Main Drainage Channels for Fanling Sheung Shui and Hinterland
Title of EIA Main Drainage Channels for Fanling, Sheung Shui and Hinterland
Completion Date October 1997
EIAO Register Office Reference EIA-127/BC
Project Proponent Territory Development Department
Project Description The project is to train the rivers in the River Indus Basin to alleviate flooding in the basin. The rivers to be trained under the project include River Sutlej in Area 30B and Indus Major, Indus Minor and River Beas.
Recommended environmentally friendly design measures of channels
a. Design of abandoned meander for wetland habitats
As a result of river training works, some existing wetland habitats for wildlife such as Painted Snipes will be affected. Abandoned meanders along the Indus River and River Beas could provide an opportunity for re-creating the wetland habitats. The design features of the meanders (Figures 1, 2 and 3) are as follows :
i. retention of original river stream course for creating wetland habitats;
ii. planting of indigenous vegetation to reprovide a riparian habitat for wildlife;
iii. marsh areas created to provide habitats for water birds and herbivores; and
iv. bamboo planting in some meanders to provide potential nesting sites for egrets and herons.
b. Ecological design features of channels
Ecological design features of channels (Figures 3 and 4) are summarised as follows :
i. grasscrete or reinforced grass lining at side slopes and base of channels above tidal influence to provide a grassy habitat;
ii. natural bottom with rip rap stone lining (to provide scour protection where required) at channels with bed at or below 0.00m PD to maintain existing aquatic habitats;
iii. planting of vegetation along outside slopes of channel embankments to replace habitats lost and to enhance the diversity of habitats and their associated fauna in the area;
iv. reprovision of weirs to ensure permanent water cover for 70% of the channel system which provides ponded water and deep water habitat for aquatic life.
v. reprovision of weirs to ensure permanent water cover for 70% of the channel system which provides ponded water and deep water habitat for aquatic life.
(Note : Modified from Figure 5.3 of the Supplementary Paper on Ecological Mitigation Utilising Abandoned Meanders dated May 1998 prepared by the Maunsell Consultants Asia Ltd)
(Note : Modified from Figure 3.15 of the Final Assessment Report dated October 1997 prepared by the Maunsell Consultants Asia Ltd)
(Note : Modified from Figure 3.12 of the Final Assessment Report dated October 1997 prepared by the Maunsell Consultants Asia Ltd)
Figure 4 - Ecological Features of Channel Design
(Note : Modified from Figure 3.10 of the Final Assessment Report dated October 1997 prepared by the Maunsell Consultants Asia Ltd)
