For discussion PWSC(95-96)64
on 7 December 1995

ITEM FOR PUBLIC WORKS SUBCOMMITTEE
OF FINANCE COMMITTEE

HEAD 704 - DRAINAGE
Civil Engineering - Drainage and erosion protection
55CD - Territorial land drainage and flood control strategy study phase III

Members are invited to recommend to Finance Committee -

1. the upgrading of part of 55CD, entitled “Yuen Long, Kam Tin, Ngau Tam Mei and Tin Shui Wai drainage master plan study”, to Category A at an estimated cost of $39 million in money-of-the-day prices; and
2. the retention of the remainder of 55CD in Category B.

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PROBLEM
PROPOSAL
PROJECT SCOPE AND NATURE
JUSTIFICATION
FINANCIAL IMPLICATIONS
PUBLIC CONSULTATION
ENVIRONMENTAL IMPLICATIONS
LAND ACQUISITION
BACKGROUND INFORMATION
55CD - Territorial Land Drainage and Flood Control Strategy Study Phase III
Checklist for Issue of PWSC Paper
55CD - Territorial Land Drainage and Flood Control Strategy Study, Phase III

(a) Necessity to go to the PWSC
(b) Authority
(c) Funding
(d) Political assessment
(e) Lobbying requirement
(f) Fallback option
(g) Attendance at the PWSC meeting
(h) Special consideration

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PROBLEM

Yuen Long, Kam Tin, Ngau Tam Mei and Tin Shui Wai drainage catchment areas are susceptible to serious and frequent flooding due to the inadequacies of the tributaries, local drainage systems and the main river channels in these areas.

PROPOSAL

2. The Director of Drainage Services, with the support of the Secretary for Planning, Environment and Lands, proposes to upgrade part of 55CD to Category A at an estimated cost of $39 million in money-of-the-day (MOD) prices to undertake a drainage master plan study.

PROJECT SCOPE AND NATURE

3. The whole project under 55CD comprises two drainage master plan studies¹ to assess the tributaries and local drainage systems in six catchment areas in the North and North-west New Territories. We propose to upgrade that part of 55CD which covers the drainage master plan study for Yuen Long, Kam Tin, Ngau Tam Mei and Tin Shui Wai to Category A. The scope of work will be to -

1. examine and assess the conditions and inadequacies of the existing tributaries and local drainage systems;
2. develop a computerised stormwater drainage asset inventory and asset management system² for the management and forward planning of the whole stormwater drainage system;
3. recommend improvement measures for the tributaries and local drainage systems to meet current standards and future needs; and
4. develop a prioritised programme of works based on a cost-benefit analysis of the recommended improvement measures.

JUSTIFICATION

4. Project 52CD “Territorial land drainage and flood control strategy study, phase II - consultants’ fees and investigations”, completed in August 1993, showed that the drainage systems in the North and North-west New Territories are overloaded due to extensive land developments. The study recommended the implementation of a number of major improvements to the main river channels and the commissioning of drainage master plan studies. The former will improve the conditions of main river channels and stream courses, while the latter will resolve the inadequacies of tributaries and local drainage systems.

5. To supplement the improvement works to the main river channels, which are in various stages of planning, design and construction, we propose to conduct a full scale investigation into the local drainage problems, develop necessary mitigation measures, maximise the system capacity and develop an asset inventory and asset management system for the efficient management of the improved drainage systems.

6. 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

7. We estimate the cost of the proposed study to be $39 million in MOD prices, made up as follows -

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

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

9. We derive the MOD prices on the basis of the Government’s forecasts of trend labour and construction prices over the period between 1995 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.

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

PUBLIC CONSULTATION

11. This is a feasibility study and public consultation is not necessary at this stage. However, appropriate public consultation will be carried out regarding the acceptability of consultant’s recommendations.

ENVIRONMENTAL IMPLICATIONS

12. The study will include an environmental review on the recommended drainage improvement works. The proposed consultancy itself will not cause any adverse environmental impact.

LAND ACQUISITION

13. This study does not require land acquisition. But the consultant will examined the requirement for land to carry out future improvements.

BACKGROUND INFORMATION

14. We upgraded 55CD to Category B in April 1994. The whole project includes a sedimentation study and two drainage master plan studies for six catchment areas in the North and North-west New Territories.

15. In November 1994, we upgraded the sedimentation study of 55CD to Category A as 68CD “Territorial land drainage and flood control strategy study - consultants’ fees and investigation”. The works started in January 1995 for completion in November 1996.

16. The part we now propose to upgrade to Category A is the drainage master plan study for four catchment areas covering Yuen Long, Kam Tin, Ngau Tam Mei and Tin Shui Wai. The study will provide plans for managing the drainage systems and address the flooding problems in the low-lying land behind the levees of the main river channels in the North and North-west New Territories. We schedule to commence the drainage master plan study proposed in this paper in January 1996 for completion in January 1998. Upon the completion of this study, we schedule to start the detailed design work in April 1998 and to start the construction works in October 1999 for completion in September 2002.

17. We intend to start the remaining drainage master plan study for San Tin and Indus catchment areas in December 1996 for completion in June 1999.

1 -- When we upgrade part of 55 CD to Category A as 68D in November 1994, we mentioned that there were six drainage master plan studies for North and North-west New Territories. Due to the close proximity of the catchment areas involved, we group these six areas into two geographical areas each under one drainage master plan study, namely one for Yuen Long, Kam Tin, Ngau Tam mei and Tin Shui Wai as proposed in this paper and the other for San Tin and Indus catchment areas.
2 -- The asset inventory and management system will comprise computer software that can assist staff of the Drainage Services Department (DSD) in recording and updating drainage assets in respect of age, engineering details, structureal condition, hydraulic capacity and maintenance histroy. DSD staff will use the system to identify operational problems, determine maintenance priorities, and assess drainage impact of new developments.

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Enclosure

55CD - Territorial Land Drainage and Flood Control Strategy Study Phase III

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 actual fees when we have selected the consultants through the usual competitive system.

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Checklist for Issue of PWSC Paper

55CD - Territorial Land Drainage and Flood Control Strategy Study, Phase III

(a) Necessity to go to the PWSC

We need to seek funding approval from PWSC/FC for upgrading part of the works under 55CD to Category A before inviting consultants to carry out the drainage master plan study.

(b) Authority

In October 1993, the Development Progress Committee agreed that there was a need to carry out drainage master plan studies in North-west and North New Territories.

(c) Funding

The 1995 RAE provides $55 million for the whole project 55CD. The current estimate of this part upgrading is $31.1 million (money-of-the-day is $39 million.) The balance of $23.9 million is for commissioning the remaining drainage master plan study for San Tin and Indus catchment areas.

(d) Political assessment

Members may be concerned about the deployment of resources and effort on consultancy studies when massive river training works are already in various stages of planning, design and construction and that the Land Drainage Ordinance is being implemented.

(e) Lobbying requirement

Lobbying is not required but we may take the opportunity to mention this at the first LegCo Lands and Works Panel meeting on 21 November 1995.

(f) Fallback option

If Members do not support the proposal, we will withdraw the paper and amend it for resubmission at the next meeting.

(g) Attendance at the PWSC meeting

Secretary for Planning, Environment and Lands (Mr Bowen Leung) and Director of Drainage Services (Mr Y Y Ng) will attend the meeting.

(h) Special consideration

Nil.

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