PWSC(97-98)80
For discussion
on 26 November 1997
ITEM FOR PUBLIC WORKS
SUBCOMMITTEE OF FINANCE COMMITTEE
HEAD 702 - PORT AND AIRPORT DEVELOPMENT
Territories Development
(Civil Engineering - Land development)
382CL - West Kowloon reclamation - hinterland drainage package 1
Members are invited to recommend to Finance Committee to increase the approved project estimate of 382CL from $125 million by $35 million to $160 million in money-of-the-day prices.
PROBLEM
For a variety of reasons which are explained in detail below, the approved project estimate (APE) of 382CL, in isolation, is insufficient for the completion of works under the project, although we have been able to identify savings for the West Kowloon Reclamation (WKR) project as a whole.
PROPOSAL
2.The Director of Territory Development (DTD), with the support of the Secretary for Works, proposes to increase the APE of 382CL from $125 million by $35 million to $160 million in money-of-the-day (MOD) prices.
PROJECT SCOPE AND NATURE
3.The scope of the 382CL project comprises the following works in the densely populated West Kowloon hinterland area -
- culvert and pipeline construction (1100 metres of culvert, 500 metres of sewer and 1400 metres of dry weather flow interceptor pipeline) ;
- road reinstatement works; and
- flow diversion works.
JUSTIFICATION
4.In conjunction with constructing the necessary drainage works in the reclamation to connect to the existing hinterland drainage systems, we had to upgrade the existing systems to maintain equivalent hydraulic performance and effectiveness in the hinterland area. Where physically possible, we further upgraded the hinterland drainage system to cater for the worst rainstorm expected within a 200-year period.
5.382CL is a pilot project of similar works under WKR project and is without any precedent in terms of complexity and intensity as the works are located in the most populous and congested part of West Kowloon. The works consist of enlargement and reconstruction of operating culverts and sewers while contending with existing underground utilities and heavy pedestrian and vehicular traffic. As Members are aware, we have experienced considerable difficulty with these drainage works since their commencement in 1991.
Diversion of Existing Utilities
6.The major difficulty we had encountered was the numerous utilities uncovered during the course of construction. In the design stage, we obtained all available records on underground installations. Unfortunately, the accuracy of these records was far below expectation as most of the utilities were laid several decades ago when standards of engineering were less sophisticated. In fact, many of these utilities were uncharted, that is, they did not appear on the record of the utility company concerned. A comprehensive pre-contract investigation on site to locate all the utilities was not practical because detailed investigation works in the heavily trafficked roads would have caused disproportionate inconvenience and disruption to the public, without producing any permanent work.
7.As a result, we were able to expose most of the existing utilities and plan for their diversion only after our contractor had carried out excavation for the drainage works. The rearrangement of these uncharted or incorrectly described utilities entailed very complex procedures. Moreover, the alignments of the culverts in this project were in most of the cases perpendicular to major roads such as Lai Chi Kok Road and Ferry Street, which serve as ideal routes for major utility installations. Thus conflicts between the new works and these major utility installations were inevitable. Diversion of these major installations was extremely complex. Some diversions were only permitted, if at all practical, in seasons of low utility demand. Some were not even feasible at all such as the critical 24-way optical fibre telephone cables. In such cases, we had to modify the design significantly to accommodate the cables.
8.In some cases, the Contractor had to carry out extra and additional works in association with the utility companies' diversion works. Diversion of utilities across roads, in addition to the drainage works, required numerous stages of temporary traffic arrangements. This was a very time consuming process as we had to minimize the inevitable disruption to traffic and provide access for local business in this heavily congested area. Because of space constraints, the utility diversion works and drainage works had to be implemented in short sections and on a one-by-one basis, with a different scheme of temporary traffic arrangement implemented for each stage.
Adverse Site and Weather Conditions
9.The roads where the existing trunk culverts are located are often not very wide. When enlarging trunk culverts in deep trenches, we had to spend a great deal of extra effort during the installation of temporary support to minimize disturbance to the buildings in the immediate vicinity. In addition, these narrow roads do not allow extra room for flow diversion. As a result, we had to review the construction method to cater for this constraint.
10.Because of the constraints of carrying out comprehensive ground investigation at the design stage, works at critical locations had often been hampered by unforeseen obstructions such as old seawalls and nullah walls which rendered temporary support to excavation much more difficult than expected.
11.Apart from the site constraints, our works on site at times suffered serious disruption because of exceptionally inclement weather. Heavy rain not only caused flooding to the works site and surrounding areas, but also washed down silty soil and refuse from upstream. The contractor subsequently spent a long time clearing the site before he was able to resume the works.
