The Greater Sydney Green Grid is a long-term vision for a network of high quality green spaces that connects communities to the natural landscape. It links tree-lined streets, waterways, bushland corridors, parks and open spaces to town centres, public transport and public spaces. The Greater Sydney Green Grid builds on the District's established open space, the Regional Tracks and Trails Framework and the Principal Bicycle Network.
Tree-lined streets, urban bushland and tree cover on private land form a component of the urban tree canopy. The urban tree canopy is a form of green infrastructure that mitigates the urban heat island effect, with a 10 per cent increase in tree canopy cover reducing the land surface temperature by 1.13 degrees Celsius26. The urban tree canopy also supports cleaner air and water, and provides local habitat. Trees remove fine particles from the air and help insulate against urban noise pollution, particularly important along busy roads. The urban tree canopy can also help make communities more resilient by reducing the impact of heat waves and extreme heat.
The urban tree canopy
The urban areas of the North District have 47 per cent tree canopy cover, with some areas in Hornsby, Ku-ring-gai and the Northern Beaches providing more than 50 per cent tree canopy cover27. Sustaining boulevards of trees along the District's busiest roads (such as Epping Road, Pacific Highway, Victoria Avenue, Albert Avenue, Archer Street, Pittwater Road and Warringah Road) is an important step towards improving amenity and air quality, and cooling the North District. The NSW Government has set a target to increase tree canopy cover across Greater Sydney to 40 per cent. Figure 25 shows tree canopy cover in the Urban Area in 2011.
Along many busy roads, where there is limited space to plant new trees, there may be opportunities to plant other forms of green groundcover, such as garden beds and hedges that can help improve the air quality.
Trees are valued by residents and contribute to the streetscape, character and amenity of the District. As the District continues to grow and change, the urban tree canopy will come under pressure. This means that expanding the urban tree canopy in public places will become even more important for sustainable and liveable neighbourhoods.
The tree canopy may be formed by a mix of native and exotic, deciduous or evergreen trees, which provide shade in summer while allowing sunlight into homes and onto roofs for solar power, particularly in winter.
Therefore, urban renewal and transformation projects will be critical to increasing urban tree canopy cover. This can be complemented by other green cover, including rain gardens, green roofs and green walls. Green cover can help slow and store stormwater and improve water quality, filtering pollution before it reaches the District's waterways.
Challenges to extending the urban tree canopy in public and private areas include the lack of sufficient space within existing street corridors and the competition with other forms of infrastructure both above and below the ground. Opportunities to relocate power lines underground or bundle them may be explored at a local or precinct scale, particularly in areas experiencing urban renewal, to provide space for the urban tree canopy and enhance the public domain. Extending the urban tree canopy should be balanced with the need to allow sunlight into homes and onto roofs for solar power.
The District's councils generally provide guidance on enhancing tree canopy and tree cover in the urban environment, and information on street trees. Some encourage permeable surfaces to allow rainwater to soak into the ground and reduce stormwater run-off, which supports the growth of canopy trees and vegetation, and reduces pollution, flooding and urban heat.
Where trees are lost as a result of development, some councils have developed programs to plant replacement trees in the public realm.
The NSW Department of Planning and Environment's Apartment Design Guide and the new Greenfield Housing Code guide the requirements for landscape areas that can support the urban tree canopy. The NSW Department of Planning and Environment is preparing an urban tree canopy manual, as part of a green infrastructure policy framework, to support the expansion of the urban tree canopy.
Connecting the Greater Sydney Green Grid
Enhancing the amenity and activity within, and accessibility to, the Greater Sydney Green Grid will promote a healthier urban environment, improve community access to places for recreation and exercise, encourage social interaction, support walking and cycling connections and improve resilience.
The long-term vision for the Greater Sydney Green Grid in the North District is shown on Figure 21.
This vision will be delivered incrementally over decades, as opportunities arise and detailed plans for connections are refined. Green Grid Priority Projects have been selected to provide district-scale connections that link open space, waterways and bushland. Table 5 lists Green Grid Projects for the District.
