Pacific Highway Upgrade, Glenugie
Located around 15km south of Grafton, the Glenugie section of the Pacific Highway Upgrade Program was completed in 2013. Seven kilometres long, the upgrade was built along side the existing highway, through the Glenugie State Forest, making use of the old carriageway alignment. Over 42 hectares of revegetation stabilised the road batters, repaired the forest and created a high quality ecological and landscape outcome.
An innovative approach to revegetating this amount of land was needed. Learning from findings on other projects, such as Nowra to Nerriga (Main Road 92) and Coopernook to Herons Creek (Pacific Highway), an approach was developed that would utilise the existing seed bank in the soils of the Glenugie forest.
Topsoil was stripped back during construction and carefully stored to ensure the seeds within the soils remained viable and the soil undamaged. Soil was stored in the location from where it was stripped, reducing haulage and ensuring local vegetation characteristics were maintained.
After the construction of the pavement, the subsoils were ripped and topsoils respread on the newly formed batters. In the warm moist forest microclimate, new seedlings had begun to sprout within weeks, and thrive without competition from weeds. A cost effective, fit for purpose, endemic landscape has begun to develop which is naturally suited to its location and will need almost no maintenance to mature and evolve.
The project outcome and application of this methodology has been documented and will be applied to future projects.