Enayam Port

Tamil Research Institute
RAPID TECHNO-ECONOMIC FEASIBILITY REPORT FOR
DEVELOPMENT OF COLACHEL PORT AT TAMILNADU
FINAL REPORT
• Dredging removes bottom biota and dumping of dredged material covers bottom habitat, both of which
may reduce fishery resources.
• Deterioration of water quality usually gives rise to changes in aquatic biota: a decrease in the number of
species and its abundance.
• Piles, concrete surfaces, rubble mounds and other similar structures in water could form new habitats,
which may introduce undesirable species.
• If toxic substances and other contaminants are re-suspended through dredging or dumping, they may lead
to contamination of fishery and shellfishery resources.
Judging from the secondary sources of information consulted and from direct interviews with fishermen and local
fisheries departments, there is no special differentiation in marine ecosystems for the coastal fringe; thus,
ecological components are similar along the coastline studied. Due to currents, sandy substrate and depth,
fisheries and marine biota are pelagic and therefore the tidal and shore marine biota are not different between
port locations.
Therefore, the total volume of material dredged is the best indicators to use to estimate the impact on the marine
ecosystem.
Alternative
Dredging (m3)
1 Enayam 6,230,070
2 Colachel 15,343,819
3 Manavalakurichi 12,805,893
4 Kanyakumari 7,692,053
Table 31 Dredging volume per alternative
4.3.3. Hydrology
Two impacts are likely to occur on terrestrial hydrology:
• Impact on fresh water resources due to water supply during port construction and operation.
• Impact on drainage network due to inland port facilities and new access roads and road widening.
Fresh water sources
Main water source along the coast for the local community is the ground. Major bore wells are fitted with
submersible pumps and water is pumped through main pumps to urban areas. In rural areas, water is also
pumped from the ground and stored in tanks. Water for irrigation comes from lakes, ponds and open tanks.
Currently, fresh water resources are a main concern along the coast.
In the municipality of Colachel, for example, the present water supply needs are partly fulfilled through localized
sources like bore wells, which cannot satisfy even the current demand. Hence, in the long term, the sustainable
water supply source needs to be increased.
One of the main concerns in coastal aquifers is the intrusion of saltwater into freshwater caused by excessive
abstraction of groundwater.
It is preferable to build the proposed port at a location far from urban or densely populated areas to avoid
disturbance to fresh water extraction and local overexploitation. Thus, the distance from towns and villages and
the surrounding population density is a good indicator of that impact.
CP1832-FR-AX-05-CP-Initial Environmental Examination-Ed4.docx AX05 - 97 97
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