Enayam Port

Tamil Research Institute
RAPID TECHNO-ECONOMIC FEASIBILITY REPORT FOR
DEVELOPMENT OF COLACHEL PORT AT TAMILNADU
FINAL REPORT
4.3. IMPACT DESCRIPTION
4.3.1. Coastal geomorphology
Dredging and reclamation works for the construction of breakwaters may intercept and change littoral processes;
particularly sediment transport. The location of a port may cause changes in current patterns and littoral drifts due
to the alteration of wave refraction, diffraction and reflection. The change of littoral drift may lead to erosion or
accretion in shore zones.
Permanent coastline changes due to a new erosion or accretion imbalance may be expected due to the
establishment of the port.
A different choice in the port site and configuration may minimize or maximize those impacts on the shoreline.
Site selection and port design should aim to minimize the impact from changes in current patterns and other
coastal hydrology elements. Therefore, the specific port location and configuration is the main data used to
assess this impact.
• Port location
The level of the impact on the waterfront for each alternative depends on the natural preservation of the affected
coastline.
The coastline running from Kanyakumari to 2 Km west of Enayam has been studied. Each section of the coast
has been categorized based on its state of preservation as per the following parameters:
Shoreline description
Assigned value
per category
RV River estuary 7
SD Sandy beach with sand dune vegetation 6
SC Sandy beach and coconut tree plantation 5
BU Beach in built-up landscape 4
RMS RMS walls, high tide line in contact with RMS wall 3
HTL No backshore, high-tide line next to built-up or degraded areas 2
DB Degraded beach 1
Table 29 Shoreline description sites and categorisation
To estimate the impact, a buffer impact of 2 km east and west of the port location has been considered.
The value is expressed as:
• Impact on coastal geomorphology= Total area of type of shoreline affected (in hectares) X value assigned
to the shoreline (on a scale of 1 to 7)
The impact will be higher for alternatives that affect well preserved coastlines with. Thus, the higher the value of
the indicator, the worse the proposed alternative would be.
• Port configuration
Alternative 2 Manavalakurichi includes a bridge connecting the coast (inland port) to the port itself. This bridge
can ameliorate the impact on sediment transport and shoreline dynamics. Thus, the final impact for alternative 2
has been considered to be the third part of its previous calculated value.
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