Kolan River Crossing


APA Group regularly relies on the significant experise offered by Atteris for complex areas in onshore pipeline routes. Time and again, Atteris delivers often unconventional and novel yet simple and cost-effective enigneering solutions.


Significant flooding of the South East Queensland’s Kolan River in early 2013 resulted in erosion and subsequent slip failure of a high and steep section of the riverbank, where a DN100 gas pipeline crosses the river. Riverbed erosion also resulted in insufficient cover for the pipeline.The pipeline was installed in 1999 after a prolonged dry period, using conventional open cut and covertechniques.

Work Performed by Atteris

APA Group engaged Atteris to design a solution to replace this section of the pipeline. The very challenging land and river topography, and the presence of thick gravel and cobble layers offered limited options for conventional open cut and cover as well as trenchless methods.

Atteris performed the following work on this project:

  • Review of site conditions, including land/river topography, geology, geomorphology, and geotechnical conditions
  • Development of a design concept; reviewing both open cut and cover and horizontal directional drilling (HDD)
  • Prepare a scope of work and specification for a geotechnical survey, including providing site attendance during the coring
  • Detail design of the crossing based on intersect HDD.