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The first in a series of Monthly Stakeholders’
Meetings was kicked off by the National Environment and Planning Agency (NEPA), at its Cross Roads offices, on World Water Day, Wednesday, March
22. The meetings which are aimed at providing critical environment and
planning information to the public and other key stakeholders will see a
series of presentations from various environmental professionals over
the course of the year.
Cowell Lyn, engineering consultant to NEPA and
coordinator of the IDB/GOJ Kingston Harbour Institutional
Cowell Lyn
Strengthening
Project, made the first presentation entitled “Engineering Methods for
Coastline Protection, with special reference to the Palisadoes”. Mr. Lyn
explained that the Palisadoes is particularly vulnerable to hurricane
disruption and outlined three main factors which contributed to this.
Mr. Lyn noted that the geological/geotechnical
composition of the Palisadoes or the tombolo, as it is more properly
known, was formed over time by littoral transport of terrigenous
sediments. These sediments which are produced by the earth originated
from rivers such as the Hope, Cane and Chalky Rivers and merged with the
eastern coastline of the Palisadoes. Mr. Lyn said that weak sections of
the tombolo were breached at least three times in the past, due to the
impact of hurricanes.
Additionally, Mr. Lyn pointed to the orientation of
the tombolo. He said Atlantic hurricanes generally approach Jamaica
along eastern and southeast trajectories in the direction of the
Palisadoes. These systems are generally very powerful, he noted. They
threaten the tombolo, which acts as a natural breakwater, and which
protects the Kingston Harbour and waterfront from the destructive
effects of storm surge and wave battering.
Areas such as Rozelle, Wiki Waki, Copacabana and
Caribbean Terrace, said Mr. Lyn, are particularly vulnerable to damage
from powerful hurricane waves and storm surges. He said that this is the
result of the Yallahs Basin, which is well over a kilometer deep and
which is located on the southern coastline of St. Thomas and southeast
St. Andrew.
Mr. Lyn indicated, however, that the town of Port
Royal fared relatively better during Hurricane Ivan. This, he said, was
because of the relatively better sheltering provided by the island shelf
on which Port Royal sits. The town, Mr. Lyn said, was protected by this
shallow platform and the Port Royal Cays.
Mr. Lyn also mentioned the various forms of shore
protection currently in existence at the Palisadoes. He pointed to the
dunes, revetments, the groyne field and the seawalls at Caribbean
Terrace. Mr. Lyn indicated, however, that the existing types were
clearly inadequate to prevent serious disruption from the very
high-energy wave climate that prevailed at the Palisadoes during the
passage of Ivan.
According to him, “the most appropriate form of
shore protection for the weaker, more vulnerable sections of the
Palisadoes would be installations of carefully designed revetments
finished with outside armouring consisting of modern, pre-cast concrete,
inter-locking units”.
Mr. Lyn ended with a call to the responsible
authorities to make the utmost effort to fully re-construct and augment
the destroyed beach dunes before the 2005 Atlantic Hurricane Season
starts in June. Based on experiences gained from Hurricane Ivan, the
dunes provide valuable resistance to complete breaching of the
shoreline.
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