12                  Summary

12.1                       Key Benefits of the Project              The Project involves the development of a proposed offshore wind farm in south eastern waters of the HKSAR, and approximately 9 km and 5km east of the Clearwater Bay peninsula and East Ninepin Island, respectively.              Up to 67 turbines will be arranged in a grid, and each will be affixed to the seabed by a foundation consisting of a jacket structure with suction caissons.  The suction caisson foundation type avoids the need for dredging or marine piling, thereby avoiding potential adverse ecological impacts on marine sensitive receivers.              The Project offers the opportunity for artificial reef development, with the presence of the foundations and sub-structures attracting marine life.  Over time, the establishment of epifauna may support a more diverse reef habitat.  Combined with restrictions on trawling and other marine traffic activity, the Project has the potential to generate an enhancement effect at the wind farm area.              The Project will be capable of producing an output of up to 200 MW of electricity, or approximately 1% of total HKSAR annual electricity needs. The energy required to build a wind farm is typically recovered in the first year of operation, thus bringing a net positive effect on greenhouse gas emissions. [*]              The benefits to local air quality are significant.  As elaborated in section 1, every year of Project operation will offset approximately 343,000 - 383,000 tonnes of carbon dioxide and 54 - 60 tonnes of sulphur dioxide.[†]              Strategically, the Project will substantially contribute to the HKSAR renewable energy target of 1 - 2% of all energy from renewable sources by 2012.

12.2                       Technical Summaries

   12.2.1   Waste & Materials Management              The proposed use of suction caisson foundations avoids the need for any marine excavation or dredging in offshore Eastern Waters.  The key potential impact during construction is therefore limited to the management of dredged sediments from within Junk Bay in relation to the laying of a portion of the transmission cable.  Up to 135,000 m3 of marine sediment would be dredged and preliminary conservative estimates are that up to 65,000 m3 may require Type 2 confined marine disposal.              Other waste types associated with Project development include minor amounts of chemical wastes, sewage and general refuse.  No significant environmental impacts from the handling and disposal of these waste types are anticipated, subject to the full implementation of the relevant waste management standards and guidelines and best practices referred in sub-section 3.5.

   12.2.2   Water Quality              The potential for water quality impacts was greatly reduced from the outset by conducting a site selection process taking into account potential impacts, as well as by selecting suction caisson foundation technology, thereby eliminating the need for offshore dredging or major water quality impacts.              The key water quality issues and potential construction and operational phase impact of the Project have been assessed.  The main concern relates to sediment dispersion during construction, particularly suspended sediment and possible contaminants, and the direct and secondary impacts of this on biological sensitive receivers.              An onsite test of a suction caisson carried out in May 2008 verified that the predicted impacts of the turbine foundations being proposed would not produce any adverse impacts.  The key area for potential impact was identified as the cable transmission route in Junk Bay where dredging would be required.              Mitigation measures including limits on dredging rate have been determined for the transmission cable works in Junk Bay, and with proper implementation of the recommended measures no adverse impacts are anticipated.

   12.2.3   Benthic Ecology              The potential for impact on benthic ecology was greatly reduced from the outset by conducting a site selection process taking into account potential impacts, as well as by selecting suction caisson foundation technology which avoids dredging.              Following desk-top review a series of field surveys were conducted that reaffirmed Eastern Waters as being of generally high marine benthic conservation interest, although not within the wind farm footprint which is composed of silty mud of low ecological value.  The conservation importance of the benthic community in Junk Bay and the Tathong Channel is relatively low.              Numerical modelling predicted adverse impacts at minor coral communities in Junk Bay from the dispersion and settlement of suspended sediment resulting from the dredging of the cable route there, although implementation of the recommended control measures is expected to effectively avoid adverse impacts.  Adverse direct impacts on seabed habitat from temporary displacement and cable jetting activities shall be of short duration and reversible, with anticipated re-colonisation of the affected areas within a short period of time.              The presence of the turbine foundations at the wind farm area will provide an artificial habitat for potential colonisation by benthic epifauna. The cumulative surface area of approximately 100,000 m2 (based on the Base Case Development Scenario of 67 tripod structures with legs nominal 5m diameter in 30m water depth) of ‘artificial reef’ sub-structures shall more than make up for the permanent loss / displacement of 48,000 m2 of silty mud of low ecological value, resulting in a significant enhancement effect at the wind farm area.

