17. Visual amenity - DPTI · 2011-05-08 · 17. Visual amenity 17.1 Overview The visual impact assessment of the project examind the existing landscape character, potential e sensitivities

Duplication of the Southern Expressway | Project Impact Report

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17. Visual amenity 17.1 Overview

The visual impact assessment of the project examined the existing landscape character, potential sensitivities of adjacent land use and degree of likely visual modification.

It also reviewed the interrelationship of the existing landform, vegetation patterning, recreational activities, frequency of views, cultural values, environmental sensitivities, land use and key view corridors to determine the landscape character. The methodology applied considered the existing landscape character and the proposed new developments of visual modifications to that characteristic.

There is no universal approach to visual assessment; however, the methodology outlined below is consistent with best practice and DTEI’s approach on previous infrastructure corridor projects.

17.2 Visual amenity methodology

Linear infrastructure presents a unique development form as it typically traverses numerous landscape character areas and areas of sensitivity. A road corridor is typically assessed as a transient experience of visual effect both travelling along and from adjacent land use.

The visual catchment of the project was assessed by numerous site visits identifying areas that have views towards or along the road corridor, areas of cultural sensitivity and an interrelation of the road alignment, associated earthworks and existing landform. Key views have been identified along the corridor, representing the driver and adjacent land. An assessment has been made of the potential effect of the duplication from these varying visual experiences.

The visual amenity assessment was completed in a methodology in three stages (Figure 17.1).

17.2.1 Stage 1 – Desktop review

The desktop review of land use patterning, mapping and information gathering on areas of significance identified several areas of significance from the available literature. These areas have tangible and intangible qualities of historical, environmental or recreational importance for community groups and include:

Warriparinga O’Halloran Hill Recreation Park Glenthorne Field River Significant remnant vegetation adjacent to the Beach Road interchange.

17.2.2 Stage 2 – Site assessment, mapping and description of existing character

The existing landscape character was mapped and described during numerous site visits to form a baseline reference for determining the potential sensitivity of the landscape to visual change.


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A hand-held global positioning system (GPS) was used to certify the potential extent of visual change and reference the elevation of visual observation of points along the corridor and surrounding publicly accessible locations, with views of the road corridor.

The level of visual modification was predicted to provide a reference to the potential visual effect.

Following the site assessment, viewpoints were mapped and supported by a photographic survey to illustrate the landscape character.

Table 17.1 lists the classifications derived to predict likely sensitivity levels of adjacent land use areas according to distance, environmental impacts, existing built form and infrastructure, and frequency of views.

Table 17.1 Landscape sensitivity to visual change

Visual sensitivity levels Nearest visible project

element 50 metres Nearest visible project element 50–150 metres

Nearest visible project element > 150 metres

Cultural significance High High Moderate River corridors High High Moderate Residential High High Moderate Recreational High Moderate Moderate Rural agricultural lands Moderate Moderate Low Commercial Moderate Low Low Industrial Low Low Low

The degree of visual change was assessed against the level of contrast and potential integration of the development in the existing landscape. Assessment of the ability of the landscape to absorb the visual effects of the development from viewpoints along the corridor considered distance, vertical and horizontal scale of works, and removal or modification of vegetation and landform created by the duplication. The level of contrast and integration of the development determines the degree of visual change.

The visual amenity impacts of the development were then determined using the matrix in Table 17.2.

Table 17.2 Visual amenity impacts

Visual sensitivity High Moderate Low

Visu

al ch

ange

High High visual impact High/moderate visual impact

Moderate/low visual impact

Moderate High/moderate visual impact

Moderate visual impact Moderate/low visual impact

Low Moderate/low visual impact

Moderate/low visual impact

Low visual impact


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17.2.3 Stage 3 – Mitigation measures and potential treatments

Following a review of the potential visual amenity impacts of the project, a series of landscape and urban design strategies were suggested to either mitigate or reduce adverse impacts. These design considerations informed the concept development phase as opportunities and constraints.

