Foxground and Berry Bypass Project

Early ecological monitoring reduces barriers and favours EIS conditions


Fulton Hogan and TfNSW

Princes Highway, Wollongong, NSW

Natascha Arens

General Manager, NSW and Vic

The Foxground and Berry Bypass is a four-lane highway with median separation for 12.5 km of the Princes Highway south of Wollongong. The upgrade included a bypass of the existing winding highway at Foxground and a bypass of Berry with access ramps at the north and south of the town.

We know that roads create barriers. The important thing is figuring out how we can reduce the size of those barriers and understanding where the natural movement points are before we build the road so we can build effective fauna structures and reduce the impact of the road in key movement areas.

Natascha Arens

The full suite of ecological monitoring

NGH was engaged in this project for five years, completing the construction and post-construction monitoring. Performance criteria were set at the EIS stage and during the construction phase NGH completed weed, aquatic, frog, and fauna surveys (spotlighting, call playback, camera detection and scat and track surveys) and water quality (including macroinvertebrates). In addition roadkill was monitored during construction and the first year of operation. Heat maps of roadkill hotspots were identified and used to make recommendations for further exclusion fencing.  

For post construction, NGH completed the same ecological monitoring to identify change between pre-construction, construction, and post-construction. Of the performance criteria set at EIS stage, five of the seven objectives were exceeded. Ecological surveys found that species diversity and abundance increased post construction.

There were a number of creek crossings that required water quality monitoring to ensure that the constructions works didn’t impact on water quality or change the substrate for the creeks. The gravelly creeks in the area are known habitats for platypus and native frogs in the area in the area.

Weed and fauna monitoring was also a big focus for this project. Many construction sites see an increase of weeds and roadkill. To address both, NGH monitored fauna crossing structures and fencing and undertook a comprehensive weed monitoring program.

During the post construction period, NGH installed infrared motion detecting cameras. On various underpasses and overpasses (rope bridges) to determine if fauna were using the structures and to assess if the new highway was forming a barrier to fauna movement. Birds, mammals and reptiles were all found to utilise the various crossing structures.

In 2019 we were approached by a PhD student studying arboreal fauna utilising rope bridges. As part of her study, NGH/TfNSW granted semi-permanent solar motion detecting cameras be installed at certain rope bridges and also incorporated these results into the last two years of monitoring data.

Thinking outside the (nest) box

An extensive nest box program was used to attempt to offset the impact lost hollow resources as a result of clearing for the route.  A large range of different sized nest boxes were installed for birds, bats, gliders, and arboreal creatures. Preliminary monitoring of the 300 nest boxes revealed that very few animals were using the boxes.

With the standard nest boxes, we weren’t getting results. We worked with TfNSW and refreshed our approached and installed a different kind of nest box. From year one to year 2, nest box use doubled. And then in year three, it increased by about 10%. Overall, nest box use increased over time.

Natascha Arens

The nest box program was re-invented to increase habitation, we made sure to approach it with a collaborative and innovative mindset. Our team collected hollows that had been removed from trees throughout construction and our tree climbers attached them to branches to see if they were more readily used than the typical man-made boxes. The team saw an increase in microbat habitation but as the new nest boxes had only been installed for a short period, we need more time to see if native fauna would occupy the new nest boxes.

Monitoring programs are very satisfying. You get to go back to the same place and see ecological changes over time and really notice the detail of the environment that you’re working in because you’re back every three to six months for five years. I always feel a very intimate connection with these places.

Natascha Arens

Foxground NSW project map
Courtesy of Transport for New South Wales

Natascha Arens

General Manager, NSW and Vic

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