Contents
of June 2002
EDITORIAL
Protecting grasslands and other matters
UPFRONT
News
BOOK
REVIEW
TREE OF THE ISSUE
Johan Barnard chooses
the Lavender Fever-berry
WORDS ON WASTE
FEATURES
World Summit: Action at last!
Unprotected, invaluable, mist belt
grassland
Detail in the urban environment
Building in the urban environment
Golf course sensitive to bushveld
environment
Corrugated iron
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EDITORIAL
Protecting grasslands and other matters
The next
issue (July/August) that we publish will be our special joint venture publication for the
World Summit on Sustainable Development. Urban Green File’s partner is Sustainable
Development International, the London based journal published by ICG Publishing and we
wish to remind readers that the only copies of this issue that we will post out will be to
our paid-up subscribers. Please be certain that your subscription is up to date by
mid-July, at the latest.
In this
issue, Leigh Darroll has written about the building of the environmental education centre
at the National Botanical Garden in Pretoria. Over the spring and summer months this
grassland is one of my favourite haunts and I have taken numerous photographs of the
herbaceous plants in flower. When I saw that the education centre was being built right on
the periphery of this fabulous piece of recovering grassland, although admittedly in an
already disturbed area, my immediate question was what would the impact of continuous
activity in such close proximity be on the grassland with its population of shy creatures
– its scrub hares, duikers, dikkops and other grassland birds? I spoke to Chris
Willis, Director of Gardens and Horticultural Services (for all the National Botanical
Gardens, countrywide) about my concerns.
He said that
the DEAT had evaluated the site for the education centre and found that it was not
necessary to conduct an Environmental Impact Assessment but that the NBI had been asked to
treat the site with sensitivity and not to enlarge it beyond what was absolutely
necessary. He said that the animal activity was largely nocturnal but that every attempt
would be made to minimise noise impact during the day, that the walkway access would be
strictly adhered to and that the impact of the centre would be monitored over a period of
time.
Asked about
the landscaped buffer zone around the centre, Willis said that the decision about what to
plant in this area had not been finalised – but that there had been talk about
utilising a fire resistant groundcover such as Carpobrotus edulis (sour fig) because of
the risk of a runaway fire in the grassland. He commented that the Garden was looking into
a more scientific management plan for the grassland and that an expert had been called in
to do the investigative work. Urban Green File will be following developments and looking
more closely at some of the grassland related educational projects in the future. Hope is
expressed that the food garden that will be developed within the parameters of the buffer
zone will be done according to permaculture principles.
We have
another article in this issue which deals with the future protection of a largely unspoilt
area of common land comprising Afro-montane mist belt grassland, immediately adjacent to
the village of Haenertsburg, and Urban Green File will continue to follow developments
there, hoping that the group of dedicated ‘villagers’ will be successful in
their efforts to establish formal protection and a management plan for their Townlands.
Our
investigation into the various regulations and permitting procedures in nature
conservation departments countrywide, concerning seed collection from indigenous plants,
is on-going and we hope to have a report for you in the September/October issue.
-----
UPFRONT
SALI Awards of Excellence
Out of a total of 51 entries, countrywide, 15 Gold Awards and 12 Silver Awards were
presented at the 2002 South African Landscapers Institute (SALI) Awards ceremony held in
early May at the Lord Charles in Somerset West. Regional panels of judges selected those
projects that were worthy of either Silver or Gold Awards and the final decision was made
by the national co-ordinating judge, landscape architect Peter Dayson. The regional judges
in KwaZulu-Natal were Jonathan Foley, head of the Department of Environment and Technology
at Natal Technikon, landscape architect Lucas Uys and landscape architect and Natal
Technikon lecturer, Ashleigh Goodbrand; in Gauteng the panel comprised landscape designer
and Pretoria Technikon lecturer Lynton Johnson, nurserymen Keith Kirsten and Roy Trendler
and environmental journalist Carol Knoll; while in the Western Cape landscape architect
Clare Burgess and landscape architect and Cape Technikon lecturer Beyers Theron did the
judging.
The SALI
Shield for the overall winner went to Vula Environmental Services for the rehabilitation
of the Chemfos Mine on the West Coast, while the latter project was also presented with
the Rand Water Trophy for the best Water Wise entry. The Evergreen Gardens Novice Trophy
went to new SALI member Worth It for The Vision Corporation in Parkmore, Sandton: while
the Parks & Grounds Trophy for the best in-house design and construction went to Blok
Designs for Willingdon Hall in the Durban area.
In his
overview Dayson commented that the general standard of the finalists was extremely high
and said that he was encouraged to note that certain projects showed the clear development
of an ‘African ethos’ in their designs. He made special mention of The Vision
Corporation which he said could aptly be called an ‘African Zen garden’,
referring also to the Ernst & Young building in Johannesburg and Ulundi airport which
were notable for the African character of their landscapes.
“The
two environmental entries involving vegetative rehabilitation at the Chemfos Mine and the
Lebalelo pipeline, were both highly innovative, excellently documented and with a high
level of community involvement in terms of economic empowerment, education and skills
training, and long term involvement. Both these projects were contractor driven,”
said Dayson.
Dayson
concluded by mentioning that there was not enough evidence of a trend towards water wise
landscaping amongst the entries – in the choice of plant material, design of
irrigation systems and site water management, generally. He suggested that it might be
appropriate for SALI to embark on an educational campaign covering such aspects, possibly
in collaboration with Rand Water.
Gold Award
winners
The judges
felt that Willingdon Hall by Blok Designs exemplified a highly effective and appropriate
landscape design relating to both the scale and character of the architecture, with very
good detailing. The landscape provided a very grand yet simple entrance to the property.
The landscape at House Brown also by Blok Designs took good cognisance of the setting and
the style of the house, manifesting excellent construction work and choice of plants. The
third Gold Award won by Blok Designs for their work done in the Durban vicinity was for
Toad Hall which the judges considered to be a very disciplined design, with a unifying
underlying structure, true to the original intention of a formal garden, with excellent
construction work and fine attention to detail.
Eksklusiewe
Tuine won two Gold Awards (both projects were done in conjunction with Jeremy Stubbs)
– one for the vegetative rehabilitation of the Lebalelo pipeline in Sekhukhuneland,
an area rich in plant diversity (see article in Jan/Feb 2002 issue of Urban Green File);
and one for a residence in Bryanston where the judges said excellent construction work was
in evidence and there was great attention to detail. The judges appraisal of the work done
at Lebalelo included the comment that it was a ground-breaking project in the present
South African context where community involvement is of vital import. The contractor was
commended for the documentation, the community involvement and the educational aspects of
the project.
Leitch
Landscapes won the following five Gold Awards. The installation of the rock and aloe
feature at Ulundi airport was considered by the judges to be an extremely appropriate
solution to a difficult problem in a rural area with limited water resources, resulting in
an eco-landscape with its own African character. Ulundi airport also won a Gold Award for
maintenance and the judges commented that this, along with the other maintenance projects
entered by Leitch in Ulundi, was a good example of the excellent results that can be
achieved when the contractor is involved from installation to maturity. The Ulundi
Legislative Assembly and the Ministerial Housing both won Gold Awards for maintenance
– the latter also won a Gold Award for installation and was commended for excellent
earth shaping, spacing of plant material and soil preparation which ensured that the
landscape reached maturity in a relatively short space of time.
Worth It
Landscapes won a Gold Award for The Vision Corporation in Sandton designed by Patrick
Watson, and the project was considered to be a fine example of the emerging African ethos
in landscape design, interpreted in an excellent manner by the contractor. The robust
sustainability of the project was considered impressive. Ernst & Young in Johannesburg
won a Gold Award for Grun-Art Designs and the judges commented that this very impressive
design with an African ethos was totally empathetic towards the architecture and
manifested a high standard of construction. Rand Merchant Bank in Newlands, Cape Town won
Marina Landscaping a Gold Award for maintenance, exemplifying the on-going involvement of
the installation contractor ensuring that the project reached its intended goal.
Evergreen
Gardens won Gold in the specialised turf category for the renovation of the greens and
surrounds at the Hans Merensky Country Club – renowned for its wild animals – in
Palaborwa, where excellent work was done under difficult conditions. The old Skaapplaas
greens were removed and resodded with the hybrid Cynodon grass, Gulf Green. Work had to be
halted on the 5th green for three days because a family of lions was feasting on a kill on
the fairway.
Vula
Environmental Services won Gold and was the overall winner this year for the
rehabilitation of the Chemfos Mine at Langebaanweg, close to Vredenburg on the West Coast.
The judges appraisal said that this was an excellent example of the dedication of a
contractor to his project with ground-breaking work being done concerning the involvement
of the local community from an economic, educational and environmental viewpoint. The
contractor was commended for his documentation of the project as were the clients, BHP
Billiton, for recognising their responsibility to both the environment and the community.
Housing company donates trees
Nu-Way Housing Developments has donated trees to the residents of Klipfontein View Ext 1.
Nu-Way’s vision is to help create vibrant communities in the areas in which they are
involved in construction and development and the donation of trees will make a significant
difference to the environment. Nu-Way was approached to make the donation by Food and
Trees for Africa (FTFA), the greening organisation responsible for the Trees for Homes
programme, aimed at improving the quality of life of impoverished communities and adding
value to subsidised housing units.
CEO of FTFA,
Jeunesse Park comments: “We are grateful that Nu-Way has seen fit to donate the trees
and we encourage other developers throughout the country to follow their example.”
Contact Linda Nyembe, Nu-Way Housing. Tel: (011) 789 3334. Email: info@nuway.co.za
Research
programme to support wetland rehabilitation
The Water
Research Commission (WRC) organised a workshop
in April this year to identify research needs in support of wetland rehabilitation. Eight
government departments and NGOs attended and the following matters were discussed: a
working definition of a wetland; criteria for rehabilitation; application of technology;
social and economic issues; information and programme management; inter-departmental
co-operation and linkage to other programmes.
Over the
years considerable research has been done on various aspects of wetlands and using this
foundation, it is envisaged that the programme will develop sustainable rehabilitation
methods, taking into account the social, environmental and economic aspects of the
structure, function and use of wetlands. The programme will be run in conjunction with
Working for Wetlands and the government departments that are responsible for wetland
management.