Figure 17.1 Visual amenity assessment


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17.3 Landscape sensitivities and areas of significance

A review of relevant literature has identified areas of significance and high sensitivity to the community adjacent to the project area.

17.3.1 Warriparinga

Warriparinga, located in the precinct bounded by Sturt Road, Marion Road and Main South Road, Bedford Park, has particular significance to Aboriginal culture.

The site also has non-Aboriginal heritage as it was settled in the 1840s. A state heritage listed farmhouse (Fairford House) remains on site (Chapter 9 – Non-Aboriginal heritage).

In the late 1990s the site was redeveloped as a wetland designed to filter water from Sturt River before it reached Patawalonga River. It is planted with native vegetation and is now a natural landscape aesthetic in an urban context.

Sturt River is a considerable catchment and linear park with strategic plans to provide a recreational linkage from Belair National Park in the Adelaide Hills to Patawalonga and the Coast Park at Glenelg. This site marks a key destination point along this trail.

The sense of tranquillity in the parkland aesthetic is a unique quality in the surrounding urban context and one that has high sensitivity to change.

17.3.2 O’Halloran Hill Recreation Park

O'Halloran Hill Recreation Park, south of Darlington in the Hills Face area, has a series of recreation walking trails, horse trails, fire tracks, connecting communities to the south. The park also encompasses the Sturt Pistol Club and Southern Field Archers Club, and hosts a venue for model aircraft flying. Although the entire area was cleared and used for grazing for more than 90 years, shady trees throughout the park still provide pleasant picnic spots.

The park is characterised by steep north-western and north-eastern gullies. A bluestone quarry near Main South Road, used for many structures in the City of Adelaide, is still visible.

There is very little remnant vegetation as the park but it has been revegetated in the recent past through various active revegetation programs. Important stands of Grey Box trees can now be found throughout the park with the addition of native planting associations that are common throughout the Adelaide Hills.

The park is characterised by the natural vegetation planting and panoramic views over the Adelaide Plains. It forms a definitive edge to the urban form of the Adelaide Plains. The geological form of the Hills Face location has unique qualities. The Southern Expressway is located in the park’s eastern gully, which reduces the potential sensitivity and visual catchments; however the sensitivity to change would still be considered as moderate.

17.3.3 Glenthorne

Glenthorne is located to the eastern side of the existing Southern Expressway corridor, south of Majors Road and bounded by Main South Road on its eastern extent. It encompasses approximately 208 hectares of what is visually classified as heavily modified agricultural landscape.

http://en.wikipedia.org/wiki/Wetland

http://en.wikipedia.org/wiki/Patawalonga_River


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Glenthorne’s rich history includes numerous recorded tenants. It was originally settled in 1839 by Major Thomas O’Halloran, the first Police Commissioner of South Australia, who was subsequently immortalised in the names of the suburb of O’Halloran Hill and Majors Road. Table 17.3 outlines Glenthorne’s ownership history.

Table 17.3 History of Glenthorne

Year Owner Comments/land use 1839 Major Thomas O’Halloran Settlement 1878 Thomas Porter Renamed O’Halloran Estate to ‘Glenthorne’ 1913 Commonwealth Compulsory acquisition and used by Australian Army for training

troops and raising horses 1946 CSIRO Research station 1998 South Australian Government Unknown 2001 The University of Adelaide Subject to Land Management Agreement with State of South

Australia

The University of Adelaide’s options for the property include developing a vineyard on the site, not a viable option, and revegetating as open woodland.

The visual sensitivity of this landscape would be described as moderate to low.

17.3.4 Field River

Field River is located to the west of the existing Southern Expressway, south of Landers Road, adjacent to Panalatinga Road interchange. The catchment area includes Happy Valley Reservoir, Main South Road and the Southern Expressway, in a total area of 5,530 hectares. Suburbs bordering the river include Hallett Cove, Sheidow Park, Trott Park, Reynella, Happy Valley and Woodcroft.

