The SENT Landfill Extension (SENTX) forms an integral part in the Strategic Plan in maintaining the continuity of landfill capacity in the Hong Kong for the cost-effective and environmentally satisfactory disposal of waste. The Environmental Impact Assessment (EIA) Report and the associated Environmental Monitoring and Audit (EM&A) Manual for the construction, operation, restoration and aftercare of the SENTX (hereafter referred to as “the Project”) have been approved under the Environmental Impact Assessment Ordinance (EIAO) in May 2008 (Register No.: AEIAR-117/2008) (hereafter referred to as the approved EIA Report) and an Environmental Permit (EP-308/2008) (EP) was granted by the Director of Environmental Protection (DEP) on 5 August 2008.

Since then, applications for Variation of an Environmental Permit (No. VEP-531/2017) were submitted to EPD and the Variation of Environmental Permits (EP-308/2008/A and EP-308/2008/B) were granted on 6 January 2012 and 20 January 2017, respectively, as the Hong Kong SAR Government has decided to reduce the scale of the design scheme of SENTX assessed in the approved EIA Report and SENTX will only receive construction waste. In May 2018, a Further Environmental Permit (FEP) (FEP-01/308/2008/B) was granted to the SENTX’s contractor, Green Valley Landfill, Limited (GVL). Thereafter, Variation of Environmental Permits (EP-308/2008/C and FEP-01/308/2008/C) were granted to the Environmental Infrastructure Division of EPD and GVL in February 2024. Following that, Variation of Environmental Permits (EP-308/2008/D and FEP-01/308/2008/D) were granted to the Environmental Infrastructure Division of EPD and GVL in April 2025 regarding updates to the extension of the waste boundary of the SENTX area.

Per requirement of EP Condition 2.6, the Permit Holder shall, within six months after the commencement of construction of the Project, submit a coherent Restoration and Ecological Enhancement Plan (REEP) to the Director for approval. The submissions shall be certified by the Environmental Team (ET) Leader and verified by the Independent Environmental Checker (IEC).

ERM was appointed by GVL to prepare the REEP (“REEP”) in accordance with Environmental Permit (EP-308/2008/D and FEP-01/301/2008/D) Condition 2.6, “a coherent restoration and ecological enhancement plan shall be submitted to the Director for approval showing details of restoration measures for the extension site…”.

1.2 Purpose of the Restoration and Ecological Enhancement Plan for SENTX

The purpose of this REEP for SENTX development is to show the details of restoration measures for the SENTX site including:

• provision of 6 hectares of mixed woodland planting composting of about 20% non-native tree species [1] to compensate the loss of shrubland and a mosaic of grassland and shrubland in the remaining areas of the extension;

• plan(s), of scale 1 to 1000 or other appropriate scale as agreed by the Director, shall include details on locations, size number and species of planting; and

• implementation programme, maintenance and management schedules.

All measures recommended in the approved REEP shall be fully and properly implemented based on the details and programme set out in this submission.

Under the requirement of Condition 2.6 of the FEP, the REEP shall be prepared and submitted to the DEP within six months after the commencement of construction of the Project.

1.3 Structure of the Restoration and Ecological Enhancement Plan for SENTX

The remainder of the REEP for SENTX is structured as follows:

· Section 2 presents the existing conditions and environment of the site;

· Section 3 presents the requirements and approach to develop the REEP;

· Section 4 presents the details of the REEP; and

· Section 5 presents the implementation program, maintenance and management of the REEP.

2. Conditions and Environment of The site

2.1 Site Location

The SENTX is a piggyback landfill, located on the western side of the Clear Water Bay Peninsula without additional encroachment into the Clear Water Bay Country Park (CWBCP), occupying the southern part of the existing SENT Landfill and 13 ha of Tseung Kwan O (TKO) InnoPark (Area 137). A layout plan of the SENTX is shown in Figure 2.1.

2.2 Topography and Landform

The geology of the peninsula is variable, comprising rocks of the Middle and Lower Jurassic Periods (pyroclastic rocks and acidic lavas) as well as smaller outcrops of granitic rocks and deposits of colluvium. This forms a rugged mountainous ridge (up to ~ 340mPD) along the Clearwater Bay Peninsula which falls steeply into the sea, occasionally forming steep cliffs. In addition, this ridge sends out lateral spurs towards the coast forming a series of steep-sided coves and bays.

The ridge, composed of alternate peaks and saddles, is angular and rugged in appearance, generally vegetated, but with rocky outcrops, especially around the tops of peaks. A feature of some importance to the SENT and SENTX sites is the saddle of land, formed between the two peaks of Ha Shan Tuk and Tin Ha Shan, which is a viewing point for a number of recreational users of the area. A number of small streams drain off the line of hills forming the peninsula, down shallow gullies formed in the hillsides and thence into Junk Bay.

The SENT/ SENTX Landfill site lies in and around what used to be Shek Miu Wan, a cove within Junk Bay. Junk Island (Fat Tong Chau) lies off Shek Miu Wan (see Figure 2.1). The Island is steep-sided, rising to 99mPD and plunging sharply into the sea. It is generally rocky with a patchy covering of shrub and trees. The infrastructure contract which preceded the SENT/ SENTX landfills has now joined Junk Island to the peninsula itself, effectively reclaiming the cove of Shek Miu Wan and turning the island into a rocky promontory (see Figure 2.1).

The SENT/ SENTX landfill, when completed, will together cover approximately 116 ha, of which about 50 ha will be reclaimed from Shek Miu Wan. It will form an extension to the lower hillsides of the western side of Clearwater Bay Peninsula.

Two footpaths pass close to the landfill sites (see Figure 2.1). One, formerly the land access to the two villages around the cove, runs from the car park at Clear Water Bay Second Beach over the saddle of land above the landfill site. From here, there are views down to the coast as well as over Junk Bay.

In addition, the High Junk Peak Hiking Trail, which is a much-used hill walking route, runs along the ridgeline down the centre of the peninsula and the new recreational facility on the site should have regard to the Trail and seek to create links with it in order to establish a comprehensive network of recreational facilities throughout the peninsula.

