For discussion
on 14 April 1999



New Territories North Development
81CD - Main drainage channels for Yuen Long and Kam Tin stage 2 - remainder
    Members are invited to recommend to Finance Committee -

  1. the upgrading of part of 81CD, entitled "Main drainage channels for Yuen Long and Kam Tin stage 2 - Kam Tin Road to Tai Kek section", to Category A at an estimated cost of $410.4 million in money-of-the-day prices; and

  2. the retention of the remainder of 81CD in Category B.

We need to improve the section of Kam Tin River from Kam Tin Road to Tai Kek to alleviate flooding hazard to the low-lying areas of Yuen Long and Kam Tin.


2. The Director of Territory Development, with the support of the Secretary for Works, proposes to upgrade part of 81CD to category A at an estimated cost of $410.4 million in money-of-the-day (MOD) prices to improve the section of Kam Tin River from Kam Tin Road to Tai Kek.


3. The scope of 81CD comprises the construction of main drainage channels and associated works to improve the following sections of tributaries of Kam Tin River -

  1. from Kam Tin Road to Tai Kek; and

  2. from Ng Ka Tsuen to Kam Sheung Road near Shui Lau Tin and from Shek Tau Wai to Kam Sheung Road near Sheung Tsuen San Tsuen.
4. The part of 81CD we now propose to upgrade to Category A comprises the works described in paragraph 3(a) above, which include -
  1. a trapezoidal drainage channel about 3.5 kilometres long along the section of Kam Tin River between Kam Tin Road and Tai Kek;

  2. roads and ramps with associated drainage works;

  3. six footbridges and two vehicular bridges;

  4. a pump chamber with the associated pumping equipment and water storage tank;

  5. a replacement gauging station;

  6. environmental mitigation measures including landscaping works; and

  7. an environmental monitoring and audit programme for works mentioned in paragraphs (a) to (f) above.
The details of the scope of the proposed works is at Annex I.


5. In recent years, extensive changes in land use and rapid development in Kam Tin have significantly aggravated the flooding problem in this area, which is already susceptible to flooding due to its low-lying topography. The *North West New Territories Base Strategy Studies* (the Study), completed in 1983, recommended a series of river training works to alleviate the flooding hazard in the North West New Territories, including the low-lying areas of Yuen Long and Kam Tin. The *Territorial Land Drainage and Flood Control Strategy Study - Phase II*, completed in 1993 under 52CD, also confirmed the recommendation of the Study. The river training works for Shan Pui River and the downstream of Kam Tin River under 60CD and 43CD respectively commenced in 1993 and are nearing completion. The proposed works under 81CD are the continuation of the downstream works aiming to alleviate flooding in the upstream areas of Kam Tin and form part of the overall flood alleviation programme. The locations of sites of 81CD in relation to other drainage channel works in the Yuen Long and Kam Tin area are shown at Annex II.

6. The existing section of the Kam Tin River between Kam Tin Road and Tai Kek is narrow and meandering. The proposed works will turn the upper reaches of the section into a wider and deeper drainage channel. This new channel will substantially increase the hydraulic capacity of the river and is capable of accommodating a 50-year return period rainstorm, thus relieving the area from flood risk.

7. As the new drainage channel will be wider and will follow a new alignment at several locations, some areas of farmland that depend on water from the river for irrigation would be affected. In order to maintain river water supply to these areas, we will construct a pump chamber and a water storage tank with a capacity of 33m3 in the middle reaches of the drainage channel, north of Shek Wu Tong to replace an existing irrigation dam.

8. The existing gauging station near Tai Kek needs to be replaced as it is located within the alignment of the proposed drainage channel.

9. To facilitate future maintenance of the proposed drainage channel and to ensure its smooth functioning, we need to construct roads and ramps. We will also construct two vehicular bridges and six footbridges for the local residents to replace the existing river-crossing facilities, which need to be demolished under the proposed works.