Contact Yuven Gounden at WRC. Tel: (012) 330 0340. Email: yuveng@wrc.org.za
Measuring carbon
inputs from trees into soil
Researchers
at Lancaster University in the UK have set up an experiment that may tell them how much
carbon is taken in from the air and deposited in the soil – and what species of tree
might be better at doing this. Young trees are now growing in large pots inside 12 special
greenhouses called solar domes at the university’s Biology Field Station. The
researchers hope to measure how much carbon is taken in by the trees and transferred to
the soil by using imported soil from a prairie in Kansas in the USA. Six tree species with
differing physiological traits have been chosen, which may allow responses to elevated CO2
concentrations to be predicted.
Many
countries such as the US, Japan, Australia and Canada want to be allowed to use carbon
sinks (reservoirs) to offset their CO2 emissions from the burning of fossil
fuels. Environmentalist are concerned that there is a limit to the amount of carbon that
forests can absorb and that the soil may soon reach saturation point. There is very little
known about the potential magnitude of these carbon sinks. Less is known about how long
forest soils can continue to act as sinks while atmospheric CO2 concentrations
carry on rising. This is vital information if carbon sinks are going to be effectively
traded for increased CO2 emissions.
James Heath
from Lancaster University says: “We should be able to quantify with accuracy inputs
of carbon to the soil from trees growing at four different CO2 concentrations.
We do this by making use of large differences in the relative abundance of carbon isotopes
between our temperate tree species and the soil that has developed beneath a Kansas
grassland – which is why we have imported 8, 5 tonnes of this soil.
“The
carbon in the Kansas soil has a completely different isotopic signature to that which is
entering it from the trees. By using mass spectrometry to follow the changes, we can
accurately calculate the total amount of carbon the trees are taking from the atmosphere
and transferring to the soil – and which could potentially act as a long term carbon
sink.”
Website: www.lancaster.ac.za
Amendments to EIA
Regulations
The National
Environmental Impact Assessment Regulations, published in terms of the Environment
Conservation Act of 1989, have been implemented and administered by the national DEAT and
the nine provincial environmental departments, since 5 September 1997. Certain amendments
to specific regulations and the Schedule of Listed Activities were considered necessary
and have been published in the Government Gazette of 10May2002. The amendments address
some of the shortcomings of the 1997 regulations.
These
amendments are not aimed at replacing the 1997 regulations but are intended to provide an
interim measure pending the publication of new EIA regulations under the National
Environmental Management Act of 1998. The amendments are primarily terminological,
attempting to address inconsistencies and ambiguities that have emerged in the
interpretation of the regulations, in particular to the List of Activities identified in
Schedule 1 (Government Notice No R 1182 of 5 September 1997).
Copies of
the amended regulations can be obtained from the Government Printer’s office in
Pretoria or from the DEAT website: www.environment.gov.za
or from Johan Benade – Tel:(012) 310 3670. Email:
jbenade@ozone.pwv.gov.za
-----
BOOK REVIEW
Conserving our Water, Preserving our Environment
Publishers:
International Turf Producers Foundation (USA)
Electronic version: www.TurfGrassSod.org and
www.LawnInstitute.com
This
extremely useful and sometimes controversial book has been compiled and published by the
International Turf Producers Foundation (ITPF) located in Rolling Meadows, Illinois, USA.
The ITPF is an independent non-profit educational foundation.
The
publication aims to encourage new thinking about the conservation and recycling of water
used for landscaping with an emphasis on turfgrass which is the most conspicuous user of
water. The initial chapters convey scientifically supported solutions that enlightened
landscape water usage can offer. Case histories illustrate the benefits that can be
realised when water suppliers and users co-operate to apply the best landscape water
conservation practices.
The
statement “plants don’t waste water, people do” is supported by the
conclusions of researchers Beard and Green in The Role of Turfgrasses in Environmental
Protection and their Benefits to Humans, where they write: “The main cause for
excessive landscape water use in most situations is the human factor. The waste of water
results from improper irrigation practices and poor landscape designs, rather than any one
major group of landscape plant materials.”
The proper
definition of the American term xeriscaping, according to Texas A&M University, is
“quality landscaping that conserves water and protects the environment”. The
renowned turf researcher, Dr James Beard, Professor Emeritus of Texas A&M, made this
controversial statement in response to one of the proposed xeriscaping guidelines for the
state of Texas which advocated that in planted areas mulches of a two inch depth or more
should cover most soil surfaces: “Research has shown that mulches under trees reflect
radiant energy onto the underside of the tree’s canopy. This results in increased
water use compared with the same trees that have bermudagrass (Cynodon dactylon) turf
growing beneath them. Mulches are rather expensive and result in a high maintenance cost
relative to turfgrass due to erosion and weeding.”
The case
study concerning water conservation on golf courses by James Snow, National Director of
the USGA Green Section, says that for several decades already the golf industry in the USA
has recognised its responsibility to reduce water use and become less reliant on potable
irrigation sources. The multi-faceted approach of the industry includes development of the
following:
*
new varieties of
turfgrass that use less water or can tolerate poor quality water
*
new technologies that
improve the efficiency of irrigation systems
*
‘best-management
practices’ in golf course maintenance that result in reduced water requirements
*
alternative water
sources that reduce or eliminate the use of potable water
*
golf course design
concepts that include careful earth shaping and good drainage used to collect runoff in
on-site storage dams; and the minimising of the number of areas maintained with grasses
that require considerable water use
*
programmes that
educate golf course superintendents and other water users about opportunities for on-going
water conservation.
Since 1982,
the US Golf Association has distributed more than 18 million dollars through a university
grants programme to investigate environmental issues related to the game of golf, with
special emphasis on the development of new grasses that use less water and require less
pesticide. Turfgrass breeders at Oklahoma State University, for example, have developed
improved, cold-tolerant, seeded-type, bermudagrass (Cynodon dactylon) cultivars, allowing
for the establishment of this stress tolerant, low water use grass in the transition zone
of the United States to replace high water use, cool season grasses. Water savings of 30%
to 50% or even more can be realised.
When the
Ruby Hill Golf Course in Pleasanton, California, was built several years ago, its fairways
and roughs were established with Cynodon dactylon, instead of the cool season grasses used
at nearly all other courses in northern California. Ruby Hill estimates that it has water
savings of about 40% compared with similar courses that use cool season grasses.
There have
been vast improvements made in irrigation system efficiency through technology in recent
years and these include the use of sophisticated on-site weather stations, weather
reporting services and other resources to determine accurate daily water replacement
needs, which reduce the tendency people have to over-irrigate. Various types of sensors
are being adapted to evaluate turf soil moisture replacement needs – including
tensiometers, porous blocks, heat dissipation blocks, neutron probes and infrared
thermometry.
Irrigation
uniformity has also been improved through careful evaluation of sprinkler-head design,
nozzle selection, head spacing, pipe size and pressure selection. State-of-the-art
computerised control systems, portable hand-held controllers and variable frequency drive
pumping systems serve to apply water in the most efficient ways to reduce both water and
energy consumption.
Alternative
water sources on golf courses include: storage ponds to collect stormwater runoff; the use
of effluent that has undergone a three-step treatment process; and the use of brackish
water or even sea water to supplement other water sources. Bermudagrass (Cynodon
dactylon), for example, is quite tolerant of water with a high salt content, while
seashore paspallum is very tolerant. Golf courses have built reverse osmosis desalination
plants to produce irrigation water from sea water where other sources are not available or
very expensive.
More than 2
000 golf courses participate in the Audubon Co-operative Sanctuary Programme for Golf
Courses which educates course personnel about environmental factors including water
conservation and protection – and recognises courses that take significant steps to
conserve water.
A highly
positive statement made in the chapter on ‘Landscape Water Conservation Techniques’
is that “people will make the effort to conserve and improve the environment when
properly informed of and motivated by the best scientific knowledge and technology”.
-----
TREE OF THE ISSUE
Johan Barnard chooses the
Lavender Fever-berry
Croton Gratissimus
Lavender Fever-berry
Croton
gratissimus is the tree that has been chosen by landscape architect Johan Barnard of
Gauteng-based Newtown Landscape Architects. He has fond childhood memories of a natural
grove of Lavender Fever-berry trees on his father’s farm in the Magaliesberg, under
which the family would picnic in the dappled shade. His main reason for favouring this
deciduous tree is the colour of its leaves and its size. He has used these trees adjacent
to office blocks and in courtyards where relatively small, slender trees have been called
for. He warns that although they will survive a mild frost, they are frost tender when
there is a severe drop in temperature.
In spring
and summer, the upper-sides of the leaves are dark green, while the under-sides are
silvery – and when the summer winds blow, the whole tree takes on a silvery
appearance. Over a long spell in autumn, the leaves turn a wonderful variety of shades of
yellow and orange. The Lavender Fever-berry loses its leaves gradually but they decompose
on the ground easily. When the leaves are walked over and crushed they give off a definite
scent of lavender.
Johan used
these trees at the Riverside Government Complex in Nelspruit on the Nels River – in
this area they occur naturally on granite outcrops in shallow soil and this ability to
grow in shallow soil also makes them good container plants. The trees were planted in
between the buildings of the Government offices on the natural rock outcrops that were
retained. They were planted in crevices in the rocks, as they would have occurred in their
natural habitat. For security reasons, small trees with loose foliage were preferred so
that a figure crouching behind a tree would be visible through the leaves and be picked up
by the cameras on top of the buildings.
He also made
use of Croton gratissimus in Linbro Park, Sandton, at MGX Holdings in the courtyard of the
executive offices, where they are well protected by the buildings. They are planted, in
conjunction with two other smallish trees, Heteropyxis natalensis (see Tree of the Issue
Nov/Dec 1999 issue) and Rhus pendulina, to protect the director’s offices from the
afternoon sun. These trees are all reasonably fast growing and provide a variety of
foliage textures and colours. The leaves of Heteropyxis are also lavender scented when
crushed – hence its common name, Lavender Tree.