2.3 Climate and Microclimate

The SENT/ SENTX landfill sites lie on an exposed area of Hong Kong's south-east coast, which take the full force of Hong Kong’s prevailing south-westerly winds between the months of August and June. This important factor has informed and guided the design of the restored areas. Mean annual rainfall is between 2,000mm and 2,400mm per year. Monthly mean temperatures are between approx. 14 degrees Celsius (January) and approx. 28 degrees Celsius (July), with mean monthly relative humidity varying between approx. 69% (December) to 83% (June).

Planting on areas of higher ground demonstrates the extent to which exposure to winds can inhibit plant establishment. Vegetation establishes less well on upper slopes that are not south or west facing, except in gullies or ravines. On lower slopes, more tree and shrub vegetation becomes established, since these areas are often less exposed.

The REEP seeks both to take cognisance of these conditions, optimise the establishment of vegetation as well as creating conditions that will be conducive to informal recreational activities which benefit from more sheltered locations. Planting and landform should be exploited to create a microclimate that will provide shelter over limited areas for picnic and other low-key informal activities.

2.4 Vegetation and Ecology

A baseline vegetation assessment was carried out around Shek Miu Wan as part of the SENTX EIA (Section 9.7). The assessment identified five types of flora/ habitat in their study area at the SENTX site as follows:

Plantation

A total of 14 exotic species were found located within the boundary of the existing SENT Landfill and all of them are common species in Hong Kong. The plantation is largely exotic woodland, dominated by the tree species Acacia confusa with tree height around 3 to 5 meters and planted as part of the existing SENT Landfill restoration. In the meanwhile, the woodland is young in age and the understorey is occupied by weeds species such as Leucaena leucocephala, Bridelia tomentosa, Lantana camara and Miscanthus sinensis etc.

Shrubland

Shrubland habitat can be found on the hillsides located within the CWBCP in a continuous patch approximately 75.3 ha. The shrubland has a rocky substrate with evidence of occasional disturbance by hill fires. Shrubland found in the valleys are taller, usually 2m to 3m height while they are shorter on hill slopes, generally 0.3m to 1.5m height. There are 80 species were recorded which are commonly found in Hong Kong. The Shrubland is dominated by several native species, including Rhaphiolepis indica, Rhodomrytus tomensora, Cratoxylum cochinchinense, Eurya nitida, Embelia laeta, Embelia ribes and Gardenia jasminoides.

Grassland

Grassland was recorded at the southeast part of the SENTX area mainly located within the CWBCP (around 19.7 ha.). The grassland is found on the rocky hills and ridges and is occasionally disturbed by hill fire. A total of 30 species, including grassy and shrubby plants, were found in the habitat, all of which are common species in Hong Kong. The grassland was dominated by Ischaemum aristatum, Rhynchelytum repens and Scleria harlandi. For shrub species, Wikstroemia chinensis, Rhus succedanea and Mimosa pudica predominated.

Seasonal Stream

There were two seasonal streams found within the vicinity of SENTX area. One is located at Ha Shan Tuk and the other is located at Hin Ha Au. Both are small seasonal streams with limited water flows during the wet season and no water flow during dry season.

Disturbed/ Developed Areas

Disturbed area is the dominant habitat within the vicinity of SENTX, including TKO Area 137, TKOIE and the existing SENT Landfill. The total area is around 171.2ha. This habitat is highly disturbed with limited vegetation cover, and the plant species are commonly found in Hong Kong (mostly for landscape purpose). There are a total of 22 plant species dominated by weeds and landscape species, such as Acacia auriculiformis and Leucaena leucocephala.

2.5 The SENT Landfill Restoration

The SENT Landfill restoration was produced following the SENT Landfill Final Restoration Landscape Masterplan Design Report (December 1996) and is shown in Figure 2.2. In Chapter 4 of the report, the objective of the restoration stated that:

…it was envisaged that the afteruse of the site would be as an informal recreational facility. Such a facility would complement recreational activity in Clear Water Bay Country Park. Only after the complete landfilling and restoration of the site would it be opened to the public.

It is likely that the restored site will act as a dual facility. With a car park perhaps located on the site of the current infrastructure area, visitors could either use the site as a transitional area permitting access to Clear Water Bay Country Park, or as a recreational facility in its own right. It is perceived that the facility should cater for the following activities:

• Hiking and strolling;

• Mountain biking;

• Picnics;

• Kite and model aeroplane flying;

• Sitting out and taking in views of the seascape and landscape.

The masterplan seeks to provide a range of visitor experiences, with woodland, shrub and open grassland areas. It aims to create a variety of spatial scales and degrees of enclosure and intimacy. There are sitting areas where individuals or groups can gain some privacy as well as open meadows for activities where more space is required, such as kite flying. In particular, the value of the new peaks and high areas is maximised by locating pavilions on their summits, which can then be used as sitting areas or viewpoints.

The landform as designed consists of a curved spur of land which runs down to the coast at gradients of 1:3, typical of gradients found elsewhere in the area. This spur leaves the uplands of the peninsula and turns west and south falling in a series of three high points. On the southern/ eastern side of the site, a ravine is created where the landfill site meets the former coast. At all points, the landform relates closely to the topography of the former coast, so that the landfill site appears as a natural extension of the landscape around it. Sufficient variety is created by peaks, spurs, ridges and valleys to provide a diverse and interesting experience for visitors (see Figure 2.2).

The restored site could offer potential links to the wider peninsula and to the High Peak Junk Trail as well as possessing a self-contained circulation pattern that allows the easiest possible access to the maximum part of the site.

The primary circulation system for the proposed recreational facility is a proposed network of maintenance tracks. Supplementing these tracks is a network of pedestrian paths designed to give comprehensive site access as well as access to viewpoints on the newly created peaks (see Figure 2.2).