A number of tributaries connect to Field River in proximity to the Southern Expressway including Panalatinga Creek and Grant Creek.

The river was named after Lieutenant WG Field who served under Colonel Light on his journey to South Australia in 1836 aboard the brig Rapid and discovered the river in 1837 while surveying the area.

In the 1840s copper was discovered at what was called the Worthing mine (on the south-eastern side of the Lonsdale Road) which promoted interest in using Field River as a means of transporting copper ore from the mine to the sea. By 1856 attempts at mining had ceased due to the lack of further investment money.

The fossil remains of the world's largest marsupial, Diprotodon, were discovered on the banks of Field River in 1972, outside of the project area. The fossil, which is at least 60,000 years old, is now in the care of the South Australian Museum.

A number of community groups, specifically Friends of the Lower Field River and schools, have rehabilitation projects underway for revegetation and other environmental studies of Field River.

The landscape amenity through the river corridor is described as incised with moderate topographic variance and meandering rocky, heavily modified escarpments. The river channel has been modified in


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some localities adjacent to the existing Southern Expressway but further west has retained its former alignment. The open space corridor is characterised by a sporadic tree copse of Eucalyptus species but is mainly infested with Olive and Ash trees.

The sensitivity of this area to visual modifications is considered high.

17.3.5 Significant remnant vegetation adjacent to Beach Road interchange

The land to the immediate west of the Southern Expressway corridor at Beach Road interchange contains threatened ecological community Grey Box (Eucalyptus microcarpa) Grassy Woodlands and Derived Native Grasslands of South-Eastern Australia, which is classified under the Environment Protection and Biodiversity Conservation Act 1999. The area contains 134 remnant individual trees and shrubs (Rural Solutions 2010).

The age and scale of these Grey Box trees provide a visual representation of the landscape vegetation associations in this area before European occupation. At the Beach Road interchange, the existing Southern Expressway traverses to the east in close proximity to the significant remnant vegetation.

This area is highly sensitive to visual change.


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17.4 Existing visual environment

17.4.1 Landscape characteristics

17.4.1.1 Urban area

Table 17.4 Urban landscape characteristics

Landscape character area

Extent Characteristics

Urban area Consists of the northern extent of the project corridor from Main South Road interchange at Darlington to Hills Face escarpment

Views contained in a narrow corridor with treatments such as noise walls and dense vegetation presenting a tunnelling effect

Adjacent land use predominantly residential towards the foothills with some commercial towards the Main South Road interchange at Darlington

Warriparinga (Aboriginal cultural site) and Sturt River crossing located in northern corner of Main South Road interchange at Darlington, providing open space of native vegetation and wetlands

Landscape vegetation treatments primarily sheoak and eucalypt woodland buffering the corridor and neighbouring land use

Figure 17.2 Southern Expressway bridge over

Sturt River from South Rd

Figure 17.3 South Road heading south


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17.4.1.2 Hills area

Table 17.5 Hills landscape characteristics



Hills area Located from transition of the foothills to open woodland and associated riparian corridors to the south

Steep gradient a diverse experience driving either south or north as the road corridor traverses to the east around and over the hills

Fragmented views of the city travelling north as the driver rounds the knoll of the hill

Visual character notably defined by cuttings into the hills face which expose the geological form of the escarpment; cuttings to the east and west in some sections with the steeper cut on the western side

Fragmented views of the escarpment and cutting along Main South Road and Flagstaff Hill Road

Existing Patrick Jonker Veloway aligned in the valley to the east; grade and horizontally separated from the Southern Expressway giving cyclists greater amenity

Vegetation limited to sparse shrub planting to the top of the escarpment and in the eastern valley; transitions to open woodland to the south

