For discussion PWSC(96-97)33
on 1 July 1996

ITEM FOR PUBLIC WORKS SUBCOMMITTEE
OF FINANCE COMMITTEE

HEAD 704 - DRAINAGE
Civil Engineering - Drainage and erosion protection
44CD - Shenzhen River improvement works, stage II - advance works

Members are invited to recommend to Finance Committee the upgrading of 44CD, retitled “Regulation of Shenzhen River, Stage II, Phase I - Reprovisioning of border road between Lok Ma Chau and Tam Kon Chau”, to Category A at an estimated cost of $200 million in money-of-the-day prices.

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PROBLEM
PROPOSAL
PROJECT SCOPE AND NATURE
JUSTIFICATION
FINANCIAL IMPLICATIONS
PUBLIC CONSULTATION
ENVIRONMENTAL IMPLICATIONS
LAND ACQUISITION
BACKGROUND INFORMATION

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PROBLEM

We need to relocate a section of the existing border road and its security facilities between Lok Ma Chau and Tam Kon Chau before we can implement the main stage II improvement works to Shenzhen River (the River) to alleviate the problem of flooding in the northern New Territories and Shenzhen city.

PROPOSAL

2. The Director of Drainage Services, with the support of the Secretary for Planning, Environment and Lands, proposes to upgrade 44CD to Category A at an estimated cost of $200 million in money-of-the-day (MOD) prices for reprovisioning a section of the border road between Lok Ma Chau and Tam Kon Chau along with its security facilities and the implementation of ecological mitigation measures. The location plan is at Enclosure I.

PROJECT SCOPE AND NATURE

3. The scope of the project comprises the following -

1. construction of about 3.6 kilometres of border road;
2. provision of border security facilities which include security fencing and lighting along the border road;
3. construction of ancillary drainage works including reinforced concrete culverts (about 55 metres long) and drain pipes (about 600 metres long);
4. ecological mitigation measures which include tree planting, reinstatement of 24 hectares of fishponds within the site and the temporary enhancement of 15 hectares of fishponds at Mai Po; and
5. environmental monitoring and audit during construction.

JUSTIFICATION

4. Rapid developments in both the northern New Territories and Shenzhen in recent years have aggravated the inadequacy of the hydraulic capacity of the River and aggravated flooding problems in the northern New Territories. Several flooding incidents in the past have disrupted transport, communication, social and commercial activities causing economic losses in both Shenzhen and Hong Kong. There is an urgent need to implement the Shenzhen River regulation project¹ to reduce the risk of flooding.

5. We started the stage I improvement works to the River under 24CD “Regulation of Shenzhen River, stage I - improvement to river bends at Lok Ma Chau and Liu Pok” in May 1995. We plan to start the main stage II improvement works in 1997. To provide adequate space for the stage II improvement works, we have to demolish the existing border road and security fence and reprovide them elsewhere. The proposed works under 44CD will provide a new border road with lighting and security fence to the south to maintain the normal border security functions.

6. The new border road will run across existing streamcourses and drainage paths. We need to construct ancillary drainage works under the new road which will include box culverts and drain pipes. These will enable stormwater from the southern side to flow under and across the new road to Shenzhen River.

7. We will carry out ecological mitigation measures under 44CD to compensate for the loss of fishponds due to the relocation of the border road. We will reinstate the remaining fishponds within the site. We will also carry out improvement works to existing fishponds at Mai Po to allow for the expected increase in the use of the fishponds by wild life during the construction of this project. We will plant trees of mangrove-related species along the southern embankment of the new border road so as to partially compensate the loss of mangroves due to the stage II river training works. We have incorporated the tree planting works under this project because the area involved is on the south side of the new border fence and will be difficult to access once we have erected the new fence.

FINANCIAL IMPLICATIONS

8. We estimate the capital cost of the project to be $200 million in MOD prices, made up as follows -

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

10. We have derived the MOD estimate on the basis of the Government’s forecasts of trend labour and construction prices for the period 1996 to 2001.

11. We will tender the civil engineering contract as a standard re-measurement contract. We have chosen the re-measurement type of contract because the proposed works involve large quantities of earth works which we cannot accurately determine beforehand. The contract will allow for adjustments to the tender prices due to inflation as the contract period will extend beyond 21 months. We will tender the supply, installation, testing and commissioning of the security lighting as a fixed price lump-sum contract.

12. We estimate the annually recurrent expenditure to be $483,000. This includes an annual cost of $20,000 to maintain the trees planted under this project. We will need to provide for the upkeep of the trees for a period of eight years, after which time they will beome self-maintaining.

PUBLIC CONSULTATION

13. We presented the proposed works to the Yuen Long District Board on 24 August 1995. Members of the District Board supported the proposal. We gazetted the road works ancillary to this project under the Roads (Works, Use and Compensation) Ordinance in November 1995 and received no objections.

ENVIRONMENTAL IMPLICATIONS

14. An Environmental Impact Assessment (EIA) was carried out in October 1995 to address the potential environmental impacts of stage II of the Shenzhen River regulation project, including the advance work under this item. Apart from measures to minimise construction noise, dust, spoil disposal, the increase in sedimentation in Deep Bay and water quality impacts from sediment releases during construction, the EIA also recommended measures to mitigate ecological impacts which include short term disturbance from construction activities and a long-term loss of mangroves and fishponds. The EIA study report concluded that with the application of the recommended mitigation measures, the environmental impacts of the stage II works will be controlled within established standards and guidelines.

15. The Advisory Council on the Environment endorsed the EIA report on 20 November 1995 on condition that we implement all the mitigation measures proposed in the report, including an environmental monitoring and audit programme.

16. We will implement part of the ecological mitigation measures recommended in the EIA report under this project. In particular, we will reinstate 24 hectares of fishponds within the site and we will plant trees along the southern embankment of the new border road to act as an ecological corridor. We will also undertake temporary enhancement of about 15 hectares of fishponds at Mai Po to compensate for the loss of fishponds due to the relocation of the new road.

17. We will also include relevant mitigation measures in the works contract under this item to control noise, dust, spoil disposal and other possible nuisances resulting from the advance works. We will set up an environmental team to carry out an environmental monitoring and audit programme during the construction period and we have included funding for this item in the project costs.

LAND ACQUISITION

18. We will clear 460 900 square metres of Government land for the proposed works and charge the land clearance costs, estimated at about $27 million, under Head 701 - Land Acquisition. The clearance will affect 61 temporary non-domestic structures. There is no requirement for rehousing. We plan to complete the clearance by October 1996.

BACKGROUND INFORMATION

19. We upgraded 44CD to Category B in October 1994. We have substantially completed the detailed design and the preparation of drawings for the border road relocation project. The proposed works are scheduled to start in November 1996 for completion in November 1998.

20. We upgraded 31CD “Shenzhen River improvement works, stage II - remaining works” to Category B in November 1991. We plan to start 31CD in the first half of 1997 for completion in late 2000.

1 -- The Shenzhen River regulation project comprises three stages. Stage I (24CD) covers the realignment, widening and deepening of two stretches of the River at Lok Ma Chau and Liu Pok. Stage II (31CD) covers the widening and deepening of sections of the River from Lok Ma Chau bend to Deep Bay and from Lok Ma Chau bend to the Liu Pok bend. Stage III covers the widening and deepening of the River from Lo Wu upstream to Muk Wu. A map showing areas covered by stages I, II and III is at Enclosure II.

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