Johan
comments that Croton gratissimus does not reach much more than 6m in height in its natural
habitat in the Magaliesberg, whereas it probably only reaches 4, 5m on the granite koppies
in Mpumalanga where the soil depth is confined. He says he prefers the tree’s natural
multi-stemmed growth habit and that although nursery specimens are usually single-stemmed,
if they are not pruned they revert to multi-stemmed with time. The rough brown bark is an
attractive feature and an additional dimension is that many birds favour the berries.
In the
warmer areas the tree grows quickly, and it is generally a sturdy strong tree which does
not break. In Nelspruit it grows on partly disintegrated granite and it should therefore,
in Johan’s opinion, be able to tolerate poor soils – although it prefers richer
soils and the soils must be well drained. It survives dry spells and does not need much
water in landscaped areas that are well-composted and mulched.
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WORDS ON WASTE
CSIR establishes Centre
for Integrated Waste Management
The 2000 White Paper on Integrated Pollution and Waste Management emphasises that South
Africa’s reintegration into the global economy necessitates an improved pollution and
waste management system. The issues involved are not the exclusive preserve of government.
“The private sector and civil society have crucial roles to play. The fostering of
partnerships between government and the private sector is a prerequisite for sustainable
and effective pollution and waste management,” are the words of Valli Moosa, Minister
of Environmental Affairs and Tourism, in his foreword to the White Paper.
“The
CSIR Centre for Integrated Waste Management (CIWM) draws on expertise from across the
organisation and covers fields as diverse as municipal waste management, waste
utilisation, mining waste, process technology, wastewater treatment, environmental
management and analytical services,” says Linda Godfrey of the acting CIWM
Secretariat.
The CSIR has
recently been involved in a number of successes in the area of waste management:
*
The potential benefits
of the wastes generated in the coal mining and coal processing industries are being
quantified in a national CSIR initiative, Coaltech 2020.
*
In a project for the
Malawian Ministry of Health and Population, the CSIR has assessed current waste management
systems for the waste generated during mass and routine immunisation programmes at 500
health centres – in conjunction with the Bill and Melinda Gates Children’s
Vaccine Programme.
*
The development of
products from waste materials including the use of hemp waste from the textiles industry
to make building products, and the recycling of building rubble into aggregates and
blocks. The CSIR has also been involved in investigating the reuse of a number of waste
materials and by-products in road construction. These projects have included the
investigation of mine rock, waste ash, phospho-gypsum, waste plastics, ferrochrome slag
and many of the dust palliatives.
*
A study on food and
agricultural waste utilisation investigated the possibility of producing ethanol and
biofuel from agricultural wastes (pineapples, bananas, oranges and mangos) –
focussing on processes suitable for small-scale production.
*
The CSIR has also
conducted a number of investigations to identify suitable areas for the siting of local
and regional landfill sites. Through a process of applying exclusionary and cautionary
criteria, using a GIS approach, followed by a site verification phase, a number of
potential sites can be identified for further detailed feasibility investigations.
*
The Green Buildings
for Africa programme (see articles in Nov/Dec 1999 and Mar/Apr 2000 issue of Urban Green
File) was developed as a voluntary commercial mechanism for the property industry to
mitigate the environmental impact of buildings.
Contact Linda Godfrey, CIWM. Tel: (012) 841 3675. Email:
ciwm@csir.co.za Website: www.csir.co.za/ciwm
Shredding waste
for easier recycling
Bulky or
awkwardly shaped items can be a problem to store and to transport for recycling. A
high-precision engineering firm in northern Ireland has been concentrating on waste
management systems for the last 10 years and has become a world leader in this field.
Ulster Engineering has developed a series of machines with numerous variations to suit a
variety of needs. Its range of shredders can deal with plastics, rubber, wood, steel and
paper.
A recent
customer was Hong Kong International Airport which had accumulated piles of wooden pallets
used in handling heavy freight. One of Ulster’s shredding machines was used to break
the pallets apart, turning them into manageable strips of wood. Ulster has also developed
a compact, mobile hydraulic shredder to destroy confidential documents. Shredded paper has
become very popular for animal bedding and the company has devised a shredding and bagging
system. The Korean Horse Breeding Federation is amongst Ulster’s customers.
Restrictions
on sending whole vehicle tyres to landfill sites led to the development of a machine,
launched in 2000, capable of shredding 330 tyres an hour. The machine is based on a
high-torque, low-speed mechanism which creates less wear on the cutting knives.
The company’s
strategy is to keep up with the constant change in the recycling market.
Contact Ulster Engineering Ltd. Tel: +44 28 9335 2526. Email: info@ulsterengineering.com
Website: www.ulsterengineering.com
Upgrading of
landfill sites
Pikitup, the
waste management utility for the City of Johannesburg, is in the process of upgrading five
landfill sites – Linbro Park, Robinson Deep, Marie Louise, Goudkoppies and Ennerdale
– in a five year programme which has been approved by the Department of Water Affairs
and Forestry. The upgrading of the sites includes improvements to stormwater drainage and
water pollution monitoring, capping of sites, rehabilitation of slopes, improved access
control to landfills including weighbridge control, booms, fencing and paving, and an
upgrade of the general infrastructure.
In addition,
Pikitup is in the process of implementing stringent controls in dealing with the
collection of recyclable materials from the landfills. In an attempt to control
reclamation on its landfills, Pikitup is making use of contractors who will manage the
reclaimers and the reclaiming process on the various sites. A permanent form of employment
has been created for the reclaimers, as they are being provided with a channel through
which they can sell reclaimed material.
Pikitup’s
Driver of the Year
Pikitup, the
waste management company for the City of Johannesburg, has acknowledged the importance of
rendering an efficient waste management service through the launch of its ‘King of
the Road’ Driver of the Year Award to recognise performance excellence amongst its
employees. There were 170 entrants from Pikitup’s 14 depots and thirty six drivers
were awarded with prize money and medals for their competency and driving skills.
Hentie Wiese
from the Midrand Depot was crowned King of the Road and won R6 000 along with a gold medal
and a floating trophy. The first runner up was Albert Ngquzuka from the Avalon Depot and
the second runner up was Henry Shakoane from the Southdale Depot.
The
competition included a driving skills test for executives, administered by the Metro
Police. The executive winner was financial director Navin Sooka.
The King of
the Road Award is the signature event at Pikitup’s Driver Training Centre. “We
believe that an excellent driver is someone who not only maintains a high standard of
driving throughout the year but takes proper care of his vehicle at all times,” said
Etienne du Plessis, GM Fleet for Pikitup. Next year’s King of the Road will be based
on more criteria, including those that will be monitored throughout the year: productivity
levels; monitoring of overloading; keeping to scheduled maintenance programmes; freedom
from traffic fines, accidents and incidents; cleanliness and general condition of vehicle.
Biogas from
organic waste
One of the
discussion topics at IFAT 2002 (the world fair for environment and waste disposal) held in
Munich in May revolved around the anaerobic fermentation of solid organic waste to produce
biogas, which delivers energy in the form of heat or electricity. Agricultural biogas
facilities are on the increase and in Germany, which is nowhere near using its full biogas
potential as yet, the Biogas Association is encouraging livestock farmers to build more
systems or so called ‘energy plants’ and to grow regenerative raw materials on
farmland and open spaces.
In
industrial facilities, effluent can be used for fermentation and the resulting biogas can
be used for generating electricity and steam, complementing the energy requirements of the
industry. Many other materials are also suitable as co-fermenters – garden waste and
food remains including fats, etc. According to the Biogas Association, up to 61 million
megawatts of electricity could be generated by biogas facilities, annually – 13% of
Germany’s total energy consumption.
Websites: www.Biogas.ch and www.bmu.de
-----
World Summit: Action at last!
The
Water Neutral project, other offset projects and other Summit events
While
governments are struggling to reach consensus on political declarations at the World
Summit on Sustainable Development, it seems that voluntary partnerships between business,
government institutions and civil society organisations will give the world significant
cause to hope that there will be delivery, on the ground. Gerald Garner reports on some of
these partnership initiatives as well as events planned for the duration of the Summit.
In office
corridors and at dinner parties, the Johannesburg World Summit on Sustainable Development
(WSSD) is often dubbed just another talk shop for politicians, bureaucrats, global
business and green activists, which will probably be marked by anti-globalisation protests
and administrative chaos. Is the outlook really that gloomy?
As with any
international summit, the WSSD will indeed be underscored by politics and bureaucracy. The
event will, in fact, be the culmination of a two year process of ‘prepcom’
meetings in which the outcomes of the Summit have been partially predetermined. Up to 160
heads of state will descend on Johannesburg in September 2002 to ratify these decisions.
In a recent address to the Water Institute of Southern Africa (WISA), at its biennial
conference in Durban, the South African Director General of Water Affairs and Forestry,
Mike Muller, commented on the Summit: “The first challenge of development is to
address poverty and this should be done in a way that will be sustainable for both current
and future generations. It is therefore essential that economic, social and environmental
issues are considered at all times.”
Two types of
outcomes are envisioned for the Summit. Political declarations and inter-governmental
agreements will be known as ‘Type1’ outputs. The wording of these will be
predetermined and finalised at the last ‘prepcom’ in Bali that, by the time this
issue is published, will already have taken place. ‘Type 2’ outputs will
comprise voluntary partnerships to deliver or implement specific projects and initiatives.
Muller explained: “The general consensus is that Agenda 21 is ten years old –
however, it is still very relevant. What we need from the Johannesburg Summit is not a
rewritten Agenda 21 document but rather implementation of projects on the ground.”
JSE plans to
participate in Summit
The Johannesburg Stock Exchange (JSE) wants to address both the local and
international business contingent during the Summit in terms of its Social Responsibility
Investment (SRI) Index.
This
initiative is part of a joint venture with the FTSE (globa lindex provider) that relates
to the creation and launch of a Social Responsibility Investment Index. FTSE launched the
FTSE4Good index in the UK last year and is successfully attracting significant funds in
relation to this index. Similarly, this concept has support from a handful of SA fund
managers who are already involved in the running of social responsibility funds. It is
intended that money out of this operation and any profits will be donated primarily to the
Nelson Mandela Children’s Fund and Unicef.
