Long 'physical barrier' to be built near Lim Chu Kang mangroves

A very long 'physical barrier' is to be constructed between Lim Chu Kang mangroves and the Western Catchment area, from Feb to Jun 10. There is no further information on the 'physical barrier' or exactly what kind of work will be involved in putting it up.
I've only had a chance to make very few trips to Lim Chu Kang mangroves and have not visited the shores along the worksite. The Western Catchment area (also a military area), has some of our last large tracks of mangroves including some very rare plants such as the Dipteris fern. Alas, there just isn't enough time to visit all our shores properly.

Construction of Physical Barrier off PCG Base (Lim Chu Kang)
from Port Marine Notice No. 12 of 2010 dated 4 Feb 2010.

With effect from 18 Feb 10 to 17 Jun 10. 24 hours daily including Sundays and Public Holidays. Off PCG Base at Lim Chu Kang (see attached plan) :-

Construction of physical barrier will be carried out within the working area. A safety boat will be deployed to warn craft to keep clear of the working area. Further general enquiries relating to the project can be directed to Mr Bobby Woon, the project manager at Tel: 9456 6876 (email:bobby@thong-huat.com.sg).

Here's a look at the worksite in relation to the PCG Base and Lim Chu Kang mangroves.