12.As a result of the above factors, which were beyond the control of the contractor, we had to extend the time for completion and pay additional cost for the works.
Programme Recovery Measures
13.Furthermore, in view of the serious delay of some sections of the drainage works, we had to introduce several programme recovery measures to expedite progress with an aim to completing the majority of the works as soon as possible. These measures included re-sequencing the works, increasing the labour and plant resources of the contractor and adopting alternative construction methods. The additional expense was partly compensated by savings of direct consequential cost payable to the contractor and in meeting site supervision charges which would otherwise have arisen if we had not taken such measures.
14.These programme recovery measures are of benefit to the public at large. Due to the nature and location of the construction, our works caused major disruption and nuisance to the public in the hinterland notwithstanding our utmost efforts to minimize the inconvenience. By implementing programme recovery measures, the knock-on delay to other public works located in the vicinity was significantly reduced.
FINANCIAL IMPLICATIONS
15.Following a review of the financial position of the project, DTD considers it necessary to increase the approved project estimate of 382CL from $125 million by $35 million to $160 million in MOD prices in order to settle the contractual claims and final account. A summary of the reasons for the proposed increase of $35 million is as follows -
| $million
(MOD) | %
|
|---|
| (a) Additional cost for maintenance of temporary works
| 11 | 32
|
| (b) Contractor's prolongation cost
| 5 | 14
|
| (c) Re-sequencing, alternative construction method and programme recovery measures
| 18 | 51
|
| (d) Additional works to cope with the contemporary standard of surface drainage system
| 1 | 3
|
| (e) Consultants' fees for construction stage
| 2 | 6
|
| (f) Site staff costs
| 4 | 11
|
| (g) Project contingencies
| (6) | (17)
|
| 35 | 100
|
16.A comparison of the cost breakdown of the approved and revised project estimates in MOD prices is at Enclosure 1.
17.Subject to approval, we will phase the 382CL expenditure as follows -
| Year | $ million
(MOD)
|
|---|
| Up to 31 March 1997 | 118.0
|
| 1997 - 98 | 40.0
|
| 1998 - 99 | 2.0
|
| 160.0
|
18.The works of 391CL - West Kowloon Reclamation Southern Area, Phase 2 have been substantially completed. We anticipate the final cost to be $810 million against the estimate of $908 million.
19.Of the $98 million savings thus identified, we propose to use $35 million to offset the increase in APE of 382CL. We have already taken the remaining $63 million into account in reducing the overall ACP budget by a further $1,042 million as announced on 18 November 1997.
20.In addition to the reduction of 391CL, other adjustments have been made to the WKR estimate identified in the proforma funding report at Enclosure 2. The overall project estimate for WKR has been reduced from $12,191 million by $492 million to $11,699 million. In November 1996, we reduced the overall project estimate for WKR from $12,793 million by $602 million to $12,191 million.
PUBLIC CONSULTATION
21.We had consulted all relevant District Boards before 382CL was upgraded to Category A on 19 July 1991. As there is no change in the approved project scope, we consider that further consultation with the District Boards will not be necessary.
ENVIRONMENTAL IMPLICATIONS
22.A Construction Environmental Impact Assessment Report produced in 1991 addressed the impacts of the works within WKR. As there is no change in the approved project scope, there is no additional environmental impact.
LAND ACQUISITION
23.This proposed increase in APE does not require additional land acquisition.
BACKGROUND INFORMATION
24.We included 332CL "West Kowloon Reclamation", in Category C of the PWP in April 1989 and have already upgraded a substantial part of the project to Category A. This, together with two other projects, namely 146CL "Yau Ma Tei Typhoon Shelter Reclamation Stage I" and 038FS "Cheung Sha Wan Wholesale Market Complex - Phase I", make up the WKR project within the ACP. The parts of the project which are already in Category A include -
| 038FS | Cheung Sha Wan wholesale market complex - phase 1;
|
|---|
| 146CL | Yau Ma Tei typhoon shelter reclamation stage 1;
|
|---|
| 354CL | WKR consultants' fees and site investigation;
|
|---|
| 365CL | WKR southern area, phase 1;
|
|---|
| 366CL | WKR northern area, phase 1;
|
|---|
| 382CL | WKR hinterland drainage package 1;
|
|---|
| 391CL | WKR southern area, phase 2;
|
|---|
| 395CL | WKR northern area, phase 2;
|
|---|
| 403CL | WKR remaining hinterland drainage works & sewerage network package 1;
|
|---|
| 407CL | WKR distributor roads & related drainage works; and
|
|---|
| 431CL | WKR southern area, phase 3.
|
|---|
25.We upgraded 382CL to Category A in July 1991 at an estimated cost of $85 million in March 1991 prices. In July 1994, Finance Committee approved an increase in the approved project estimate from $85 million by $40 million to $125 million in MOD prices to cover the additional cost in dealing with illegal and other uncharted utility installations.
