Options
Scheme 1 (Sewerage Master Plan – SMP Option)
Scheme 2 (Recommended Option)
construction of two Pumping Station P1s (P1A and P1B) located east and west of the pedestrian bridge (each P1A and P1B comprises a pumping station, deodourizer, standby generator and control kiosk).
construction of rising main sewer (exposed) over existing bridge (approximately 20m in length).
construction of underground gravity sewers aligned existing footpaths and through the Sok Kwu Wan First Street and side streets to Pumping Station P2.
construction of Pumping Station P2 behind the football court at the base of the disused quarry (P2 comprises a pumping station, deodourizer, standby generator and control kiosk).
a rising main sewer (underground) aligned the seaward edge of the footpath to STW.
construction of STW located at the disused quarry alongside the coastal footpath; and
construction of a rising main sewer along the coastline to the submarine effluent outfall (approximately 710m in length).
Total length of gravity sewer is approximately 1,400m.
|
Approximate Dimension (m) |
Site Area |
||
|
Length |
Width |
Height* |
|
P1A |
|
202.5m2 |
||
Pumping Station |
11.85 |
4.0 |
300mm |
14.22m2 |
Deodourizer |
3 |
1 |
3 |
9m2 |
Standby Generator |
5 |
4.5 |
3.5 |
70m2 |
Control Kiosk |
2.6 |
1.5 |
1.5 |
5.85m2 |
P1B |
|
241 m2 |
||
Pumping Station |
11.85 |
4.0 |
300mm |
14.22m2 |
Deodourizer |
3 |
1 |
3 |
9m2 |
Standby Generator |
5 |
4.5 |
3.5 |
78.75m2 |
Control Kiosk |
2.6 |
1.5 |
1.5 |
5.85m2 |
P2 |
|
310 m2 |
||
Pumping Station |
11.85 |
4.0 |
300mm |
14.22m2 |
Deodourizer |
3.5 |
1.5 |
3.2 |
9m2 |
Standby Generator |
5 |
6 |
3.5 |
105m2 |
Control Kiosk |
2.6 |
1.5 |
1.5 |
5.85m2 |
STW |
Refer to Figure 10.13 for layout |
Refer to Figure 10.13 for layout |
7.0m max. |
1529 m2 |
Note: * Height above ground level
Construction Phase
(i) loss of vegetation (a separate tree survey has been compiled);
(ii) presence of construction machinery;
(iii) open trenches during installation;
(iv) construction of pumping stations and STW;
(v) slope stabilization works; and
(vi) construction traffic on site.
Operation Phase
Initial Comments
landscape impact assessment shall assess the source and magnitude of developmental effects on the existing landscape elements, character and quality in the context of the site and its environs and;
visual impact assessment shall assess the source and magnitude of development effects on the existing views, visual amenity, character and quality of the visually sensitive receivers within the context of the site and its environs.
Assessment Methodology for Landscape Impacts
1) Description of Landscape Baseline Conditions.
2) Assessment of the degree of sensitivity of the LCAs and LRs.
· Quality of landscape characters/resources,
· Importance and rarity of special landscape elements,
· Ability of the landscape to accommodate change,
· Significance of the change in local and regional context, and
· Maturity of the landscape.
The degree of receiver sensitivity is classified as low, medium or high.
3) Identification of potential sources of landscape impacts.
4) Assessment of potential magnitude of change.
· Compatibility of the Project with the surrounding landscape,
· Duration of impacts under construction and operation phases,
· Scale of development, and
· Reversibility of change.
The magnitude of change is classified as negligible, small, intermediate or large.
Magnitude of Change
Large |
Moderate Impact |
Moderate/ Significant Impact |
Significant Impact |
Intermediate |
Slight/Moderate Impact |
Moderate Impact |
Moderate/ Significant Impact |
Small |
Slight Impact |
Slight/Moderate Impact |
Moderate Impact |
Negligible |
Negligible |
Negligible |
Negligible |
|
Low |
Medium |
High |
Sensitivity of Receiver
5) Identification of potential landscape mitigation measures.
