2.0       DESCRIPTION OF PROJECT

2.1       Dredging Works

East Channel

The Proposed dredging plan (Figure 1) envisions the deepening and widening of the channel, in order to accommodate the larger vessels coming into service recently (described as “Post Panamax”).

The east channel extends from the seaward end of the East Channel to Kingston Harbour Limit (Port Royal Point) (see Figure 1, on a bearing of 284 degrees). In order to secure the Port’s future maritime access for the next 15- 20 years, it is estimated that a dredged depth of 18m would be required. This is to accommodate wave/swell induced vertical movements, even though the design ships’ draught is 14.5m. There are several coralline high spots which would have to be lowered to the 18m contour.  Further, the Port Authority intends to dredge the northern part of Rackham Cay to 18m in order to provide a minimum channel depth of 18m through the opening between Rackham and Gun Cays.  The width required for the east channel to safely accommodate the design ship is 230m.

Outer Harbour

The outer harbour channel would be less exposed to swell, thus the proposed depth for dredging here would be 16.4m, and the width proposed would be a minimum of 170m. The sediment in the outer harbour is composed largely of sand and silt.

Inner Harbour

The inner harbour, which is protected from the swell effects, is to be dredged to 15.7m with a minimum width of 160m. The bed within the inner harbour is generally formed of soft materials such as soft clays, weak peaty clays silts, etc. There are also deposits of organic material of anthropogenic origin deposited by Greenwich sewage treatment plant. Other sources include industrial and other waste carried into the harbour by gullies and other drains over several years.

2.2       Reclamation Works

It is proposed to reclaim a small part of Hunts Bay (in the south east), adjacent to the Portmore Causeway. And the north western corner of Gordon Cay (see Figure 2).  This would be to create more container storage space as part of the Port Expansion. This would involve the placement of suitable Rock Armory to create a containment berm for fill material.  Suitable dredged material would then be used as fill.

2.3       Spoil Disposal Alternatives

The proposed options for disposal of the dredged material are as follows:

Alternatives:

1.        Place all of the dredged material in the proposed Hunts Bay reclamation platform.

2.        Dispose of all the material at a suitable marine disposal site.

3.        A combination of the above options with some material being placed in the Hunts Bay reclamation platform or some other land bank location.

If dredging takes place to fully accommodate the “Post Panamax” vessels, the estimated total quantities of material to be dredged is 10,559,888m³. Approximately 3,000,000m³ of suitable material to be used as fill at Gordon Cay and Hunts Bay (see Figure x).