Managing tree and vegetation impacts

All level crossing removal options unfortunately have an impact on trees and vegetation adjacent to rail lines. As we progress with the construction of the Blackburn Road Level Crossing Removal Project, however, our aim is to minimise the impact on trees and vegetation where possible.

Assessing trees and vegetation

Trees and vegetation within, and adjacent to, the rail corridor are assessed on site by independent arborists to determine:

• structural strength, including the size and location of tree roots
• health and life expectancy
• location of construction works and services in proximity.

Extensive investigations have been carried out by independent arborists, to determine the impacts construction works will have on trees. Arborist assessments were completed in late 2015 and 2016, to determine the impact the final works would have on the future health and stability of nearby trees.

An independent arborist is also on site during the construction works to provide further advice in relation to the impact the works have on tree branches and roots.

Commitment to vegetation management

Trees, vegetation and green space are important to local communities and support biodiversity along the rail corridor. Minimising the impact of tree and vegetation removal is considered as part of both project design and construction.

Parts of the rail corridor are very narrow and the construction works results in unavoidable tree impacts. Every effort, however, will be made to protect existing vegetation throughout construction where possible.

Construction impacts

In Blackburn the Belgrave–Lilydale rail line is being lowered up to nine metres underneath Blackburn Road. Major excavation work for the railway line cutting will be carried out in late December 2016 to January 2017. Before this work can occur structural foundations along both sides of the corridor need to be constructed. Around 1200 piles will be installed along the railway corridor using large piling rigs.

Due to the narrow rail corridor the piling rigs will be positioned close to neighbouring fence lines and trees. To get access for machinery down the rail corridor we need to trim nearby trees and remove others.

A 5m wide access track and vertical clearance is required for this. Works within the rail corridor can affect root systems and impact on tree stability and health, which may cause them to pose a safety risk to the public and to people using the railway line. Trees assessed as posing a safety risk may need to be trimmed or removed.

This includes trees located within private properties along Glen Ebor Avenue, Cromwell Court and Oliver Avenue and the line of introduced Cypress Trees at Morton Park which back right onto the rail corridor. At South Parade tree trimming and removal has been carried out to install a new drainage system which will protect the area from flooding, including in the Blackburn underpass.

Clearing trees and vegetation

Once confirmed for removal, trees are identified and marked on  construction plans. To ensure impacts are fully considered and that all relevant approvals are in place, we consult with the project team, the community and stakeholders and the City of Whitehorse.

Trees are mulched on site to allow for the easy and safe removal of mulch from within the rail corridor, and re-use in landscaping.

Replanting trees

The Blackburn Road Level Crossing Removal Project has a strategy to mitigate tree removal by landscaping and replanting. We are finalising these plans with the City of Whitehorse.

Replanted vegetation adjacent to rail lines must meet strict safety requirements to avoid becoming a future safety risk to the operation and maintenance of the rail line and the community.

Current plans allow for the planting of more than 17,000 plants and shrubs and approximately 230 trees of varying heights and species. New plantings will be mostly native with some exotic species used in appropriate locations. Trees and vegetation will provide screening benefits to residents abutting the rail corridor and provide visual amenity to the wider community.

Where trees are impacted in private properties we are working with land owners to provide replacement planting.