It is
envisaged that Nicky Newton-King, Director: New Business at the JSE, will address the
Business Day function at the Hilton Hotel on 1 September 2002 on the JSE’s commitment
and contribution to sustainable development in South Africa.
Johannesburg Climate
Legacy
This project was given coverage in the March/April issue of Urban Green File
(page 15). As with the Water Neutral programme, delegates will be encouraged to purchase
Carbon Neutral certificates to offset the emissions generated by their vehicles in
travelling to Johannesburg. The income generated will be used to fund ‘low energy’
development projects. The Development Bank of SA has been appointed to administer thea
trust fund for this project. It is estimated that the Summit will generate 500 tonnes of
carbon, mainly through delegates flying to South Africa or travelling across country by
train or bus, as well as the increased use of cars and public transport within the
Johannesburg area during the Summit.
Over the
past few months advertisements in the press have called for companies to submit possible
offset projects to the organising committee and the selection of projects will be made by
the middle of June. Melissa Whitehead of IIEC Africa explains the parameters that offset
projects have to meet: “Projects must be within South Africa, they must not be
land-use change projects and must be new initiatives. It is important for the projects to
show how sustainable development can be of benefit to the community.”
Possible
offset projects include green building initiatives, especially energy efficiency in
commercial and industrial buildings, the use of low sulphur diesel in transport and energy
efficiency in the hospitality industry as well as in the health industry (hospitals) and
educational institutions (residences).
Contact Melissa Whitehead at IIEC Africa. Tel: (011) 482 5990
WaterDome
The Africa Water Task Force will host the WaterDome at the Northgate Sundome
from 28 August to 3September. The organising committee for this event is chaired by Mike
Muller – Director General of DWAF in South Africa. The WaterDome will be the primary
venue for a series of water-related side events to the World Summit and several launches
of new initiatives. The African Water Task Force will use the WaterDome as a platform to
launch the Water and Sustainable Development in Africa Paper, and to position this Paper
as an instrument in the communication strategy in the run up to the 3rd World Waste Forum
that is scheduled for 16 – 23 May 2003. The WaterDome will comprise conferences and
an exhibition of successful water-related sustainable development projects and
initiatives, including the African Water Village. The event will be opened on 28August by
Kofi Annan and a presentation will be given by the Prince of Orange titled ‘No water
No Future’. The African Water Initiative, part of the New Partnership for African
Development (NEPAD), will be launched on 31 August 2002.
Contact RaiVision at e-mail: info@raivision.nl or
website: www.waterdome.net
Energy
efficiency display in Melville
The
International Institute for Energy Conservation (IIEC), a non-profit non-governmental
organisation and an affiliate of the US based Civil Engineering Researech Foundation
(CERF) will be hosting an exhibition at its Melville Office in Johannesburg during the
World Summit. CERF/IIEC has been involved in the promotion of sustainable energy
technologies and practices in South Africa since 1993.
There will
be a practical showcasing of all CERF/IIEC projects and some of the work done in
partnership. Some of the issues to be showcased are:
*
Dissemination of
information on projects that promote best practices of energy efficiency and environmental
sustainability
*
Demonstrations of
solar cookers/stoves and solar water heating systems
*
Demonstration of an
environmentally sound information technology model developed to indicate the links between
environmentally sound parameters, building costs and energy performance for low income
housing
*
Promotion of the
sponsorship of trees for Food and Trees for Africa in aid of the establishment of a
sustainable forest between Alexandra and the Hartbeespoort Dam
*
Display of drawings
from local schools expressing their understanding of energy and sustainable environment
*
An energy efficient
internet café for all IIEC/CERF alumni or associates.
Visitors to
the CERF/IIEC exhibition and energy efficient show house will enjoy discounted cocktail
hours with selected and accredited restaurants in Melville. “We aim to show that
energy conservation can be achieved through any medium and with any partner. IIEC
therefore encourages everyone to visit Melville during the Summit and experience the
benefits of energy conservation in all spheres of life,” concludes Whitehead.
Contact Melissa Whitehead at IIEC Africa. Tel: (011) 482 5990.
From
commitments to action – five key areas of intervention
During her
address at the annual environmental lecture of the American Museum of Natural History in
New York on 14 May 2002, Nane Annan called for the outcome of the Johannesburg World
Summit to be a move from commitments to action. She identified specific areas where
concrete results are both essential and achievable and pleaded for governments, businesses
and civil society to build a new ethic of global stewardship.
Annan said
that in Stockholm thirty years ago, the first United Nations Conference on the Human
Environment was a watershed. It inspired legions of green activists at grass-roots level
and led to the establishment of environment ministries and agencies in countries that did
not already have them. It put the environment on the international agenda. “Ten years
ago, the international community gathered again for the Earth Summit in Rio de Janeiro.
With the conceptual breakthrough of sustainable development, the Summit generated both
heat and light. No longer, it was hoped, would environmental protection be regarded as a
luxury or afterthought. Rather, environmental factors would be integrated with economic
and social issues and become a central part of the policy-making process. Developed
countries, which had benefited immensely from a wasteful and hazardous path of
modernisation, would help developing countries combat poverty and avoid that same
polluting path. In adopting Agenda 21, a blueprint for sustainable development, rich and
poor seemed to have agreed on a common vision for growth, equity and conservation over the
long-term.”
“At the
end of August, at the World Summit on Sustainable Development in Johannesburg,”
commented Annan, “we have a chance to restore the momentum that was felt so palpably
after the Earth Summit. At its core, Johannesburg is about the relationship between human
society and the natural environment.”
Annan said
that those present in the room during her lecture were among the 20 % of humanity that
enjoyed privilege and prosperity undreamt of by former generations. “Yet the model of
development that has brought us so much has also exacted a heavy toll on the planet and
its resources. It may not be sustainable even for those who have already benefited, let
alone for the vast majority of our fellow human beings, many of whom live in conditions of
unbearable deprivation and squalor and naturally aspire to share the benefits that we
enjoy.”
The
Johannesburg Summit, she said, aims to find practical ways for humanity to respond to the
challenges of bettering the lives of all human beings, while protecting the environment.
The Summit also aims to move from commitments – of which there have been plenty, 30
years ago and 10 years ago – to action. Annan identified five specific areas of
importance in which to achieve sustainable development. She referred to these areas of
intervention by the acronym ‘WEHAB’ – water, energy, health, agriculture
and biodiversity.
Water and sanitation
More than one billion people are without safe drinking water and twice that
number lack adequate sanitation. More than three million people die every year from
diseases caused by unsafe water.
Actions
required:
•
improved access to
water
•
improved efficiency of
water use, for example by getting more ‘crop per drop’ in agriculture, which is
the largest consumer of water
•
better watershed
management
•
reduction in leakages,
especially in cities where water losses are an astonishing 40% or more of total water
supply.
Energy
Two billion people currently have no access to energy, condemning them to
remain in the poverty trap.
Actions
required:
•
make clean energy
supplies accessible and affordable
•
increase the use of
renewable energy sources
•
improve efficient use
of energy
•
address
over-consumption – people in the developed countries use far more energy per capita
than those in the developing world.
Agriculture
Perhaps as much as two thirds of the world’s agricultural land is
degraded. As a result, agricultural productivity is declining sharply. In Africa, millions
of people are threatened with starvation.
Actions
required:
•
increase agricultural
productivity
•
reverse human
encroachment on forests, grasslands and wetlands
•
promote research and
development
•
implement the UN
Convention to Combat Desertification.
Biodiversity and
ecosystem management
Biodiversity is declining at an unprecedented rate – as much as a thousand
times what it would be without the impact of human activity. Half of the tropical
rainforests and mangroves have already been lost. About 75 percent of marine fisheries
have been fished to capacity and 70% of coral reefs are endangered.
Actions
required:
•
preserve as many
species as possible
•
clamp down on illegal
and unsustainable fishing and logging practices while helping people who currently depend
on such activities to make a transition to more sustainable ways of earning their living.
Health
The links between the environment and human health are powerful. Toxic
chemicals and other hazardous materials are basic elements of development. Yet more than
one billion people breathe unhealthy air, and three million people die each year from air
pollution – two thirds of them poor people, mostly women and children, who die from
indoor pollution caused by burning wood and dung. Tropical diseases such as malaria and
African guinea worm are closely linked with polluted water sources and poor sanitation.
Actions
required:
•
reduce waste
•
eliminate the use of
certain chemicals and substances
•
encourage research and
development – particularly studies that focus on the diseases of the poor.
-----
Haenerstburg Townlands
Unprotected, invaluable, mist belt
grassland
Public
open space comprising valuable Afro-montane mist belt grassland in serios need of
management
There is a
200 ha stretch of relatively undisturbed Afro-montane mist belt grassland interspersed
with patches of Afro-montane forest and wetland habitat which is adjacent to the village
of Haenertsburg in the Magoebaskloof area of Limpopo province. This site, the Haenertsburg
Townlands, was originally common land used for the grazing of horses belonging to the
villagers and travellers, and although this public open space is known to be state land,
whether the title holder is the provincial government or the municipality seems to be a
matter of uncertainty, which is at present being investigated by the Department of Public
Works. It is this uncertainty about the titleholder that has been the main obstacle in
attempts by the residents and other surrounding landowners, over a number of years, to
establish some sort of formal protection for this exceptional site.
In 1993,
after a visit by an official of the regional Nature and Environmental Conservation
Department, the Director General sent a letter to the Haenertsburg Local Area Committee
stating that the Haenertsburg Townlands site was of great conservation importance as it
was one of the only few remaining portions of North Eastern Mountain Sourveld in the
vicinity – most of this veld type has been destroyed by forestry.
During 1998,
the Land Development Objective (LDO) process was undertaken in the Greater Haenertsburg
Area and the importance of conserving the Haenertsburg Townlands was given full support as
“the last grasslands left, needing to be protected and preserved”. It seems that
there is agreement in principle that the site should be conserved but no action has been
taken.