The planting for the restored SENT site was designed to simulate natural patterns of hillside vegetation create the following types of vegetation:

• Woodland

• Shrubland

• Grassland

• Amenity Woodland

• Tree Stands

• Firebreak Woodland

The design of planting will follow the vegetation structure typical of natural hillside woodland, shrub and grassland in Hong Kong, so that an entirely natural effect will be created that is of maximum benefit to wildlife (see Figure 2.3).

During the preparation of this Restoration and Ecological Enhancement Plan for SENTX development, the above SENT Landfill Restoration works have been taken into account and made reference to, especially the existing established plant species of successful and high survival rate. Besides, trail nursery is also being undertaken (refer to Section 4.2) in accordance with EP Condition 2.7, that “trial nursery for native plant species …to fine tune the planting matrix and management intensity of the recommended indigenous tree species”. The trail nursery is still in progress, and only preliminary results were reviewed and discussed in Section 4.2, while the full monitoring results will be provided in later stage. Further details and result of the trial nursery works under both the SENT and SENTX projects will be adopted to refine the implementation of the SENTX REEP.

3. Requirements and Approach for The restoration and ecological enhancement plan (REEP)

3.1 REEP Requirements

Specific design objectives and criteria for the SENTX REEP are set out in the following documents:

• EP (EP-308/2008/D and FEP-01/308/2008/D) Condition 2.6; and

• The ecological mitigation requirements of the SENTX Project EIA Report (Chapter 9).

3.2 Environmental Permit (EP-308/2008/D and FEP-01/308/2008/D) Condition 2.6

According to EP Condition 2.6, “Within six months after the commencement of construction of the Project , four hard copies and one electronic copy of a coherent restoration and ecological enhancement plan shall be submitted to the Director for approval showing details of restoration measures for the extension site including provision of 6 hectares of mixed woodland planting composting of about 20% non-native tree species to compensate the loss of shrubland [2] and a mosaic of grassland and shrubland in the remaining areas of the extension. The plan(s), of scale 1 to 1000 or other appropriate scale as agreed by the Director, shall include details on locations, size, number and species of planting, implementation programme, maintenance and management schedules. The submission shall be certified by the ET Leader and verified by the IEC as conforming to the information, requirements and recommendations set out in the approved EIA Report. All measures recommended in the approved restoration and ecological enhancement plan(s) shall be fully and properly implemented in accordance with the details and programme set out in the submission.”

3.3 Ecological Mitigation Requirements of the SENTX EIA

3.3.1 Ecological Mitigation Requirements

Agreement No. CE 10.2005(EP) South East New Territories (SENT) Landfill Extension - Feasibility Study:

Environmental Impact Assessment Report (hereafter referred to as the approved EIA) defines a number of ecological (flora) mitigation measures that the restoration of the landfill must fulfil. Section 9.10.3 of the approved EIA Report addresses the issue of habitat mitigation. The following compensation planting is recommended as mitigation for the habitats affected due to the proposed SENTX site.

• Provision of 6 ha of mixed woodland planting to compensate for the loss of shrubland. To enhance the ecological value of the encroached area within CWBCP, mixed woodland will be planted on the affected areas (approximately 6 ha, originally shrubland)[3]; and

• Provision of a mosaic of grassland and shrubland in the remaining areas of the Extension Site.

The mixture of grassland, shrubland and woodland habitats is recommended to diversify the habitats to support various wildlife, in particular butterflies, birds and herpetofauna and blend into the existing undisturbed ecological environment…This recommendation also complies with the mitigation measures proposed in the existing SENT Landfill EIA, which suggested compensatory planting of native woodland.

Indigenous plant species with a shallow root system, softwood in nature and adaptive to seashore habitat are recommended to be used in the restoration plan, such as Gordonia axillaris, Phyllanthus emblica, Celtis sinensis and Macaranga tanarius, which have been well established in coastal areas with exposure to strong wind and salt spray, and with a sandy soil base.

Indigenous tree species Celtis sinensis and Ficus microcarpa have also been recorded in the SENT Landfill site (from years 2003 to 2006) and during the baseline surveys of this Project, although they occurred in low abundance in SENT Landfill and some individuals were distorted in tree form due to competition by exotic tree species on the crown layer.

With special care and management in place and the optimal planting matrix with other plant species, native tree species could be used for restoration in landfill site. Taking into consideration the relatively poor substrate and the difficulties of establishment of some native trees in Hong Kong, it is recommended to include approximately 20% of non-native tree species in the compensatory woodland. The non-native tree species can serve as a nurse species to facilitate the establishment of the native tree species, especially the shading, and it can be replaced by established native tree species progressively. Plant species can also make reference to food plants of butterfly species (in particularly butterfly species of conservation interest recorded within the CWBCP)….

It is also recommended that a trial nursery for native plant species be set up in advance during the construction phase in order to fine tune the planting matrix and management intensity of the recommended indigenous tree species. It should be noted that native shrubs and tree species have been used for restoration of the existing SENT Landfill, native plant species that could not successfully be established on the existing SENT Landfill should be reviewed before the preparation of the compensatory planting list. Special care and intensive management of native plants should be implemented in order to ensure proper establishment of the native plants. Compensatory planting and restoration of the Extension can be implemented progressively according to the filling plan of the Extension. Planted and restored areas will serve their ecological function once completed.

Detail of location and commencement schedule of the trial nursery is shown in Appendix A.

3.4 Proposed Approach for the REEP

According to the above requirements, the following describes the broad approach to the REEP for the SENTX restoration.

3.4.1 Planting Design

The planting for the restored SENTX site is also illustrated in Figures 3.1, 3.1.1, 3.1.2 and 3.1.3. Planting design has been guided by the approved EIA Report Section 9 mitigation requirements (see Section 3.3.1).

In addition, the approved EIA Report Section 10 Mitigation Measure AM4 requires that:

The restored Extension will be substantially vegetated so as to mimic the patterns of natural vegetation on surrounding hills. At least 18.8ha of the area of the Extension Site will be planted with woodland mix planting at no less than 1.2m spacings. 80% of all plants planted will be native species. The remainder of the site will be planted as a grassland / shrub mosaic.

