• Design to retain natural features with high biodiversity value – mature native trees
  • Design to protect sensitive natural areas and avoid biodiversity connectivity barriers
  • Design to enhance natural processes – implementing Water Sensitive Urban Design (WSUD)

Design to retain natural features with high biodiversity value – mature native trees

Urbanisation has led to a dramatic decline of mature aged native trees in Canberra, mainly hollow-bearing ones. They are important habitat for many species, from birds to mammals and bats.

Design should allow for natural native tree maturation and regeneration in woodlands and wooded riparian ecosystems. Retain a range of native tree age classes on site (saplings through to mature and dead hollow bearing trees).

Allow for processes such as:

  • safe limb fall
  • natural accumulation of coarse woody debris and
  • natural regeneration through seed drop.

This will protect the tree’s ecological context (surroundings).

Mature native trees retained in a greenfield development - Ginninderry
  • Increase public safety and create space for amenity and natural functions. This is done by having suitable tree protection/buffer zone left to surround the tree.
  • Planting of native grasses, wildflowers and shrubs within the urban open space created provides habitat and foraging for wildlife.
  • Introduction of woody debris and rocks increases structural habitat diversity.
  • Path widths and lighting are kept to a minimum to reduce barriers to connectivity and use by wildlife.
  • Retained trees function as ‘stepping stone’ corridor to connect woodland patches for wildlife.
Urban woodland restoration – Weston
  • Previously mown grass filled with weed species restored with targeted weed removal and introduction of diverse understorey plantings.
  • Mulching under existing trees has increased their health and lifespan. It is retaining important habitat in the urban area for longer.
  • Garden beds and no mow areas have resulted in natural recruitment of eucalyptus seedlings. This will provide multi age succession vegetation.
  • Community is engaged with maintenance, has enhanced appreciation and understanding of nature and increased wellbeing.
Fowles Street Park - Weston
Ecological restoration project at Fowles St Park, Weston. Restoration with weed removal, understorey planting and coarse woody debris introduction has resulted in natural tree recruitment, increased biodiversity and increased use by the community.

Design to protect sensitive natural areas and avoid biodiversity connectivity barriers

Urbanisation and associated construction and building works can threaten biodiversity through direct disturbance and new disturbance regimes. Increased levels of visitor or recreational use can cause soil compaction and erosion, damage vegetation, introduce weeds and pollute sensitive natural areas.

Good design solutions can protect the environment and allow for continued wildlife movement. It also provides residents with active transport options or access to nature and green space for wellbeing and recreational purposes.

Sensitive ecosystem path design – Molonglo River
  • Elevated, permeable path is well integrated with the site topography and construction technique reduced soil disturbance and erosion.
  • Allows for vegetation growth and movement of species beneath the walkway, retaining ecological connectivity.
  • Allows public access while protecting the steep riverbanks and associated riparian ecosystems from foot traffic and other disturbances.
  • Provides opportunities to connect people with nature and encourage appreciation.
Well considered, engineered connectivity solutions - road crossings in Tidbinbilla
  • Culvert is sized adequately to allow sufficient water flow but also movement of wildlife.
  • Culvert is located at the correct stream bed depth. This is to avoid vertical steps, ensure continuous flow and retain connectivity for aquatic animals.
  • Including natural substrate in the culvert provides:
    • a habitat
    • different water velocities and,
    • encourages aquatic animals to pass under the road.
  • Allows for access roads or other linear infrastructure while maintaining connectivity. Span bridges and other solutions can also be considered. Specific species may have specific design requirements.

Design to enhance natural processes – implementing Water Sensitive Urban Design

Water Sensitive Urban Design (WSUD) refers planning, design or construction of the built environment. This is to minimise water runoff, sediment and pollution entering natural waterways and affecting catchments. Many WSUD assets such as man-made wetlands, vegetated swales and tree pits/rain gardens can become significant biodiversity features. This is done if the design and plant selection is done correctly.

There are many examples of both retrofitted and new urban WSUD assets in Canberra. These examples provide improved water quality, biodiversity and amenity to residents.

Retrofitted urban wetland – Lyneham and Dickson
  • Wetlands improve water quality by trapping nitrogen, phosphorous and sediments.
  • Collected water is used for irrigation throughout north Canberra.
  • Increases urban biodiversity. This is done through a diverse array of locally occurring aquatic and terrestrial plants. These plants are habitat to several wildlife species:
    • water birds
    • frogs
    • water bugs and
    • turtles.
  • Structural elements including snags and rocks added to further promote species diversity and abundance.
  • Provides opportunities for natural recreation in suburbs, as well as educational and volunteering programs for the community.
Banksia Street wetlands
Wetlands at Banksia Street and Goodwin Street are two of several new or naturalised wetlands that have been developed in the Sullivan’s Creek catchment in Canberra's inner north.

Related content