Only small area of Ping Chau coral damaged
We refer to B. W. Darvell's letter (South China Morning Post, April 3) regarding the coral threat on Ping Chau. Further to the letter of the Environmental Protection Department (EPD) (Post, April 9), the Architectural Services Department (ASD) and the Agriculture and Fisheries Department (AFD) would like to respond to some other points raised by Dr Darvell.
The construction of a temporary pier is part of a project to construct a navigation radar station on Ping Chau. The radar station was initiated by the Marine Department for monitoring and regulating the expected increase in marine traffic in the area. The ASD is responsible for constructing this radar station. It was agreed that a temporary sea loading point would be required to facilitate the construction works. The ASD consulted the AFD in August 1995 on the location and the need to construct a temporary pier.
In considering the temporary pier which is a small structure (15 metres x nine metres), to be built with prefabricated concrete blocks on a sandy shore without the use of fine material and to be dismantled on completion of the project, the AFD did not anticipate any impact on the surrounding coral on the eastern coast of the island. The ASD was informed of the assessment and the Director of Environmental Protection was kept posted. The location of the temporary pier was agreed by concerned departments including the AFD, ASD and EPD.
Work started on March 18, of this year. On March 25, the AFD received a report that fine fill material had been used in the construction of the pier and had escaped to the surrounding waters causing sedimentation on the coral. The AFD conducted a site visit on March 27 and found that the affected area was relatively small when compared to the whole coral bed off the eastern coast of Ping Chau. Meetings were immediately held among the AFD, ASD and the contractor to draw up remedial measures to prevent further damage.
These measures include the following: The pier will be constructed by using concrete units with large rubble infill and a cover layer of hard paver or equivalent.
Any soil and sediment currently on the pier site will immediately be carefully removed.
The seaward approach to the pier for barges will only be allowed at high tide and restricted to a buoyed channel. Only shallow draught barges will be used to gain access to the front of the pier.
Marine anchoring will not be permitted and the barges will be secured at the pier using land-based mooring points.
The barges will depart immediately once loading or unloading has finished. The contractor began implementation of these remedial measures, on April 2. They will be supervised closely by staff of the ASD. The AFD will also assist in monitoring of the situation.
EDWARD WONG for Director of Agriculture and Fisheries P. L. KWAN for Director of Architectural Services