Information
used in this article was obtained from Pieter Winter of the Haenertsberg Environmental
Monitoring and Action Group (HEMAG) who is a taxonomist and curator of the Herbarium at
the University of the North and from the chairman of the Haenertsburg Development
Foundation, tourism consultant, Mike Gardner.
Natural features and
biodiversity
The village of Haenertsburg is in the Woodbush range, west of Duiwelskloof and
Tzaneen – a granite based portion of the escarpment extending north from the Wolkberg
and geologically very distinct from the latter. Magoebaskloof is in the Woodbush range, as
is the second largest indigenous forest in the country, Grootbosch, which is surpassed in
size only by the Knysna forest.
Vegetation
in the area and on the Haenertsburg Townlands is of the Acock’s veld type North
Eastern Mountain Sourveld of which, according to Low and Rebelo, only 7,42% is conserved.
Pieter Winter is of the opinion that mist belt grassland on granite, as opposed to
sedimentary rocks, probably has a far lower conservation percentage because granitic soils
are deeply weathered and therefore more sought after for agriculture and particularly
sylviculture. Afro-montane grasslands support high plant diversity and numbers of endemic
plants (those that occur nowhere else). Aloe lettyae is endemic to the Woodbush range and
the immediate surrounding granitic areas with high rainfall; Wahlenbergia brachiata and
Indigofera rehmannii are endemic to the Woodbush range; while Hemizigia rehmannii and
Tricalisia capensis var. transvaalensis are endemic to both the Woodbush range and the
Wolkberg Centre. A new species of Gymnosporia, first recognised in the Haenertsburg
Townlands, is endemic to the mist belt forests of the ‘Northern and Eastern Transvaal’
mountains.
Biotic
diversity, in general, is high in grasslands and the fact that the Townlands is one of the
very few remaining patches of NE Mountain Sourveld means that it conserves invaluable
genetic resources. The Haenertsburg area protects the habitat of certain endemic and rare
species such as the Wolkberg Zulu butterfly, the Blue Swallow and many species of
wildflower, and ensures ecosystem diversity and the resulting evolutionary processes which
support the sustainability of the environment and all its life forms. The existing
complement of fauna on the Townlands includes bushbuck, duiker, bush pig, genet, civet and
porcupine.
There are
two known natural springs on the site which feed into Ebenezer Dam, a vitally important
water storage dam for the entire area including the city of Polokwane. The grasslands also
act as sponges and retain moisture far longer than the vast surrounding areas planted to
exotic timber forests.
The
Haenertsburg Townlands are the largest area of grassland in the vicinity, supporting,
according to Winter, over 630 plant species that apart from their conservation value have
medicinal, cultural and nutritional value for the local rural communities.
Mismanagement of the
site
As reported above, numerous unsuccessful attempts have been made by the
Haenertsburg community to liaise with government and establish some sort of formal
protection for the site, including appropriate management to preserve its high botanical
diversity. The site is the State’s responsibility and is not being managed by the
State. During 2001, a proposal, co-ordinated by consulting ecologist Cathy Dzerefos, was
made to the Botanical Society of SA for the funding of a formal botanical survey of the
Townlands and in April 2002, the Haenertsburg Development Foundation applied to the
National Lottery for funding for an Environmental Management Plan for the Townlands. It is
believed that the area is also essential for outdoor leisure activities and that correctly
managed it will boost tourism in the area, as well as serve environmental education
purposes.
Winter says
that although the community and some of the surrounding timber growers are in favour of
conserving the site, general lack of understanding and sometimes total disregard for the
value of the grasslands has resulted in activities that have meant loss of habitat and
general degradation of the Townlands. The site has been used for the dumping of
construction rubble and garden refuse; driving off-road vehicles, motorbikes and quad
bikes across the veld without any attention being paid to existing roads and paths;
unmanaged grazing of domestic livestock; and clearing of horse trails that could have been
better planned to minimise impact.
Gardeners in
the village with property bordering the stream banks have planted exotic ornamentals in
close proximity to the stream and cannas, roses and irises have escaped into the riparian
zone. A stand of poplars has been planted in a wetland and poplars have been planted
elsewhere along the stream, ostensibly purely for ‘aesthetic purposes’ and
apparently, according to Winter, with the consent of the Department of Water Affairs.
Other alien invasive species are spreading across the site and although Working for Water
was involved in an initial clean-up, no follow-up has been done and the recovered wattle
is over 4m in height once again.
A private
timber grower has ploughed firebreaks in the pristine vegetation of the Townlands, instead
of on the land allocated for silviculture. Ad hoc infrastructure developments on the site,
such as the excavation of a long ditch for a water supply pipe (after two years the pipe
has not yet been connected or buried), have proceeded without public consultation. The
grassland is burnt every season to protect private property and this has become a
conservation concern because, although fire is a natural determinant of grasslands,
research has shown that certain plants are adversely affected by too frequent or
out-of-season fires. The Greater Tzaneen Municipality is generally responsible for fire
management in the municipal area but it is not clear whether this grassland falls under
its jurisdiction.
Voluntary management actions
Virtually all the positive ‘management’ actions, which have been far from
adequate, over the past few years have been undertaken on a voluntary basis by
organisations such as the Haenertsburg Residents and Ratepayers Association, Haenertsburg
Rotary Club, local private sector timber growers, the Haenertsburg Primary School, the
Fire Protection Association and HEMAG.
A
preliminary fire management plan has been drawn up and discussed with key timber growers
and the Tzaneen Fire Department, both of whom are willing to take environmental concerns
into consideration in future. Mowing of tracers for the burning of firebreaks, instead of
ploughing as in the case of the timber grower reported above, seems to be generally
acceptable to the plantation owners. Baseline botanical diversity information has been
collected and is available for integration into the Environmental Management Plan.
Haenertsburg Primary School’s environmental club has held alien plant removal days
with the help of Elaine Tribe, one of the parents, and other community members have
participated with enthusiasm.
The 10km
Louis Changuion Hiking Trail which extends across and around the Townlands remains only
partly accessible because vegetation has closed in over certain stretches, through lack of
maintenance because of lack of funding. Some funding from the Rotary Club has allowed for
short sections of the trail to be upgraded. Once a year, the Haenertsburg Spring Hunt with
its horses and hounds takes place on the Townlands attracting riders from as far afield as
Gauteng. This is generally considered to be a sustainable way of utilising the common
land, as the impact of horses hooves seems negligible. The main damage was done, recently,
when the course was being mowed in preparation for the event and about a dozen plants of
the endemic Aloe lettyae were destroyed. Winter says that had warnings been heeded this
could easily have been avoided and the course will, in future, be moved away from the area
in which the aloe populations are found. The Hunt made a cash contribution to HEMAG as
some sort of reparation.
Deriving sustainable
benefit from the Townlands
There are very few recreational facilities for the communities living in and
around Haenertsburg and an appropriate day visitor picnic site could provide valuable
income for the on-going management of the Townlands. The picnic site could also become the
starting and ending point for an upgraded hiking trail that could include an
interpretation centre where the story of the value of grasslands and the role of the
landscape in water conservation could be told, for the benefit of visitors and school
groups from the two local boarding schools which attract children from as far afield as
Venda. The site also presents a unique opportunity for students from the University of the
North to study the biology of a fast disappearing grassland type.
There is a
constant demand from tourists staying in the Magoebaskloof area for relatively easy, short
walking trails and with repair and proper management the trail on the Townlands will meet
this need. In September and early October, thousands of visitors are attracted to the
annual Cherry Blossom Festival and these visitors would certainly appreciate the
experience of the vast diversity of wildflowers to be found on the Townlands – 25
species of Helichrysum alone and several terrestrial and epiphytic orchids, along with the
endemics mentioned earlier.
Winter has
suggested that with proper management and the co-operation of conservation authorities,
certain wildflowers that occur in abundance, and even medicinal herbs, could be picked and
processed or sold freshly-cut to visitors. Mike Gardner feels that the bottling and sale
of spring water could also be investigated. “I think these ideas need to be explored,
as I believe if you don’t use it, you lose it. Any resource which can be sustainably
utilised should be, in my opinion – especially if this will take pressure off other
over-exploited resources,” comments Winter.
The northern
fringe of the Townlands, along the Broederstroom River, is utilised for ceremonies of the
Zion Christian Church. Water is drawn from the river and sold to church members in plastic
containers and one of the recommendations of a proposed management plan for the site is to
improve the facilities where the water sellers gather alongside the heavily trafficked R71
which links Polokwane to Tzaneen.
Gardner is
of the opinion that the very small (about the size of half a tennis court) remaining
habitat of the endangered Wolkberg Zulu butterfly (Alaena margaritacea) can be increased
by providing the necessary set of circumstances and these are present on the Townlands.
The only area in which the butterfly is nfound, to the best of Gardner’s knowledge,
is along a small portion of firebreak on a hillside, 5km away from the Townlands, where
short grass and lichen“covered rocks, on which it lays its eggs, are in evidence. The
terrain of portions of the Townlands replicates this and it may be necessary, in Gardner’s
opinion, to create a managed environment there for this small yellowish-orange butterfly
which is threatened by the destruction of its habitat.
In an area
like Haenertsburg which has become almost totally dominated by alien vegetation and exotic
timber plantations, the presence of the Townlands constitutes a very appealing and
aesthetic component to the local environment and it is important that such areas are
retained, at least for their value as a ‘witness area’, representing what was
formerly the general nature of the Woodbush Range. There are also important historical
linkages with the past, as old saw pits are still visible in the remnant patches of
indigenous forest and foundations of old dwellings are, as yet, untouched and may contain
valuable artefacts dating back to the days of Chief Makgoba and earlier.
The year
2002 is the International Year of the Mountains and this would be a most appropriate time
to involver the community of Haenertsburg in developing a plan for the sustainable
management of these local grasslands which are such a valuable resource to the local
community and South Africa as a whole.