   12.2.4   Pelagic Ecology              The potential for impact on pelagic ecology was greatly reduced from the outset by conducting a site selection process taking into account potential impacts, as well as by selecting suction caisson foundation technology, avoiding both areas known to be sensitive and eliminating the need for piling or dredging at the wind farm.              Based on desk-top review and field survey it is evident that the waters of the proposed wind farm are not frequented by Indo-Pacific hump-backed dolphins and are only lightly utilized by finless porpoises – with this species preferring more sheltered coastal waters around the Ninepins and Po Toi islands.   Given this low usage of the Study Area and the preferred construction method, no adverse long-term impacts are anticipated during construction and no mitigation measures are proposed.  Nevertheless, a 250m marine mammal exclusion zone will be implemented during construction and monitoring of marine mammals over a suitable period of time is recommended in order to be able to detect overall changes in use of the area.              Regarding fishes, at worst only a marginal increase in suspended sediment above baseline levels is predicted at most locations during construction only.  Although the worst-case assessment scenario of concurrent marine dredging and jetting at Junk Bay is predicted to result in elevated sediment levels at the reef fish community at Fat Tong Chau, levels remain significantly below the WQO criteria.              A review of potential noise impacts has been completed, and this does not suggest any adverse impacts from marine vessel activity during Project construction or operation, or from underwater turbine noise.  Adverse impacts from the electromagnetic field are not anticipated.

   12.2.5   Avifauna              The potential for impact on avifauna was greatly reduced from the outset by conducting a site selection process taking into account potential impacts and avoiding areas known to be sensitive.              A total of 57 bird species were identified in the Study Area by boat surveys between May 2006 and December 2007, among which several species or species groups are considered of relatively higher sensitivity due to their conservation significance, distribution and / or abundance within the Study Area (Sub-section 7.6). These species include White-bellied Sea Eagle, the breeding terns, Red-necked Phalarope, Black-tailed Gull and Cattle Egret, Aleutian Tern and White-winged Black Tern.              The impact assessment suggests that potential impacts on all birds resulting from construction and operation of the proposed wind farm will not be significant. The widely-used model developed by Scottish Natural Heritage has been used and predicts negligible collision risk for all the most sensitive species in the Study Area based on their distribution and abundance. The significance of construction and operation impacts on avifauna is anticipated to be very low.  Overall, the proposed wind farm is considered to have no adverse impacts on avifauna.

   12.2.6   Fisheries              The potential for impact on fisheries was greatly reduced from the outset by conducting a site selection process taking into account potential impacts and avoiding areas known to be most productive.              The Project will lead to the permanent direct loss to commercial fishing of approximately 16 km2 of low productivity / value fishing ground within Hong Kong waters, although the potential for a significant enhancement effect may be achieved with the implementation of fishery resource enhancement and management measures.  There is also unrestricted fisheries habitat of similar character and value in waters contiguous with the proposed wind farm throughout the Study Area.              Both the wind farm site and cable route lie far from identified nursery grounds of commercial species. The total area impacted by the transient jetting operation is extremely small, and impacts will be negligible.              No significant water quality-induced impacts are predicted on the popular fishing area around the Ninepin Islands or any of the fish culture zones in the Study Area during Project construction.

   12.2.7   Cultural Heritage              Following desktop study and marine geophysical survey, a total of eight partially buried targets with marine archaeological potential have been identified.  It has been identified that one target within the wind farm footprint may potentially be impacted by array cable installation, and mitigation measures have been proposed accordingly.  A buffer separation zone to avoid direct impacts on all targets during construction and operation has also been proposed as a best practice.              Further marine geophysical investigations adopting seismic surveys shall be conducted in parallel with the detailed engineering design prior to any site works. In addition to the mitigation measures stated in the EIA documents, the further marine geophysical survey report shall recommend appropriate mitigation measures to address adverse impact, if any. All the mitigation measures should be implemented and monitored before the commencement of construction works.              The planning approach has been a precautionary one of impact avoidance by sensitively locating turbines and marine cables, and re-locating if necessary.  With this approach, no adverse impacts on cultural heritage are anticipated.