In summary, therefore, the planting requirements are for a minimum of 18.8ha of woodland and a mosaic of grassland and shrubland, which comprises 80% of native species.

In addition, the planting layout has been designed with considering the following factors:

• Response to the established SENT restoration planting design;

• Existing planting and landscape design at SENT landfill; and

• Prevention of Fire.

3.4.2 Response to the Established SENT Restoration Planting Design

The ecological restoration design at SENTX aims to establish the beginnings of a vegetation structure which can develop and offer a wide range of ecological habitats for both flora and fauna, from grassland and shrubland through to woodland. However, this is neither a simple nor a short-term matter, as the development of habitats can take many years.

Ecological diversity is best encouraged by the planting of native plant species and communities. The numbers of non-native species used will be restricted to about 20% as required [4].

In order to establish a woodland that offers the widest possible range of opportunities for the natural development of habitats and ecological niches for wildlife, it is most effective to follow or mimic the natural process of woodland vegetation development.

Woodland development begins with the colonisation of a grassland or rocky site by dwarf shrub species. These in tum are followed by pioneer species, aggressive and opportunistic plants, surviving in locations which other plants find too exposed, too arid or where soils are too impoverished. These species develop quickly and are short-lived. They act as nurses, protecting the native tree and shrub species which colonise the site from wind and providing them with nutrients in the form of leaf litter and organic matter, which enriches the soil. This process is known as ecological succession.

The native trees and shrubs which colonise the site, eventually develop into what is termed a climax woodland community, the endpoint of a stable woodland ecosystem that will survive and persist for thousands of years unless there is external interference, such as fire.

A climax woodland community is composed of several layers of vegetation, each adapted to the various environmental conditions within the woodland (see Figure 3.2). The climax layer of vegetation is composed of the tallest woodland species, which tend to be the longest lived. These trees, 15 metres or more in height, capture most of the light falling on the woodland and maintain a competitive advantage over other species.

The sub-climax layer is composed of smaller trees 10 metres or more in height. These develop opportunistically in gaps left in the canopy layer, where sunlight penetrates and are also found at the edges of the woodland.

Below the sub-climax species is the understorey layer, composed of large shrubs up to five metres in height. Generally, these are suppressed by the low light levels near the woodland floor, but develop vigorously in pockets of light where older trees have died, and in sunny clearings. Many large shrubs demand high levels of light and develop along the edge of the woodland.

The herb layer is composed of large grasses and smaller shrubs up to two metres tall, which will generally tolerate lower light levels. Finally, the ground layer, is composed of smaller plants still, including mosses, low grasses and tree seedlings. These plants will generally have to tolerate extremely low levels of light.

The planting mix approach noted above is appropriate for the creation of a natural woodland structure. Using planting matrices (see Figures 4.1 to 4.6), different plant species can be laid out in the positions relative to each other so that they would normally occupy in a natural woodland.

3.4.3 Existing Planting and Landscape Design at SENT Landfill

As noted in Section 2.5, the SENT landscape restoration masterplan provides for the following vegetation types

• Woodland

• Shrubland

• Grassland

• Amenity Woodland

• Tree Stands

• Firebreak Woodland

As these still conform to the EIA requirements and compatibility of the SENT Landfill, it is proposed to retain these broad vegetation types at SENTX.

3.4.4 Prevention of Fire

The prevention of fire, or at least the containment of any fires that may start, is one of the design criteria incorporated into the REEP. The control or containment of fire can be achieved in a number of ways:

• By creating man-made barriers to fire e.g. footpaths or roads or drainage channels;

• By clearing or limit the growth of vegetation by cutting; and

• By planting belts of vegetation that are resistant to fire.

Physical barriers may simply be areas of ground wide enough to prevent fire crossing. A width of every one metre can be sufficient to serve this purpose. In this regard, footpaths or roads can be useful, as can streams, drainage channels (Appendix D) or rock faces.

Clearance of vegetation can contribute to fire control. Areas can be kept permanently free of vegetation in order to stop the spread of fire. This method does however give rise to recurrent maintenance costs. The cutting of grassland on a biannual basis is essential in limiting the amount of biomass vulnerable to fire.

The planting of belts of trees resistant to fire is a further method of controlling fire. As the species traditionally used have often been non-natives, this has in the past produced areas of rather unnatural looking vegetation amongst the woodland cover. Recently however, native species such as Ficus microcarpa have been used as fire-breaks, reflecting concerns regarding the effect on ecology and wildlife stemming from the introduction of non-native species.

In the design for the REEP, the principal method of fire control is the exploitation of the numerous proposed on-slope U-channels draining the hillsides. Planting will be set-back along these channels to create 5 metre-wide belts free of vegetation which serve to subdivide blocks of woodland and which permit maintenance of the U-channels.

The main drainage gullies will fall from the main ridge of land to the east and west and will run through the principal woodland spine located in the main valley. This woodland has been designed so that the gully will serve to compartmentalise and separate areas of this woodland.

Generally, maintenance access tracks and footpaths will compartmentalise areas of woodland and help control spread of fire. On the boundaries of the site where it adjoins areas of advance planting, belts of fire-resistant woodland will be planted to prevent the spread of fire in and out of the site.

4. Development of the Restoration and Ecological Enhancement

4.1 Approach to Planting Design

As required by the approved EIA Report and EP condition, three different types of vegetation are envisaged on the SENTX site in order to simulate the natural patterns of vegetation in the vicinity. These are:

• Woodland;

• Shrubland; and

• Grassland.

In addition, the following vegetation types will also be created to correspond to types currently in use at the SENT landfill restoration:

• Tree Stands;

• Amenity Woodland; and

• Firebreak Woodland.

The design of planting will follow the vegetation structure and relative distribution typical of natural woodland and shrub, so that an entirely natural effect is created that is of maximum benefit to wildlife.