6) Summary of Landscape Impact Assessment
Assessment Methodology for Visual Impacts
1) Description of Visual Baseline Conditions.
2) Assessment of the degree of sensitivity f the VSRs.
· Value and quality of existing views,
· Availability and amenity alternative views,
· Type and estimated number of receiver population,
· Duration or frequency of view, and
· Degree of visibility.
The degree of receiver sensitivity is classified as low, medium or high.
3) Identification of potential sources of visual impacts.
4) Assessment of potential magnitude of change.
· Compatibility of the project with the surrounding landscape,
· Duration of impacts under construction and operation phases,
· Scale of development,
· Reversibility of change,
· Viewing distance, and
· Potential blockage of view.
The magnitude of change is classified as negligible, small, intermediate or large.
Magnitude of Change
Large |
Moderate Impact |
Moderate/ Significant Impact |
Significant Impact |
Intermediate |
Slight/Moderate Impact |
Moderate Impact |
Moderate/ Significant Impact |
Small |
Slight Impact |
Slight/Moderate Impact |
Moderate Impact |
Negligible |
Negligible |
Negligible |
Negligible |
|
Low |
Medium |
High |
Sensitivity of Receiver
5) Identification of potential visual mitigation measures.
6) Summary of Visual Impact Assessment
Site Location and Environs
Landscape Baseline Conditions
Sheltered Coastline Area (LCA1)
Sok Kwu Wan Restaurant/Retail Area (LCA2)
Exposed Coastline Area (LCA3)
Vegetation (LS1)
> Sheltered Coastline Area – LCA1 (Refer to Figure 10.4 Photo 1, 2, 3,4,5,6)
> Sok Kwu Wan Restaurant / Retail Area – LCA2 (Refer to Figure 10.4 Photo 7, 8, 9, 10, 11)
> Exposed Coastline Area – LCA3 (Refer to Figure 10.4 Photo15)
> Vegetation – LS1
Visual Envelope
Existing Visually Sensitive Receivers
Primary Low Rise Residential / Retail - VSR1 (Refer to Figure 10.4 Photo 8,9)
Secondary Low Rise Residential - VSR2 (Refer to Figure 10.4 Photo 1,4)
Restaurants alongside Coastal Footpath - VSR3 (Refer to Figure 10.4 Photo 7,8)
Pedestrian - VSR4
Boat Travelers - VSR5 (Refer to Figure 10.4 Photo 8,14)
Mo Tat Wan - VSR6 (Refer to Figure 10.4 Photo 16)
Lo So Shing (VSR7)
Sok Kwu Wan Population
|
Land Use Zonings |
P1A |
“Conservation Area” (“CA”) |
P1B |
“Residential (Group C)” (“R(C)”) |
P2 |
“Open Space” (“O”) |
STW |
“Conservation Area” (“CA”) |
One Sewerage Treatment Works (STW). Construction of the STW would include excavation, formwork, reinforcement and fixing, concreting, backfilling and slope stabilization.
Three Pumping stations; each with a 2.5m high site boundary wall. Construction of the pumping stations each with a deodourizer, standby generator, and control kiosk would include excavation, formwork, reinforcement and fixing, concreting, and backfilling.
Submarine Outfall. Marine works in the construction phase includes a steel working platform of size 15m wide by 25m long close to the shore for the horizontal directional drilling system. Dredging work will be at a location which is approximately 300m from the boundaries of the gazetted Fish Culture Zone. The length of the outfall is approximately 765m.
Sewer. The construction of the proposed sewerage works would include breaking up pavement, excavation of trench, installation of pipes and bedding, backfilling, and reinstating road surface. The total length of the sewer is approximately 1,400m.