Figure 17.4 Hills rock cutting and transition of

hills area to urban context


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17.4.1.3 Riparian area

Table 17.6 Riparian landscape characteristics



Riparian area An area of high amenity; transitional area between open woodland south of the foothills and residential suburban character further south

Topographic variance with incised river corridors to the east and west of the Southern Expressway

Open pastoral landscape with sporadic tree vegetation in Glenthorne to the east of the road corridor with panoramic views south and Sellicks Hill and Willunga Hill escarpments

Flora and fauna habitat corridor to the west of the Southern Expressway connects O’Halloran Hill Recreation Park and Field River catchment with associated areas of habitat value

Existing informal trails network predominantly to the west of the Southern Expressway for pedestrian connectivity and amenity

Patrick Jonker Veloway to the east of the Southern Expressway predominantly parallel with continuous flow under local bridge structures at Majors Road and Panalatinga Road interchange

Panalatinga Road interchange a diversion of the Southern Expressway corridor following Field River with views specifically to the south along the incised valley and riparian landscape

Various pedestrian and cycling connections interwoven under the Southern Expressway for access and circulation

Vegetation coverage a mixture of exotic species, olives and ash trees, with native species (eucalypts, wattles, sheoak, native grasses and sedges)

Figure 17.5 Views of the Field River corridor

from the Young Street bridge


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17.4.1.4 Suburban area

Table 17.7 Suburban landscape characteristics



Suburban area Located just north of Sherriffs Road interchange and extending south towards Hackham Creek

Light industry located in the northern portion of this character area forming a contrasting defining edge

The Southern Expressway corridor cut into the landscape for most of this character area

Several overpass structures along this section of the Southern Expressway: O’Sullivan Beach Road, Flaxmill Road, Beach Road and Honeypot Road vehicular bridges; Sugarbush Road, Glenhelen Road, Poznan Crescent and Peppermint Grove pedestrian bridges – form dominant elements and way finding devices along the road corridor

To the south-western corner of the Beach Road interchange an area of significant remnant vegetation (specifically Grey Box) with high amenity value and a vegetation buffer to the neighbouring commercial and residential precinct along Beach Road.

Informal pedestrian access tracks (unsealed paths) predominantly along the western side of the Southern Expressway, developed from desire lines making various connections and amenity to the residential areas

Vegetation along the road corridor in the character area predominantly revegetation to the batters of the Southern Expressway consisting of but not limited to cypress, boobialla and sheoak

Figure 17.6 Open space corridors to the west

vary with open grassland and dense vegetation buffers


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17.4.1.5 Southern Vales

Table 17.8 Southern Vales landscape characteristics



Southern Vales Located from the edge of the suburban subdivision development, encompassing Hackham Creek and Main South Road interchange at Old Noarlunga

Open panoramic views to the south with rural pastoral landscape framed in the view

Elevated views above the new subdivision developments a visual transition for driver and surrounding land use

Main South Road forms a dominant visual element presenting a strong contrast in form and pattern to the surrounding topography

Vegetation patterning formalised at Main South Road interchange and the Southern Expressway with linear bands of cypress presenting a bold planting statement in dryland grass; patterning primarily viewed when travelling south at more elevated viewpoints; northbound experience at a lower elevation

Views from surrounding residential developments and open space, typically elevated locations to the north of the intersection with panoramic views towards the interchange; views present a complexity of elements with the road corridors, Main South Road and the Southern Expressway providing dominant forms in underlying character and form of Hackham Creek riparian and rural qualities further south

Figure 17.7 Views to the south of Main South

Road interchange at Old Noarlunga characterise the Southern Vales


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17.4.2 Bridge structures

17.4.2.1 Characteristics

Existing vehicular bridge structures are typically steel structural beams with concrete crash barriers. Abutments are typically vertical interlocked keystone retained soil systems (RSS) walls. There are exceptions to this typical form of construction:

the Southern Expressway bridge over Lander Road is a concrete arch structure the bridges at Young Street, Grant Creek, Sherriffs Road and Christie Creek are constructed of

Super-T concrete beams with concrete crash barriers supported by in-situ concrete columns and headstocks. Abutments are vertical interlocked keystone RSS walls; landscaped batters have been used for both Grant Creek and Christie Creek bridges.