As shown in Figure 3.2, woodland planting is concentrated on the lower slopes of the landfill and on intermediate slopes that might be partially sheltered by existing Clear Water Bay Country Park landforms, including the valley/ gulley on the eastern side of the SENTX Site. This creates a band of woodland on the lower western slopes of the SENTX landfill connecting with that at SENT, together with a second band of woodland following the valley created on the eastern side of the SENTX site where it adjoins the Clear Water Bay Country Park. Planting on the lower slopes will assist in screening the road and industrial estate from the lower slopes as well as providing sheltered spaces for picnics and sitting out.

As required by EP Condition 2.6 (EP-308/2008/D and FEP-01/308/2008/D), restoration measures for the SENTX site include provision of 6 hectares of mixed woodland planting composting of about 20% non-native tree species to compensate the loss of shrubland. Furthermore, aftercare phase mitigation measure AM4 of the approved EIA stipulates that at least 18.8 ha of the area of the SENTX will be planted with woodland mix planting at no less than 1.2m spacings, consisting of 80% native tree species. Accordingly, in the area of SENTX lying within the CWBCP, there will be 3.8 ha of woodland, including compensatory planting of 16,850 nos. of trees (refer to Figure 3.1 for the location and area). In areas of SENTX lying outside of CWBCP, there will be 15.0 ha of woodland, including compensatory planting of 66,775 nos. of trees.

Elsewhere, at areas of higher elevation, areas of shrubland will be planted in fingers running up hillsides, as they would naturally occur. Shrubland is generally a pioneer habitat consisting of small trees and shrubs in a mosaic of grassland, taking advantage of sheltered locations or less exposed topography. In compliance with the approved EIA, there will be 2.56 ha of shrubland, consisting of 80% native species. The species list and size planting for shrubland is provided in Table 4.1 (Shrubland Mix A), while the number of plantings is provided in the table below.

Species	No. of plantings	Species	No. of plantings
Shrubland Mix A		Shrubland Mix B (Food Plants of Butterfly included)
Acacia mangium	1,766	Acacia auriculiformis	3,278
Syzygium buxifolium	1,412	Rhaphiolepis indica	2,622
Ixora chinensis	1,059	Lespedeza formosa	2,622
llex asprella	1,059	llex asprella	1,967
Phyllanthus emblica L.	1,766	Urena lobata	2,622
Lespedeza formosa	1,766	Vitex negundo L. var. cannabafolia	3,278
TOTAL:	8,828	TOTAL:	16,389

Grassland will be established at areas of highest exposure/ elevation where it would naturally occur in the environment. Grassland will be created by hydroseeding using a mixture of grass species suited to the site and its conditions which will therefore establish quickly. Further grass species are likely to colonise the site at a later date. Grass will be allowed to develop naturally and will be cut each year to ensure that it poses no unnecessary fire risk.

To align with the preferred use of native species for shrubland and woodlands, the hydroseeding grass seed mix ensures a composition of 80% native species. Seed mix (A), designated for use from April to August inclusive, requires a minimum application rate of 25 g/sq m. Seed mix (B), between September and March, contains 50% of native species. To ensure effectiveness across seasons, the seed mix incorporates exotic species for cooler months, as native species achieve optimal growth primarily in warmer conditions. In total the size of grassland planting will be 94,918.03 m². It is also important to consider the commercial availability of grass seedlings, even though native species are preferred.

Species	g/sq m	Species	g/sq m
Grassland Seed Mix A (Apr-Aug)		Grassland Seed Mix B (Sep-Mar)
Cynodon dactylon	18-20	Cynodon dactylon	15
Paspalum notatu	3-5	Paspalum notatu	10
Chloris gayana	0-4	Lolium perenne	5
Eragrostis curvula (2% maximum)	0-4
Cenchrus echinatus	0-4

Tree Stands - Occasional tree stands will be planted across the site. These will be groups of trees with no significant understorey, which are to be employed primarily for scenic effect and which will help to create a parkland feel to areas of the site. They will be primarily native trees planted at light standard size.

Amenity Woodland - Though the emphasis of the project is on the use of native species and the creation of a natural structure of woodland and shrub habitats, a certain number of semi-ornamental species have been added to the ornamental woodland mix adjacent to the access road. These add interest and variety to areas frequently seen by the public whilst still performing an adequate screening function along the road edge. The planting structure will still be loose and informal, and species will be selected to prefer native or adapted non-native species and no invasive species will be selected.

Belts of Firebreak Woodland will be planted to the southeast of the SENTX site, dividing the restored woodlands from the indigenous woodlands of Clear Water Bay Country Park.

Having outlined the principal types and patterns of vegetation for the SENTX site, the following sections of the Report detail the technical aspects of the ecological restoration works.

The technical proposals in this section have also been informed by the experience gained at the SENT landfill restoration, which has been recorded during monitoring of planting.

4.2 Selection of Planting Species

The approach to species selection and vegetation structure on the restored SENT landscape proceeds from the objective of establishing as close an approximation as possible to a native woodland and shrub habitat. This will create planting that will appear natural but which also promotes wildlife and nature conservation.

The concept of the planting mix recognises that, just as is the case in the wild, different communities of plants will naturally colonise different areas, depending on the soil, microclimatic and hydrological conditions. Planting mixes were therefore developed for different areas around the site, depending on the type of plant community appropriate to that location, degree of exposure, and on the function which planting is to serve. The following mixes were developed:

Woodland Mix A	(a pioneer species orientated mix for exposed slopes)
Woodland Mix B	(a native species orientated mix for sheltered slopes)
Woodland Mix C	(a semi-ornamental mix of species for areas most frequented by the public)
Firebreak woodland	(a mix of tree species more resistant to fire)
Shrub Mix A	(for edges of woodland and exposed areas)
Shrub Mix B	(for edges of woodland and sheltered areas)
Tree Stand	(for open areas readily visible to the public)

Mixes are laid out according to a predetermined matrix (Figures 4.1 to 4.6) which seeks to recreate the kind of woodland vegetation structure found naturally.

It is well established that woodlands composed of species native to a given location are of most value to wildlife and to the ecology of a given area. For this reason, the palette of plants used at SENTX will be drawn predominantly (80% of the total) from the range of species native to Hong Kong.

