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| | | Flood Prevention in Mong Kok | | | | Q1 What is being done to eliminate flooding in Mong Kok? top | | | To solve the flooding problem in Mong Kok, a comprehensive drainage improvement programme at over $3.6 billion is being implemented in stages.
The Drainage Services Department has started implementing the West Kowloon Drainage Improvement Scheme since 1996 with three contracts under Stage 1 awarded in 1998. A total of about 10 kilometres of stormwater drains in Yau Ma Tei, Kowloon Tong, Sham Shui Po and Lai Chai Kok will be enlarged or replaced for completion in June 2003.
A total of eight have been awarded under Stage 2 and Stage 3, phase 1 of the improvement scheme. It includes on-line improvements of 34 kilometres of stormwater drains in Tsim Sha Tsui, Yau Ma Tei, Sham Shui Po and Lai Chi Kok for completion in 2004. The Stage 2 works also include the construction of the Tai Hang Tung Flood Storage Scheme and the Kai Tak Transfer Scheme, both started in early 2001 for completion in 2004.
| | | | Q2 How can you ensure that the projects will be completed within the shortest period of time and with the least disruption to the public? top | | | We are aware that drainage works in public roads are extremely difficult, disruptive and time consuming due to lack of space and conflicts with various utilities and structures. To ensure that the project will be completed with the least disruption to the public, we have included a flood storage facility in Tai Hang Tung and the Kai Tak Stormwater Transfer Scheme in Stage 2. The construction started in early 2001 for completion in 2004. We are also planning for the construction of the Lai Chi Kok Transfer Scheme.
For works to be carried in existing roads, traffic impact assessments will be carried out to ascertain their effects.
| | | | Q3 After completion of the drainage works in Nathan Road in October 1999, will there be no more flooding in Mong Kok? top | | | Completion of the drainage works in Nathan Road, being an advance part of the Stage 1 works, has brought relief to the flooding situation in Mong Kok in the summer of 1999. However, there is still a high risk of flooding in extreme conditions of very heavy rainfall such as when Black Rainstorm warning is issued.
We expect that the flooding problem in Mong Kok will improve significantly when all major elements of the massive drainage improvement scheme in West Kowloon are completed in 2004.
| | | | Q4 Are there any short-term measures to provide interim relief to flooding in Mong Kok before completion of the West Kowloon Drainage Improvement Scheme? top | | | Every effort will be maintained to help the drainage system to operate at its best before major elements of the massive drainage improvement scheme in West Kowloon are completed. The drainage system is desilted regularly and before the onset of rainy season to prevent the Stormwater drains from blockage and hence, reduce flooding.
During the coming rainy season, our maintenance staff will continue to monitor the situation in Mong Kok. When adverse weather comes, we will deploy our staff to flooding black spots to carry out immediate relief measures. We shall maintain close coordination with relevant Government departments in this respect.
| | | | Q5 Illegal discharge and dumping of construction wastes into public drains is considered to be one of the causes of flooding. What measures are being implemented by the Government to tackle the problems? What are the latest figures in respect of successful prosecution against discharge and dumping of construction wastes into public drains? top | | | Some localized flooding is caused by blockage of roadside gullies in highly populated areas or indiscriminate disposal of wastes from construction sites. Before each rainy season, we remind the personnel in charge of construction sites to exercise strict control on their construction activities. We continue to maintain close liaison with other relevant departments in this respect. Memoranda are sent to all Government works departments seeking their support in taking active measures in their construction sites to ensure that there will be no adverse drainage impact on the stormwater drainage system due to construction activities. Advisory letters are issued regularly to authorized persons (APs), who manage private development projects, asking them to exercise stringent control over their contractors to prevent illegal discharge and blockage of public sewers and drains by construction waste.
| | | | |  | | | | Flood Prevention in the New Territories | | | | Q1 Why is there always flooding in the NT? What is Government's plan to alleviate the problem? top | | | The NNT and NWNT are the two major flood prone areas in the territory. Due to the low-lying topography in these areas, the overflow of natural watercourses, which do not have adequate capacity to cater for the discharge, in times of heavy rain causes severe flooding. The problem has been exacerbated in recent years by intensive developments on natural flood plains.
Since 1997, we have implemented a comprehensive flood prevention strategy that is based on the large scale river training works for main watercourses and the village flood protection scheme for low-lying villages. The Government has committed considerable resources (about $8.7 billion) to implement these projects in order to reduce the livelihood of rivers overflowing their banks. Most river training works include the widening, deepening and straightening of existing rivers. The newly completed rivers included Ping Yuen River and ShenzhenRiver.
In addition to river training projects, there are 27 village flood pumping schemes operating very successfully to protect low-lying villages that are at levels below the water levels in the drainage channels. | | | | Q2 After the completion of the river training schemes, will there be no more flooding in the NT? top | | | Upon the completion of the major river training schemes, the flooding situation in most areas of the NT will improve significantly. Nevertheless, there may still be minor flooding in some extremely low-lying agricultural lands but both the frequency and severity will be much reduced.