Impact to Sheltered Coastal Area – LCA1
Impact to Sok Kwu Wan Retail / Restaurant Area – LCA2
Impact to Exposed Coastline Area – LCA3
Impact to Vegetation – LS1
Table 10.1 SUMMARY OF LANDSCAPE IMPACT ASSESSMENT IN CONSTRUCTION PHASE
IDEN-TITY NO. |
LANDSCAPE RECEIVER |
DESCRIPTION OF EXISTING LANDSCAPE CONDITION |
RECEIVER SEN-SITIVITY |
POTENTIAL SOURCE OF IMPACT |
MAGNITUDE OF CHANGE (Construction) |
LANDSCAPE IMPACT (Construction) BEFORE MITIGATION |
MITIGATION MEASURES |
RESIDUAL IMPACT (Construction) UPON MITIGATION |
LCA1 |
Sheltered Coastline Area |
A steeply sloped, vegetated valley with an alluvial plain at its base. Low-rise residential units (approximately 15 units) scatters in the higher area and some (approximately 10 units) are at the base of the valley. A concrete bridge connects the east and west side of the valley. |
Medium |
Disturbance of vegetation (approximately 445m2) from construction of P1A and P1B. Disturbance of footpath for the sewer. |
Small |
Slight/ Moderate adverse |
Short excavation sections and immediate back filling upon completion of sections. Protect existing trees and minimise damage to vegetation. |
Slight adverse |
LCA2 |
Sok Kwu Wan Retail / Restaurant Area |
The ferry pier and open-air seafood restaurants lining the waterfront First Street. Low-rise residential buildings lining the Second Street. A 150 years old Tin Hau Temple is located within the southern section of the area. A amenity/recreation area with ball courts, a children’s play area, and a disused quarry are located within the northern section of the area. |
Medium |
Construction activities in First Street; disturbance to footpath. Construction of P2 at the base of the disused quarry behind the football court. Disturbance of vegetation (approximately 310m2) |
Intermediate |
Moderate adverse |
As above.
|
Slight adverse |
LCA3 |
Exposed Coastline Area |
The coastline is in most part rocky and natural. A paved footpath is inbetween the vegetated cliff and the steep vegetated and rocky hillside. A refuse transfer collection facility is located at the coastline. |
Medium |
Disturbance to footpath and coastal vegetation. STW at the disused quarry; possible slope stabilization works. Construction of the outfall. Vegetation disturbance is approximately 1529m2. |
Intermediate |
Moderate adverse |
As above.
|
Slight/ Moderate adverse |
LS1 |
Vegetation |
3 broad classification of vegetation: Woodland (approximately 5.1ha); Shrubland/grassland (approximately 23.8 ha); Cultivation (approximately 1ha)
|
Low |
Disturbance of vegetation Woodland (insignificant, predicted 5 no. trees to be felled, 1 no. to be transplanted); Shrubland/grassland (approximately 2283m2, 1%); Cultivation 0% |
Small |
Slight adverse |
Protect existing trees and minimise damage to vegetation by close coordination and on-site adjusting alignment of pipeline. Compensatory planting to affected areas. |
Negligible |
Note: LCA – Landscape Character Area; LS – Landscape Resource
Table 10.2 SUMMARY OF LANDSCAPE IMPACT ASSESSMENT IN OPERATION PHASE
IDEN-TITY NO. |
LANDSCAPE RECEIVER |
DESCRIPTION OF EXISTING LANDSCAPE CONDITION |
RECEIVER SEN-SITIVITY |
POTENTIAL SOURCE OF IMPACT |
MAGNITUDE OF CHANGE (OPERATION) |
LANDSCAPE IMPACT (OPERATION) BEFORE MITIGATION |
MITIGATION MEASURES |
RESIDUAL IMPACT (OPERATION) UPON MITIGATION |
LCA1 |
Sheltered Coastline Area |
A steeply sloped, vegetated valley with an alluvial plain at its base. Low-rise residential units (approximately 15 units) scatters in the higher area and some (approximately 10 units) are at the base of the valley. A concrete bridge connects the east and west side of the valley. |
Medium |
Presence of P1A at west side of foot bridge and P1B at the east side (site area 202.5m2 for P1A and 241m2 for P1B; each with a 2.5m high fence wall). |
Small |