10. The upstream and downstream sections of the proposed drainage channel fall within the site boundary of the West Rail project of the Kowloon Canton Railway Corporation (KCRC). The alignment of the midstream section of the drainage channel crosses that of the Eastern Access Road to the West Rail station. We plan to start works in July 1999 for completion in March 2002 which is within the construction period of the West Rail project. In order to avoid interface problems with KCRC contractors and to ensure cost-effectiveness and timely completion of the drainage channel, we will entrust the whole of the works to KCRC for construction in conjunction with the West Rail project. We will reimburse KCRC the cost of the works and the on-cost.

11. To integrate with the layout of the West Rail project, KCRC will re-design the alignment for the parts of the drainage channel within the site boundary of the West Rail project. KCRC will also extend the drainage channel upstream to Ho Pui. KCRC will bear the additional cost due to the realignment and extension of the channel. The proposed alignments of the original drainage channel designed by the Director of Drainage Services (D of DS) and the channel re-designed by KCRC are shown at Annex III.


12. We estimate the capital cost of the project to be $410.4 million in MOD prices (see paragraph 13 below), made up as follows -

$ million
(a) Drainage channel160.5
(b) Pump chamber , water storage tank and gauging station4.3
(c) Roadworks and associated drainage works77.1
(d) Footbridges and vehicular bridges53.5
(e) Environmental mitigation measures (including landscaping works)8.6
(f) Environmental monitoring and audit (EM&A) programme5.4
(g) Contingencies30.9
(h) On-cost139.5
Sub-total379.8(at December 1998 prices)
(i) Provision for price adjustment30.6
Total410.4 (in MOD prices)

13. Subject to approval, we will phase expenditure as follows -

Year$ million
(Dec 1998)
$ million
1999 - 200071.71.0262573.6
2000 - 01128.11.06217136.1
2001 - 02112.81.09934124.0
2002 - 0361.61.1378270.1
2003 - 045.61.177656.6

14. We have derived the MOD estimate on the basis of the Government's latest forecast of trend of labour and construction prices for the period from 1999 to 2004. KCRC will tender the proposed works as part of a fixed price lump-sum contract for West Rail depot and station with remeasurement for earthworks and foundation works, the quantities of which may vary according to the actual ground conditions. Prices for the proposed works will be indicated separately in KCRC*s main contract. The contract will not provide for price adjustment.

15. We estimate the annually recurrent expenditure to be $4.48 million.


16. We consulted the Pat Heung Rural Committee, Kam Tin Rural Committee and Yuen Long District Board on the proposed works on 22 January 1994, 28 March 1994 and 14 April 1994 respectively. Members of the Rural Committees and District Board supported the proposed project for the relief it would bring to the flooding problem in Yuen Long and Kam Tin.

17. We presented the findings and the environmental mitigation measures recommended in the Environmental Impact Assessment (EIA) report to the Environmental Improvement Committee of the Yuen Long District Board on 13 June 1996. Members had no objection to the findings and the recommended mitigation measures. We then consulted the EIA Subcommittee of the Advisory Council on the Environment (ACE) on the EIA report on 1 July 1996. The ACE endorsed the report with conditions as prescribed in paragraph 22 below.

18. We gazetted the proposed drainage works under the Foreshore and Seabed (Reclamations) Ordinance on 16 September 1994 and received no objection.

19. We also gazetted the proposed road works ancillary to the drainage channel under the Roads (Works, Use and Compensation) Ordinance on 25 November 1994 and again on 20 December 1996 for modifications to the road scheme. With the West Rail project given the formal go-ahead in December 1996 and its alignment confirmed in early 1997, we found that the alignment of the West Rail overlapped with the upstream and downstream portions of the drainage channel and the gazetted road scheme. KCRC re-designed the alignment of the drainage channel of these portions, and gazetted the West Rail including the affected portions of the drainage channel under the Railways Ordinance on 3 October 1997. On the same day, we de-gazetted the road scheme ancillary to the whole drainage channel and gazetted the road scheme ancillary to the midstream of the channel from Shek Wu Tong to south of Tai Hong Tsuen under the Roads (Works, Use and Compensation) Ordinance. We received eight objections. We had a series of discussions with the objectors. Four objectors subsequently withdrew their objections. We persuaded one objector to withdraw his objection on condition that the land resumption limit would be revised to avoid resuming a portion of his land. The remaining three objectors, who objected to the resumption of their land, refused to withdraw their objections.