-----
Detail in the urban environment
Melrose
Arch, Johannesburg
Melrose Arch
is a mixed use ‘urban node’, based on strong urban design principles, in the
suburb of Melrose in Johannesburg. Preserving the old exotic trees of this heavily treed,
previous residential area, which came into existence in the 1930s, was a condition of
approval of the township development plans. According to Rodney Brown of the co-ordinating
landscape architects Van Riet & Louw, in this phase of the development forty trees
have been transplanted and only five (all liquidambers) have been lost. Brown was part of
the design team responsible for developing the urban fabric of furnishings and paving
featured in this photographic coverage of the open space within the precinct.
He also
provided input into a number of environmental aspects, such as stormwater attenuation for
use as an irrigation source and flood management of the spruit, which were thoroughly
investigated with the intention of improving sustainability – as were other aspects
such as the use of solar power and grey water recycling. An on-going investigation into
wildlife management in the Sandspruit area by consultant Ben Breedlove has produced some
interesting possibilities, including live transmissions through intranet of happenings
such as fledglings in nests cracking open their eggs, but these might also prove to be too
costly.
Wildlife
management may make up in part only for the fact that (like so many developments in South
Africa) the precinct turns its back on the spruit. Brown says the reasons for this are
largely the decision to create the ‘superbasement’ which resulted in an 11m
difference in ground levels at the spruit; security – the spruit park is uncontrolled
public open space; the noxious emissions and noise from the highway which make the spruit
inappropriate for recreation; as does possible radiation from the overhead powerlines. The
idea of relocating the powerlines underground remains a possibility.
-----
Building in the urban environment
Developments
at the National Botanical Garden, Pretoria
The new
environmental education centre and a separate visitors’ centre at the National
Botanical Garden in Pretoria are both projects that were made possible by funding from the
Department of Environmental Affairs & Tourism’s Poverty Relief Programme. The
grant required a commitment to labour intensive construction methods and support for
emerging contractors in the projects. Leigh Darroll visited the garden and spoke to Alexis
Symonds, from the National Botanical Institute in Pretoria, and Mike Godfrey from Mithro
Construction Management.
The new
education and visitors’ centres form part of a larger scheme for development at the
garden and are aimed at establishing it as a premier tourist destination in the city and
in Gauteng, and at enhancing its environmental education services and outreach programmes.
The terms of
the grant of some R2,2 million from the Poverty Relief Programme required that, in
construction, the simultaneously built projects should resource small or emerging
businesses to support black economic empowerment, and should maximise labour use –
providing jobs, even if only temporarily, to local unemployed people. The construction
programme was arranged to meet these requirements and Godfrey points to a number of
successes – in the formalisation of previously informal businesses, in the
involvement of small business subcontractors, and in the temporary employment of more than
60 otherwise jobless people, many of them women, from Pretoria and its environs.
“While
we have constructed very simple, conventional buildings,” says Godfrey, “the
process of construction and the methods we used in managing it, opened up new avenues of
opportunity for emerging contractors to participate in the economy.”
The buildings
The centre for environmental education is located on the south-western edge of
the conserved grassland (see article in Urban Green File September/October 2000) in the
eastern part of the garden. It is designed to provide a facility for teachers and learners
and accommodates office space for the environmental education staff at the garden; a
lecture hall that can seat up to 150 people; a laboratory and research-cum-resource
facility that can be used by teachers and the garden’s assistant education officers;
and service spaces such as a kitchen, storerooms and ablution facilities.
The
grassland is used as an outdoor classroom in a number of different teaching and learning
programmes and it was therefore important for the education centre to be close to it. The
site for this building, which was identified by the NBI, is in an already disturbed area
of the grassland – where it is crossed by the sewer line. This also would facilitate
the sewerage connection for the new building and avoid any further impact that would
otherwise arise from service network extensions. The site is close to the access road that
runs eastward from the Cussonia Drive entrance to the garden and, by locating the
education centre at this edge, the intrusion into the grassland reserve is minimised.
The new
visitors centre, next to the garden’s entrance gateway, will incorporate a gift shop
and a plant sales area. The existing parking area is being upgraded to accommodate
increased traffic of buses and cars, and new pathways and signage are to be introduced.
The
buildings are simple, single level structures, brick walls and thatched roofs, designed to
allow for the involvement of small contractors; to suit labour intensive building methods;
and to continue the rustic aesthetic that has been established in other earlier buildings
such as the lapa and restaurant and is seen as appropriate to the environment of the
garden. The design and the materials specified also support passive climate control,
obviating the need for and additional cost of insulation and expensive mechanical climate
control equipment.
The
buildings take advantage of a north orientation and the wall mass of the rough-faced red
clay bricks provides an effective thermal reservoir. High thatched roofs, pitched at the
required 45º to allow for efficient rainwater runoff, contribute to cool interiors. An
adequate eaves overhang shades the walls from the summer sun at its height but allows the
lower winter sun’s warmth to penetrate the interiors and to be absorbed by the
bricks. The sense of space internally is enhanced by the exposed roof structures of robust
gum poles. This is especially evident in the education centre where the spans across the
auditorium and the office wing, with its generous passageway – which allows for easy
movement of groups of school children in and out of the building – push the roofs to
double-volume height. The roof void also assists with effective ventilation, allowing hot
air to rise and promoting the circulation of cool, fresh air as it is drawn in through
doors and windows that are positioned to ensure cross-ventilation.
Finishes and
fittings are simple and functional. Wooden window- and doorframes are finished with brass
hardware. Ceramic floor tiles were specified not only for their contribution to passive
climate control but also for durability and low maintenance in respect of budget
constraints and because they offered another labour intensive subcontracting opportunity.
Godfrey
acknowledges that there are opportunities for innovation in the management of the new
facilities – to conserve water and energy and to minimise waste. At present,
lighting, for example, is purely functional neon tubing. Energy saving opportunities are
being assessed and alternative, efficient lighting products are currently being sourced.
The intention is to supplement or replace the installed lighting when sufficient funding
becomes available. Water conserving sanitary fittings are also being investigated.
Furniture in the new education centre has mostly been salvaged from existing offices, with
some new and some donated equipment installed.
Empowerment
Godfrey explains how the contract was managed to ensure effective empowerment
and the transfer of skills through direct, hands-on experience.
The main
contractor, Moepi Construction, was responsible for appointing the subcontractors, as in a
conventional building contract, and for sourcing the labour for the projects. It is
interesting to note that the site manager, who took on the responsibility of sourcing
labour, favoured women as workers, commenting that they were more efficient and more
committed than the men and citing the fact that the money earned goes home to the families
and communities as a major benefit.
As a
construction management company, Mithro Construction was employed by Moepi Construction,
which is owned by James Baloyi. With the standing that Mithro has in the industry, it has
access to credit and capital that is unavailable to emerging contractors. Thus, Mithro was
able to use its credit facilities to service the needs of the main contractor in carrying
out the contract. This has a number of advantages in terms of empowerment. Firstly, it
affords the emerging contractor the liquidity to access further credit with a range of
suppliers, as required for the project, and thus to establish its own credibility with
these suppliers for future contracts. Secondly, it offers the emerging contractor the
opportunity to demonstrate his capacity and skills in built work – as a reference for
future work. And it offers the opportunity for skills transfer – in construction
management and contractual management – in a direct, practical way. This might cover
basic business management skills, such as ensuring an adequate and timely income stream to
pay labour wages and suppliers, as well as considerations such as the planning and
ordering of materials and fittings, timing of subcontract work, and similar.
As the
implementing agency for the grant from the Poverty Relief Fund, the NBI was also involved
in assisting the contractor with concerns such as the management of cash flow, employment
advice, controls on the number of people employed and appropriate payment commitments.
Godfrey
reports that Moepi Construction, previously an informal business, is now registered as a
closed corporation and has the legal and financial footing to take on contracts of up to
R5 million. It has subsequently been appointed to two other large contracts in Pretoria
– one for construction work at the Brooklyn Police Station and another for
construction of the new Hamilton Road Bridge. In Godfrey’s words: “This is
effective empowerment.”
He also
highlights the transfer of skills and building of capacity amongst the small-business
subcontractors involved in the projects. The subcontractors included some who operate as
suppliers of skilled labour only – such as bricklayers, painters, glaziers and
tilers; others who function on a supply and installation basis, such as the electricians
and plumbers; and others – such as the roofing contractor – who offer a design,
construct and supply service and source their materials and labour independently. By
appointing small businesses, mainly from the informal sector, the contract presented
opportunities to a resource base that is ignored in most formal building projects.
The plumbing
subcontract in this project was handled similarly to the main contract. The plumbing
company also employed the construction manager to provide assistance with access to
finance, so enabling it to establish its own credit-worthiness with suppliers through this
project.
“This
is a new approach which is appropriate to nurturing emerging businesses in the new South
African economy,” says Godfrey. “Importantly, it is a process that needs to
managed. It becomes a circular teaching and learning experience. The whole industry needs
to look at new ways of doing things.”
This
approach meant that there was not a formal professional team appointed. With the brief
from the NBI, drawings were prepared by the construction manager and approved by a
professional engineer and the contract then proceeded.
Education
The National Botanical Garden in Pretoria runs a number of environmental
education and training programmes. As one of the gardens of the National Botanical
Institute, it focuses on indigenous species and especially those endemic to its locality.
Alexis Symonds, assistant director of environmental education at the National Botanical
Institute, says that the long-established schools programme, which is linked specifically
to the curriculum, is well used by schools in and around Pretoria and from as far afield
as Mpumalanga. Schools bring learners from different grades to the garden for specific
lessons, many of which are taught in the grassland.
The garden
also offers a certificate programme for the training of assistant education officers,
which attracts people from all around Pretoria. Qualified assistant education officers
facilitate the environmental education activities for school and pre-school groups. The
laboratory and resource facility in the education centre is available to the education
officers, as well as to teachers who use it to research material for lessons.
A proportion
of the Poverty Relief funding has been committed to a new programme of bussing in groups
of children from disadvantaged schools. Groups of sixty children are brought to the garden
twice a week. “In this way,” says Symonds, “we can extend the lessons on
the values of our natural environment, of indigenous planting, waterwise gardening and
sustainability.”
A food
garden is also to be planted next to the new education centre. This is a new dimension for
the recently introduced pre-school programme. Symonds suggests that it is important for
young children to learn how plants grow and how they can be used. “We are often
consulted on indigenous waterwise gardening for township schools and we are working with
various partners to promote the planting and management of food gardens in these areas.”