Works Bureau
November 1997
(JJ210)
Enclosure 1 to PWSC(97-98)80
382CL - West Kowloon reclamation - hinterland drainage package 1
A comparison of the approved and revised project estimates in MOD prices is as follows -
| Approved
Estimate
$ million
(MOD)
| Revised
Estimate
$ million
(MOD)
|
|---|
| (a) Culvert and pipeline construction | 79 | 104
|
| (b) Reinstatement works | 14 | 16.5
|
| (c) Flow diversion works | 16 | 23.5
|
| (d) Consultants' fees for construction stage | 2 | 4
|
| (e) Site staff costs | 8 | 12
|
| (f) Project contingencies | 6 | 0
|
| 125 | 160
|
2.As regards (a) (culvert and pipeline construction), of the total increase of $25 million -
- $2 million is due to additional cost in maintaining temporary traffic arrangement schemes at junctions;
- $2 million is due to additional temporary works such as steel bridges and decks for carrying out the works located at busy junctions such as Nam Cheong Street/Lai Chi Kok Road;
- $14 million is due to change in construction method of Yen Chow Street and Man Cheong/Saigon Street box culverts;
- $4 million is due to employing additional labour, plant and materials for the implementation of programme recovery plans; and
- $3 million is for the contractor's prolongation cost due to extension of construction period.
3.As regards (b) (reinstatement works), of the total increase of $2.5 million -
- $1 million is due to the additional maintenance of temporary facilities such as temporary lighting and guarding;
- $1 million is due to further additional works to cope with the contemporary standard of the surface drainage system; and
- $0.5 million is for the contractor's prolongation cost due to rescheduling of work to facilitate other project works.
4.As regards (c) (flow diversion works), of the total increase of $7.5 million -
- $2.5 million is due to additional cost in maintaining the temporary dry weather flow interception system prior to the completion of the permanent works;
- $3.5 million is due to additional cost for maintaining the flow diversion works at Man Cheong/Saigon Street and Nam Cheong Street ; and
- $1.5 million is for the contractor's prolongation cost due to extension of construction period.
5.As regards (d) (consultants' fees for construction stage), of the total increase of $2 million -
- $1 million is for devising additional temporary traffic arrangement proposals; and
- $1 million is for the additional design of re-sequencing and alternative construction methods.
6.As regards (e) (site staff costs), of the total of $4 million -
- $2 million is due to the extension of time in completing the contract works, thus prolonging the period of site supervision; and
- $2 million is due for extended working hours for the more intensive supervision of the programme recovery measures.
7.As regards (f) (project contingencies), a reduction of $6 million is possible due to the substantial completion of the works.
(JJ210)
Enclosure 2 to PWSC(97-98)80
Proforma Funding Report
Project : West Kowloon Reclamation
| | Estimate
at Oct 96
$ million
(MOD)
| Updated
Estimate
$ million
(MOD)
|
|---|
| (a) Funds approved
|
| 038FS | Cheung Sha Wan wholesale market complex - phase 1
| 559 | 559
|
|---|
| 146CL | Yau Ma Tei typhoon shelter reclamation stage 1
| 445 | 445
|
|---|
| 354CL | WKR consultants' fees and site investigation
| 250 | 250
|
|---|
| 365CL | WKR southern area, phase 1
| 694 | 694
|
|---|
| 366CL | WKR northern area, phase 1
| 2,065 | 2,010
|
|---|
| 382CL | WKR hinterland drainage package 1
| 125 | 160
|
|---|
| 391CL | WKR southern area, phase 2
| 908 | 810
|
|---|
| 395CL | WKR northern area, phase 2
| 2,871 | 2,840
|
|---|
| 403CL | WKR remaining hinterland drainage works and sewerage network package 1
| 998 | 998
|
|---|
| 407CL | WKR distributor roads and related drainage works
| 580 | 580
|
|---|
| 431CL | WKR southern area, phase 3
| 423 | 330
|
|---|
| Project Estimate under Head 702 :
| 9,918 | 9,676
|
| (b) Land acquisition and compensation*
| 2,273 | 2,023
|
| Total Project Cost for West Kowloon Reclamation (ACP portion) :
| 12,191 | 11,699
|
* The land acquisition and compensation requirements are reduced to $2,023 million as saving is identified.