Slight/ Moderate adverse |
Architectural finishes to P1s. |
Negligible |
LCA2 |
Sok Kwu Wan Retail / Restaurant Area |
The ferry pier and open-air seafood restaurants lining the waterfront First Street. Low-rise residential buildings lining the Second Street. A 150 years old Tin Hau Temple is located within the southern section of the area. A amenity/recreation area with ball courts, a children’s play area, and a disused quarry are located within the northern section of the area. |
Medium |
Presence of P2 (site area 310m2) at the base of the disused quarry behind the football court. P2 has a 2.5m high fence wall. |
Small |
Slight/ Moderate adverse |
Architectural finishes to P2. |
Negligible |
LCA3 |
Exposed Coastline Area |
The coastline is in most part rocky and natural. A paved footpath is in between the vegetated cliff and the steep vegetated and rocky hillside. A refuse transfer collection facility is located at the coastline. |
Medium |
Presence of STW (site area 1529m2, maximum 7m above ground; refer to Figure 10.13 for STW layout.) at the disused quarry. Reformed slope behind STW. STW has a 2.5m high fence wall. |
Small |
Slight/ Moderate adverse |
Architectural and soft landscape finishes to STW. Planting to reformed slope. |
Slight adverse |
LS1 |
Vegetation |
3 broad classification of vegetation: Woodland (approximately 5.1ha); Shrubland/grassland (approximately 23.8 ha); Cultivation (approximately 1ha)
|
Low |
- |
Negligible |
Negligible |
None required. |
Negligible |
Note: LCA – Landscape Character Area; LS – Landscape Resource
Impact to Primary Low Rise Residential – VSR1
Impact to Secondary Low-Rise Residential – VSR2
Impacts to Restaurants along Coastline – VSR3
Impacts to Pedestrian – VSR4
Impacts to Boat Traveler - VSR5
Impacts to Mo Tat Wan – VSR6
Impacts to Lo So Shing – VSR7
Table 10.3 SUMMARY OF VISUAL IMPACT ASSESSMENT IN CONSTRUCTION PHASE
IDEN-TITY NO: |
VISUAL SENSITIVE RECEIVER |
DESCRIPTION OF EXISTING VIEW |
RECEIVER SENSI-TIVITY |
MIN. VIEWING DISTANCE (M) |
POTENTIAL SOURCE OF VISUAL IMPACT |
MAGNITUDE OF CHANGE (Construction) |
VISUAL IMPACT (Construction) BEFORE MITIGATION |
MITIGATION MEASURES |
RESIDUAL IMPACT (Construction) UPON MITIGATION |
VSR1 |
Primary Low Rise Residential/Retail |
Views are open towards Picnic Bay including the fish culture zones, Lamma Quarry, First Street and Second Street. The views to the south are the steep woodland hillside. |
Medium |
Adjacent |
Construction of sewer pipeline at First Street and side streets. |
Intermediate |
Moderate adverse |
Use of hoarding to screen construction activities and trenches. Short excavation and immediate backfilling of sections upon completion of works. |
Slight/Moderate adverse |
VSR2 |
Secondary Low Rise Residential |
Views are open to the surrounding hillsides and over Picnic Bay and Lamma Quarry.
|
Medium |
Adjacent |
Construction activities of P1A, P1B and sewer. |
Small
|
Slight/ Moderate adverse |
As above. |
Slight adverse |
VSR3 |
Restaurants alongside Coastal Footpath |
Views are open to Picnic Bay including the fish culture zones and towards Lamma Quarry.
|
Medium |
Adjacent |
Construction of sewer. |
Intermediate |
Moderate adverse |
As above. |
Slight/Moderate adverse |
VSR4 |
Pedestrain |
Pedestrians along the paved footpath will experience views of the surrounding vegetated hillsides, Picnic Bay including the fish culture zones, the Lamma Quarry, Hong Kong Island across the ocean. At some sections of the footpath, the views will be enclosed with vegetation on bothsides.
|
Medium |
Adjacent |
All associated construction activities. |
Intermediate |
Moderate adverse |
As above. |
Slight/Moderate adverse |
VSR5 |
Boat Travelers |
Views include the fish culture zones and waterfront restaurants in the foreground with vegetated hillsides and rocky coastline in the background.