   12.2.8   Landscape & Visual Impacts              The potential landscape and visual impact was greatly reduced from the outset by conducting a site selection process taking into account potential impacts.              Landscape and visual impacts are acceptable with mitigation measures.  Whilst the project will give rise to certain significant local effects on the landscape, such impacts can be reduced to a large extent by specific measures referred in section 10.              Although offshore wind turbines would be entirely new features in the local landscape, international research shows that a clear majority of the public have more favourable responses towards their appearance compared with other types of development. In the particular landscape and visual context of this Project, it is concluded that for most visual sensitive receivers the wind farm will not represent an unacceptable impact.

12.3                       Stakeholder Feedback              The Project Proponent together with CLP has conducted extensive consultations with project stakeholders, including: individuals, organisations, Government Departments and many others.  The feedback from these consultations has been important during the preparation of this EIA Study Report.  Table 12.1 considers some of the key issues raised by Consultees and how they were addressed in the EIA.

Table 12.1     Incorporation of Stakeholder Feedback into EIA


How it was addressed

If we are going to do a project, why not make it bigger?

We have tried to strike a balance between making the project big enough to be significant, but making it appropriate in environmental and other aspects.  The project did increase in size during development as it became clear that it could be increased with little or no additional environmental impact.  Constraints have limited the project increasing any further

How can education be maximised so that HK people can learn about sustainable development

This is beyond of the scope of the EIA, but allowance has been made in the proposed management so that education could be carried out

9 months of bird survey work is not enough, should cover full year

Bird survey was extended to 12 months, with additional 6 months for white bellied sea eagles

Impact on White Bellied Sea Eagles might be unacceptable

This is addressed in chapter 7.  During 12months of study no eagle was spotted near the site, the survey was extended a further 6 months with the same result.

Impact on Chinese White Dolphins should be minimised

No Chinese White Dolphins were spotted and this area is not known to be a habitat dolphins use.  This was one reason the site was selected, as good site search can eliminate issues, which is better than mitigation if possible. 

Impact on fisheries should be considered

The study shows that the wind farm will likely have a net positive impact on fisheries due to proposed management of the site. 

Are there opportunities to enhance fisheries beyond measures required for the wind farm?

There might be, but that is beyond the scope of this EIA

What will it look like? 

This is addressed in chapter 10, care was taken to design a layout and positioning that would reduce the potential for impact.  Additional photomontages were created for viewpoints that were expressed as being of interest

Wind farm should not be built on the Nine Pin Islands

The wind farm is over 5km east of the main Nine Pin Islands

Concern over a substation at the cable landing point

No substation will be built at the cable landing point, only a small cable connection pit is needed which will be underground and fully restored.  The area selected is reclaimed land.


12.1                       Environmental Outcomes


The environmental outcome of the project is the development of a substantive renewable generating capability from an offshore windfarm in south-eastern waters of Hong Kong.  Site selection and design have minimised and/or negated any significant environmental impacts of the project on the existing ecology and landscape of the site area, both the exposed offshore area of the windfarm site, and the waters and coastline adjacent to the cable route.  Key outcomes include:


*     Air Quality - Annual offset of approximately 350,000 tonnes of Carbon Dioxide, 55 tonnes of Sulphur Dioxide, 400 tonnes of Nitrogen Dioxide and 15 tonnes of particultes.

*     Water Quality - Suction caissons adopted for windfarm foundations negating dredging, and jetted cable installation adopted for majority of route to minimise seabed disturbance.

*     Benthic Ecology - Windfarm sited on low value seabed, with cable set away from coral communities; mitigation and monitoring to be conducted during construction.

*     Pelagic Ecology - Minimally evasive construction negates adverse impact on fish stocks and other marine life (dolphins, turtles); while the creation of substantial habitat around the turbine foundations, coupled with fishing access controls within the windfarm footprint is anticipated to benefit the environment.

*     Avifauna - Siting away from coastlines and known communities reduce distubance and negligible collision risk for the most sensitive species in the Study Area

*     Landscape - While the windfarm will be a new feature in the landscape, it is sited away from habitation and will not develop unacceptable impacts on the character of the area.


[*]   Life Cycle Assessment of Onshore and Offshore Sited Wind Power Plants based on Vestas V90-3MW turbines, June 06, Vestas.

[†]   Based on offsetting prediucted emissions from Castle Peak Power station after FGD unit fitted