It should be made clear that flooding is a natural phenomenon and, therefore, it is not possible to eliminate the flooding risk absolutely. Instead, it is necessary to determine the levels of risk that are acceptable to the community and design the drainage system accordingly.
| | | | Q3 What is the progress of the river training scheme in the NNT and NWNT? top | | | Progress of the large-scale river training projects in the NT is very good. In the NWNT, over 16.5 kilometres of drainage channels and 13 village flood protection schemes have been constructed in Yuen Long and Kam Tin areas. Construction of 23.5 kilometres of drainage channels (worth $2.2 billion) is underway. In the NNT, about 28.5 kilometres of drainage channels in Shenzhen River, River Indus and River Beas have been completed and the construction of 5.5km of drainage channels (worth $0.6 billion) is underway.
Planning and design for another 46.5 kilometres of river channels is underway including the Yuen Long Bypass Floodways, the upper reaches of Kam Tin River, Ngau Tam Mei drainage channel and some smaller channels in NNT and NWNT.
| | | | Q4 Does the Government have any measures to accelerate the river training schemes? If not, what are the major problems? top | | | Considering the amount of time needed for these works, the present programme is already a very ambitious plan. Indeed, the Government has already tried to accelerate the works by implementing the upstream and downstream works in parallel. For example, 3 river training projects are now under construction in the Kam Tin basin and 2 river training projects are also under construction in the Ngau Tam Mei Basin.
Most river training projects by their own nature are very large and complex. Apart from the time needed for the planning, design and construction, they require extensive consultations with local residents; resolution of environmental issues and difficult land resumption issues; and the necessary statutory procedures. These processes involve heavily the interest of the public and need serious attention from the Government.
Another very important factor affecting the time for implementation of such a comprehensive programme of works is the sequence of completing the various projects. To avoid creating drainage bottlenecks, it is necessary that the downstream sections of the rivers be improved before the upstream reaches. | | | | Q5 Regulation of Shenzhen Stage III has completed in April 2007. Will the flooding problem on both sides of Shenzhen River become part of the history? top | | |
The Project of Regulation of Shenzhen River consisted of three stages and mainly involved straightening, widening and deepening the 18-km river channel. The first two stages were completed in 1997 and 2000 respectively. The third stage of the works mainly involved the widening and deepening of the 4-km long section upstream of the Liu Pok bend to the confluence with Ping Yuen River, together with the reconstruction of Lo Wu Railway Bridge, Lo Wu Old Pedestrian Bridge, Man Kam To Vehicular Bridges and two Dongjing Water Main. Coupled with the regulation of Ping Yuen River on Hong Kong side, the completion of the third stage of works has resolved the flooding problem in Ta Kwu Ling area. The discharge from Shenzhen Reservoir will no longer lead to flooding. The flooding protection standard of the trained river channel has been raised to one in 50 years return period. It is believed that the experience of waist-deep flooding on both sides of Shenzhen River during rainstorm will become part of history.
| | | | | Q6 Are there any short-term measures to provide interim relief to the flooding in New Territories before completion of these river training schemes? top | | | The Government will do everything within its power to reduce flooding. Apart from major river training projects, many other works are being carried out on a local scale that will reduce flooding or help villagers avoid flood losses. Examples are:
(i) Carrying out local drainage improvement projects
(ii) Carrying out constant maintenance and cleansing of existing stream courses and drainage systems.
(iii) Flood warning systems (flood sirens) are in operation at flood prone villages.
(iv) Installing river gauges at the critical rivers for measuring the water depth of the rivers.
| | | | Q7 Will the victims of flooding in the flood-prone areas in the NT be offered compassionate re-housing? top | | | Upon completion of the river training projects in the NT in 2005, most areas will no longer be subjected to flooding. Only limited scattered houses within flood plains will still be affected by minor localized flooding. Regarding the flooding problem to these isolated houses, re-housing is one of the options being considered by the Government. However, this is a complicated issue as the Government has to be fair to those on the general waiting list of re-housing.
Nevertheless, some flood prone areas within the project limit of the major river training works will be vacated for the implementation of the projects, e.g. Tak Yuet Lau and part of Ho Sheung Heung and Tin Ping Shan. About 250 households (650 villagers) have been re-housed in 1999 as a result of the training works in River Indus in Northern New Territories.
| | | | Q8 What can the Government do to safeguard the flood-prone areas in the NT from possible flood damage due to discharge from the Shenzhen Reservoir? top | | | We have an agreement with the Shenzhen Authority for notification of discharge from the Shenzhen Reservoir. Under normal circumstances, the Shenzhen Authority will inform HKSAR 3 hours in advance of the discharge. In case of abnormal heavy rainfall that results in sudden surge of water level in the Shenzhen Reservoir and requires urgent discharge, notification will be given as quickly as possible.
Flood warning systems have been installed to alert local villagers where there is possible flooding in the NT. When being alerted to a possible discharge, relevant government departments will stand ready to assist any villagers in need.