|
Medium |
200m |
Construction activities of STW located at the base of the disused quarry and outfall, including sea-borne traffic. |
Intermediate |
Moderate adverse |
Minimise damage to vegetation at the coastal cliff of the STW site. |
Moderate adverse |
VSR6 |
Mo Tat Wan |
Views include the entrance to Picnic Bay, surrounding vegetated hillsides, Lamma Quarry, Hong Kong Island across the East Lamma Channel. |
Medium |
250m |
Sea-borne construction traffic and activities at outfall area. |
Intermediate |
Moderate adverse |
If night lighting is required for the marine fleets near Mo Tat Wan, the light source should be directed away from the residential units. |
Moderate adverse |
VSR7 |
Lo So Shing |
Views include surrounding vegetated hillsides, Picnic Bay including the fish culture zones and Lamma Quarry and the waterfront restaurants. |
Slight |
450m |
Sea-borne construction traffic |
Small |
Slight adverse |
None identified. |
Slight adverse |
VSR = Visually Sensitive Receiver
Table 10.4 SUMMARY OF VISUAL IMPACT ASSESSMENT IN OPERATION PHASE
IDEN-TITY NO: |
VISUAL SENSITIVE RECEIVER |
DESCRIPTION OF EXISTING VIEW |
RECEIVER SENSI-TIVITY |
MIN. VIEWING DIS- TANCE (M) |
POTENTIAL SOURCE OF VISUAL IMPACT |
MAGNITUDE OF CHANGE (Operation) |
VISUAL IMPACT (Operation) BEFORE MITIGATION |
MITIGATION MEASURES |
RESIDUAL IMPACT (Operation) UPON MITIGATION |
VSR1 |
Primary Low Rise Residential/Retail |
Views are open towards Picnic Bay including the fish culture zones, Lamma Quarry, First Street and Second Street. The views to the south are the steep woodland hillside. |
Medium |
Adjacent |
None. Pipeline is underground. |
Negligible |
Negligible |
None required. |
Negligible
|
VSR2 |
Secondary Low Rise Residential |
Views are open to the surrounding hillsides and over Picnic Bay and Lamma Quarry.
|
Medium |
Adjacent |
View of P1A at west side of footbridge and P1B at east of footbridge (P1A site area 202.5m2, P1B site area 241m2, each with a 2.5m high fence wall). Short portion of exposed pipeline across footbridge (approximately 20m). |
Small |
Slight/ Moderate adverse |
Architectural finishes to pumping stations. Appropriate paint finishes to exposed pipeline. |
Negligible |
VSR3 |
Restaurants alongside Coastal Footpath |
Views are open to Picnic Bay including the fish culture zones and towards Lamma Quarry.
|
Medium |
Adjacent |
None. Pipeline is underground. |
Negligible |
Negligible |
None required. |
Negligible |
VSR4 |
Pedestrian |
Pedestrians along the paved footpath will experience views of the surrounding vegetated hillsides, Picnic Bay including the fish culture zones, the Lamma Quarry, Hong Kong Island across the East Lamma Channel. At some sections of the footpath, the views will be enclosed with vegetation on coastal cliff.
|
Medium |
Adjacent |
Pumping stations and STW. Short portion of exposed pipeline across footbridge (approximately 20m). Reformed slope behind STW. |
Small |
Slight/ Moderate adverse |
Architectural and soft landscape finishes to pumping stations and STW. Appropriate paint finishes to exposed pipeline. Planting to reformed slope. |
Slight adverse |
VSR5 |
Boat Travelers |
Views include the fish culture zones and waterfront restaurants in the foreground with vegetated hillsides and rocky coastline in the background. |
Medium |
200m |
STW at disused quarry partially screened by existing vegetation at coastal cliff. Reformed slope behind STW. |
Small |
Slight/ Moderate adverse |
Architectural and soft landscape finishes to STW. Planting to reformed slope. |
Slight adverse |
VSR6 |
Mo Tat Wan |
Views include the entrance to Picnic Bay, surrounding vegetated hillsides, Lamma Quarry, Hong Kong Island across the East Lamma Island. |
Medium |
250m |
None (outfall is submarine) |
Negligible |
Negligible |
None required. |
Negligible |
VSR7 |
Lo So Shing |
Views include surrounding vegetated hillsides, Picnic Bay including the fish culture zones and Lamma Quarry and the waterfront restaurants. |
Medium |
450m |
None. |
Negligible |
Negligible |
None required. |
Negligible |
VSR = Visually Sensitive Receiver
Landscape Objectives
The guiding objectives for landscape design and mitigation treatment include the following:
to establish a coherent language within the overall landscape character and built elements.
to visually screen the built elements.
to establish low maintenance planting areas through species selection.