20. On 20 November 1998, the Chief Executive in Council overruled the objections raised by the three objectors and authorized the proposed road works with modifications to the resumption limit.

21. The LegCo Panel on Planning, Lands and Works discussed the proposed upgrading on 23 March 1999. No adverse comments were raised.


22. Under the EIA Ordinance, the project is a designated project and an Environmental Permit is required. We obtained the Environmental Permit on 17 December 1998. In May 1994, we employed consultants to carry out an EIA to assess the environmental impact due to the construction and operation of a series of flood control projects in Yuen Long, Kam Tin and Ngau Tam Mei. Following completion of the EIA report in May 1996, we consulted the ACE in July 1996. ACE endorsed the report on condition that (a) old river channels would be considered for restoration into wildlife habitats; (b) the disposal of contaminated mud should be to the satisfaction of the Fill Management Committee (FMC) and that such disposal would have no adverse effects on the environment; and (c) the proponents should review the conceptual off-site compensation measures in light of Government*s latest policy on off-site compensation and report back to the EIA Sub-committee of the ACE their specific proposals for this project.

23. The EIA report concluded that the environmental impact of the proposed works could be controlled to within established standards and guidelines through the implementation of the mitigation measures as recommended in the EIA. We will implement these measures. As regards the conditions set by ACE, the consultants of Agriculture and Fisheries Department have started a study to address the issues of the restoration of the old river channels and off-site compensation, and will report the findings to the EIA Sub-committee in due course. We have also obtained approval from the FMC for the arrangements to dispose of contaminated mud. The key measures in respect of dredging works include the use of a closed mechanical grab, no stockpiling of contaminated mud, proper disposal of dredged materials and regular maintenance dredging. We estimate the cost of implementing the environmental mitigation measures ($8.6 million) and EM&A programme ($5.4 million) to be $14 million which has been included as part of the overall project estimate.


24. Government has already resumed the land within the site boundary of the West Rail project, including the upstream and downstream sections of the drainage channel. Government will handover the required land to KCRC in April 1999 for construction of the West Rail works in July 1999. The acquisition and clearance costs for the land within the site boundary of the West Rail project will be borne by KCRC according to the West Rail Project Agreement established between the Administration and KCRC. For the midstream section which is outside the site boundary of the West Rail project, we will resume about 6.5 hectares of agricultural land for the project. The land acquisition and clearance will affect 13 households involving 37 persons and 61 temporary structures. The Director of Housing will offer eligible families accommodation in public housing in line with the existing policy. We will charge the costs of land acquisition and clearance for the midstream section of the drainage channel and associated works, estimated at $113 million, to Head 701 - Land Acquisition.


25. Stage 1 of the main drainage channels for Yuen Long and Kam Tin is under construction under 60CD entitled *North West New Territories development - main drainage channels for Yuen Long and Kam Tin Stage 1 Phase 1* (which started in October 1993 for completion in May 1999) and 43CD entitled *North West New Territories development - main drainage channels for Yuen Long and Kam Tin Stage 1 Phase 2* (which started construction in October 1995 for completion in May 1999).

26. We upgraded 81CD to Category B in September 1995. We upgraded part of 81CD to Category A in March 1999 for the construction work of the section from Kam Tin San Tsuen to Wang Toi Shan to start in August 1999 for completion in April 2002.

27. D of DS has completed the detailed design and drawings for the proposed works using in-house resources.

28. We plan to start the construction works in July 1999 for completion in March 2002. We will commence the remaining works under 81CD in October 2000 for completion in January 2003.


Works Bureau
April 1999