For discussion PWSC(96-97)1
on 17 April 1996

ITEM FOR PUBLIC WORKS SUBCOMMITTEE
OF FINANCE COMMITTEE

HEAD 704 - DRAINAGE
Civil Engineering - Drainage and erosion protection
75CD - Stormwater drainage master plan study on northern Hong Kong Island

Members are invited to recommend to Finance Committee the upgrading of 75CD to Category A at an estimated cost of $22.5 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
75CD - Stormwater drainage master plan study on northern Hong Kong Island

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PROBLEM

The existing stormwater drainage system on the northern Hong Kong Island, which was designed and built some 30 years ago, is inadequate to meet the current flood protection standards.

PROPOSAL

2. The Director of Drainage Services, with the support of the Secretary for Planning, Environment and Lands, proposes to upgrade 75CD to Category A at an estimated cost of $22.5 million in money-of-the-day (MOD) prices for the appointment of consultants to undertake a drainage master plan study on the northern Hong Kong Island.

PROJECT SCOPE AND NATURE

3. The scope of the project comprises the following -

1. review the capacity of the existing stormwater drainage system on the northern Hong Kong Island using hydrological/ hydraulic modelling;
2. identify the critical areas of stormwater drainage requiring improvements;
3. recommend priorities for programmes to upgrade and extend the stormwater drainage system to meet performance targets;
4. formulate measures with a prioritised programme of works to improve the stormwater drainage system based on costs and benefits analysis;
5. prepare a computerised asset inventory of the stormwater drainage system; and
6. establish an asset management system to facilitate future system maintenance and development appraisal.

JUSTIFICATION

4. The northern Hong Kong Island is a major residential and commercial area with an estimated population of 1 031 100. Due to intensive urbanisation and rapid developments in the area, there have been numerous modifications and extensions on a piecemeal basis to the existing stormwater drainage system. As a result, some parts of the stormwater drainage system are unable to meet the current flood protection standards and flooding occurs during severe rainstorms. Recent frequent flooding occurred at Ko Shing Street in Sai Ying Pun and at Bonham Strand West and Wing Lok Street in Sheung Wan.

5. Such problems are particularly severe in the low-lying hinterlands of the new reclamation and in the western to central mid-levels where the capacities of many pre-war drains are grossly inadequate and the drains themselves are in a poor state of repair. We need to investigate cost-effective methods to replace and improve the drainage system up to the current standards of capacity and reliability.

6. We propose to conduct a study on the existing stormwater drainage system on the northern Hong Kong Island. The proposed study will identify areas which need upgrading to meet the requirements of current and planned urban developments and to recommend improvement measures. The study will also develop an asset inventory and asset management system for the efficient management and deployment of resources of the improved drainage system, maximise the system capacity and provide forward planning of the system.

7. In view of the shortage of in-house staff resources, the Director of Drainage Services proposes to engage consultants to undertake the study.

FINANCIAL IMPLICATIONS

8. We estimate the cost of the proposed study to be $22.5 million in MOD prices (see paragraph 9 below), made up as follows -

A breakdown by man months of the estimate for consultants’ fees is at Enclosure I.

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

10. We derive the MOD estimate on the basis of the Government’s forecasts of trend labour and construction prices over the period between 1996 and 1999. We will award the proposed consultancy on a lump-sum basis with provision for inflation adjustment as the project duration is more than 12 months.

11. The proposed consultancy will not give rise to any recurrent expenditure.

PUBLIC CONSULTATION

12. As this is a feasibility study, we consider public consultation unnecessary.

ENVIRONMENTAL IMPLICATIONS

13. The proposed consultancy will not have any adverse environmental impacts. The study will include an environmental review on the recommended drainage improvement works to identify the potential environmental concerns, the mitigation measures required and the need for an Environmental Impact Assessment.

LAND ACQUISITION

14. This study does not require land acquisition.

BACKGROUND INFORMATION

15. The 1995 Policy Address includes a commitment to conduct seven drainage master plan studies over the next three years covering all flood prone areas in the territory. The tentative programme for implementing the seven drainage master plan studies is indicated on the map at Enclosure II. On 5 January 1996, Members approved the first drainage master plan study by upgrading part of 55CD as 83CD “Yuen Long, Kam Tin, Ngau Tam Mei and Tin Shui Wai drainage master plan study” at an approved project estimate of $39 million in MOD prices. 75CD is the second of the studies.

16. We upgraded 75CD to Category B in September 1995 to carry out drainage master plan study on northern Hong Kong Island.

17. We schedule to commence 75CD in June 1996 for completion in September 1997. We will accord top priority to implement improvement works which we identify as urgently required in the drainage master plan study.

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Enclosure I to PWSC(96-97)1

75CD - Stormwater drainage master plan study on northern Hong Kong Island

Breakdown of estimate for consultants’ fees -

Notes -

1. The average estimated cost per professional man month is about equivalent to a Senior Engineer on MPS point 47.
2. The average estimated cost per technical man month is about equivalent to a Technical Officer on MPS point 20.
3. The figures given above are based on estimates prepared by the Drainage Services Department. We will only know the actual man months and fees when we receive the fee proposals from the consultants through the usual competitive consultants selection procedure.

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