The Adelaide Crafers Highway was built to replace the 10 km section of the South East Highway known as Mt Barker Road between the Portrush Rd/Cross Rd/Glen Osmond Rd intersection and Crafers. Potential environmental impact was a key determinant in route selection.

Relatively steep and large cuts and fills were necessary because of the

• steep slopes of most of the site
• design standards of the road.

Gentler cuts and fills would have extended the disturbance over a much larger area and, in some cases, would not have been feasible to construct because of the terrain.

Less steep cuts would have been easier to landscape and maintain but their construction would have required clearing of unacceptably large areas of valuable native vegetation.

Revegetation Program

As part of the revegetation program more than 60 000 trees were planted to integrate the highway verges with the largely natural character of the area through which the highway passes.

Selected grass species were hydroseeded on to erosion-prone steep slopes to prepare them for direct seeding and planting of native species.

Weed control was undertaken in selected sites adjacent to the construction area to

• protect the landscaped areas from reinvasion by weeds
• minimise the overall environmental impact of the construction project.

The Assessment Report recommended that a stone reserve containing native bushland along the new road corridor be rehabilitated to natural woodland, ‘ to partially compensate for the clearance of vegetation which would be required for the project’. This land was transferred from the Highways Commissioner into the care and control of the University of Adelaide with some funding for ongoing management. The University of Adelaide manages the adjoining Waite Conservation reserve, which now incorporates the former stone reserve, through the Friends of the Waite Conservation reserve volunteer group.