However, it was recognised that a wholly native woodland might naturally take many decades to develop, particularly on such an exposed site as that at SENTX. In order to ensure a successful and reasonably rapid establishment of woodland, 20% non-native species have been incorporated into the planting. These tend to be faster growing pioneer species which will provide a degree of shelter for the slower-growing natives. However, the use of competitive and dominant species such as Casuarina equisetifolia and Acacia confusa will be limited.

Planting mixes are also informed by the recommended species in the mitigation section of Chapter 9 of the approved EIA Report.

The trial nursery details and results are also considered when selecting the planting species (Summary Report of Findings of the SENTX Trial Nursery refer to Appendix E). From the Summary Report, one of the best exotic tree species in terms of survived rate, growth rate and health condition, was Acacia auriculiformis, which has been adopted as a pioneer tree in woodland mix. The second-best species were Acacia confusa and Dalbergia odorifera, where Acacia confusa is also adopted as a pioneer tree. For shrubland planting species, from the Summary Report, Acacia auriculiformis with good survival rate and health condition is adopted in the REEP as a shrubland mix pioneer species. Table 4.1 presents all the selected species for SENTX.

Table 4.1 proposed planting mixes for use at sentx

		Species	%		Species	%
	Woodland Mix A (Exposed)
Pioneer spp.	A1	Acacia confusa	20
Climax spp.	A2	Camellia crapnelliana	16
	A3	Sapium sebiferum	12
	A4	Rhaphiolepis indica	12
	A5	Phyhllanthus emblica L.	20
	A6	Celtis sinensis	20
		Total	100

	Woodland Mix B (Sheltered) (outside CWBCP)			Woodland Mix B (Sheltered) (within CWBCP)
Pioneer spp.	B1	Acacia auriculiformis	20	B1	Acacia auriculiformis	20
Climax spp.	B2	Machilus breviflora	16	B2	Machilus breviflora	16
	B3	Ficus subpisocarpa	16	B3	Cratoxylum cochinchinense	16
	B4	Litsea glutinosa	12	B4	Litsea glutinosa	12
	B5	Ficus microcarpa	16	B5	Schefflera heptaphylla	16
	B6	Syzygium levinei	20	B6	Syzygium levinei	20
		Total	100		Total	100

	Woodland Mix C (Amenity)			Woodland Mix D (Firebreak)
Pioneer spp.	C1	Acacia confusa	20	D1	Acacia confusa	20
Climax spp.	C2	Pongamia pinnata	20	D2	Ficus microcarpa	60
	C3	Rhodomyrtus tomentosa	12	D3	Schima superba	20
	C4	Ilex asprella	12
	C5	Phyllanthus emblica L.	16
	C6	Rhodoleia championii	20
		Total	100		Total	100

	Shrubland Mix A			Shrubland Mix B (Food Plants of Butterfly included)
Pioneer spp.	SA1	Acacia mangium	20	SB1	Acacia auriculiformis	20
Climax spp.	SA2	Syzygium buxifolium	16	SB2	Rhaphiolepis indica	16
	SA3	Ixora chinensis	12	SB3	Lespedeza formosa	16
	SA4	llex asprella	12	SB4	llex asprella	12
	SA5	Phyllanthus emblica L.	20	SB5	Urena lobata	16
	SA6	Lespedeza formosa	20	SB6	Vitex negundo L. var. cannabafolia	20
		Total	100		Total	100

4.3 Soils and Soil Ameliorants

The soil medium is only one of a number of layers of material that will be deposited as part of the landfill and restoration of the SENTX site (see Figure 4.7). However, providing a good soil medium is important to the establishment and growth of planting in the restored areas.

Prior to first phase landscape restoration at SENT, a number of soil medium, soil conditioner and soiling method trials were carried out and it was determined that the optimal soiling method was to pit plant seedlings into the final cover layer composed of screened CDG and C&D Fines, and backfill them with soil mix to meet the specification of the Civil Engineering & Development Department (CEDD) of the HKSAR Government’s General Specification for Engineering Works. The detail of the specification as follows (also see Figure 4.7):

CEDD GS Clause 3.30

(1) Soil-mix shall be ready and evenly mixed before delivery onto the Site.

(2) Soil-mix shall consist of friable, completely decomposed granite and soil conditioner in the proportions of 3:1 by volume. Soil-mix shall be free of grass or weed growth, sticky clay, salt, chemical contamination, and any other deleterious materials and stones exceeding 25 mm diameter in any direction, and shall possess the following properties: (a) PH value between 5.5 and 7.0; (b) Organic matter more than 10%; (c) Nitrogen content more than 0.2%; GS (2006 Edition) 3.10 (d) Extractable phosphorous (P) content more than 45 mg/kg; (e) Extractable potassium (K) content more than 240 mg/kg; (f) Extractable magnesium (Mg) content more than 80 mg/kg; (g) Soil texture content: Sand (0.05 - 2.0 mm): at the range of 20% - 75%; Silt (0.002 - 0.05 mm): at the range of 5% - 60%; Clay (less than 0.002 mm): at the range of 5% - 25%.

CEDD GS Clause 3.31(1)

Soil conditioner shall be organic material and shall be free of weed growth, impurities, foreign materials, contamination and substances injurious to plants. Soil conditioner shall have the following properties: (a)PH value between 5.0 and 7.5, (b) Moisture content measured in accordance with Clause 6.78(2) between 30% and 50%, (c) Fine and freely flowing consistency, (d) Stable composition, (e) Not capable of raising the temperature of the treated soil more than 50∘C above the temperature of the untreated soil, (f) Not giving off toxic nor obnoxious fumes, (g) Organic matter content not less than 85% (dry matter), and (h) Carbon: nitrogen ratio between 20 and 55.

CEDD GS Clause7.98(1)

Biodegradable mats for erosion control shall be woven coir mesh mats or woven jute mats. The mats shall have the material properties stated in the Contract. (2) The mats must be produced by proprietary manufacturers and specifically designed for the erosion control of sloping ground.

