With the increasing public awareness of environmental protection, it is our policy to incorporate environmental friendly features into our drainage improvement and flood control projects as far as possible.  Design of plain concrete channels for major floodway projects some ten years ago is now replaced by more environmental friendly design.  With a view to harmonizing the works with the surrounding and to preserve the natural habitat, we have incorporated various environmental friendly designs, including:

• Grasscreting and extensive vegetation along channel embankment to enhance aesthetic value and diversity of microhabitats;
• Using gabions and geo-fabric reinforced grass lining to stabilize side slopes;
• Utilizing unlined channel beds to enable colonization of flora and fauna;
• Creating unlined embankment, if possible, to facilitate vegetation; Retaining meanders;
• Creating shallow ponds as aquatic planting bays to allow freshwater fish, amphibians and water birds to thrive; and
• Creating wetland habitats and reed beds to flourish diversified wildlife.

Mangrove created along the bank of Kam Tin Riverprovides
     compatibility and integrator with the environment

Reed pond under construction in San Tin creates valuable
wetland habitat that benefits migratory birds and enriches
                               local ecology

     Great egrets at a preserved meander in Kam Tin River

 Green banks and preserved meanders in 
 Upper Ng Tung River after training works

These efforts have culminated into large tracts of green banks, rich reed ponds, preserved meanders, and mangrove habitat over the years.

Apart from environmental friendly designs in flood control projects, we also apply the same concept to redress some existing nullahs in Yuen Long and other urban areas.  Aged concrete slopes or granite parapets alongside open channels are being replaced by hydromulch, grasscrete and/or planters.  Examples of our effort can be seen at nullahs in Kai Tak, Jordan Valley and Tsui Ping.

 
Jordan Valley Nullah–Present condition after improvement works

  
    Kak Tak Nullah(Choi Hung Road Section–Before(left)and
                         after (right) improvement works

  
Tsui Ping Nullah–Before(left)and after(right)improvement works

To promote good practice for planning and execution of maintenance works and for vetting of development proposals affecting environmentally sensitive watercourses, an internal circular was prepared taking into account related local researches and overseas experience.

Ecological Enhancement Work of Yuen Long Bypass Floodway Project