For discussion PWSC(96-97)109
on 5 March 1997

ITEM FOR PUBLIC WORKS SUBCOMMITTEE
OF FINANCE COMMITTEE

HEAD 704 - DRAINAGE
Civil Engineering - Drainage and erosion protection
59CD - West Kowloon stormwater drainage improvement

Members are invited to recommend to Finance Committee -

1. the upgrading of part of 59CD, entitled "West Kowloon drainage improvement, stage 2 - consultants’ fees and investigations" to Category A at an estimated cost of $68 million in money-of-the-day prices; and
2. the retention of the remainder of 59CD retitled "West Kowloon drainage improvement - stages 1, 2 and 3" in Category B.

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PROBLEM
PROPOSAL
PROJECT SCOPE AND NATURE
JUSTIFICATION
FINANCIAL IMPLICATIONS
PUBLIC CONSULTATION
ENVIRONMENTAL IMPLICATIONS
LAND ACQUISITION
BACKGROUND INFORMATION
West Kowloon stormwater drainage improvement

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PROBLEM

West Kowloon is susceptible to frequent flooding due to the inadequate capacity of the existing drainage system in the area.

PROPOSAL

2. The Director of Drainage Services, with the support of the Secretary for Planning, Environment and Lands, proposes to upgrade part of 59CD to Category A at an estimated cost of $68 million in money-of-the-day (MOD) prices for the appointment of consultants to carry out site investigations and detailed design for the West Kowloon stage 2 drainage improvement works.

PROJECT SCOPE AND NATURE

3. Project 59CD on "West Kowloon stormwater drainage improvement" comprises three stages of works to be carried out according to a prioritised programme. The part of the project we now propose to upgrade to Category A is for an investigation and design consultancy for works under stage 2, namely the construction of about 56 kilometres of stormwater pipes and box culverts. The scope of the proposed consultancy includes -

1. site investigations and surveys;
2. traffic impact assessment; and
3. detailed design, including preparation of tender documents and assessment of tenders.

4. The remainder of 59CD comprises of the improvement works under stage 3 and the construction of the improvement works under stages 1 and 2 and investigations, detailed design and construction of the improvement works under stage 3.

JUSTIFICATION

5. West Kowloon is a major residential and commercial area which comprises Sham Shui Po, Mong Kok, Yau Ma Tei, part of Tsim Sha Tsui and part of Kowloon City. We designed the existing drainage system many years ago with its capacity to meet the flow requirements at that time. However, rapid urbanisation has led to conversion of natural pervious land, which allows a higher degree of ground infiltration and depression storage, into buildings and paved areas. This has resulted in more rainwater running into the existing drainage system. As a result of this development, there is overloading of the existing drainage system and the low-lying areas of West Kowloon are prone to frequent flooding during typhoons or heavy rainstorms.

6. We completed 65CD "West Kowloon stormwater drainage improvement study - consultants' fees and investigation" in December 1995 to examine the deficiencies of the drainage system and to develop a drainage master plan for West Kowloon. The study results showed that over 60% of the existing drains, i.e. 103 kilometres out of a total of 162 kilometres of drains, did not meet the current standards for flood protection. In particular, 65 kilometres of these drains are critically inadequate in capacity to cope with heavy rainstorms.

7. We propose to conduct site investigations and detailed design works to facilitate the implementation of the drainage improvement works to the existing system. The improvement works would cope with the continuous development in the area and reduce flooding during typhoons or heavy rainstorms causing severe inconvenience and nuisance to the public. As West Kowloon is a heavy traffic area, we also propose to carry out a traffic impact assessment to identify the impacts of the project on the traffic conditions in West Kowloon and then formulate necessary traffic management schemes to minimise inconvenience to the public during the construction stage.

8. In view of the shortage of in-house staff resources, the Director of Drainage Services proposes to employ consultants to carry out the work stated in paragraph 3 above.