Councils will lead the delivery of the Greater Sydney Green Grid through land use planning and infrastructure investment mechanisms such as development and land use controls, agreements for dual use of open space and recreational facilities, direct investment in open space, and other funding mechanisms such as local development contributions and voluntary planning agreements.
State, regional and district parklands and reserves form a principal element of the Greater Sydney Green Grid for both biodiversity and recreational purposes.
The NSW Government supports the delivery of regional open space and Green Grid connection through the Metropolitan Greenspace Program.
The NSW Government also supports delivery of regional open space using special infrastructure contributions.
Transport for NSW is establishing a Principal Bicycle Network in collaboration with councils. Opportunities to integrate the Principal Bicycle Network with the Greater Sydney Green Grid will be an important part of linking centres.
In some areas, rail lines and other linear infrastructure prevent Green Grid connections. Where feasible, planning and investment must consider opportunities for connections across rail lines, roads and other linear infrastructure.
Table 5: North District Green Grid projects
|1||Lane Cove National Park and Lane Cove River
enhanced open spaces along the Lane Cove River foreshores to create unique recreational experiences, linking the Lane Cove National Park to Macquarie Park, Macquarie University, Chatswood and Epping. Funding has been granted towards flood mitigation of a heavily used crossing point of the Lane Cove River, linking Ku-ring-gai and Ryde local government areas, and connecting to the Great North Walk. The project will create design options to improve track accessibility under wet conditions along the Browns Waterhole Track, North Epping and South Turramurra.
|2||Eastwood to Macquarie Park Open Space Corridors
will be extended and enhanced, including Shrimptons Creek, Terrys Creek and the Booth Road-North Road-Welby Street Green Link. A $450,000 grant to the City of Ryde will upgrade ELS Hall Park, a popular park to link two major recreational corridors (Shrimptons Creek and County Road shared pathways). This will involve new tree planting, wayfinding signage, picnic shelters and enhancements to the dog off-leash area.
|Projects important to the District|
|3||Northern Beaches Coastal Lagoons
combining three related projects at Curl Curl Lagoon and Greendale Creek, Dee Why Lagoon and Wheeler Creek, and Warriewood Wetlands and Narrabeen Creek that support the recreational needs of the surrounding communities and wider District, and protect Narrabeen, Curl Curl and Dee Why lagoons as a recreation asset and wildlife sanctuary.
|4||Coastal Walk and Cycleway from Barrenjoey Head to Manly
continuing to support the completion of the Coastal Walk, reviewing current foreshore access, developing staging strategies for the completion of any missing links or sections of lower quality, and improving pedestrian and cycle access from surrounding suburbs, and sustainable transport connections from areas further west.
|5||Great North Walk
upgrading Berowra Valley sections of the 250-kilometre Great North Walk from Newcastle to Lane Cove (National Parks and Wildlife Service) and potentially including links from train stations and centres to the Great North Walk, particularly the link from Hornsby to Berowra Valley through Hornsby Quarry.
|6||Parramatta River and Sydney Harbour Foreshore
improving foreshore access by completing missing links along the northern Parramatta River foreshore, and continuing to support the delivery of Sydney Harbour Federation Trust projects, including the proposal to transform the HMAS Platypus site in Neutral Bay into a public park with buildings adapted for a range of new uses.
|7||Garigal National Park - Oxford Falls and Deep Creek
improving links to the new Northern Beaches Hospital precinct, improving walking and cycling links to Narrabeen Lagoon and protecting the Garigal National Park from the impacts of nearby development.
|8||Pittwater Road Corridor
establishing street trees along the corridor, exploring options for new development setbacks to incrementally widen the corridor to improve the environment for walking and cycling, linking the corridor to surrounding bushland patches in Ingleside and initially focusing on the areas between Queenscliff to Brookvale, Dee Why to Collaroy and North Narrabeen to Mona Vale.
Figure 21: North District Green Grid opportunities
Source: Greater Sydney Commission, 2017, adapted from Sydney Green Grid, published report prepared by Tyrrell Studio and Office of the Government Architect for the Greater Sydney Commission. Source: Greater Sydney Commission, 2017, adapted from Sydney Green Grid, report prepared by Tyrrell Studio and Office of the Government Architect for the Greater Sydney Commission.