The food
garden will form part of the landscaped buffer zone that surrounds the building to provide
a firebreak and to limit the impacts on the natural grassland from people using the
centre. A number of other theme and demonstration gardens, which will also be used in the
educational courses, are to be planted in the main garden.
-----
Golf course sensitive to bushveld
environment
Mowana
Lodge, Kasane, Botswana
Mowana
Safari Lodge borders on the Chobe River in Kasane and has been in existence for about ten
years. The lodge is adjacent to the Chobe Reserve and the town of Kasane is at the meeting
point of four countries – Zambia, Zimbabwe, Namibia and Botswana. The Cresta
Marakanelo Group made the decision to utilise a flat stretch of largely denuded land - an old landing strip – adjacent to the lodge
for a 9-hole golf course designed to international standards. A competition was held for
the design and supply of this course and the team of DDV Landscape Design Group and Wonder
Gardens Africa won the competition on the strength, according to Douw van der Merwe of
DDV, of their presentation which was based largely on environmental aspects and the
retention of a strong bushveld flavour. One of the most important design criteria was the
extensive utilisation of water on the course to create different habitats for aquatic bird
species with different requirements.
Douw van der
Merwe says that Kasane is on a floodplain and the idea was to create some of the ambience
of a floodplain on the course – a kind of transition from dry bushveld into the
floodplain adjacent to the Chobe River. When the Zambezi comes down in flood, it pushes
the Chobe back up its course and raises the river by up to 2, 5m. A large borrow pit
(quarry) on the golf course site was turned into a dam with shallow sides, mud flats, a
large area of open water and islands to attract waterfowl and especially waders, which are
not catered for by the fast flowing Chobe; while a small meandering artificial stream
provides habitat for other aquatic species. The water features are designed to catch
stormwater runoff from the course and stormwater outlet pipes from the neighbouring
housing estate also feed onto the course.
Another
important aspect of the design was that nothing exotic should be brought into the area.
The turfgrass used on the fairways, tees and greens is bermudagrass or Cynodon dactylon
– common kweek, which grows in the area. Van der Merwe commented that the toned-down
green colour of the Cynodon is also visually more appropriate in the natural bushveld
setting. A mixture of veld grasses has been used in the rough and in keeping with the
policy of not bringing exotic species onto site, grass seed has been collected on site and
in areas the soil has merely been ripped and the change in moisture content has encouraged
seed in the topsoil (where there is an extensive seedbank) to germinate.
The area
adjacent to the landing strip was invaded by the pioneering sickle bush, Dichrostachys
cinerea, and this had to be removed, while all the large specimens of bushveld trees
– apple-leaf, leadwood, monkey thorn, jackal-berry and sausage tree – were
retained. Supplementary planting of a wide variety of species indigenous to the area was
done – 1200 new trees were planted. Many of these, along with the existing trees,
were brought into play as features on the course. Van der Merwe explained that the idea
behind using a wide range of tree species (over 30) on the course was to attract as
diverse a number of bird species as possible.
The sycomore
fig, for example, has been planted to attract Green Pigeons and the star chestnut seems to
be the favourite roosting area for Yellowbellied Bulbuls. Some of the sickle bush was
retained and this is favoured by the Hartlaub’s Babbler. Van der Merwe comments that
the bird is often mistaken for the common babbler when it is in the dense thickets. The
Collared Palmthrush lives and forages in the lala palm.
Fairways
were placed along already disturbed areas, largely on the previous landing strip, while
use was made of existing roads and no big trees were moved, except one that was dying.
Care has been taken to keep the areas of bush around the course in a natural state and,
consequently, a double row of sprinklers has been installed on the fairways, as opposed to
the more favoured three rows, because of the potential risk of spraying the adjacent bush
and creating unnatural habitat.
Although
water is drawn from the Chobe River it is also returned to the river. Water for irrigation
purposes is pumped out of the Chobe at night by means of a high pressure pump, while the
pump used to keep the water circulating through the water features only operates by day
and serves to top up the features. Water from the features flows back through the marginal
plantings of reeds, which serve to remove excess nutrients, into the Chobe. The black
cotton soils on the course do not drain easily and the course is shaped to collect surface
runoff and drain excess water into the water features.
All the
buildings on site are thatched and a portion of the lodge is built around a large baobab.
The course is not continuously visible from the main road, although there is the odd
glimpse through the thick bush on the perimeter of the site.
The decision
was made not to pump irrigation water out of the large dam because its function is
primarily as a habitat for birds and the continuously fluctuating levels that this removal
of water would have caused would not have been beneficial to the habitat created for
wading birds, and would have resulted in erosion along the edges of the dam. Some marginal
planting was done on the edges (Phragmites and Cyperus species) but the bulk of the
marginal species have been left to come in on their own – seeds are brought in by
birds and in the water from the Chobe. Phragmites was planted at a depth of 1, 5m which
stops the plants from becoming too invasive. Bog planting, aside from creating habitat,
cuts down evaporation because it shelters areas of water from the wind. Indigenous fish
such as certain Tilapia species from the Chobe breed in the dam and migrate back into the
river along the man-made stream.
Van der
Merwe commented that different wading birds have different requirements: some choose to
wade in still water and others in runn ing water – so the water features on the
course were designed to attract different wading species.
A large
water surface was required to attract a variety of aquatic species. The creation of
islands in the large expanse of open water also means that there is less of an area
subject to evaporation. The islands accommodate the resident hippos and crocodiles (the
crocs moved in two weeks after the dam was filled) and provides protection for rarely seen
birds such as the African Skimmers which have been attracted by the white calcrete beach
(waste material obtained from the landing strip) to breed on the island, while the mud
flats and shallows around the island create habitat for birds like the Threebanded Plover.
Thickets along the edges of the dam attract the Swamp Boubou while a variety of Warblers
live in the reeds. Van der Merwe says that Squacco Herons and Slaty Egrets are a common
site on the course, while he has also seen the water loving Lesser Jacana and the Rock
Pratincole, a wader which favours rocky areas along the banks.
Care has
been taken not to encroach too severely on bird habitat by playing directly over the water
in sensitive areas such as near the islands where the Skimmers are breeding – so that
although the golf course is in touch with water on seven of the nine holes, the golfer
only crosses over short expanses of water.
The tees and
fairways were seeded with Cynodon dactylon (bermudagrass); 80% of the seed used was hulled
to speed up the germination process. The greens and greens’ surrounds were sprigged
with a hybrid Cynodon, Gulf Green. The greens were constructed according to modified USGA
specifications utilising graded local quartzite sand. Van der Merwe warned that Gulf Green
is a prolific grower and needs to be vertidrained and scarified regularly. Local sand was
also used in the bunkers – some of it very white but other darker in colour.
Van der
Merwe said that a drawback of Cynodon grass was ant infestation. He emphasised that ants
needed to be sprayed when an infestation occurred because they undermined surfaces
creating little hollow areas and these attracted harvester termites. He said that the
situation was exacerbated on the Mowana course where the removal of sickle bush uncovered
ants nesting in the ground beneath piles of dead wood. Both ant and termite infestations
can have devastating effects on fairways and need to be treated. He said that insects
infestations were always pre-empted by bird activity and that there was never any need for
preventive spraying.
He
emphasised that only curative treatment was used on the course and pointed out that
because Cynodon was a much tougher grass than the bent varieties commonly used on greens,
there was no need for an overnight decision to be made to use a fungicide, as there was
time to assess the extent of the problem prior to resorting to spraying. An outbreak of
dollar spot in November (when humidity is at its highest in Kasane) had to be treated and
a herbicide was used to rid the course of pampas grass after it had been cut back
manually.
The
greenkeeper is in the process of researching organic fertilisers but use had been made of
minimal quantities of 2:3:2 for root establishment and ammonium sulphate to heighten the
colour in the bermudagrass. He said that the quantities used would ensure that there were
no residual nutrients and that any incidental excess in the water features would be
removed by the marginal plantings of reeds prior to being returned to the river.
Although
this is a 9-hole course, it is designed to play as an 18-hole course with changes in
length and approach being made to holes on the return nine. The golf course was handed
over in August 2001.
Wonder
Gardens Africa’s construction team in Kasane comprised largely local people –
even the posts of key Wonder Gardens personnel had to be advertised to be certain that
there were no locals capable of filling those positions. The construction team included 30
local people and this team has been reduced to 16 who have been trained by Wonder Gardens
to fulfil maintenance functions on the course. The training in construction skills was
done on site and Wonder Gardens will be providing these trainees with certificates of
competence which will allow them to source work elsewhere.
“Guy
Palmer of Widnell Projects, who is an amateur naturalist and has a good understanding of
the terrain, spearheaded this unique project and made an invaluable contribution to it,”
commented Van der Merwe.
Project team
Client: Cresta Marakanelo
Project managers: Widnell Project Management
Golf course design: DDV Landscape Design Group
Quantity surveyors: McIntosh Latilla Botswana
Main contractor: Wonder Gardens Africa
List of trees planted
Acacia nigrescens (knob-thorn)
Acacia polyacantha (white thorn)
Acacia sieberiana var. woodii (paperbark thorn)
Acacia tortilis (umbrella thorn)
Adansonia digitata (baobab)
Albizia versicolor (large-leaved false-thorn)
Antidesma venosum (tassel-berry)
Berchemia discolor (brown ivory)
Clerodendrum glabrum (tinderwood)
Colophospermum mopane (mopane)
Combretum imberbe (leadwood)
Combretum molle (velvet bushwillow)
Croton gratissimus (lavender fever-berry)
Diospyros mespiliformis (jackal-berry)
Dombeya rotundifolia (wild pear)
Ficus sycomorus (sycomore fig)
Gardenia volkensii (bushveld gardenia)
Hyphaene petersiana (northern lala palm)
Kigelia africana (sausage tree)
Kirkia acuminata (white seringa)
Philenoptera violacea (apple-leaf)
Mimusops zeyheri (Transvaal red milkwood)
Peltophorum africanum (African wattle)
Phoenix reclinata (wild date palm)
Pterocarpus angolensis (kiaat)
Pterocarpus rotundifolius (round-leaved teak)
Rhus pyroides (common wild currant)
Sclerocarya birrea (marula)
Sterculia africana (African star chestnut)
Syzigium cordatum (water berry)
Terminalia sericea (silver cluster-leaf)
Ziziphus mucronata (buffalo thorn)
-----
Corrugated iron
The
ultimate sustainable building material?