Mitigation Measures - Construction Phase
screening of site construction works by use of hoarding that is appropriate to its site context;
retaining existing trees and minimising damage to vegetation where possible by close co-ordination and on site alignment adjusted of rising main and gravity sewer pipelines. Tree protective measures should be implemented to ensure trees identified as to be retained are satisfactorily protected during the construction phase;
careful and efficient transplanting of affected trees (1 no.) to temporary or final transplant locations (the proposed tree to be transplanted is a semi-mature Macaranga tanarius and is located at the proposed pumping station P2 location);
short excavation and immediate backfilling of sections upon completion of works to reduce active site area;
conservation of top-soil for reuse; and
if night lighting is required for the marine fleets near Mo Tat Wan, the light source should be directed away from the residential units.
Mitigation Measures - Operational Phase
planting to reformed slope areas in-keeping with the surrounding landscape character.
appropriate finishes to reinstated areas of footpath in-keeping with existing finishes;
architectural finishes to proposed structures that are sympathetic to the surrounding landscape (refer to Figures 10.13, 10.14.1, 10.14.2);
soft landscape finishes to the proposed structures to reduce visual prominence; and
appropriate paint finishes to sections of exposed pipeline to reduce visual prominence.Summary of Mitigation Measrues
Table 10.5 Implementation Schedule of Mitigation Measures
Mitigation Measure |
Funding Agency |
Implementat-ion Agency |
Management Agency |
Maintenance Agency |
Construction Phase |
||||
Screening of site construction works by use of hoarding that is appropriate to its site context. |
DSD |
DSD’s Contractor |
DSD’s Consultant |
DSD’s Contractor |
Retaining existing trees and minimizing damage to vegetation where possible by close coordination and on site alignment adjusted of rising main and gravity sewer pipelines. Tree protective measures should be implemented to ensure trees identified as to be retained are satisfactorily protected. |
DSD |
DSD’s Contractor |
DSD’s Consultant |
DSD’s Contractor |
Careful and efficient transplanting of affected trees (1 no.) to temporary or final transplant location. |
DSD |
DSD’s Contractor |
DSD’s Consultant |
DSD’s Contractor |
Short excavation and immediate backfilling of sections upon completion of works to reduce active site area. |
DSD |
DSD’s Contractor |
DSD’s Consultant |
DSD’s Contractor |
Conservation of top-soil for reuse. |
DSD |
DSD’s Contractor |
DSD’s Consultant |
DSD’s Contractor |
If night lighting is required for the marine fleets near Mo Tat Wan, the light source should be directed away from residential units. |
DSD |
DSD’s Contractor |
DSD’s Consultant |
DSD’s Contractor |
Operation Phase |
||||
Planting to reformed slope areas in-keeping with the surrounding landscape character. |
DSD |
DSD’s Consultant & Contractor |
DSD |
DSD |
Appropriate finishes to reinstated areas of footpath in-keeping with existing finishes. |
DSD |
DSD’s Consultant & Contractor |
DSD |
DSD |
Architectural finishes to proposed structures that are sympathetic to the surrounding landscape. |
DSD |
DSD’s Consultant & Contractor |
DSD |
DSD |
Soft landscape finishes to the proposed structures to reduce visual prominence. |
DSD |
DSD’s Consultant & Contractor |
DSD |
DSD |
Appropriate paint finishes to sections of exposed pipeline to reduce visual prominence. |
DSD |
DSD’s Consultant & Contractor |
DSD |
DSD |
Photomontage