Topsoiling will involve depositing 1.5m of screen CDG as subsoil over the impermeable liner. CDG should be as described in Geoguide 3, Guide to Rock and Soil Descriptions 1988.

A Soil mix will be a free drainage material of sandy loam character, and should be evenly textured, fertile, and dark brown or black in colour. Soil mix will be free from pest, such as red imported fire ants. It should be delivered and backfilled on site which is tested for N/P/K value, organic matter content, pH value, physical content of sand, slit and clay, and water content, etc. The analysis should be carried out by a laboratory certified by the Independent Consultants and approved by the Employer’s Representative.

Soil conditioner should be properly composted organic material. Composed organic material should be stable and should not be liable to decompose further generating heat. Certificate of analysis stating composition and physical and chemical characteristics of the soil conditioner. The analysis should be carried by a laboratory by the Employer’s Representative.

A geotextile jute or coir matting will be laid together with the finished soil layer in order to ensure slope stability and prevention of erosion. This matting ensures erosion control and at the same time allows plants to grow through it. This will then decompose naturally and add to soil organic matter.

Seedling trees will then be pit planted into this medium with pits being a minimum of 300mmm x 300mm x 300mm. Slow release N:P:K fertiliser will also be added to the backfill.

Soil-mix will be used as a planting medium for compensatory planting in accordance with Section 3.30 of General Specification for Civil Engineering Works (2020 Edition). According to the Specifications, the soil-mix “consists of friable, completely decomposed granite and soil conditioner in the proportions of 3:1 by volume. It is free of grass or weed growth, sticky clay salt, chemical contamination, and any other deleterious material and stones exceeding 25 mm diameter in any direction, and shall possess the following properties:

a) PH value between 5.5 and 7.0;

b) Organic matter more than 10%;

c) Nitrogen content more than 0.2%

d) Extractable phosphorous (P) content more than 45 mg/kg;

e) Extractable potassium (K) content more than 240 mg/kg;

f) Soil texture content:

Sand (0.05 – 2.0mm)	at the range of 20%-75%;
Silt (0.002 – 0.05mm)	at the range of 5% - 60%;
Clay (less than 0.002 mm)	at the range of 5% - 25%.

4.4 Method of Planting

Seedling trees and shrubs will be pit planted as described above in the soiling section of the report at 1.5m centres (see approved EIA Landscape Mitigation Measure AM4). Once soil mix has been backfilled, it will be firmed up and a slight depression created around the seedling to help catch runoff water.

For native species, a 300 x 300mm piece of synthetic weed mat will be pinned using U-pins around the seeding in order to suppress weed growth and competition.

Finally, for native species, a plastic microclimatic growth tube (MGT) of approved design will be placed around native species seedling to provide protection from wind burn and desiccation. The MGT will be fixed in place by one or more metal rebar stakes driven into the ground to a depth of at least 150mm (see Figure 4.8).

5. Implementation program, maintenance and management

5.1 Implementation program

Construction works will commence in 2019, two years prior to commencement of waste filling. The SENTX site will be developed and operated under four phases, and each will last for about two years (Appendix B for drawings of construction phases).

Upon the completion of each phase, the areas that reached the final profile will begin restoration immediately. Therefore a tentative programme for restoration and ecological enhancement is as follows:

• Construction Commencement: 2019

• Completion of Phase 1-2 Filling: 2025

• Completion of Phase 1-2 Capping & Earthworks Restoration: 2025

• Completion of Phase 1-2 Ecological Enhancement: 2026

• Completion of Phase 3-4 Filling: 2025

• Completion of Phase 3-4 Capping & Earthworks Restoration: 2025

• Completion of Phase 3-4 Ecological Enhancement: 2026

• Completion of Phase 5 Filling: 2026

• Completion of Phase 5 Capping & Earthworks Restoration: 2027

• Completion of Phase 5 Ecological Enhancement: 2028

• Completion of Phase 6 Filling: 2026

• Completion of Phase 6 Capping & Earthworks Restoration: 2026

• Completion of Phase 6 Ecological Enhancement: 2027

• Completion of Phase 8 Filling: 2026

• Completion of Phase 8 Capping & Earthworks Restoration: 2026

• Completion of Phase 8 Ecological Enhancement: 2027

• Completion of Final Restoration and Park Admin Office and Visitor Facilities: TBA

In accordance with condition no.7 in Annex II of Lands Department approval memo dated 27 December 2018, and in order to prepare for the restoration works for the return of land back to CWBCP after completion of landfill works, a restoration proposal including surface treatment, landform, slope profile, planting proposal, etc. shall be submitted to the Country and Marine Parks Authority (CMPA) 12 months before completion of the works.

Upon completion of Restoration and Aftercare Phase of the Project, the Project Proponent shall make for site hand-over arrangements and fulfil the special conditions imposed in the approval/ consent given by Lands Department and CMPA in respect of the restoration/ reinstatement works within CWBCP.

5.2 Management and Maintenance

Designing the REEP for SENTX and implementing that design is not enough to ensure that a diverse, functional and visually pleasing landscape and environment will develop. Only through a long-term programme of restoration and ecological enhancement management can the actions of the various parties who may be involved in maintaining the site, be co-ordinated and directed so as to ensure that habitats and planting develop as intended and that the amenity of the site is preserved for recreational users. The implementation party of the maintenance and management works is GVL.

Ecological diversity cannot be optimised by leaving a site solely to nature. The problem with this approach is that in the short-term, certain species that are naturally dominant will tend to outcompete or suppress less vigorous species. Natural woodland and shrub habitats can take decades to develop their full range of ecological niches and natural diversity, through a process of succession, decay and regrowth. Simple management techniques can assist in this process and effectively help to diversify woodland and shrub habitats sooner than might be the case if left to develop naturally.

Management is also important in creating and maintaining a recreational facility that is useable and attractive to the public. The clearance of paths and maintenance of essential features such as drainage channels and maintenance paths are all part of the management process.