A number of major river training projects in the NNT are currently under construction and, upon completion, will effect considerable improvements. In particular, the Shenzhen River Regulation Project has been designed to take into account of the discharge. | | | | Q9 What is the progress of the Drainage Master Plan (DMP) Studies being undertaken? Can these studies be advanced in view of the flooding problems in recent years? top | | | | The Government is also conducting a series of eight Drainage Master Plan Studies, which focus on assessing the conditions of the secondary drainage systems and recommending improvements works. Results of these studies help draw up the long-term flood prevention strategy and improvement schemes for the drainage systems in these areas in order to cope with current and future development needs. Seven of the studies have been completed before 2000. | | | | Q10 Some Green Groups called on the Government to take steps to stop destruction and degradation of natural stream courses and said that concrete-lined river channels are threatening some (30) freshwater fish species with extinction. What will the Government do to protect these special species? top | | | An environmental impact assessment (EIA) would be conducted for all river training works contracts. The study would identify necessary environmental protections and ecological mitigation measures. They generally include:
(a) unlined channel bed to enable re-colonisation of flora and fauna after the completion of works;
(b) use of grasscrete lining at channel sides and base to provide medium ecological value habitat for invertebrates and higher fauna;
(c) re-vegetation of embankment slopes;
(d) planting of mangroves along certain sections of channel embankments such as in Yuen Long and Kam Tin drainage channels;
(e) provision of engineered wetland/marschcrete areas to provide medium to high ecological value habitat; and
(f) keeping existing meander or original rivers wet by not blocking its connection with the trained rivers after river straightening works to maintain wetland for aquatic lives.
| | | | Q11 After completion of the drainage works in Nathan Road in October 1999, will there be no more flooding in Mong Kok? top | | | Completion of the drainage works in Nathan Road, being an advance part of the Stage 1 works, has brought relief to the flooding situation in Mong Kok in the summer of 1999. However, there is still a high risk of flooding in extreme conditions of very heavy rainfall such as when Black Rainstorm warning is issued.
We expect that the flooding problem in Mong Kok will improve significantly when all major elements of the massive drainage improvement scheme in West Kowloon are completed in 2004. | | | | | | | | | Flood Prevention in Sheung Wan | | | | Q1 What programme is being carried out to alleviate the flooding problem in Sheung Wan around Wing Lok Street? top | | | To resolve the flooding problem in the Sheung Wan low-lying area, we are now implementing a $220 million in 3 phases. The project comprises the construction of intercepting drains along Queen'ss Road Central and a stormwater pumping station at waterfront.
About 660 m of stormwater drains will be constructed along Queen's Road Central to reduce about 30% of stormwater entering this low-lyng area from the upland catchment. The works started in July 2006 for completion by June 2008. Construction of an underground storage tank with a pumping station is to cope with the flood water accumulated at the low-lying area in Sheung Wan. The foundation works started in June 2006 and the whole project will be completed by end 2009.
It is believed that the flood protection level in the low-lying area in Sheung Wan will be raised to withstand a rainstorm with a return period of one in 50 yeas upon completion of two projects.
| | | | Q2 What interim measures have taken to mitigate the flooding problem before the completion of the permanent works in Sheung Wan? top | | | A "Flood Watch" programme was launched on 3 April 2006 to alert the residents and shop owners of possible flooding in Sheung Wan. When flooding is likely to occur due to high tide, storm surge or heavy rains, SMS messages will be sent to alert the residents and shop owners in the area for better preparation.
To improve the flooding situation in Wing Lok Street, we increases the frequency of inspection and drainage cleansing works so as to improve the flow of drains. In addition, we also inspect drainage outlets in the district in order to ensure they are functioning properly. If the weather gets worse, like Amber Rainstorm Signal is hoisted or Sheung Wan Flood Watch is triggered, an emergency team will be deployed to the district to clear the blocked drains and outlets. | | | | | | | | | Flood Prevention in Urban Areas | | | | Q1 DSD has commenced implementation of 3 large drainage tunnels in Tsuen Wan, Lai Chi Kok and Hong Kong West. Can you let me know their implementation programme? top | | | We are going to construct 3 drainage tunnels including the Hong Kong Island West Drainage Tunnel, the Tsuen Wan Drainage Tunnel and the Lai Chi Kok Transfer Scheme (LCKTS).
To improve the floodoing situation in Northern Hong Kong, a 11 km long Hong Kong Island West Drainage Tunnel, with diameters ranging from 6.25 m to 7.25 m, wil be built in mid-level of Hong Kong Island. Valued at HK$3 billion, works will start in end 2007 for completion in end 2010.
The Tsuen Wan Drainage Tunnel is 5.1 km long with diameter of 6.5 m. It will collect stormwater via 3 intakes located at Kwai Chung, Lo Wai and Tso Kung Tam, Tsuen Wan, and divert flow of upper catchment areas to Yau Kom Tau for discharge. Cost about HK1 billion, works will started in end 2007 for completion in end 2011.
Under the LCKTS, a total of 3.7km of drainage tunnel with diameter of 4.9 m, 6 intakes, 1 stilling basin, 1 outfall structure with pumping facilities and about 180 m of collector channels will be built. The scheme will be studied together with the "Inter-Reservoir Transfer Scheme" under the Water Supplies Department. Works will start in early 2008 for completion in end 2011.
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