Environmental management

The project had several significant environmental aspects to be managed during design, construction and maintenance phases. These are outlined below.

Archaeology

Archaeological sites were scattered throughout the route and were studied by archaeologists and the Karuah Local Aboriginal Land Council. Sites that were not directly on the road footprint were left as they were protected from disturbance. Representatives of the Land Council were invited to search for and salvage more artifacts when certain earthworks operations took place. The Land Council kindly allowed the artifacts from other construction projects in the area to be displayed in the main project office. Remnants from a 100 year old log causeway leading onto Horse Island were found near the route of the bypass. This area, like the aboriginal sites, were also barricaded off to protect it from accidental disturbance.

Flora

Two threatened plant species were known to exist in the vicinity of the bypass. Angophora inopina (black apple) and Tetratheca juncea (black eyed susan) are protected and where possible were replanted in the final landscaping works. A seed collection program was carried out for these and all species during construction.

(Images right - Left to right: Angophora inopina (black apple) and Tetratheca juncea (black eyed susan))

Fauna

There was an abundance of fauna in the area particularly on the western half of the project. A number of management strategies were undertaken to minimise impact on these fauna species. These included: 

• The construction of a number of fauna underpasses that contained perching rails and escape poles in them to prevent predators attacking fauna while they crossed from one side of the highway to the other. 
• Prevention of the clearing of trees that possibly contained fauna. This was done by a 3-stage process. Firstly qualified ecologists assessed all vegetation and marked the trees that had potential habitats. Secondly, all other vegetation was cleared around the trees, and thirdly the marked trees were cleared days later in the presence of fauna rescue specialists. The noise of the machinery tended to encourage any fauna to move away prior to felling. Any hollows that were removed were replaced with artificial nest-boxes and natural branch-hollows in neighbouring trees on a one-for-one basis. 
• Special 'floppy top' fencing to prevent koalas and other ground-based fauna from entering onto the roadway. This fencing made from chainwire mesh had the top section of the fence loose so that when a koala climbed to the top it flexed downward making it impossible for the koala to climb over it.

Erosion and sedimentation control

Erosion and sedimentation control was managed by various strategies such as sediment ponds, progressive revegetation, hay bale structures, diversion bunds, sediment fences and felled vegetation barriers (also known as timber windrows). A professional soil conservationist was employed to provide expert advice.

Air, noise, and water quality

Monitoring of air, noise and water quality was undertaken to watch for potential exceedences of guidelines recommended by the Environmental Protection Authority and the RTA.

Wetlands

To construct the bridges over the wetland, a temporary access road was built in order to allow access for equipment to build the piles and columns which supported the bridges. The access road was removed at the end of construction and the wetlands has been rehabilitated over time. Careful management strategies were employed near all wetlands to minimise any harm to these sensitive areas.

Acid sulphate soil

Acid sulphate soils are soils that oxidise when exposed to the air, and create sulphates during the process. When the sulphates mix with water, there is potential for acidic runoff to occur. This can have adverse impacts on the environment, particularly to aquatic fauna and the local oyster industry.

A comprehensive environmental management plan was prepared that managed all of the above environmental issues and others and incorporated all the environmental requirements and obligations set for the project by Planning NSW.

The management plan incorporated twelve environmental control plans, which addressed the management of specific issues as follows:

• Acid sulphate soils.
• Air quality.
• Indigenous and European heritage. 
• Fauna and flora. 
• Urban design, landscaping and revegetation. 
• Noise and vibration. 
• Soil and water. 
• Waste, resource use and recycling. 
• Wetlands and waterways management. 
• Spoil, material stockpiling and disposal. 
• Bushfire risk.