For keeping topsoil layer quality, maintenance works such as watering, weeding, fertilization and aeration, etc. should be undertaken regularly. Removal of invasive weed/ weed trees should be supplemented in the routine maintenance works. On the other hand, if the exotic tree plantings are casting excessive shade on other planting, crown thinning should be carried out to the exotic tree plantings. Each session of the crown thinning should not remove more than 25% of live foliage of each tree, with at least 3-month interval in-between each session. If any dead and/or unsatisfactory tree and/or shrub is found, replacement of tree and/or shrub (may not necessarily be the same species) should be taken.

Ultimately the maintenance degree on restored and ecological enhanced site will be diminished year by year until the end of the 30-year aftercare period. The Project Proponent shall also make mutual agreement with the future maintenance department(s) for long-term maintenance and management of the proposed plantings after the 30-year aftercare period prior to the conclusion of the aftercare period. Table 5.1 to Table 5.4 show the ecological and landscape maintenance work schedule.

Table 5.1 ecological & landscape maintenance works schedule (woodland and shrub planting areas)

Operation	Frequency of Operation (i.e. times per year)
Operation	Year 1	Year 2-5	Year 5-10	Year 10-30
Inspect planted areas and firm-up loose plants in all areas	12	4 (Years 2&3)	1	1
Inspect typhoon damage, firm up and remove damaged wood resulting	As required	As required	As required	As required
Remove invasive weeds and/ or plants from all planting areas	12	4 (Years 2&3) 2 (Years 4&5)	1	As required
Removal of invasive plant including Leucacena leucocephala from all planting areas	12	4 (Years 2&3) 2 (Years 4&5)	1	As required
Check, replace, reinstate MGTs and Weed Mat	12	12 (Year 3)	-	-
Remove litter	12	12	12	-
MGTs and Weed Mats	Install (Year 1)	Remove (Year 2)	-	-
Remove dead wood	As required	As required	-	-
Inspect plantings (incl. pests/ fungus and treat as necessary)	4	4	2	1
Thin plantation of non-native nurse species to favour native species	-	As required depending on success of native plant establishment	As required depending on success of native plant establishment	As required depending on success of native plant establishment
Cut back vegetation next to footpaths	-	1	1	2
Apply slow-release fertiliser	2 (March & June)	1 (March)	-	-
Watering planting areas	As required	As required	-	-
Grass cutting (with strimmer)	4	4	As required (depending on canopy closure)	-
Soil aeration	4	4	2	1
Crown thinning	As required	As required	-	-
Replacement of dead/ unsatisfied planting	As required	As required	-	-

Table 5.2 Ecological & Landscape Maintenance Works Schedule (Grassland Planting Areas)

Operations (per Year)	Frequency of Operation (i.e. times per year)
Operations (per Year)	Year 1	Year 2-5	Year 5-10	Year 10-30
Inspection hydroseeded areas	12	4	2	1
Remove litter	12	12	12	-
Inspection typhoon damage, make good erosion	As required	As required	As required	As required
Remove invasive weeds and/or plants from all hydroseeded areas	12	4	2	As required
Removal of invasive plant including Leucacena leucocephala from all planting areas	12	4 (Years 2&3) 2 (Years 4&5)	1	As required
Inspect for pests/ fungus and treat as necessary	4	4	2	1
Apply slow-release fertiliser	2 (March & June)	1 (March)	-	-
Watering	As required	As required	-	-
Grass cutting (with motorised mower)	1	1	1	1

Table 5.3 Ecological & Landscape Maintenance Works Schedule (Other Landscape Features)

Operations (per Year)	Frequency of Operation (i.e. times per year)
Operations (per Year)	Year 1	Year 2-5	Year 5-10	Year 10-30
Drainage
Clear drains of leaf litter and as required obstructions	As required	As required	As required	As required
Inspect and repair drains (as required)	4	4	4	4
Track and Access Roads
Inspect surfaces, etc. for damage	4	4	4	4
Repair damage	As required	As required	As required	As required
Spray out weeds	2	2	2	2
Pavilions and Site Furniture
Inspection for typhoon damage	As required	As required	As required	As required
Spray out weeds	4	4	4	4
Footpath
Inspect and make good (as required)	4	4	4	4
Spray out weeds	2	2	2	2
Landscape on Retained Slopes and Natural Slopes
Inspect and make good (as required)	4	4	4	4
Inspect for erosion after very heavy rainstorms	As required	As required	As required	As required

Table 5.4 Ecological & Landscape Maintenance Works Schedule (Monitoring)

Operations (per Year)	Frequency of Operation (i.e. times per year)
Operations (per Year)	Year 1	Year 2-5	Year 5-10	Year 10-30
Ecological monitoring	2	2	1	1
Monitor planting trials	2	2	1	1
Review Management Plan	1	1	1	As required
Soil monitoring	1	1	1	1
Fencing Around Trial Nursery Sub-Areas (Monitoring Blocks)	1 (install at Year 1)	-	1 (Remove at Year 5)	-
Check and make good fencing around Trial Nursery Sub-Areas (Monitoring Blocks)	4	4	-	-

[1] The feasibility of 20% non-native species will be confirmed in accordance with the result of the trial nursery referring to EP Condition 2.7. Noting that this ratio was not reachable in the current SENT Landfill.

[2] The feasibility of 20% of non-native species will be confirmed in accordance with the result of the trial nursery referring to EP Condition 2.7. Noting that this ratio was not reachable in the current SENT Landfill.

[3] There will be no additional encroachment of the CWBCP under the current scheme of SENTX. As required in EP Condition 2.6 (EP-308/2008/D and FEP-01/308/2008/D), restoration measures for the SENTX site include provision of 6 hectares of mixed woodland planting composting of about 20% non-native tree species to compensate the loss of shrubland and a mosaic of grassland and shrubland in the remaining areas of the SENTX site.

[4] The feasibility of 20% of non-native species will be confirmed in accordance with the result of the trial nursery referring to EP Condition 2.7. Noting that this ratio was not reachable in the current SENT Landfill.