Implementing Sediment and Erosion Controls

Melanie Dixon September 25, 2020

Applied Environment and Safety provided onsite environmental support for the rebuild of the TransGrid Wagga Wagga to Tumut transmission line. This was a substantial project involving the replacement of 243 structures over an 18-month period. 

The transmission line traversed diverse landscapes from low lying cropping paddocks to steep rocky terrain within the Snowy Mountains region. The project’s most significant environmental challenge was sediment and erosion control for the large scale construction of access tracks and structure pads. 

Sediment and erosion control measures included: 

  • Preparation of sediment and erosion control plans.
  • Full engagement with the civil contractors on construction requirements for tracks and pads.
  • Ongoing maintenance of controls over the life of the project.
  • Rehabilitation of disturbed areas following completion of works.

Prior to breaking ground, Applied Environment and Safety worked closely with the civil contractors to ensure best practice controls were incorporated into construction. Ensuring the access tracks and pads were constructed correctly decreased the maintenance required over the project lifespan.

Some sites proved especially challenging with highly erodible soils, steep terrain and livestock. Livestock enjoy investigating and quickly destroying a well-designed catch drain. 

Routine inspections throughout the project ensured erosion and sediment deposition was avoided, and controls were maintained.

Following completion of the works, disturbed areas were rehabilitated in accordance with the requirements of landowners and best practice. Applied Environment and Safety  worked closely with landowners throughout the project to ensure a mutual understanding of how disturbed areas would be remediated. 

Generally, rehabilitation works involved levelling the subsoil back to natural ground level and spreading stockpiled topsoil over the site with a pasture seed mix. Alternatively, disturbed areas that were to remain following the project were upgraded with longer term, more durable erosion and sediment controls. This included rock drains and coir logs for erosion control.