The pedestrian bridges along the Southern Expressway are all steel beam construction with concrete deck. The bridges are encased with a wire mesh cage, circular in cross section.

Figure 17.8 Typical local road bridge (over)

Figure 17.9 Typical pedestrian bridge

17.4.3 Noise mitigation treatments


Concrete sleeper with textured brick patterning walls are located along various sections of the Southern Expressway between Marion Road and Panalatinga Road interchange. Other treatments used are pre-cast concrete painted in charcoal or dark green.

Earth mounds are the alternative treatment and are used where space is available. These areas have been revegetated with upper, middle and lower storey plantings.

Figure 17.10 Existing noise abatement treatments with vegetated mounding and precast walls


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17.4.4 Retaining walls


Concrete block keystone walls are present towards the southern sections of the Southern Expressway predominantly to the eastern side of the corridor between O’Sullivan Beach Road and Honeypot Road.

Timber framed crib walls are located between Marion Road and Panalatinga Road interchange.

Figure 17.11 Keystone concrete block wall

Figure 17.12 Timber framed crib wall

17.4.5 Bikeways and pedestrian recreation trails


The Patrick Jonker Veloway extends from Marion to Reynella, where it connects to the Coast to Vines Trail. The veloway is a bicycle-only formalised access path. The Patrick Jonker Bikeway extends further south for the extent of the Southern Expressway to Main South Road interchange at Old Noarlunga. The existing veloway and bikeway are in good condition and provide amenity and connections predominantly on the eastern side of the Southern Expressway.

Various unsealed recreation trails exist along the western side of the corridor; some are more formalised with provision for vehicle fire emergency access near O'Halloran Hill, Majors Road.

Figure 17.13 Veloway in revegetation

Figure 17.14 Unsealed pedestrian recreation path


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17.5 Effects of the project on the existing environment and mitigation strategies

17.5.1 Visual modification classifications

In each area the likely visual modifications have been classified:

High: The development will potentially cause a noticeable adverse change to the existing character value of the landscape. Mitigation techniques such as dense buffer planting and consideration of reducing visual mass of structural forms will be critical to reduce the contrast and increase integration to adjacent landscape characteristics.

High/Moderate: The development is moderately integrated with the adjacent landscape but does contrast in shape and form. The sensitivity of the adjacent land use increases the potential for adverse visual effects. Mitigation techniques such as graded batters to reduce angular earthwork profiles and revegetation will reduce the visibility and improve integration.

Moderate: The development causes a noticeable visual change but the scale and form are only a slight modification. The development will typically be viewed as a low lying depression or linear line in the landscape with associated small to moderate batters. Structural forms are integrated to adjacent land form and in vegetation corridors. Mitigation techniques such as revegetation with appropriate species will help visual integration.

Moderate/Low: The development is seen in the context of the landscape and is integrated to the existing landform and vegetation. The duplication is seen as a proportional increase to the existing expressway corridor. Minimal mitigation treatments will be required to limit any adverse effects with sufficient integration.

Low: The development does not alter the appearance of the existing landscape character. The scale and form slightly increase the existing expressway but are insufficient to present an adverse effect on the perceived character and neighbouring land use amenity. No mitigation measures are required.

17.5.2 Visual effects of landscape character and structural elements

During the site assessment of the existing landscape, the current design was reviewed and the potential visual amenity described. Tables 17.9 to 17.13 describe the classifications of visual change along the corridor and from key viewpoints in landscape areas. Table 17.14 describes the visual effects of structural elements.