FINANCIAL IMPLICATIONS

9. We estimate the cost of the proposed consultancy to be $68 million in MOD prices (see paragraph 10 below), made up as follows -

A breakdown by man months of the estimate for consultants' fees is at the Enclosure 1.

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

11. We have derived the MOD estimate on the basis of the Government's forecasts of trend labour and construction prices for the period 1997 to 2002. We will award the proposed consultancy on a lump-sum basis. The consultants will in turn appoint contractors for the site investigation and survey works on a re-measurement basis through a tendering process. The consultants will adopt this form of contract as they cannot determine in advance the exact extent of the site investigation and survey works required. We will allow for inflation adjustment in the consultancy agreement as the project duration will be more than 12 months.

12. The proposed project will not give rise to any recurrent expenditure.

PUBLIC CONSULTATION

13. We presented the findings and recommendations of the study under 65CD to Sham Shui Po and Kowloon City District Boards on 9 November 1995 and to Yau Tsim Mong District Board on 16 November 1995. The District Boards supported the implementation of the entire project.

ENVIRONMENTAL IMPLICATIONS

14. The Director of Environmental Protection completed an environmental review in August 1995 and concluded that the project would have no long term environmental impacts and an environmental impact assessment was not necessary. The proposed project itself will not have any adverse environmental implications.

LAND ACQUISITION

15. This project does not require land acquisition.

BACKGROUND INFORMATION

16. We upgraded 59CD "West Kowloon stormwater drainage improvement" to Category B in December 1993. In June 1994, we upgraded part of 59CD to Category A, as 65CD "West Kowloon stormwater drainage improvement study - consultants’ fees and investigation" with an approved project estimate of $15.9 million, to examine the deficiencies of the drainage system and to develop a drainage master plan for improvement of the system. We completed the final study report in December 1995. The study recommends implementing the improvement works to the existing drainage system in three stages according to a prioritised programme of works -

1. Stage 1

   Stage 1 comprises improvement works to about 9.2 kilometres of drains which are critically inadequate in capacity. We will implement works of this stage in conjunction with the sewerage improvement works in the same roads under the Sewage Services Trading Fund project 4SS "North West Kowloon sewerage stage III phase II".

2. Stage 2

   Stage 2 comprises improvement works to about 56 kilometres of drains which are also critically inadequate in capacity.

3. Stage 3

   Stage 3 comprises improvement works to about 38 kilometres of drains which are moderately inadequate in capacity.

17. In April 1996, we engaged consultants to carry out site investigations and detailed design for the West Kowloon drainage improvement stage 1 works under a Category D project 84CD "West Kowloon stormwater drainage improvement, stage 1 - site investigations and detailed design" with an approved project estimate of $11.5 million. The detailed design work under this consultancy started in April 1996 for substantial completion in early May 1997. We plan to start the stage 1 construction work in January 1998 for completion in April 2001 in conjunction with the sewerage improvement works under 4SS "North West Kowloon sewerage stage III phase II".

18. We plan to start the proposed design consultancy for stage 2 works in June 1997 for completion in December 1999. We plan to start the drainage improvement works in December 1999 for completion in June 2004.

19. For stage 3 works, we plan to start the detailed design and constructionthe stage 3 works in early 2000 works for stage 3and in 2002 respectively.

Planning, Environment and Lands Branch
February 1997
(JJ165)

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Enclosure to PWSC(96-97)109

West Kowloon stormwater drainage improvement

Breakdown of estimate for consultants’ fees

Notes

(1) A multiplier factor of 3 is applied to the average MPS point to arrive at the full staff costs including the consultants' overheads and profit, as the staff will be employed in the consultants’ offices. (At 1.4.95, MPS pt. 40 = $51,440 p.m. and MPS pt. 16 = $17,270 p.m.)

(2) Out-of-pocket expenses are the actual costs incurred. The consultants are not entitled to any additional payment for overheads or profit in respect of these items.

(3) The figures given above are based on estimates prepared by the Director of Drainage Services. We will only know the actual man months and fees when we have appointed the consultants through the usual competitive lump-sum fee bid system.

(JJ165)

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