Monitoring the Impacts of a Coastal Protection Structure on La Guira Bay, Tobago

O'Brien-Delpesh, Charmaine; ,

Monitoring the Impacts of a Coastal Protection Structure on La Guira Bay, Tobago

by Charmaine O'Brien-Delpesh, Inst of Marine Affairs, Carenage,

Document Type: Proceeding Paper

Part of: Coastal Engineering Considerations in Coastal Zone Management

Abstract:

In the mid 1980s the Trinidad and Tobago Government embarked on a tourism development thrust centered around the island of Tobago. A key feature of this thrust involved extending the Crown Point Airport runway to facilitate wide-bodied aeroplanes. Part of La Guira Bay which is located at the southern end of the runway had to be reclaimed and a coastal protection structure constructed at the central region of the bay. The Institute of Marine Affairs (IMA) was commissioned by the Airports Authority of Trinidad and Tobago (AATT) in 1988 to undertake an Environmental Impact Assessment (EIA) of the airport runway extension. The EIA, which included monitoring the construction phase of the project, was completed in 1990. During the period May 1988 to October 1990, field studies revealed that the beach immediately west (downdrift) of the coastal protection structure was experiencing erosion (flanking). The structure was therefore extended by 50 m at its western end. Monitoring during the subsequent operational phase of the project showed that erosion still continued to progress downdrift (west) along the beach, clear evidence that the extended coastal protection structure had failed to arrest the erosion process (flanking) which continued unabated up to October 1992. Erosion was also evident at the eastern and western ends of the beach; however, these latter cases were due to sand mining activities. This paper analyses the findings of the marine geology data that were collected on this project during the period May 1988 to October 1992.

Return to search