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Table 17.9 Visual effects on landscape character and mitigation strategies – Urban area

Urban area Amenity value and key views

To the north and east of the duplication the level of sensitivity to change is high, specifically from Warriparinga and neighbouring residential properties.

Key areas of existing landscape amenity are Warriparinga and Sturt River. Key views are from within Warriparinga, which presents a natural open space

divorced from the surrounding urban context. The other major view corridor is from South Road, heading towards Sturt River.

Appropriate revegetation to the north and west of the duplication will provide a visual buffer and integrate the development.

Provision of pathways and connections to the west of the duplication will enable the current movement of pedestrians to be retained, providing amenity value.

Patrick Jonker Veloway to be retained. Potential visual effects

For the duplication to the northern and western side of the existing carriageway, the visual effects are likely to have a high to moderate effect. On the southern and eastern side the effects will be moderate to low.

Mitigation strategies

Grade batters and feather planting to reduce contrast of elevated landform when viewed within Warriparinga

Open span bridge structures over Sturt River to permit views and access along river Incorporate sympathetic plantings and pedestrian linkages to the western side of

duplication for neighbouring residents

Table 17.10 Visual effects on landscape character and mitigation strategies – Hills area

Hills area Amenity value and key views

From residential areas west of the duplication, the degree of sensitivity to change is high. Further to the south the degree of sensitivity decreases to low.

Key views are from the existing Southern Expressway escarpment heading north, with panoramic views of the city.

Views from the east on Flagstaff Road and adjacent residential properties look across the hills towards the project site.

Views across the open space agricultural land of Glenthorne and revegetated O’Halloran Hill provide visual amenity as a transition from the urban residential form.

Potential visual effects

The duplication will present a high visual effect to the adjacent residential areas due to their close proximity. Visual effects from other areas in the character area are described as moderate to low.


Incorporate sympathetic plantings and pedestrian linkages to the western side of duplication for neighbouring residents

Revegetate earthwork batters with appropriate scaled planting to the eastern side of the duplication adjacent to the escarpment

Realign the Patrick Jonker Veloway where required with planted batters to provide integration with landscape treatments

Use feather plantings along corridor with copse of trees to reduce the linear visual effect of the corridor


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Table 17.11 Visual effects on landscape character and mitigation strategies – Riparian area

Riparian area Amenity value and key views

The level of sensitivity to change is high to the western side of the corridor associated with Field River.

The Field River corridor provides an environmental and aesthetic area of cultural significance.

Pedestrian and cyclist amenity will improve with improved connections. There are opportunities for enhancement of the river corridor in areas affected by

works, with revegetation of appropriate native species and removal of weeds. Key views are from the expressway to the west, at various river and creek crossings,

specifically the Field River corridor, Grant Creek, Christie Creek and Hackham Creek.

Views from adjacent elevated residential areas at Panalatinga to the west will see an alteration to the existing landscape. The scale and form of the development will contrast with the natural aesthetic of the river corridor. Landscape treatments proposed will evolve and mature over time integrating the structural elements of the expressway.


The duplication will present a high to moderate visual effect at the Panalatinga Road interchange. The scale and form of the development will provide visual change but the treatment of landscape works will bring integration and contextual treatments to the locality. In other riparian areas the degree of change to visual amenity will be low to moderate with enhanced habitat and recreation corridors proposed as part of the works.


Grade batters to integrate with existing land forms and revegetate with open woodland planting

Integrate structural elements with planting of appropriate scale to reduce the visual presence of structural elements from residential areas and recreation trails

Table 17.12 Visual effects on landscape character and mitigation strategies – Suburban area

Suburban area Amenity value and key views

The level of sensitivity to change is moderate to low with some localised areas of moderate to high where the duplication is in close proximity to residential areas.

The expressway duplication for most of the suburban area will be lower-lying than the adjacent residential or industrial land use, thus reducing its visual presence.

