Trigg SUPP


The Trigg State Underground Power Project (SUPP) is a civil and electrical construction project in conjunction with Mainswest, Western Power, the State Government and the City of Stirling. The purpose of which is to provide a safer environment, improved street scapes, reduce maintenance and sustain a more reliable supply of power by the undergrounding of all power cables and the removal of overhead lines in the suburb.

Trigg is a coastal suburb located approximately 15km north west of the Perth CBD and is bordered by North Beach, Karrinyup and Scarborough. It is well known for its beautiful beaches and great surfing / fishing as well as having significant bushland reserves and large public open spaces.

Projects Facts

  • The project was delivered on time and within budget
  • 700,000m2 of approximate project area
  • 633 properties changed over to underground power
  • 27,000m of new underground cable installed
  • 5 new Primary Equipment sites installed
  • 180 new LED Streetlights installed
  • 279 redundant wooden poles and overhead conductor bays removed
  • 43,000 man-hours worked
  • 181 employees, specialist contractors and visitors inducted on site
  • 3,500 resident communication notices delivered


This is the first major project that Mainswest has undertaken during the Coronavirus pandemic and this required a shift in our policies and procedures to continue essential infrastructure works whilst ensuring the health and safety of our stakeholders and taking all steps to minimise the risk of Covid-19 by;
  • Keeping updated with relevant information and following the WA Health Department recommendations
  • Keeping contact registers for large groups of visitors to our worksites
  • Maintaining 1.5m social distancing
  • Minimising physical contact
  • Covering coughs and sneezes with your elbow or a tissue
  • Providing Sanitiser on all worksites
  • Discouraging attendance by anyone who is feeling unwell or displaying symptoms

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