The following case study was OCR'd from The World Bank's Regional Studies
Program Report No.26 entitled : "Coastal Zone Management: Case Studies from the
Caribbean" authored by Gillian Cambers, Environment Division, Dec.1992,
p.10-13
CAUTION:
"any citation and the use of this paper should take account of its
provisional character"
A. Case Studies Relating to Industrial and Urban Development in the
Coastal Zone
Industrial Development at Point Lisas, Trinidad.
This case study shows how changes upstream and in the adjoining coastal
lands had serious ecological and sociological impacts on the
beach/mangrove zone and the offshore zone. These adverse impacts could
have been lessened or removed completely had an Environmental Impact
Assessment been conducted and its recommendations implemented by an
effective agency.
In Trinidad the west coast is the most environmentally stressed coastal
area, over 88% of the population live in this area and it employs 93% of
the labor force. This case study deals with an industrial estate on the
west coast at Point Lisas. Prior to the industrial estate the area was
marginal sugar cane land with fringing mangroves along the coast.
In 1966 the Point Lisas Industrial Port Development Corporation was
established, the Govemment acquired majority shares in this company. A
study by McShine (1985) listed the industries located on the estate as :
iron and steel, fertilizers, urea, methanol and a power station. In 1978
the Govemment identified Point Lisas as a priority area for housing.
As a result of these developments a decision was taken to divert the
Couva River into Carli Bay, see Figure 1. This was designed primarily to:
(a) Improve the drainage from the new housing area and industrial estate
and to accommodate the increased runoff;
(b) Accommodate large volumes of hot water to be released from the power
station, fertilizer and methanol plants;
(c) To increase the water circulation in Carli and Couva Bays so that the
water temperature at the cooling water intake site in Couva Bay would not
be increased.
By 1985 a new dredged channel into Carli Bay had been completed, however,
this had not been joined to the river. Initially the dredge spoil was
dumped in the Bay, however, this caused siltation problems in the dredged
channel so the spoil was dumped between the original river channel and
the dredged channel. In addition a dam was built near the proposed
housing development, the proposed lake would be used as a recreational
area for the housing development, and as a reservoir for an emergency
water supply to the industrial estate.
The resulting ecological impacts are as follows:
(a) The dredging of the new river mouth and channel has resulted in
the loss of benthic habitats in Carli Bay which has led to a decline in
the number of commercially important fish and shrimp. The dredging and
dumping of the spoil has destroyed some 15 hectares of wetlands with the
subsequent loss of oysters, mussels and edible land crabs.
(b) The construction of the dam on the Couva River has led to the
accumulation of untreated sugar factory wastes in the lake. It has also
formed a barrier that will hinder animals that need to migrate from fresh
water to the sea (or vice versa) for breeding purposes.
The resulting sociological impacts are as follows:
(a) The complete abandonment of the commercial shell fish trade.
(b) The construction activities have caused siltation of some of the
natural drainage channels leading to stagnant water conditions.
(c) The untreated sugar waste in the lake means that it cannot serve
its recreational or emergency reservoir functions.
Additional ecological and sociological impacts were anticipated if the
new channel was joined to the river. These included the drying out of
the lower reaches of the Couva River thereby depleting the commercially
important mussel beds, and the loss of road access to fishing facilities
and the only sandy beach in the area. McShine (1985) recommended that
the new cut should not be made.
Case Study Assessment: The development described in this case study was
partly in the coastal zone and partly upstream of the coastal zone. The
industrial estate itself lies in the coastal zone. The housing estate
and the sugar factory lie upstream, the housing estate some 1.5 km from
the beach zone.
This case study has described the impact of one small aspect of these
developments, namely the river mouth diversion. Obviously the total
impact of the industrial and housing estates on the coastal zone will be
far greater. The river diversion has resulted in the loss of habitat in the
beach/mangrove zone and in the ofshore zone thereby resulting in the
destruction of a viable fishing industry. One aim of the project, to
provide a lake-reservoir, cannot be fulfilled due to pollution. In
addition it appears that the cut joining the new channel to the existing
river may not be made due to changes in the industrial and housing
components of the project and a setback in the project funding. Thus the
damage to the coastal environment may have been for nothing.
Much of the environmental damage is irreversible. For example the loss
of the benthic habitat and the decline of the fish and shrimp industry is
a long term effect of the dumping of the dredge spoil which will continue
to result in high siltation for many years to come. Similarly the loss
of wetlands results in the loss of habitat for oysters, mussels and
crabs, again, this is irreversible. The construction of the dam and the
creation of the polluted lake could be reversed if the wastes from the
sugar factory were treated, this would obviously have an associated cost
factor. Similarly the dam could be modified to allow fish migration up
and down stream. Thus with this case study some of the damage could be
reversed at a cost. As the case study showed, additional damages would
result if the new channel was joined to the river.
Most of the environmental damage could have been reduced or eliminated
had an environmental impact assessment (EIA) been conducted prior to the
project. These impacts could have been predicted. Unfortunately no EIA
was carried out.
As a follow up to this case study, some furher work was done on the
economic aspects of the Point Lisas Industrial Estate, Manwaring and
McShine (1989). This study analyses the impact of the change in land
use from agriculture and fishing to a heavy industrial estate, port and
urban development. The Government invested over US$ 1.3 billion in the
estate. An EIA should have been mandatory for a project of this size.
Manwaring & McShine went on to analyze the benefits and costs to the
economy of Trinidad and Tobago derived from the Estate. Using the Net
Present Value Method, they showed that from a financial and economic
point of view, the Government investment over a fifteen year time period,
will result in net negative returns to the economy. They conclude that
the economic benefits would have increased if a comprehensive EIA had
been carried out.
References:
Manwaring, G., McShine, H. 1989. Economic Aspects of the Point Lisas
Case Study. Conference on Economics and the Environment,
Barbados 1989, Caribbean Conservation Association.
McShine-Mutunhu, H. 1985. Couva River Diversion - A Problem in Environmental
Planning. Proceedings of the Caribbean Seminar on Environmental Impact
Assessment, Barbados 1985, Caribbean Conservation Association.
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