The key area of amenity at Beach Road with a group of significant trees (Grey Box) will be retained.

Local vehicular road bridges will be widened or lengthened to provide connections. Bridges will be integrated to local context with appropriate way-finding devices.

New pedestrian bridges will connect and enhance way finding along corridor. Unsealed pedestrian access tracks will be provided on the western side of the

corridor. The bicycle and pedestrian shared path to the west will be retained.


The duplication will present a moderate visual effect in the suburban character area. The scale and form of the development will provide visual change but the treatment of landscape works will integrate and contextualise treatments to the locality.


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Suburban area Mitigation strategies

Buffer revegetation planting to screen industrial areas Grade batters to integrate with existing land forms and revegetate with appropriate

species Integrate pedestrian unsealed path network on the western side of the duplication to

provide access along and across the corridor via proposed pedestrian bridges and local vehicular bridges

Integrate structural elements with revegetation to reduce the visual mass and presence of the corridor specifically adjacent to residential areas

Table 17.13 Visual effects on landscape character areas and mitigation strategies – Southern Vales area

Southern Vales Area Amenity value and key views

The level of sensitivity to change is moderate to low with some localised areas of moderate to high where the duplication is in close proximity to residential areas.

Key views of the character area are from elevated open spaces in residential subdivisions and from the expressway towards Clarendon Hill.

Revegetated batters will enhance the amenity of the interchange with Main South Road while providing a visual buffer from neighbouring residential properties.


The duplication will present a moderate to low visual effect in the southern vales character area. The scale and form of the development will provide visual change but the treatment of landscape works will integrate and contextualise treatments to the locality.


Grade batters to blend into existing landform Appropriate planting to the western side of the duplication to minimise the scale of

the interchange with Main South Road and screen from neighbouring residential properties

Install a light well (sky light) for pedestrian culvert in central median of expressway at interchange with Main South Road, to enable natural light and ventilation

Table 17.14 Visual effects of structural elements

Vehicular bridges

Bridges proposed to be widened will have limited visual effect. The span of piers will be consistent with existing bridges. Pier designs are to be consistent with existing to provide visual continuity of materials and form.

Local road bridges to be lengthened will be separated by a median (8.5 metres) of landscape treatments which will mitigate the slight contrast in materials and aesthetic proposed. Concrete Super ‘T’ and RSS walls with rebates are proposed to break up the scale of the abutments.

Materials will be concrete and steel with simple colour tones, pattern and form to integrate the structural elements with the adjacent landscape treatments.

Pedestrian bridges

New concrete Super ‘T’ bridges are proposed with a central pier. The pedestrian bridges can be used for way finding and subtle contextual referencing to the locality with the form of throw screens. The pedestrian bridges will enhance the amenity.


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Noise walls/mounds

Several concepts have been developed based on existing landscape character areas. These treatments reference the local context.

Earth mounds and landscape planting treatments will be used where possible to reduce built form structures in the open space corridors adjacent the duplication.

Simplicity of form, colour and patterning will reduce the scale and mass of structural elements and visually integrate with landscape treatments.

17.6 Conclusion

The project will have a visual effect on the amenity of the existing landscape. The effects will primarily be experienced by those who live or work in the area as they will be more sensitive to change.

The various landscape character areas along the corridor will have different impacts depending on the existing landform, land use and vegetation patterning. The level of contrast and integration will be determined by the height and width of the duplication, new structural forms and their relationship to existing landform and vegetation.

The assessment included a detailed review of the sensitivities and likely visual changes as a result of the project. As landscape treatments mature, the visual modification of the development will decrease as the level of integration increases.

Opportunities for enhancing and accentuating landscape character areas will be explored in the concept development and detailing, and realised during and after construction.

Documents

17. Visual amenity - DPTI · 2011-05-08 · 17. Visual amenity 17.1 Overview The visual impact assessment of the project examind the existing landscape character, potential e sensitivities