Dr Hennie de
Clercq, executive director of the Southern African Institute of Steel Construction,
presented a paper of this title at the Built Environment Professions Convention on
Sustainable Development recently held in Sandton. As well as highlighting certain
attributes of corrugated iron in factors that fall outside the formal criteria used to
define sustainable materials, Dr de Clercq pointed out that the management of lifetime
efficiencies in resource consumption in buildings, is of far greater significance than the
consumption of those resources in the production of building materials. An abridged
version of the paper is published here.
Dr de Clercq
began his presentation by confessing a certain nostalgia for corrugated iron and suggested
that people have developed a “sustainability instinct” – by which we
recognise and respect materials and artefacts that have given us really good service over
a long time.
What
criteria do we use to measure the quality of service rendered by a product, and how does
corrugated iron fare in such an assessment?
A broader view of
sustainability
Sustainability is commonly defined in terms of reducing, to an absolute
minimum, both the use of non-renewable natural resources and the production of substances
or effects that are detrimental to the ecosystem of the region or the world, during the
entire lifecycle of any artefact.
However,
there are many projects in the developing world that are excellent in these terms, yet end
up as a total waste of resources. This happens when a project does not serve the purpose
that its creators or the community had in mind for it, or when the community cannot afford
to operate and maintain the facility – often the case when the technology is not
really internalised and understood by the users to the extent that they are able to
innovate and extrapolate from it and link it to associated technologies.
Clearly,
more than environmental impact should be considered when assessing the sustainability of
capital works.
Corrugated iron since
1830
Corrugated iron was first produced in London in the 1830s by rolling wrought
iron sheets of a limited length to a small thickness, passing these through corrugated
rollers and dipping each sheet in a bath of molten zinc – so making it deserving of
the name galvanised iron.
It didn’t
make a major impact in Britain or Europe, where other cladding materials were well
established, but found its place in many of the countries then newly settled by the
British – Australia, New Zealand and South Africa – which were poor in natural
building materials. By the 1840s, the first corrugated iron buildings were seen in South
African towns. It came to be used extensively – to roof or clad virtually every
verandahed home, shop or factory, as well as farmhouses and sheds.
During the
gold and diamond rushes in different parts of the world in the later 19th century,
corrugated iron was recognised as ideal for construction in remote locations – a
rugged, prefabricated, easy to transport material, available at reasonable cost and
allowing for rapid construction with ordinary skills. It became the trademark of mining
towns like Kimberley, Pilgrims Rest and later Johannesburg. That these old, ‘temporary’
buildings are now, after almost 150 years, the defining elements in mining-related tourist
destinations in South Africa, testifies to their durability and charm. In re-use, they
have proven to be upwardly mobile.
The British
Army also saw to the distribution of corrugated iron in the 1800s. One building, which
still stands today at the observatory in Johannesburg, was manufactured in England and
transported first to India where it was erected to serve as an officer’s mess. Later
it was demounted and dispatched to Pretoria to serve the same purpose, before finally
being transferred to its present site.
Applications
of corrugated iron extended further in the later 20th century when it was recognised as
the most economical material for very large roofs of shopping centres and industrial
buildings.
Over time,
the material itself also changed. In the 1890s mild steel replaced wrought iron.
Developments of higher steel strengths enabled the use of thinner sheeting and other
technological advances have seen continuing improvements in the material and in the
rolling and installation processes.
An inspirational
material
Corrugated iron is a simple material and the fact that it has been around for a
long time has allowed people the opportunity to come to grips with it, to innovate and
extrapolate from the existing technology. It is used today in water tanks and reservoirs,
in grain silos, for culverts beneath roads and railways, and for crash barriers on
roadways, among a host of other engineering applications. Architects have also used the
material in houses, industrial and other buildings of unique design. The work of Jo Noero
Architects and architect, Ora Joubert, amongst others in South Africa, and that of Glenn
Murcutt in Australia (recent recipient of the Pritzker Prize for Architecture), testifies
to the material’s inspirational qualities and its adaptability.
In contemporary urban
use
A further chapter in the history of corrugated iron, not yet fully played out,
relates to its role in the rapid urbanisation of South Africa’s population. The
history of our country has given rise to a huge demand for housing for the poor. In
response we saw first, pre-1994, the uninspired mass construction of housing townships
around the country. Since 1994, the new government has delivered more than a million
houses for poor and low-income families. At the same time, we have seen the haphazard
construction of backyard shacks and the rapid development of informal settlements,
especially on the outskirts of urban centres. Corrugated iron plays a role in all these
areas.
In the small
(40m2 on average) houses for low-income families, corrugated iron roofing
provides shelter and facilitates the extendibility of the home.
In informal
settlements and the backyards of township houses, makeshift constructions of whatever
materials can be obtained, carry the mark of poverty and cannot be considered acceptable
accommodation. Nonetheless, such shacks are a present-day reality and it is worth
considering them critically.
In and
around Johannesburg, discussions with a number of shack dwellers indicated that a shack
should meet the following criteria, in order of priority.
•
a reasonably secure
and robust refuge for family and property
•
affordable
•
keep out rain and sun
and serve as a wind shield
•
quick and easy to
build
•
spread of fire from
shack to shack is not easy
•
materials can be
salvaged and reused elsewhere (in view of impermanent tenure)
•
not too hot in summer
or cold in winter
It will be
noted that the thermal performance of the house – which is one of the predominant
factors used to determine sustainability in Europe – comes exactly last in the list
of priorities. This can perhaps be attributed to Johannesburg’s relatively mild
summers and winters; people accept that indoor temperatures can vary and they dress
accordingly.
Corrugated
iron as a single, thin skin of metal is surely not great in terms of its thermal
characteristics. However, it meets all the other criteria listed above, making it an ideal
shack building material. Second-hand sheets can be bought quite cheaply or obtained
otherwise; doors and windows can be purchased or improvised. A roadside trade in building
materials tends to flourish where new informal settlements are established. People with
ordinary skills and some advice from others more experienced can quickly put a house
together. Indeed the technology underlying corrugated iron has proven so accessible that
people with no special skills have proceeded to build, in the idiom of the shack, double
storey houses, churches and other structures.
Sustainability in
formal terms
Clearly corrugated iron has played and still plays a significant role in
construction in South Africa. It is also important to question whether it is an acceptable
building material in terms of its impact on regional and global ecosystems.
Very little
information is available in industry on the questions of sustainability of materials, in
terms of embodied energy or operational energy. Drawing on what is available and
proceeding with his own calculations, De Clercq assessed corrugated iron, as typically
used in the roofs of houses and the walls and roofs of industrial buildings, in comparison
with other commonly used materials.
The study is
limited to the Johannesburg region and focuses on embodied energy, with operational energy
excluded as neither houses nor factories are commonly heated or cooled in Johannesburg.
Further, the supply of iron ore and other non-energy materials used in the production of
corrugated iron are considered to be almost inexhaustible, and emissions and pollution
produced in the manufacturing process, transport and construction are assumed to be
relatively proportionate to the amount of energy embodied in the finished material.
In walls
The study compares the embodied energy per tonne of: corrugated iron (new, from
raw materials); recycled corrugated iron (where the steel has been remelted); reused
corrugated iron (where it is used as a second-hand material); and brickwork, mortar and
plaster. Although masonry has a lower embodied energy per ton, in actual application per
square metre of wall area, the embodied energy in a single skin of corrugated iron (0,133
GJ/m2) is about 7% of that in a brick wall (2,01 GJ/m2). This
proportion is reduced over a building’s lifetime, of an assumed 50 years, when 30% of
the corrugated iron (a low figure in terms of current practice) will be reused, whereas
brick construction, most often, would be demolished and dumped.
In roofs
The roof of
a small house, 8m by 6m in plan, was used as the basis for this assessment of three
different materials. Taking account of factors such as: typical roof pitch, mass of the
roof covering, mass of timber in the roof structure, durability of both the roofing
material and the structure, proportions of the material that would be reused and recycled,
plus a common provision for energy consumed in waste disposal, a measurement of embodied
energy is determined for each installation. These are shown in the table below, together
with the embodied energy in each installation after 101 years – when the corrugated
iron and the concrete tiles have been replaced for the second time (every 50 years) and
the thatching for a fourth time (every 25 years).
The results
are actually counter-intuitive. Where thatch, as a natural material, would be expected to
have the lowest embodied energy and steel, with a high embodied energy per ton, is
conventionally viewed as environmentally unfriendly, this is shown not to be the case over
the long-term.
It is worth
noting that the costs of the respective roofs, including timber structure, in current
terms, would be as follows: corrugated iron (new) – R2 000 to R2 600; thatch
(including lightning mast) – R22 000; and concrete tiles – R9 500. These costs
and the measures tabled do not include ceilings, although these would preferably be
incorporated in houses roofed with corrugated iron or concrete tiles.
Relating
these findings to our current urban lifestyles, consider that the embodied energy in any
of the roofs assessed, equates to the energy consumed in driving a car less than 50km per
year in each of the 100 years used in the calculations.
Embodied energy versus
operational energy
It must be recognised that in buildings, only about 5% of total lifecycle
energy consumption can be termed embodied energy, with regard to the materials used and
the construction process; the 95% balance is taken up in operational energy consumption
over the building’s service lifetime. Our emphasis in assessing and managing
sustainability in buildings must, therefore, be focused on optimising operational
efficiencies rather than on the energy embodied in the building materials.
In
conclusion, and reviewing all the factors considered in his paper, De Clercq suggests that
corrugated iron, having provided – in South Africa more than anywhere else –
exceptional service in diverse applications over a long period of time, meets the terms of
humankind’s sustainability instinct.
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