An environmental audit of the F3 Freeway: Wahroonga to Berowra, New South Wales

A major freeway construction project is described in terms of the environmental controls adopted and the success achieved. A monitoring program was carried out during and post-construction. Significant stream sedimentation occurred following exceptional rain. Manual labour is effective in rehabilitating natural habitat and sediment control structures. Sediment storage capacity should be at least 500m3 per hectare of disturbed catchment in steep terrain. A quick cover crop of native seed and exotic grasses at a dose rate of 50kg/ha is satisfactory in nutrient-poor soils and will not cause a weed problem in undisturbed natural areas. Concrete batch plants can generate serious water quality problems. Access should be provided to sediment traps for cleanout/repair once construction is complete. Over-clearing can be minimised by placing fill embankments directly adjacent to undisturbed vegetation. This is more effective in filtering and dissipating stormwater and is less costly. Permanently flowing water must not be discharged into dry sclerophyll woodland; this vegetation is not tolerant to wet soil conditions and will die. Sediment and water retaining structures should be excavated in original material whenever possible, rather than built up on natural ground using embankments. These structures tend to leak at the interface between natural ground and fill.

  • Authors:
    • Rooney, W S
  • Publication Date: 1991-12


  • English

Media Info

  • Pagination: 127-33
  • Serial:
    • Volume: GE15
    • Issue Number: 2

Subject/Index Terms

Filing Info

  • Accession Number: 01432576
  • Record Type: Publication
  • Source Agency: ARRB
  • Files: ATRI
  • Created Date: Aug 24 2012 5:06PM