, FSAAE, FICE, FSAICE, MSAConsE(Retd), FAArb, BSc Eng (Civil), PhD Eng (Civil),Civil Engineer, Geotechnical and Civil Consultant, Arbitrator

Dr Ross Parry-Davies

Dr Ross Parry-Davies with his wife Renée


the provision of lateral support for basement excavations, which

were initially used on the SA Mutual basement in Port Elizabeth.

Ross is perhaps best known for his subsequent work with the

late Ruben Stander, innovatively using grout jacking for the fi rst

time to provide a lateral support system for the Trust Bank base-

ment excavation in central Johannesburg, at the time the deepest

in the world, which not surprisingly won wide acclaim.

Another ‘fi rst’ was when Ross used soil nails to reinforce

slopes on De Waal Drive in Cape Town, 20 years before the ‘new’

technique of soil nailing was claimed. He then went on to build a

unique through-fl ow rockfi ll dam in Lesotho.

From 1970 to 1974, Ross held the position of Executive

Director of Westcott & Associates and built the Van Eck Power

Station. He also founded the geotechnical company Ground

Engineering Ltd in Johannesburg in 1970, but in 1974 he sold the

company to LTA where, as Chief Executive of the Geotechnical

Division of LTA until 1987, he was involved in the Drakensberg

and Palmiet Pump storage hydro schemes, the freezing of the

western portal of the Huguenot Tunnel where the ground

freezing techniques smoothed the way for construction, and the

stressed strengthening of the Laing Dam in East London.

Ross founded the specialist civil and geotechnical consul-

tancy R Parry-Davies & Associates in 1987 on retiring from

LTA, and remained involved with consulting on mainstream

engineering projects, as well as appearing as an arbitrator

and expert witness, and was a specialist consultant on the

acclaimed rehabilitation of Chapman’s Peak Drive. He always

held himself available to give advice, opinion or mentor on his

passion – engineering.

Ross Parry-Davies had a long relationship with SAICE,

not only serving on Council for six years, but also serving as

chairman of the SAICE Committee to produce the Code of

Practice on Lateral Support (1989). In 1990 he was the recipient

of SAICE’s Geotechnical Medal for his outstanding contribu-

tion to the art and science of geotechnical engineering in South

Africa. He was also chairman of the sub-committee that updated

the SA Code of Practice for Lateral Support, for which he was

again honoured by SAICE when he received the Geotechnical

Division’s J E B Jennings Award in 1991 for his contribution

to the 1989 Code of Practice on Lateral Support in Surface

Excavations. And it was Dr Ross Parry-Davies who initially

aimed to unify the civil engineering profession by including pro-

fessional technologists and technicians in SAICE.

In 1991, when he was well into his sixties, Ross Parry-Davies

was awarded a doctorate in engineering from the University of

Pretoria. In the following two decades he was actively engaged

as arbitrator, mediator and adjudicator in many disputes on geo-

technical contracts.

In his seventies, Ross was nominated as Specialist Consultant

on stressed strengthening of two hundred-year old dams on

Table Mountain (1999–2000) and the restoration of Chapmans

Peak Drive (2003).

In 2002 he co-supported the funding and publication of the

widely acclaimed Th e Romance of Cape Mountain Passes by

Dr Graham Ross (fellow SAICE stalwart), an entertaining and

valued tribute to South African engineering and its history.

Ross was honoured at being elected as Fellow of the South

African Academy of Engineering in 2002 and as an Honorary

Fellow of SAICE in 2004.

Dr Ross Parry-Davies lived a full and active engineering life,

in service to, and to the benefi t of, humankind. He embodied

all that makes us passionate about our industry – developing

techniques from Anchors to Zero Tolerances, working from

Arniston to Zebedelia, while he found solutions, touched lives

and changed history, always supported by his loving caravan

companion, site agent, and sometimes-bricklaying wife, Renée.

Ross Parry-Davies’ SAICE Honorary Fellowship Citation

aptly reads: “.… he brought distinction to the profession of civil

engineering, he has been a leading contractor, distinguished

academic and consultant, a loyal servant to the profession, and a

defi nite example to the species ingenior and the innovators who

make things happen and solve problems through bright ideas and

lateral thinking .…”

During his life Ross received the highest honour that any

Civil Engineer in this country could hope for, the highest honour

that any Freemason in the world could hope for, the highest

honour from his school’s (Queens College) Old Boys Association,

and felt privileged to have worked with and got to know many

wonderful people. His appreciation of, and gratitude for, achieve-

ments and friends, remained paramount. But above all, he was

always thankful for the privilege of spending over 60 years of his

life with his wife, Renée.

Dr Ross Parry-Davies epitomised the South African Civil

Engineer – innovative, curious, determined, willing, humane,

always rising to the challenge with honesty, dignity and humour,

providing the right solution on time and within budget. He will

be missed.

Brenda [email protected]


Course Name Course Dates LocationCPD Accreditation

NumberCourse

PresenterContact

GCC

8-9 November Midrand

SAICEcon10/00706/13 Theuns Eloff [email protected] November Port Elizabeth

Bridge Maintenance 19 November 2012 Midrand SAICErail12/01156/15 Ed Elton [email protected]

Basics of Track Engineering

20-21 November 2012 Midrand SAICErail12/01155/15 Ed Elton [email protected]

Railway Transport 22-23 November 2012 Midrand SAICErail11/00887/14 Ed Elton [email protected]

Technical Report Writing 3-4 October 2012 Midrand SAICEbus12/01067/15 Les Wiggill [email protected]

ReinforcedConcrete Design toSANS 10100-1:2000

23 October 2012 Midrand SAICEstr12/01066/15 Greg Parrott [email protected]

Structural SteelDesign Code toSANS 10162:1-2005

24 October 2012 Midrand SAICEstr12/01158/15 Greg Parrott [email protected]

Business Finances for Built Environment Professionals

11-12 October 2012 Midrand SAICEfi n12/01021/15Wolf

[email protected]

Handling Projects in a Consulting Engineer’s Practice

8-9 October 2012 Midrand SAICEproj12/01022/15Wolf

[email protected]

Leadership and Management Principles & Practice in Engineering

29-30 August 2012 MidrandSAIMechE-0543-02/15

David Ramsay

[email protected] September 2012 Cape Town

SAICE Training Calendar 2012

Powerful Interface User-defined Beam Creep and Shrinkage Reinforcement Design

Environmental Engineering - SAICE

Documents

Transcript of Environmental Engineering - SAICE